5G无线通信网络中英文对照外文翻译文献
通信外文翻译外文文献英文文献及译文
通信外文翻译外文文献英文文献及译文通信外文翻译外文文献英文文献及译文Communication SystemA generalized communication system has the following components:(a) Information Source. This produces a message which may be written or spoken words, or some form of data.(b) Transmitter. The transmitter converts the message into a signal, the form of which is suitable for transmission over the communication channel.(c) Communication Channel. The communication channel is the medium used transmit the signal, from the transmitter to the receiver. The channel may be a radio link or a direct wire connection.(d) Receiver. The receiver can be thought of as the inverse of the transmitter. Itchanges the received signal back into a message and passes the message on to its destination which may be a loudspeaker，teleprinter or computer data bank.An unfortunate characteristic of all communication channels is that noise is added to the signal. This unwanted noise may cause distorionsof sound in a telephone, or errors in a telegraph message or data.Frequency Diversion MultiplexingFrequency Diversion Multiplexing(FDM) is a one of analog technologies. A speech signal is 0~3 kHz, single sideband amplitude (SSB) modulation can be used to transfer speech signal to new frequency bands,four similar signals, for example, moved by SSB modulationto share the band from 5 to 20 kHz. The gaps between channels are known as guard spaces and these allow for errors in frequency, inadequate filtering, etc in the engineered system.Once this new baseband signal, a "group" of 4 chEmnels, has been foimed it ismoved around the Lrunk network as a single unit. A hierarchy can be set up withseveral channels fonning a "group". several groups a "supergroup" and several"supergraup" eicher a "nmsrergroup" or "hypergroup".Groups or supergroups are moved around as single units by the communicationsequipment and it is not necessary for the radios to know how many channels are involved. A radio can handle a supergroup provided sufficient bandwidth is available. The size of the groups is a compromise as treating each channel individually involves far more equipment because separate filters, modulators and oscillators are required for every channel rather than for each group. However the failure of one module will lose all of the channels associated with a group.Time Diversion MultiplexingIt is possible, with pulse modulation systems, to use the between samples to transmit signals from other circuits. The technique is knownas time diversion multiplexing (TDM). To do this, it is necessary to employ synchronized switches at eachend of the communication links to enable samples to be transmittedin turn, from each of several circuits. Thus several subscribers appear to use the link simultaneously. Although each user onlyhas periodic short time slots, the original analog signals between samples can be reconstituted at the receiver.Pulse Code ModulationIn analog modulation, the signal was used to modulate the amplitude or frequency of a carrier, directly. However, in digital modulation a stream of pulse, representing the original，is created. This stream is then used to modulate a carrier or alternatively is transmitted directly over a cable. Pulse Code Modulation (PCM) is one of the two techniques commonly used.All pulse systems depend on the analog waveform being sampled at regular intervals. The signal created by sampling our analog speech input is known as pulse amplitude modulation. It is not very useful in practice but is used as an intermediate stage towards forming a PCM signal. It will be seen later that most of the advantages of digital modulation come from the transmitted pulses having two levels only, this being known as a binary system. In PCM the height of each sample is converted into a binary number. There are three step in the process of PCM: sampling, quantizing and coding.Optical Fiber CommunicationsCommunication may be broadly defined as the transfer of information from one point to another. When the information is to be conveyed over any distance acommunication system is usually required. Within a communication system the information transfer is frequently achieved by superimposing or modulating the information on to an electromagnetic wave which acts as a carrier for the informationsignal. This modulated carrier is then transmitted to the required destination where it is received and the originalinformation signal is obtained by demodulation. Sophisticated techniques have been developed for this process by using electromagnetic carrier wavesoperating at radio frequencies as well as microwave and millimeter wave frequencies. However，拻 communication?may also be achieved by using an electromagneticcarrier which is selected from the optical range of frequencies.In this case the information source provides an electrical signal to a transmitter comprising an electrical stage which drives an optical source to give modulation of the light-wave carrier. The optical source which provides the electrical-optical conversion may be either a semiconductor laser or light emitting diode (LED). The transmission medium consists of an optical fiber cable and the receiver consists of an optical detector which drives a further electrical stage and hence provides demodulation optical carrier. Photodiodes (P-N, P-I-N or avalanche) and , in some instances,phototransistor and photoconductors are utilized for the detection of the optical signal and the electrical-optical conversion. Thus there is a requirement for electrical interfacing at either end of the optical link and at present the signal processing is usually performed electrically.The optical carrier may be modulated by using either an analog or digital information signal. Analog modulation involves the variation of the light emitted from the optical source in a continuous manner. With digital modulation, however, discrete changes in the light intensity are obtained (i.e. on-off pulses). Although often simpler to implement, analog modulation with an optical fiber communication system is lessefficient, requiring a far higher signal to noise ratio at the receiver than digital modulation. Also, the linearity needed for analog modulation is not always provided by semiconductor optical source, especially at high modulation frequencies. For thesereasons，analog optical fiber communications link are generally limited to shorter distances and lower bandwidths than digital links.Initially, the input digital signal from the information source is suitably encoded for optical transmission. The laser drive circuit directly modulates the intensity of the semiconductor laser with the encoded digital signal. Hence a digital optical signal is launched into the optical fiber cable. The avalanche photodiode detector (APD) is followed by a fronted-end amplifier and equalizer orfilter to provide gain as well as linear signal processing and noise bandwidth reduction. Finally, the signal obtained is decoded to give the original digital information.Mobile CommunicationCordless Telephone SystemsCordless telephone system are full duplex communication systems that use radio to connect a portable handset to a dedicated base station，which is then connected to a dedicated telephone line with a specific telephone number on the public switched telephone network (PSTN) .In first generation cordless telephone systems5(manufactured in the 1980s), the portable unit communications only to the dedicatedbase unit and only over distances of a few tens of meters.Early cordless telephones operate solely as extensiontelephones to a transceiver connected to a subscriber line on the PSTN and are primarily for in-home use.Second generation cordless telephones have recently been introduced which allowsubscribers to use their handsets at many outdoor locations within urban centers such as London or Hong Kong. Modern cordless telephones are sometimes combined with paging receivers so that a subscriber may first be paged and then respond to the pageusing the cordless telephone. Cordless telephone systems provide the user with limited range and mobility, as it is usually not possible to maintain a call if the user travels outside the range of the base station. Typical second generation base stations provide coverage ranges up to a few hundred meters.Cellular Telephone SystemA cellular telephone system provides a wireless connection to the PSTN for any user location within the radio range of the system.Cellular systems accommodate alarge number of users over a large geographic area, within a limited frequency spectrum. Cellular radio systems provide high quality service that is often comparable to that of the landline telephone systems. High capacity is achieved by limiting the coverage of each base station transmitter to a small geographic area called a cell so that the same radio channels may be reused by another base station located some distance away. A sophisticated switching technique called a handoff enables a call to proceeduninterrupted when the user moves from one cell to another.A basic cellular system consists of mobile station, basestations and a mobile switching center (MSC). The Mobile Switching Center is sometimes called a mobiletelephone switching office (MTSO), since it is responsible for connecting all mobiles to the PSTN in a cellular system. Each mobilecommunicates via radio with one of the base stations and may be handed-off to any number of base stations throughout the duration of a call. The mobile station contains a transceiver, an antenna, and control circuitry，and may be mounted in a vehicle or used as a portable hand-held unit. Thebase stations consists of several transmitters and receivers which simultaneously handlefull duplex communications and generally have towers which support several transmitting and receiving antennas. The base station serves as a bridge between all mobile users in the cell and connects the simultaneous mobile calls via telephone lines or microwave links to the MSC. The MSC coordinates the activities of all the base stations and connects the entire cellular system to the PSTN. A typical MSC handles 100000 cellular subscribers and 5000 simultaneous conversations at a time, and accommodates all billing and system maintenance functions, as well. In large cities, several MSCs are used by a single carrier.Broadband CommunicationAs can be inferred from the examples of video phone and HDTV, the evolution offuture communications will be via broadband communication centered around video signals. The associated services make up a diverse set of high-speed and broadband services ranging from video services such as video phone，video conferencing，videosurveillance, cable television (CATV) distribution, and HDTV distribution to the high-speed data services such as high-resolution image transmission, high-speed datatransmission, and color facsimile. The means of standardizing these various broadbandcommunication services so that they can be provided in an integrated manner is no other than the broadband integrated services digital network (B-ISDN). Simple put, therefore, the future communications network can be said to be a broadband telecommunicationsystem based on the B-ISDN.For realization of the B-ISDN, the role of several broadband communicationtechnologies is crucial. Fortunately, the remarkable advances in the field of electronics and fiber optics have led to the maturation of broadband communication technologies.As the B-ISDN becomes possible on the optical communication foundation, the relevant manufacturing technologies for light-source and passive devices and for optical fiberhave advanced to considerable levels. Advances in high-speed device and integratedcircuit technologies for broadband signal processing are also worthy of close attention. There has also been notable progress in software, signal processing, and video equipment technologies. Hence, from the technological standpoint, the B-ISDN hasfinally reached a realizable state.On the other, standardization activities associated with broadband communication have been progressing. TheSynchronous Optical Network (SONET) standardization centered around the T1 committee eventually bore fmit in the form of the Synchronous Digital Hierarchy (SDH) standards of the International Consultative Committee in Telegraphy and Telephony (CCITT), paving the way for synchronous digital transmission based on optical communication. The standardization activities of the 5integrated services digital network (ISDN), which commenced in early 1980s with the objective of integrating narrowband services, expanded in scope with the inclusion of broadband services, leading to the standardization of the B-ISDN in late1980抯and establishing the concept of asynchronous transfer mode (ATM)communication in process. In addition, standardization of various video signals is becoming finalized through the cooperation among such organizations as CCITT, the International Radio-communications Consultative Committee (CCIR), and theInternational Standards Organization (ISO), and reference protocols for high-speedpacket communication are being standardized through ISO, CCITT, and the Institute of Electrical and Electronics Engineer (IEEE).Various factors such as these have made broadband communication realizable.5Therefore, the 1990s is the decade in which matured broadband communicationtechnologies will be used in conjunction with broadband standards to realize broadband communication networks. In the broadband communication network, the fiber opticnetwork will represent the physical medium for implementing broadband communication, while synchronous transmission will make possible the transmission of broadband service signals over the optical medium. Also, the B-ISDN will be essentialas the broadband telecommunication network established on the basis of optical medium and synchronous transmission and ATM is the communication means that enables the realization of the B-ISDN. The most important of the broadband services to be providedthrough the B-ISDN are high-speed data communication services and videocommunication services.Image AcquisitionA TV camera is usually used to take instantaneous images and transform them into electrical signals, which will be further translated into binary numbers for the computer to handle. The TV camera scans oneline at a time. Each line is further divided into hundreds of pixels. The whole frame is divided into hundreds (for example, 625) of lines.The brightness of a pixel can be represented by a binary number with certain bits, for example, 8 bits. The value of the binary number varies from 0 to 255, a range great enough to accommodate all possible contrast levels of images taken from real scene.These binary numbers are sorted in an RAM (it must have a great capacity) ready for processing by the computer.Image ProcessingImage processing is for improving the quality of the imagesobtained. First, it is necessary to improve the signal-to-noise ratio. Here noise refers to any interference flaw or aberation that obscure the objects on the image. Second, it is possible to improve contrast, enhance sharpness of edges between images through various computational means.Image AnalysisIt is for outlining all possible objects that are included in the scene. A computer program checks through the binary visual informationin store for it and identifies specific feature and characteristics of those objects. Edges or boundaries are identifiablebecause of the different brightness levels on either side of them. Usingcertain algorithms, the computer program can outline all possible boundaries of the objects in the scene. Image analysis also looks for textures and shadings between lines.Image ComprehensionImage Comprehension means understanding what is in a scene. Matching the prestored binary visual information with certain templates which represent specific objects in a binary form is technique borrowed from artificial intelligence, commonly referred to as "templeite matching"emplate matching? One by one,the templates are checked against the binary information representing the scene. Once a match occurs, an object is identified. The template matching process continues until all possible objects in the scene have been identified, otherwise it fails.通信系统一般的通信系统由下列部分组成:信源。
通信技术类英文文献
通信技术类英文文献以下是一篇通信技术类英文文献，供参考：Title: 5G Wireless Communication: The Future of Communication TechnologyAbstract: The fifth-generation (5G) wireless communication is the next-generation technology, which is 100 times faster than the 4G technology and provides a higher bandwidth, low latency, and more reliable and secure communication. The 5G wireless communication aims to provide the flexibility of different services, including multimedia, cloud computing, internet of things (IoT), and virtual reality (VR). This paper provides an overview of the5G wireless communication technology, including its features, architecture, and its applications.Introduction: The rapid growth of wireless communication technology has brought significant changes in the way people interact with each other. The 5G wireless communication technology is the revolutionary technology that aims to provide a higher level of communication, which is 100 times faster than the 4G technology. The 5G wireless communication is expected to be the future of communication technology, which will change the way people interact with each other.Features of 5G Wireless Communication:The 5G wireless communication has various features that provide a higher level of communication. These features are:1. High Bandwidth: The 5G wireless communication provides a high bandwidth, which increases the data transfer rate. This high bandwidth provides a better experience for multimedia services, such as streaming video, music, and gaming.2. Low Latency: The 5G wireless communication provides a lower latency, which improves the response time of the communication. This low latency is ideal for real-time applications such as autonomous vehicles, AR/VR, and remote surgeries.3. Massive IoT: The 5G wireless communication supports a large number of IoT devices with a higher density of devices per unit area. This feature enables the functionality of IoT applications in various industries, such as smart homes, smart cities, and healthcare.4. Network Slicing: The 5G wireless communication provides network slicing, which enables the partitioning of the network into multiple virtual networks. This feature provides the flexibility to provide different services with different requirements such as high speed, low latency, and high reliability.5. Security: The 5G wireless communication provides a higher level of security for communication. This security is provided through various features such as authentication, encryption, and privacy.Architecture of 5G Wireless Communication:The 5G wireless communication has a different architecture thanthe previous generations of wireless communication technology. The architecture of the 5G wireless communication is divided into three layers: the user plane, the control plane, and the management plane.1. User Plane: The user plane is responsible for the transmission and reception of user data. This layer involves the transmission and reception of user data through the radio access network (RAN) and the core network.2. Control Plane: The control plane is responsible for controlling the signaling messages between the user equipment (UE) and the network. This layer involves the control of signaling messages related to call setup, call tear down, and mobility management.3. Management Plane: The management plane is responsible for the management of the network resources and the configuration of the network. This layer includes the management of the network functions such as orchestration, automation, and telemetry.Applications of 5G Wireless Communication:The 5G wireless communication has various applications, which will have a significant impact on different industries. Some of the applications are:1. Smart City: The 5G wireless communication enables the functionality of smart city applications such as smart transport, smart parking, and smart street lighting.2. Healthcare: The 5G wireless communication provides a higher level of healthcare with the use of various applications such as telemedicine, remote surgery, and health monitoring.3. Industrial Internet of Things (IIoT): The 5G wireless communication enables the functionality of IIoT applications such as predictive maintenance, asset tracking, and real-time manufacturing process monitoring.4. Agriculture: The 5G wireless communication provides the functionality of precision agriculture applications such as intelligent irrigation, crop monitoring, and farm automation.Conclusion:The 5G wireless communication is the next-generation technology, which is expected to be the future of communication technology. The 5G wireless communication provides a higher level of communication with its features such as high bandwidth, low latency, and massive IoT. The implementation of the 5G wireless communication will have a significant impact on different industries such as healthcare, smart city, and IIoT.。
移动通信与制造业中的5G技术外文文献翻译2019-2020
移动通信与制造业中的5G技术外文翻译2019-2020英文Review of Mobile Communication and the 5G in ManufacturingZsolt Temesvári, Dóra Maros, Péter KádárAbstractThis article intends to demonstrate the importance of cutting-edge technologies in providing mobile coverage in factories and in industrial buildings. The current paper examines indoor and outdoor radio network systems and investigates already operating mobile networks, as well as the 5G, which is currently in the state of standardisation [1]. Furthermore, building on the available data transfer rates, current article - relying on the standardisation process –estimates the preference of the 5G within manufacturing. In the world of IoT (Internet of Things) [2], M2M (Machine-to-Machine Communication) [3] and Smart Factories [4], the available mobile networks most likely will not be able to handle the high traffic load sufficiently [5]. The article seeks to answer whether the development of new mobile technologies will be able to support the Industry 4.0 revolution for Smart Factories and manufacturers [6].Keywords: Mobile communication, Indoor systems, 5G, manufacturing, InnovationIntroductionThe demand for technological progress in mobile technologiesshows an ever increasing trend. Designing, optimization and dimensioning of telecommunication networks have been an inseparable part of development of information infrastructure and telecommunications from the beginning. These networking problems have been changed towards 4G/5G wireless networks, as well as networks convergence [7]. Due to the advancement of these mobile networks, current residential (user) needs can be properly served, but the industry's stakeholders require higher data transfer rates. The service providers (in most countries) have made significant efforts in order to make the 4G (LTE) networks available - in rural, suburban and industrial areas as well – nationwide.In the world of M2M, IoT, Big Data and Smart Factories, the 4G most likely will not be able to sufficiently handle the growing needs set by manufacturing and industrial automation technology. Smart manufacturing has become the development trend and been widely recognized all over the world based on cyber-physical manufacturing systems (CPMS). Through the development trend of CPSM, the Industrial IoT (IIoT) is one of the key issues with the characteristic of automation, collaborative, real-time monitoring and smart connected control. Along the applications of advanced technologies in manufacturing, large amount of data have been generated during the manufacturing processes. The current mobile technologies, the 3G and the 4G and other communicationsystems can’t meet with the demands of CPMS for high reliability, high data transfer rate, low latency, etc., which hinders the advancement of CPMS [5]. In these segments the efficiency and continuous improvement will have to be achieved through the innovation of the various manufacturing processes. For example, in the near future the automation of robots or warehouse transportation operations will require increased data transferability from the systems [8]. The 5G that is presently in the state of standardisation could be a key to fulfil these requirements in the segment of manufacturing. The 5G will offer solutions for manufacturers and telecom operators that want to use cutting-edge technologies and to keep their competitiveness and profitability. If 5G at the end fulfils the expectations that stakeholders desire, the future is going to look a lot different is many segments of everyday life [9]. Through the new generation of mobile network the option is given to build Smart Factories and to take advantage of new technologies such as artificial intelligence, automation, the IoT, or augmented reality in troubleshooting. The 5G will also allow for advancements in M2M. The most important technical requirements of the 5G are the high availability, low data error probability, high reliability, ultra low latency (and response time). Other fundamental technical requirements include an extremely strong network security, high connection density and bandwidth. The 5G will provide real-time control during the manufacturing processes and sustain real-time connectivitybetween distinct operational locations, if needed [8], and has a significant potential to promote IIoT and CPMS [5].The article seeks to answer how the 5G will be able to change the operational and communicational methods of the manufacturing sector (automotive industry, robotics, logistics, etc.) and whether the new mobile technologies are in line with the growing needs of manufacturing, machines and users. Current paper also examines indoor mobile services that enhance the development of the industrial sector. In the following chapter the radio base stations types will be described, including the structure of outdoor macro and indoor base stations.1. Radio Systems in ManufacturingMobile services can be divided into two parts: indoor and outdoor (macro) systems. An indoor system is required where the macro base station cells cannot serve the demand of a facility due to field strength, capacity or quality problems. The indoor base stations - which include individual indoor antenna system and other equipment - ensure the mobile communication for manufacturing facilities. A large building could have a high mobile network capacity demand, therefore these indoor systems should be implemented in order to ensure good coverage, capacity and quality on the 2G, 3G and on the 4G networks as well. These systems are used for mobile communication because manufacturers rely on fixed-line networks throughout the manufacturing processes, but thesefixed infrastructures are not flexible enough and are also considered expensive. The 4G is capable providing high data rate, but industrial stakeholders also have to consider whether to apply wired or not wired technology.The radio base station, which is the access network, consists of three important elements. The first element is the so-called Base Band Unit (BBU) that has the appropriate hardware, software and ensures the baseband processing for the uplink and downlink. The second element is the Remote Radio Unit (RRU), which is a radio frequency transmitter and receiver. This amplifier device is responsible for ensuring the appropriate power and connects to the BBU via an optical fibre. The coaxial cable (“jumper” cable) is set up between the RRU and the passive antenna. The radio waves of the given technology are emitted with the appropriate characteristics through the antenna. Fig. 1 shows the mentioned process [10].1.1. Outdoor Radio SystemsRadio base station equipments differ in their structure. The most commonly used is the tower which allows choosing among lattice, monopole and wood towers. The monopole and wood structures have a relatively small load capacity (but demand less physical space as well), and the construction process is easier, while aesthetically looks discrete. Wood towers are also widely used in natural reserves.The construction of mobile towers can be complicated in rural environment due to legislative requirements. Therefore mobile service providers often choose to settle in to existing objects instead of building new towers. These objects can be for instance temples, silos or water towers if the height of these buildings is adequate for ensuring mobile services with proper coverage and good quality.The construction of base stations in an urban environment presents similar difficulties. In urban areas towers are rarely constructed due to the regulations by local authorities and the possible residential complaints. Therefore the institutionalized way to ensure mobile coverage is to choose existing objects, for example rooftops, industrial chimneys, street lamp posts.1.2. Indoor Radio SystemsAn indoor radio network system is necessary if the macro (outdoor) network can’t ensure mobile coverage inside the buildings. For example if the base station is too far from the target building, therefore the radio signals can’t penetrate indoor with the proper power level. In such cases these buildings require their own individual indoor radio system in order to ensure the adequate mobile coverage and quality. The radio devices are the same that are used for outdoor base stations: indoor systems also have BBU, RRUs and antenna systems. One of the differences between outdoor and indoor base stations is that more antenna and passive devicesare used for indoor systems. Another dissimilarity is that indoor base stations use much longer coaxial cables (between the RRUs and the antennas), causing more attenuation for the radio signal and decreasing the signal-to-noise ratio (SNR). However the distance between BTSs and the user terminals is minor (compared to outdoor systems, where the distance can be tens of kilometres between the BTS and the user terminals), therefore the longer coaxial cable does not cause problems in the service to a specific point. For outdoor base stations the RRUs are installed close to the antennas and are connected to them with short feeder coaxial cables which are also known “jumpers”. One RRU feeds only one antenna. In indoor stations, generally one RRU (or more, depending on the size of the area) by technology is installed for the whole indoor mobile system feeding a lot of antennas. The signal can reach all the antennas using passive elements, like splitters and couplers. The RRUs (the technologies using different frequency ranges) are joined with a passive element called Hybrid Matrix. This passive element is used for connecting different technologies and different RRUs in order to have all the technologies in one coaxial cable that is forwarded to all antennas that are connected to the indoor system. Splitters are intended to split radio signals in to two directions. The couplers can distribute the signal with imbalance power, which can be important in cases where more antennas are integrated in a given direction.2. Existing and New Broadband Mobile Networks2.1. The 3G networksThe 3G networks (using WCDMA) are single-frequency wideband networks, which means that each 3G mobile cell operates on the same wideband frequency and interferes with each other and with the surrounding cells. Therefore the SNR (signal-to-noise-ratio) proves to be an important factor. It is also relevant to take into account that the dominance of the cells should be increased, while the overlap and the interference should be decreased in the service area of the 3G cells in order to approach the theoretical maximum of data transfer rate, performance and quality. Indoor systems have their own 3G cells to serve the demand of buildings, factories or other industrial facilities. The latency of these networks is around 100-500 ms and the theoretical maximum download speed that can be reached through this technology is 42 Mbps.2.2. The 4G networksThe operation of the 4G networks (using OFDM) is basically similar to the 3G networks: every cell uses the same wideband frequency and interferes with each other. The planning strategy is also similar to the 3G’s, the SNR (the dominance of the cell) should be maximized, the overlap and the interference minimized in order to achieve the theoretically maximum data transfer rate (which depends on the width offrequency band). The network latency is around 10 ms and the frequency-dependent theoretical data transfer rates are shown on Fig 5.2.3. The 5G networkThe standardisation process of the fifth generation mobile network is currently under way. All parties of the telecommunications market are closely involved in this collaborative effort and the first release is expected by 2020. As it is expected the allocated frequency for the 5G will be in higher ranges than it is for the 3G and the 4G networks. One of the highest frequency band that is used for mobile communication is the 2600 MHz, but the primary band - assigned for the 5G - is expected to be at around 6 GHz, which is a relatively high range in terms of mobile services. The propagation of radio signals weakens by increasing the frequency and penetrates with more attenuation through objects and material. In this high range the number of base stations should be increased in order to ensure nation-wide coverage, which also means that it could be the largest investment that mobile operators have ever made regarding the access, core and transmission network as well. It is assumed that (after the disconnection of terrestrial broadcasting) the 700 MHz and the 3500 MHz (frequency range that is currently allocated to radiolocation, fixed-satellite services, etc.) band will be also used for the 5G. The 700 MHz band is essential to achieve nationwide or indoor coverage.The 5G will provide new innovations in many sectors, as well as in manufacturing. One of the most important developments of the 5G will be the near real time communication sans delay. This will allow new features and technologies in manufacturing as well, which is described in the following chapters. The data transfer rate is expected to be 10 to 20 Gbps for one user, and the capacity of a 5G cell can be ~1000 fold compared to the 3G’s and the 4G’s cells combined. The complexity of the 5G network will also be reduced compared to the 4G and the battery of a 5G device is expected to use 100th of the energy required for a 4G terminal. The 5G is also expected to serve machines rather than human beings, and the number of these devices can be raised in the tens of billions by 2020. The comparison of data transfer rate is shown on Fig. 6 by existing mobile technologies respectively.2.4. Mobile Services for IoT, Low-Power Wide AreaThe Low-Power Wide Area (LPW A) is a wireless wide area network technology that is intended to interconnect low-bandwidth and battery-powered devices with low bit rates. This solution was devised in response to the growing need of M2M and IoT communication. LPW A can operate at a relatively low cost with greater power efficiency and can serve a greater number of connections over a large area. The LPWAN’s can forward packet sizes from 10 to 1000 bytes with an uplink of 200 Kbps. The range of the service can spread kilometres in rural areas(depending on the carrier technology), but in an urban environment the cell range is much smaller. LPW AN is not a technology, but an umbrella term for various low-power solutions that operate on licensed or unlicensed frequencies.Narrowband-IoT (NB-IoT), also known as CAT-NB1, is standardised by 3GPP and uses licensed frequencies. The NB-IoT makes features available and allows IoT applications to become available wide range in a very secure operating environment. NB-IoT also improves the power consumption of user terminals and provide coverage deep indoors. This technology operates on existing mobile networks, allowing service providers to apply easily this technology in their network. The NB-IoT operate with low power (~ 20-30 dBm) under the LTE network on a 180 KHz wide carrier and it offers an approximately 200 Kbps data transfer rate in both directions (uplink and downlink). The NB-IoT is considered to be a relatively low cost option as it doesn’t need a gateway. Other technologies and infrastructures typically have their own gateways collecting the sensor data which communicate with the main server. With NB-IoT, the sensor data is directly connected to the main server.The LTE Cat-M1 is also a technology for IoT devices and Machine-type Communication (MTC), through which the terminals can connect directly to the 4G networks. LTE-M operates on higher bandwidth than NB-IoT, on a 1.4 MHz wide carrier. This technology canalso provide higher data traffic rate, 1 Mbps peak rate in uplink and downlink direction and also use low power (~ 20-30 dBm).3. The 5G For ManufacturingBy installing indoor radio systems, the 5G will be able to ensure coverage in factories and provide innovation for the manufacturing sector as well. The ultra low network latency, very high capacity and reliability, high bandwidth and connection density, very low device cost and energy consumption add up to a high quality product, that is able to serve the systems well. Currently only the fixed-line wired systems are able to operate within such dimensions, the available mobile technologies are not in line with the above mentioned criteria, that’s why manufacturers rely on wired technologies. The 5G will offer higher flexibility, lower cost and almost zero round trip time, therefore its use in manufacturing could be beneficial and valuable. The onset of the 5G is expected to boost the digitalization phase starting from connecting previously isolated systems and equipment to gather data and information. As the 5G will be expanding, other options of potential industrial use will arise and also bring Smart Factories, Augmented Reality assisted maintenance. Expectations are that by 2020 over 50 billion sensors will be connected globally to the internet, with low-cost designs of hardware components, and the amount of data to be collected, sensed and transmitted is expected to increase at an all-time high rate [20].Whereas the previous mobile technologies have been designed to increase spectral efficiencies and enable high bandwidth required applications for human users, the 5G will be driven by various newly emerging use cases. This cellular system will serve as a new paradigm of MTC, and grant the demand for human-type traffic as well. MTC will include a large variety of concepts, such as Industry 4.0, IoT, Smart Features, etc. Each of the concepts have their own requirements and demands, ranging from limited energy consumption, over smart cities operating with millions of sensors to the Smart Factories which will be served with wireless systems (instead of fixed-line wired systems that are currently in use in these sectors) with set requirements regarding latency and reliabilities. The 5G needs to consider all these aspects in order to become a widely used technology for future industries.The virtual plant concept gives the chance to carry out global system design, verification, simulation and physical mapping at lower cost that inquires robots with the ability to increase the flexibility of the global production system. These robots should be multipurpose and intelligent enough to communicate, adapt and interact with each other and with humans as well, and to be operable remotely from all around the world. In order for this to be realized, wireless connectivity is essential, wired connectivity and its complex cabling is not flexible enough in terms of the ever-changing environment and the cable upgrading entails highoperational expenditure. The wireless carrier network might connect to all physical elements of a production plant with machine (computing) elements that process and collect significant amount of data through a cloud that is responsible for the operation. This communication faces with electromagnetic interferences and distributed over a large area (indoor mobile systems) that can ensure coverage for several buildings. While the 4G coverage and connectivity is capable enough to deal with that environment today, the stringent latency requirements will soon need the 5G’s abilities. Due to the fact that significant amount of data is collected via wireless networks, it is imperative to find new methods in order to handle, process and transform it into a common format that can be used by machines and humans both, and tap into the potential of Cloud Computing. Therefore analytics systems and Big Data are essential in a digital factory. Cyber- physical systems (CPS) will be also needed to handle the complexity of the production process, including of IT systems built around machines, supplies and storage systems. All this leads to increasing efficiency in the factories, by using preventive and predictive maintenance, which can reduce the time of off-service, minimize production latencies, avoid failures and reduce energy consumption with lower cost.中文移动通信与制造业中的5G技术摘要本文旨在证明尖端技术在工厂和工业建筑中提供移动覆盖的重要性。
5G无线网络：速度并不是全部_双语达人_双语阅读-可可英语
5G无线网络：速度并不是全部_双语达人_双语阅读-可可英语When it comes to the wireless networks of the future, speed won't be everything.一提到未来的无线网络，速度并不能代表全部。
The advent of so-called 5G, or fifth-generation, wireless technology will bring incredible speed, for sure, with the industry aiming to see your network connection jump by 100 times. (Yes, 100.) More importantly, the network will be smart enough to act differently depending on how it's accessed, whether from a heart monitor when you're relaxing at home or from a self-driving car zipping down a crowded highway.5G，或者说第五代无线技术的到来，无疑会带来难以置信的速度体验，目标是让你的网络连接速度快100倍。
（是的，100倍）。
更重要的是，网络将变得十分只能，以至于可以在不同的场合运作。
无论你在家中放松，还是沿着拥挤的街道开车，都可以通过中心操控器接入。
That's according to Hans Vestberg, CEO of Ericsson, one of the world's largest suppliers of telecommunications equipment.世界最大的电子通讯设备提供商之一Ericsson的总裁Hans Vestberg说。
5g通讯英文作文
5g通讯英文作文英文：As the world enters the era of 5G communication, theway we communicate and interact with each other is about to change drastically. 5G, the fifth generation of wireless technology, promises to bring faster speeds, lower latency, and more reliable connections than ever before. With 5G, we will be able to download movies in seconds, stream high-quality videos without buffering, and connect millions of devices at once.However, the benefits of 5G technology go far beyondjust faster internet speeds. It has the potential to revolutionize industries such as healthcare, transportation, and manufacturing. For example, 5G can enable remote surgeries to be performed in real-time, self-driving carsto communicate with each other and the surrounding infrastructure, and factories to operate more efficiently with the help of connected devices.But with all of these advancements come concerns about privacy and security. As more devices become connected to the internet, there is an increased risk of cyber attacks and data breaches. It is important for companies and governments to prioritize the development of secure 5G networks and implement measures to protect user data.In addition, the rollout of 5G technology will not be without its challenges. The infrastructure required to support 5G networks is complex and expensive, and there may be resistance from local communities to the installation of new cell towers and other necessary equipment.Despite these challenges, I am excited about the possibilities that 5G technology brings. It has the potential to transform the way we live, work, and communicate with each other, and I look forward to seeing how it will shape our future.中文：随着世界进入5G通讯时代，我们之间的交流和互动方式将会发生巨大的变化。
无线通信5G介绍英文论文 A Brief Introduction About 5G Network
A Brief Introduction About 5G Network JiaAbstractWith the rapid development of wireless technologies, theconcept of the Fifth Generation (5G) wireless communication system started to emerge. But most people know little about 5G，including some aspects of 5G wireless communication networks ,just like what 5G is about: what are the building blocks of core 5G system concept, what are the main challenges and how to tackle them. Besides,A number of countries and organizations working on 5G, 5G development situation in China is of concern to everyone, China also needs to have its own place in such a competitive environment. Keywords:5G Network, history,Core concept, Challenges, Solutions, In chinaTable of Content1. Introduction................................................................................................................. - 3 -2. Research and development history ............................................................................. - 3 -3. Core Concept .............................................................................................................. - 4 -4. Challenges and Solutions............................................................................................ - 5 - 4.1 5G Transport Challenge ........................................................................................ - 6 - 4.2 5G Transport Challenge and some Solutions........................................................ - 7 - 4.3 Machine to Machine Communication................................................................... - 7 - 4.3 Core Network Virtualisation ................................................................................. - 8 -4.4 Summary............................................................................................................... - 8 -5. 5G In China................................................................................................................. - 9 - 5.5.1 White paper........................................................................................................ - 9 - 5.5.2 5G standards ...................................................................................................... - 9 - 5.5.3 China communications companies .................................................................... - 9 -5.5.4 Summary.......................................................................................................... - 10 -6. Conlusion.................................................................................................................. - 10 -7. Acronyms.................................................................................................................. - 11 -8. References................................................................................................................. - 11 -1. Introduction5G (Fifth-generation mobile communications) is a new generation of mobile communication mobile communication systems for 2020, with high spectral efficiency and low power consumption, in terms of transfer rate and resource utilization improvement over 4G system 10 times, its wireless coverage performance and user experience will be significantly improved. 5G will be closely integrated with other wireless mobile communication technology, constitute a new generation of ubiquitous mobile information network, to meet future mobile Internet traffic 1000x development needs in 10 years.[1]In this paper I will show you some latest research and development history,what are the building blocks of core 5G system concept, what are the main challenges and how to tackle them firstly. In the rest of paper I will show how 5G development in China in recent years and my conclusion after research literature.2. Research and development historyFebruary 2013, the EU announced that it would grant 50 million euros to accelerate the development of 5G mobile technology, plans to launch a mature standard in 2020. [2][3]May 13,2013,South Korea's Samsung Electronics Co., Ltd. announced that it has successfully developed the 5th generation mobile communication (5G) core technology, which is expected to begin in 2020 to commercialization. The technology can transmit data at ultra-high frequency 28GHz to 1Gbps per second speed, and the maximum transmission distance of up to 2 km. In contrast, the current fourth generation Long Term Evolution (4GLTE) and services of only the transmission rate 75Mbps. Prior to the transmission bottleneck is widely believed that a technical problem, while Samsung Electronics is the use of 64 adaptive array antenna elements transmission technology to crack this problem. Compared with the transmission speed of 4G technology in South Korea, 5G technology is hundreds of times faster. Using this technique, download a high-definition (HD) movie just need 10 seconds.Back in 2009, Huawei has launched the early research related technologies, and to show the prototype of the 5G base in later years.In November 6, 2013,Huawei announced that it would invest $600 million in 2018 for the 5G technology development and innovation, and predicted that users will enjoy 20Gbps commercial 5G mobile networks in 2020. May 8, 2014, the Japanese telecom operator NTT DoCoMo announced officially, Ericsson ,Nokia, Samsung and other six manufacturers to work together, began testing override 1000 times than existing 4G networks the carrying capacity of the high-speed network 5G network, the transmission speed is expected to 10Gbps. Outdoor testing scheduled to commence in 2015, and expects to begin operations in 2020.[3]March 1, 2015, the British "Daily Mail" reported that the British 5G network has successfully developed and tested for data transmission within 100 meters per second data transfer of up to 125GB, is 6.5 times the 4G network, in theory, a 30 seconds to download movies, adding that investment in public test in 2018, 2020 officially put into commercial use.[4]February 11, 2015 in the afternoon news, IMT-2020 (5G) to promote the group (hereinafter referred to as "advance group") held a conference in Beijing 5G concept of white paper. White Paper from the mobile Internet and networking composed mainly of application scenarios, business needs and challenges of starting summed continuous wide area coverage, high reliability of the four major technology 5G scene of high capacity, low power consumption and low latency connection. Meanwhile, the combination of core technologies and key capabilities 5G and 5G concept proposed by the "flag sexuality index + a set of key technologies" common definition.March 3,2015,the European Economic and Social Commission for Digital Furusawa Ottinge officially announced the EU's vision of public-private partnerships 5G, and strive to ensure that the right to speak in the next generation of mobile technology in Europe in the global standard.Ottinger said that, 5G vision of public-private partnership involves not only fiber, wireless or satellite communications network integrated with each other, will also use the software-defined networking (SDN), network functions virtualization (NFV), Mobile Edge computing (MEC) and Fog Computing technology. In the spectrum, the EU's vision of public-private partnership will be designated 5G hundreds of megahertz to improve network performance, 60 GHz and higher frequency bands will also be taken into account.A number of countries and organizations announced, 5G network will be operational between 2020 ~ 2025.3. Core ConceptWhat is 5G? I believe many people will be so questionable when see 5G. Judging from the word meaning, 5G refers to the fifth generation of mobile communications. However, how should it define? Currently, the global industry for 5G concept not yet agreed. China IMT-2020 (5G) group released the White Paper considers the concept 5G, 5G integrated key capabilities and core technology, 5G concept by "important targets" and "a group of key technologies" to a common definition. Among them, the flag indicators "Gbps rate user experience" is a set of key technologies, including large-scale antenna array, ultra-dense networking, new multi-site, full-spectrum access and new network architectures.Recalling the course of development of mobile communications, each generation ofmobile communication systems can be defined by sexual performance indicators and signs of key technologies. Wherein, 1G using FDMA, only analog voice services; 2G mainly using TDMA, can provide voice and low -speed digital data services; 3G to CDMA technology is characterized by user peak rate of 2Mbps to reach tens of Mbps, support multimedia data services; 4G OFDMA technology as the core, the user peak rate of up to 100Mbps ~ 1Gbps, can support a variety of mobile broadband data services.5G key competencies richer than previous generations of mobile communications, user experience, speed, density of connections, end to end delay, the peak rate and mobility and so will be the 5G key performance indicators. However, unlike the case in the past only to emphasize different peak rate, the industry generally believe that the rate of the user experience is the most important performance indicators, it truly reflects the real data rate available to the user, and the user experience is the closest performance. Based on the technology needs of the main scene 5G, 5G user experience rate should reach Gbps magnitude.Faced with diverse scenes of extreme performance demands differentiation, 5G cannot have solutions for all scenarios. In addition, the current wireless technology innovation has diversified development trend, in addition to the new multi -access technology, large -scale antenna array, ultra -dense network, the whole spectrum access, the new network architecture, also is considered to be the main technical direction.5G can play a key role in the major technology scene. [5]4. Challenges and SolutionsIn this part I outline some observed research challengesand directions in the mobile network development and show some may become the future trends and solutions that may lead to improved network performance while meeting the constantly increasing user demands. the new network architecture Gbps user exerperience rate Ultra -dense network Large -scale antenna array New multi -access technology The new network architecture Figure 1 - 5G Concept4.1 5G Transport ChallengeIn order to understand the 5G transport challenges one must understand how 5G may evolve the radio access segment.Among the various initiatives that are looking into 5G, we can defines 5G in terms of scenarios which the next generation wireless access networks will have to support. [6]A total of five future scenarios have been defined,namely amazingly fast (users want to enjoy instantaneous network connectivity), great service in a crowd, ubiquitous things communicating (i.e., effective support to Internet of Things), super real time and reliable connections, and best experience follows you. Each of these scenarios introduces a challenge .Three of these challenges (i.e., very high data rate, very dense crowds of users and mobility) are more traditional in the sense that they are related to continued enhancement of user experience and supporting increasing traffic volumes and mobility. Two emerging challenges, very low latency and very low energy, cost and massive number of devices, are associated with the application of wireless communications to new areas. Future applications may be associated with one or several of these scenarios imposing different challenges to the network. In METIS twelve specific test cases were defined and mapped onto the five scenarios. The selected test cases essentially sample the space of future applications. Once technical enablers that fulfill there quirements for these test cases are defined, it is expected that other applications subject to the same fundamental challenges, will successfully be supported. As a consequence, defining technical enablers for the 5G test cases means also defining technical solutions to the 5G challenges.While METIS[7] is focused on wireless access, the challenges defined for 5G are expected to impact also the transport. Support for very high data rates will require both higher capacity radio access nodes as well as a densification of radio access sites. This, in turn, translates into a transport network that needs to support more sites and higher capacity per site, i.e. huge traffic volumes. The great service in a crowd scenario will put requirements on the transport network to provide very high capacity on-demand to specific geographical locations. In addition, the best experience follows you scenario, suggests a challenge in terms of fast reconfigurability of the transport resources. On the contrary, the other 5G challenges are not expected to play as important role for shaping the transport, as for example the case of very low latency and very low energy, cost and massive number of devices. A properly dimensioned transport network based on modern wireless and/or optical technologies is already today able to provide extremely low latency, i.e., the end-to-end delay contribution of the transport network is usually almost negligible. In addition, while a huge number of connected machines and devices will create a challenge for the wireless network, it will most probably not significantly impact the transport. This is due to the fact that the traffic generated by a large number of devices over a geographical area will already be aggregated in the transport. The three scenarios for the transport network described above are summarized along with their corresponding challenges and test cases. Note that does not report all the original test cases but only those that pose challenges to the transport network. This information will be used later inthe paper to identify the appropriate transport technologies.4.2 5G Transport Challenge and some SolutionsThis section provides an overview of a number of transportoptions for 5G wireless networks. A 5G transport network can be divided in two different segments, i.e., small cell transportand metro/aggregation (Fig. 2). The small cell transport segment aggregates the traffic to/from the wireless small cells towards the metro/aggregation segment. Different solutions in terms of technology (e.g., optics, wireless) and topology (e.g., tree, ring, mesh) are possible depending on the specific wireless access scenario. The metro/aggregation segment, on the other hand, connects different site types (i.e., macro and/or small cells) among themselves and to the core network, the latter via the service edge (service node for the interconnection among different network domains).For the metro/aggregation segment one promising solution is represented by a dense-wavelength-division multiplexing (DWDM)[8] -centric network. In such a network, packet aggregation takes place at the edges of the network (e.g., at small/macro cells sites and at the service edge), while at center (i.e., between access and metro rings) switching is done completely in the optical domain thanks to active optical elements such as wavelength selective switches (WSSs) and reconfigurable optical add-drop multiplexers (ROADMs). It has already been demonstrated that DWDM-centric solutions have the potential to offer high capacity (in the order of tens to hundreds of Gbps) and lower energy consumption than their packet-centric counterparts (i.e., with packet aggregation at the center of the network). [9] For this reason the DWDM-centric metro/aggregation concept may represent a good candidate for future 5G transport networks.[10]4.3 Machine to Machine CommunicationMachine to Machine Communication Besides network evolution, we observe also device evolution that become more and more powerful. The future wireless landscape will serve not only mobile users through such devices as smartphones, tablets or game consoles but also a tremendous number of any other devices, such as cars, smart grid terminals, health monitoring devices and household appliances that would soon require a connection to the Internet. The number of connected devices will proliferate at a very high speed. It is estimated that the M2M traffic will increase 24-fold between 2012 and 2017 .[11]M2M communication is already today often used in fleet monitoring or vehicle tracking. Possible future usage scenarios include a wide variety of e-health applications and devices, for instance new electronic and wireless apparatus used to address the needs of elderly people suffering from diseases like Alzheimer’s, or wearable heart monitors. Suchsensors would enable patient monitoring and aid doctors to observe patients constantly and treat them in a better way. It will also reduce the costs of treatment, as it can be done remotely, without the need of going to a hospital.Remote patient monitoring using a Body Area Network (BAN), where a number of wireless sensors, both on-skin and implanted, record the patient’s health parameters and sends reports to a doctor, will soon become a reality and an important part of 5G paradigm. Therefore, in order to offer e-health services, 5G will need to provide high bandwidth, meet extremely high Quality of Service (QoS) requirements, e.g., ultra low latency and lossless video compression for medical purposes, and implement enhanced security mechanisms. Furthermore, extended work will need to be done to efficiently manage radio resources, due to high diversity of traffic types, ranging from the reports sent periodically by the meters, to high quality medical video transmission.4.3 Core Network VirtualisationMoving towards 5G imposes changes not only in the Radio Access Network (RAN) but also in the Core Network (CN), where new approaches to network design are needed to provide connectivity to growing number of users and devices. The trend is to decouple hardware from software and move the network functions towards the latter one. Software Defined Networking (SDN) being standardised by Open Networking Foundation (ONF) assumes separation of the control and data plane[12]. Consequently, thanks to centralization and programmability, configuration of forwarding can be greatly automated.Moreover, standardisation efforts aiming at defining Network Functions Virtualisation (NFV) are conducted by multiple industrial partners including network operators and equipment vendors within ETSI.[13] Introducing a new software based solution is much faster than installing an additional specialised device with a particular functionality. Both solutions would improve the network adaptability and make it easily scalable. As a result of simpler operation, one can expect more dynamic and faster deployment of new network features.4.4 SummaryI only list a partial of the challenges of 5G networks and possible solutions , in fact, before making a formal universal 5G are still many problems to be overcome, it also requires effort frontline researchers.5. 5G In China5.5.1 White paperFebruary 11, 2015，China released White paper about concept of 5G.It instantly make more people are concerned about 5G. People eager to 5G network as soon as possible. The White Paper published, the concept from various angles, core competencies, technical characteristics of 5G defined and interpreted. At the same time, this is the IMT-2020 (5G) to promote the group last year after the publication of the White Paper 5G vision and needs another masterpiece. The foreseeable future, as the Chinese government pay more attention to the development of 5G and adopt a more open attitude, with the joint efforts of the industry, and China will play an increasingly important role in the global 5G development, global industry will also be unified 5G standard stride forward.5.5.2 5G standardsChina will actively participate in the development of 5G standards, will help China to further enhance the patent position in international communication standards, escort for our mobile phone manufacturing.China is a big manufacturing country, the state has proposed the creation of a strategic shift to China, 3G and 4G standards successful experience will help us win more patents in the development of 5G standard time, to achieve the transformation of China to create the goal.5.5.3 China communications companiesFebruary 12, 2015, the International Telecommunication Union standard 5G start research work, and clearly the IMT-2020 work plan: will complete the IMT-2020 international standard preliminary studies in 2015, 2016 will be carried out 5G technical performance requirements and evaluation methods Research, by the end of 2017 to start collecting 5G candidate to complete standards by the end of 2020.It is worth noting that, in the 5G standards, Huawei, ZTE and other Chinese telecommunications companies such as Ericsson veteran communications companies also play an important role, in which Huawei from between 2013 to 2018, five years is ho throw $ 600 million 5G conduct research and innovation.Recently, ZTE 5G key technologies to achieve new progress. Following the end of the year to complete Massive MIMO antenna array massive field test, ZTE independently developed the proposed super dense network UDN, multiple users to share access to Multi-User Shared Access and other core technologies through demonstration, in Pre5G phase is expected to be applied.[14]Huawei CEO HuHouKun rotation, said in 2015, the company will spend the equivalent of about 10% in 2014 research and development budget, or $ 60 million, the development of 5G technology. Overall, the company's commitment in the next few years, $ 600 million investment in 5G technology. 5G is a next-generation mobile communications standard, is expected early in the next decade and put into use.[15]5.5.4 SummaryChina needs to have its own place in the 5G market, China's communications companies are also very hard, believe in the future, China's R & D level 5G will lead other countries.6. ConlusionIn this paper，I presented a summary of the concept,chanlleges,solusions and 5G in china.For 2020 and the future of the mobile Internet and networking business needs, 5G will focus on supporting the continuous wide area coverage, hot high-capacity, low power consumption and low latency connection highly reliable four main technical scenario, the use of large scale antenna array , ultra-dense networking, new multi-site, full-spectrum access and new network architectures, such as the core technology, through the evolution of new 4G air interface and two technical routes to achieve Gbps rate user experience, and to ensure consistency in service under a variety of scenarios .5G network to achieve real business there are a lot of unresolved issues. Also faced include how to design network architecture, including many technical challenges. Compared with previous generations of communications technology, 5G era biggest challenge is not how to increase the rate, but the user experience with traffic density, the number of terminals from a series of interwoven problems. As much as possible while also reducing user costs. This is the 5G network must be solved.5G study conducted in China are enthusiastic, China needs to accelerate the pace of its own 5G technology to get rid of dependence on foreign companies.5G study conducted in China are enthusiastic, China needs to accelerate the pace of its own 5G technology to get rid of dependence on foreign companies. 5G accelerate the development is conducive to China stand at the forefront of the competition in the next wave of data, a competitive advantage.7. Acronyms5G - Fifth-generation mobile communicationsSDN - software-defined networkingNFV - network functions virtualizationMEC - Mobile Edge computingFDMA - Frequency Division Multiple AccessTDMA - Time Division Multiple AccessCDMA - Code Division Multiple AccessOFDMA - Orthogonal Frequency Division Multiple AccessDWDM - dense-wavelength-division multiplexingBAN - Body Area NetworkQoS - Quality of ServiceRAN - Radio Access Network8. References[1]Chen Si ,Li Hua Sheng,”5G technology trends and challenges for radio management”, /news/41/a888991.html[2]”Samsung developed 5G technology”，/link?url=m_HOSi6QF36L7im-m0NRBaQggvikTgV0GLWBNy vN1OllSGp6_nYwU2B_fXsl6tEnyO0lXAw4Fnk0Ku0vtPSBMq#reference-[2]-764107 0-wrap[3] C114 China Communication Network,(Shanghai) ,March2015 ,”The EU announced 5G Vision: To guarantee the right to speak of global standards”/15/0311/10/AKE0JHMD000915BE.html[4]People’s Posts and Telecommunications News (PPTN),March,2015,”Bell Labs: 5G urgent task is to be completed as soon as possible standardization”/info/2015-03/11/c_134058306.htm[5] Baidu Encyclopedia，”5G network”/view/6220993.htm”[6] METIS deliverable D1.1, ”Scenarios, requirements and KPIs for 5G mobile and wireless system”, April 2013.[7] METIS deliverable D6.1, ”Simulation guidelines”, October 2013.[8] Shuqiang Zhang, Ming Xia, S. Dahlfort, ”Fiber routing, wavelength assignment and multiplexing for DWDM-centric converged metro/aggregation networks,” in Proc. of ECOC, Sept. 2013.[9] B. Skubic, I. Pappa, ”Energy consumption analysis of converged networks:Node consolidation vs metro simplification,” in Proc. of OFC,March 2013.[10] Matteo Fiorani,”Challenges for 5G Transport Networks”,IEEE,2014[11]Cisco, “Global Mobile Data Traffic Forecast Update,2012-2017,” Feb. 2013, White Paper.[12]Open Networking Foundation, “SDN Architecture Overview,” Dec. 2013.[13]ETSI, “Network Functions Virtualisation,” Oct. 2012, White Paper.[14]”ZTE 5G MUSA and UDN developed key technologies to achieve new progresss”/news/127/a892565.html[15]”Huawei will invest $ 600 million R & D 5G”/2015-04/02/content_543144.htm。
5G网络英文介绍
With the rapid development of wireless technologies, the concept of the Fifth Generation (5G) wireless communication system started to emerge. But most people know little about 5G，including some aspects of 5G wireless communication networks ,just like what 5G is about: what are the building blocks of core 5G system concept, what are the main challenges and how to tackle them. Besides, A number of countries and organizations working on 5G, 5G development situation in China is of concern to everyone, China also needs to have its own place in such a competitive environment.
随着无线技术的飞速发展，第五代(5G)无线通信系统 的概念开始出现。但大多数人对5G知之甚少,包括5G 无线通信网络的某些方面,就像5G是什么:什么是核心 5G系统的构建块的概念,主要的挑战是什么,以及如何 解决这些问题。此外，一些国家和组织致力于5G, 5G 在中国的发展情况是每个人都关心的，中国也需要在
5G key competencies richer than previous generations of mobile communications, user experience, speed, density of connections, end to end delay, the peak rate and mobility and so will be the 5G key performance indicators. However, unlike the case in the past only to emphasize different peak rate, the industry generally believe that the rate of the user experience is the most important performance indicators, it truly reflects the real data rate available to the user, and the user experience is the closest performance. Based on the technology needs of the main scene 5G, 5G user experience rate should reach Gbps magnitude.
无线通信外文文献译文
无线通信电机及电子学工程师联合会2005年国际研讨会上关于微波，天线，传播和无线通信的电磁兼容技术在技术发展上的最新动态竹内清一地区10主任东京电机大学摘要本文介绍无线通信技术的最新发展趋势以及组成无线通信技术的四个部分。
第一个也是最重要的发展是全球互联网流量的增长。
在全球互联网流量增长的重要趋势总结在全球地理区域和他们的互联网渗透方面。
第二个部分是实现无线通信所必备的骨干网络中的硬件配套技术的发展。
第三部分是无线通信的中心问题，特别是本地个人用户，第四和最后一个部分是总结发言。
1简介许多技术的发展显然是需要通过无线通信的实现，以满足环保要求的社会背景需要这的种技术发展。
例如，互联网流量每年约增加一倍，而这种快速增长的互联网流量和WWW（全球资讯网）需要为骨干网络配置无线并不一定需要，但对本地无线通信的实现至关重要的巨大带宽。
骨干网主要靠光纤电缆的技术发展以及相关的配套技术配套支持运行的。
这样的等配套技术包括信息处理和WDM（波分复用）和他们使取得的高效无线通信成为了可能。
无线通信，特别是无线互联网特别是无线互联网对于集中，甚至不断移动的短距离范围内的本地个人用户非常重要。
在IEEE 802.11是无线局域网用于与合作媒介访问控制协议的一般原则，也可以扩展到其他类型的无线网络，如无线个人区域网络（WPAN的）。
该服务区的范围变得越来越小，以便让当地个人用户的充分利用无线通讯媒介用于无线互联网流量。
无线通信是无线互联网最便捷的传输介质，这种无线传输介质的有效使用是至关重要的。
可靠的访问几十兆赫可以跨相当大的在其中无线互联网将需要十倍多的细胞的语音系统的地理区域，每个这样的monocles将测量面积小，几十平方米的大约是百分之常规细胞的大小。
它比传统电池可以容纳更多给定的数据速率的有源器件。
为了使这成为可能的，有效的射频频谱空间复用是必要的，从而能够让个人用户访问更贴近低功率的传输点。
对于快速增长的互联网流量的整体通信系统可以由的三个关键的重要领域的技术发展来支持，1）硬件技术需要个人用户的高密度无线传输的实现，2）配套硬件技术的光纤电缆，3）整体通信系统的运作和维护方面的软件技术，我们主要回顾了前两部分的硬件方面2互联网的发展表1显示了最高的互联网普及率最高的24个国家。
5g通信移动外国参考文献
5g通信移动外国参考文献1. Rappaport, T. S., Shu, F., Sun, S., & Mayzus, R. (2013). Millimeter wave mobile communications for 5G cellular: It will work!. IEEE access, 1, 335-349.2. Andrews, J. G., Buzzi, S., Choi, W., Hanly, S. V., Lozano, A., Soong, A. C., ... & Zhang, J. (2014). What will 5G be?. IEEE Journal on selected areas in communications, 32(6), 1065-1082.3. Boccardi, F., Heath Jr, R. W., Lozano, A., Marzetta, T. L., & Popovski, P. (2014). Five disruptive technology directions for 5G. IEEE Communications Magazine, 52(2), 74-80.4. Al-Fuwaires, M., & Faisal, K. (2018). 5G wireless communication systems: prospects and challenges. Wireless Personal Communications, 98(1), 159-175.5. Szydelko, M., Wysocki, T. A., & Monti, P. (2016). 5G mobile networks evolution: requirements, trends, and challenges. In 2016 8th International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT) (pp. 5-10). IEEE.6. Lopez, O., Guijarro, M., Casado, T., & Cano, J. C. (2016). 5G mobile networks: A vision. Current Trends in Communications Engineering, 4(1), 36-43.7. Khan, F. H., Ahmed, R., & Ali, W. (2018). Key enabling technologies for 5G mobile networks: state-of-the-art and research challenges. Journal of Network and Computer Applications, 107, 77-104.8. Boudhir, A., Huq, K., & Bardakjian, A. (2017). A survey of 5G wireless communication technologies and challenges. IEEE Transactions on Retrofitting Evolution, 76(2), 153-202.9. Parkvall, S., Ericson, A., & Furuskar, A. (2017). 5G NR: The next generation wireless access technology. Academic Press. 10. Mellado, M., & López, V. (2017). Cloud-based architecturesfor 5G mobile networks: design principles and requirements. Journal of Network and Computer Applications, 87, 203-217.。
蜂窝无线通信系统中英文对照外文翻译文献
中英文对照外文翻译文献(文档含英文原文和中文翻译)原文：RESEARCH OF CELLULAR WIRELESS COMMUNATIONSYSTEMA wide variety of wireless communication systems have been developed to provide access to the communications infrastructure for mobile or fixed users in a myriad of operating environments. Most of today’s wireless systems are based on the cellular radio concept. Cellular communication systems allow a large number of mobile users to seamlessly and simultaneously communicate to wireless modems at fixed base stations using a limited amount of radio frequency (RF) spectrum. The RF transmissions received at the base stations from each mobile are translated to baseband, or to a wideband microwave link, and relayed to mobile switching centers (MSC), which connect the mobile transmissions with the Public Switched Telephone Network (PSTN). Similarly, communications from the PSTN are sent to the base station, where they are transmitted to the mobile. Cellular systems employ eitherfrequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), or spatial division multiple access (SDMA) .Wireless communication links experience hostile physical channel characteristics, such as time-varying multipath and shadowing due to large objects in the propagation path. In addition, the performance of wireless cellular systems tends to be limited by interference from other users, and for that reason, it is important to have accurate techniques for modeling interference. These complex channel conditions are difficult to describe with a simple analytical model, although several models do provide analytical tractability with reasonable agreement to measured channel data . However, even when the channel is modeled in an analytically elegant manner, in the vast majority of situations it is still difficult or impossible to construct analytical solutions for link performance when error control coding, equalization, diversity, and network models are factored into the link model. Simulation approaches, therefore, are usually required when analyzing the performance of cellular communication links.Like wireless links, the system performance of a cellular radio system is most effectively modeled using simulation, due to the difficulty in modeling a large number of random events over time and space. These random events, such as the location of users, the number of simultaneous users in the system, the propagation conditions, interference and power level settings of each user, and the traffic demands of each user, combine together to impact the overall performance seen by a typical user in the cellular system. The aforementioned variables are just a small sampling of the many key physical mechanisms that dictate the instantaneous performance of a particular user at any time within the system. The term cellular radio system, therefore, refers to the entire population of mobile users and base stations throughout the geographic service area, as opposed to a single link that connects a single mobile user to a single base station. To design for a particular system-level performance, such as the likelihood of a particular user having acceptable service throughout the system, it is necessary to consider the complexity of multiple users that are simultaneously using the system throughout the coverage area. Thus, simulation is needed to consider the multi-user effects upon any of the individual links between the mobile and the base station.The link performance is a small-scale phenomenon, which deals with the instantaneouschanges in the channel over a small local area, or small time duration, over which the average received power is assumed constant. Such assumptions are sensible in the design of error control codes, equalizers, and other components that serve to mitigate the transient effects created by the channel. However, in order to determine the overall system performance of a large number of users spread over a wide geographic area, it is necessary to incorporate large-scale effects such as the statistical behavior of interference and signal levels experienced by individual users over large distances, while ignoring the transient channel characteristics. One may think of link-level simulation as being a vernier adjustment on the performance of a communication system, and the system-level simulation as being a coarse, yet important, approximation of the overall level of quality that any user could expect at any time.Cellular systems achieve high capacity (e.g., serve a large number of users) by allowing the mobile stations to share, or reuse a communication channel in different regions of the geographic service area. Channel reuse leads to co-channel interference among users sharing the same channel, which is recognized as one of the major limiting factors of performance and capacity of a cellular system. An appropriate understanding of the effects of co-channel interference on the capacity and performance is therefore required when deploying cellular systems, or when analyzing and designing system methodologies that mitigate the undesired effects of co-channel interference. These effects are strongly dependent on system aspects of the communication system, such as the number of users sharing the channel and their locations. Other aspects, more related to the propagation channel, such as path loss, shadow fading (or shadowing), and antenna radiation patterns are also important in the context of system performance, since these effects also vary with the locations of particular users. In this chapter, we will discuss the application of system-level simulation in the analysis of the performance of a cellular communication system under the effects of co-channel interference. We will analyze a simple multiple-user cellular system, including the antenna and propagation effects of a typical system. Despite the simplicity of the example system considered in this chapter, the analysis presented can easily be extended to include other features of a cellular system.2 Cellular Radio SystemSystem-Level Description：Cellular systems provide wireless coverage over a geographic service area by dividing the geographic area into segments called cells as shown in Figure 2-1. The available frequency spectrum is also divided into a number of channels with a group of channels assigned to each cell. Base stations located in each cell are equipped with wireless modems that can communicate with mobile users. Radio frequency channels used in the transmission direction from the base station to the mobile are referred to as forward channels, while channels used in the direction from the mobile to the base station are referred to as reverse channels. The forward and reverse channels together identify a duplex cellular channel. When frequency division duplex (FDD) is used, the forward and reverse channels are split in frequency. Alternatively, when time division duplex (TDD) is used, the forward and reverse channels are on the same frequency, but use different time slots for transmission.Figure 2-1 Basic architecture of a cellular communications system High-capacity cellular systems employ frequency reuse among cells. This requires that co-channel cells (cells sharing the same frequency) are sufficiently far apart from each other to mitigate co-channel interference. Channel reuse is implemented by covering the geographic service area with clusters of N cells, as shown in Figure 2-2, where N is known as the cluster size.Figure 2-2 Cell clustering:Depiction of a three-cell reuse pattern The RF spectrum available for the geographic service area is assigned to each cluster, such that cells within a cluster do not share any channel . If M channels make up the entire spectrum available for the service area, and if the distribution of users is uniform over the service area, then each cell is assigned M/N channels. As the clusters are replicated over the service area, the reuse of channels leads to tiers of co-channel cells, and co-channel interference will result from the propagation of RF energy between co-channel base stations and mobile users. Co-channel interference in a cellular system occurs when, for example, a mobile simultaneously receives signals from the base station in its own cell, as well as from co-channel base stations in nearby cells from adjacent tiers. In this instance, one co-channel forward link (base station to mobile transmission) is the desired signal, and the other co-channel signals received by the mobile form the total co-channel interference at the receiver. The power level of the co-channel interference is closely related to the separation distances among co-channel cells. If we model the cells with a hexagonal shape, as in Figure 2-2, the minimum distance between the center of two co-channel cells, called the reuse distance ND, is（2-1）R3D N Nwhere R is the maximum radius of the cell (the hexagon is inscribed within the radius).Therefore, we can immediately see from Figure 2-2 that a small cluster size (small reuse distance ND), leads to high interference among co-channel cells.The level of co-channel interference received within a given cell is also dependent on the number of active co-channel cells at any instant of time. As mentioned before, co-channel cells are grouped into tiers with respect to a particular cell of interest. The number of co-channel cells in a given tier depends on the tier order and the geometry adopted to represent the shape of a cell (e.g., the coverage area of an individual base station). For the classic hexagonal shape, the closest co-channel cells are located in the first tier and there are six co-channel cells. The second tier consists of 12 co-channel cells, the third, 18, and so on. The total co-channel interference is, therefore, the sum of the co-channel interference signals transmitted from all co-channel cells of all tiers. However, co-channel cells belonging to the first tier have a stronger influence on the total interference, since they are closer to the cell where the interference is measured.Co-channel interference is recognized as one of the major factors that limits the capacity and link quality of a wireless communications system and plays an important role in the tradeoff between system capacity (large-scale system issue) and link quality (small-scale issue). For example, one approach for achieving high capacity (large number of users), without increasing the bandwidth of the RF spectrum allocated to the system, is to reduce the channel reuse distance by reducing the cluster size N of a cellular system . However, reduction in the cluster sizeincreases co-channel interference, which degrades the link quality.The level of interference within a cellular system at any time is random and must be simulated by modeling both the RF propagation environment between cells and the position location of the mobile users. In addition, the traffic statistics of each user and the type of channel allocation scheme at the base stations determine the instantaneous interference level and the capacity of the system.The effects of co-channel interference can be estimated by the signal-tointerference ratio (SIR) of the communication link, defined as the ratio of the power of the desired signal S, to the power of the total interference signal, I. Since both power levels S and I are random variables due to RF propagation effects, user mobility and traffic variation, the SIR is also a random variable. Consequently, the severity of the effects of co-channel interference onsystem performance is frequently analyzed in terms of the system outage probability, defined in this particular case as the probability that SIR is below a given threshold 0S IR . This isdx p ]SIR Pr[SIR P )x 0SIR 0SIR 0outpage （⎰=<= （2-2）Where is the probability density function (pdf) of the SIR. Note the distinction between the definition of a link outage probability, that classifies an outage based on a particular bit error rate (BER) or Eb/N0 threshold for acceptable voice performance, and the system outage probability that considers a particular SIR threshold for acceptable mobile performance of a typical user.Analytical approaches for estimating the outage probability in a cellular system, as discussed in before, require tractable models for the RF propagation effects, user mobility, and traffic variation, in order to obtain an expression for PSIR （x ）. Unfortunately, it is very difficult to use analytical models for these effects, due to their complex relationship to the received signal level. Therefore, the estimation of the outage probability in a cellular system usually relies on simulation, which offers flexibility in the analysis. In this chapter, we present a simple example of a simulation of a cellular communication system, with the emphasis on the system aspects of the communication system, including multi-user performance, traffic engineering, and channel reuse. In order to conduct a system-level simulation, a number of aspects of the individual communication links must be considered. These include the channel model, the antenna radiation pattern, and the relationship between Eb/N0 (e.g., the SIR) and the acceptable performance.SIR(x)p翻译：蜂窝无线通信系统的研究摘要蜂窝通信系统允许大量移动用户无缝地、同时地利用有限的射频（radio frequency，RF）频谱与固定基站中的无线调制解调器通信。
计算机第五代5g移动通讯通信技术介绍简介概述外文文献翻译成品：5G的五个颠覆性技术方向中英文双语对照
Five Disruptive Technology Directions for 5G ABSTRACT: New research directions will lead to fundamental changes in the design of future 5th generation (5G) cellular networks. This paper describes five technologies that could lead to both architectural and component disruptive design changes: device-centric architectures, millimeter Wave, Massive-MIMO, smarter devices, and native support to machine-2-machine. The key ideas for each technology are described, along with their potential impact on 5G and the research challenges that remain.I.INTRODUCTION:5G is coming. What technologies will define it? Will 5G be just an evolution of 4G, or will emerging technologies cause a disruption requiring a wholesale rethinking of entrenched cellular principles? This paper focuses on potential disruptive technologies and their implications for 5G. We classify the impact of new technologies, leveraging the Henderson-Clark model [1], as follows:1.Minor changes at both the node and the architectural level, e.g., the introduction of codebooks and signaling support for a higher number of antennas. We refer to these as evolutions in the design.2.Disruptive changes in the design of a class of network nodes, e.g., the introduction of a new waveform. We refer to these as component changes.3.Disruptive changes in the system architecture, e.g., the introduction of new types of nodes or new functions in existing ones. We refer to these as architectural changes.4.Disruptive changes that have an impact at both the node and the architecture levels. We refer to these as radical changes.We focus on disruptive (component, architectural or radical) technologies, driven by our belief that the extremely higher aggregate data rates and the much lower latencies required by 5G cannot be achieved with a mere evolution of the status quo. We believe that the following five potentially disruptive technologies could lead to both architectural and component design changes, as classified in Figure 1.1.Device-centric architectures.The base-station-centric architecture of cellular systems may change in 5G. It may be time to reconsider the concepts of uplink and downlink, as well as control and data channels, to better route information flows with different priorities and purposes towards different sets of nodes within the network. We present device-centric architectures in Section II.limeter Wave (mmWave).While spectrum has become scarce at microwave frequencies, it is plentiful in the mmWave realm. Such a spectrum ‘el Dorado’ has led to a mmWave ‘gold rush’ in which researchers with diverse backgrounds are studying different aspects ofmmWave transmission. Although far from fully understood, mmWave technologies have already been standardized for short-range services (IEEE 802.11ad) and deployed for niche applications such as small-cell backhaul. In Section III, we discuss the potential of mmWave for a broader application in 5G.3.Massive-MIMO.Massive-MIMO1 proposes utilizing a very high number of antennas to multiplex messages for several devices on each time-frequency resource, focusing the radiated energy towards the intended directions while minimizing intra-and inter-cell interference. Massive-MIMO may require major architectural changes, in particular in the design of macro base stations, and it may also lead to new types of deployments. We discuss massive-MIMO in Section IV.4.Smarter devices.2G-3G-4G cellular networks were built under the design premise of having complete control at the infrastructure side. We argue that 5G systems should drop this design assumption and exploit intelligence at the device side within different layers of the protocol stack, e.g., by allowing Device-to-Device (D2D) connectivity or by exploiting smart caching at the mobile side. While this design philosophy mainly requires a change at the node level (component change), it has also implications at the architectural level. We argue for smarter devices in Section V.5.Native support for Machine-to-Machine (M2M) communicationA native2 inclusion of M2M communication in 5G involves satisfying three fundamentally different requirements associated to different classes of low-data-rate services: support of a massive number of low-rate devices, sustainment of a minimal data rate in virtually all circumstances, and very-low-latency data transfer. Addressing these requirements in 5G requires new methods and ideas at both the component and architectural level, and such is the focus of Section VI.II.DEVICE-CENTRIC ARCHITECTURESCellular designs have historically relied on the axiomatic role of ‘cells’ as fundamental units within the radio access network. Under such a design postulate, a device obtains service by establishing a downlink and an uplink connection, carrying both control and data traffic, with the base station commanding the cell where the device is located. Over the last few years, different trends have been pointing to a disruption of this cell-centric structure:1.The base-station density is increasing rapidly, driven by the rise of heterogeneous networks. While heterogeneous networks were already standardized in 4G, the architecture was not natively designed to support them. Network densification could require some major changes in 5G. The deployment of base stations with vastly different transmit powers and coverage areas, for instance, calls for a decoupling of downlink and uplink in a way that allows for the corresponding information to flow through different sets of nodes [5].2.The need for additional spectrum will inevitably lead to the coexistence of frequency bands with radically different propagation characteristics within the same system. In this context, [6] proposes the concept of a ‘phantom cell’ where the data and control planes are separated: the control information is sent by high-power nodes at microwave frequencies whereas the payload data is conveyed by low-power nodes at mm-Wave frequencies. (cf. Section III.)3.A new concept termed centralized baseband related to the concept of cloud radioaccess networks is emerging (cf. [7]), where virtualization leads to a decoupling between a node and the hardware allocated to handle the processing associated with this node. Hardware resources in a pool, for instance, could be dynamically allocated to different nodes depending on metrics defined by the network operator.Emerging service classes, described in Section VI, could require a complete redefinition of the architecture. Current works are looking at architectural designs ranging from centralization or partial centralization (e.g., via aggregators) to full distribution (e.g., via compressed sensing and/or multihop).Cooperative communications paradigms such as CoMP or relaying, which despite falling short of their initial hype are nonetheless beneficial [8], could require a redefinition of the functions of the different nodes. In the context of relaying, for instance, recent developments in wireless network coding [9] suggest transmission principles that would allow recovering some of the losses associated with half-duplex relays. Moreover, recent research points to the plausibility of full- duplex nodes for short-range communication in a not-so-distant future.The use of smarter devices (cf. Section V) could impact the radio access network. In particular, both D2D and smart caching call for an architectural redefinition where the center of gravity moves from the network core to the periphery (devices, local wireless proxies, relays). Based on these trends, our vision is that the cell-centric architecture should evolve into a device-centric one: a given device (human or machine) should be able to communicate by exchanging multiple information flows through several possible sets of heterogeneous nodes. In other words, the set of network nodes providing connectivity to a given device and the functions of these nodes in a particular communication session should be tailored to that specific device and session. Under this vision, the concepts of uplink/downlink and control/data channel should be rethought (cf. Figure 2).While the need for a disruptive change in architectural design appears clear, major research efforts are still needed to transform the resulting vision into a coherent and realistic proposition. Since the history of innovations (cf. [1]) indicates that architectural changes are often the drivers of major technological discontinuities, we believe that the trends above might have a major influence on the development of 5G.LIMETER WA VE COMMUNICATIONMicrowave cellular systems have precious little spectrum: around 600 MHz are currently in use, divided among operators [10]. There are two ways to gain access to more microwave spectrum:1.To repurpose or refarm spectrum. This has occurred worldwide with the repurposing of terrestrial TV spectrum for applications such as rural broadband access. Unfortunately, repurposing has not freed up that much spectrum, only about 80 MHz, and at a high cost associated with moving the incumbents.2.To share spectrum utilizing, for instance, cognitive radio techniques. The high hopes initially placed on cognitive radio have been dampened by the fact that an incumbent not fully willing to cooperate is a major obstacle to spectrum efficiency for secondary users.3.Altogether, it appears that a doubling of the current cellular bandwidth is the best-case scenario at microwave frequencies. Alternatively, there is an enormous amount of spectrum at mmWave frequencies ranging from 3 to 300 GHz. Many bands therein seem promising, including most immediately the local multipoint distribution service at 28-30 GHz, the license-free band at 60 GHz, and the E-band at 71-76 GHz, 81-86 GHz and 92-95 GHz. Foreseeably, several tens of GHz could become available for 5G, offering well over an order-of-magnitude increase over what is available atpresent. Needless to say, work needs to be done on spectrum policy to render these bands available for mobile cellular.3.Propagation is not an insurmountable challenge. Recent measurements indicate similar general characteristics as at microwave frequencies, including distance-dependent pathloss and the possibility of non-line-of-sight communication. A main difference between microwave and mmWave frequencies is the sensitivity to blockages: the results in [11], for instance, indicate a pathloss exponent of 2 for line-of-sight propagation but 4 (plus an additional power loss) for non-line-of-sight. MmWave cellular research will need to incorporate sensitivity to blockages and more complex channel models into the analysis, and also study the effects of enablers such as higher density infrastructure and relays. Another enabler is the separation between control and data planes, already mentioned in Section II.Antenna arrays are a key feature in mmWave systems. Large arrays can be used to keep the antenna aperture constant, eliminating the frequency dependence of pathloss relative to omnidirectional antennas (when utilized at one side of the link) and providing a net array gain to counter the larger thermal noise bandwidth (when utilized at both sides of the link). Adaptive arrays with narrow beams also reduce the impact of interference, meaning that mmWave systems could more often operate in noise-limited rather than interference-limited conditions. Since meaningful communication might only happen under sufficient array gain, new random access protocols are needed that work when transmitters can only emit in certain directions and receivers can only receive from certain directions. Adaptive array processing algorithms are required that can adapt quickly when beams are blocked by people or when some device antennas become obscured by the user’s own body.MmWave systems also have distinct hardware constraints. A major one comes from the high power consumption of mixed signal components, chiefly the analog-to-digital (ADC) and digital-to-analog converters (DAC). Thus, the conventional microwave architecture where every antenna is connected to a high-rate ADC/DAC is unlikely to be applicable to mmWave without a huge leap forward in semiconductor technology. One alternative is a hybrid architecture where beamforming is performed in analog at RF and multiple sets of beamformers are connected to a small number of ADCs or DACS; in this alternative, signal processing algorithms are needed to steer the analog beamforming weights. Another alternative is to connect each RF chain to a 1-bit ADC/DAC, with very low power requirements; in this case, the beamforming would be performed digitally but on very noisy data. There are abundant research challenges in optimizing different transceiver strategies, analyzing their capacity, incorporating multiuser capabilities, and leveraging channel features such as sparsity.A data rate comparison between technologies is provided in Fig. 3, for certain simulation settings, in terms of mean and 5% outage rates. MmWave operation is seento provide very high rates compared to two different microwave systems. The gains exceed the 10x spectrum increase because of the enhanced signal power and reduced interference thanks to directional beamforming at both transmitter and receiver.IV.MASSIVE MIMOMassive MIMO (also referred to as ‘Large-Scale MIMO’ or ‘Large-Scale Antenna Systems’) is a form of multiuser MIMO in which the number of antennas at the base station is much larger than the number of devices per signaling resource [14]. Having many more base station antennas than devices renders the channels to the different devices quasi-orthogonal and very simple spatial multiplexing/de-multiplexing procedures quasi-optimal. The favorable action of the law of large numbers smoothens out frequency dependencies in the channel and, altogether, huge gains in spectral efficiency can be attained (cf. Fig. 4).In the context of the Henderson-Clark framework, we argue that massive-MIMO has a disruptive potential for 5G:At a node level, it is a scalable technology. This is in contrast with 4G, which, in many respects, is not scalable: further sectorization therein is not feasible because of (i) the limited space for bulky azimuthally-directive antennas, and (ii) the inevitable angle spread of the propagation; in turn, single-user MIMO is constrained by the limited number of antennas that can fit in certain mobile devices. In contrast, there is almost no limit on the number of base station antennas in massive- MIMO provided that time-division duplexing is employed to enable channel estimation through uplink pilots.It enables new deployments and architectures. While one can envision direct replacement of macro base stations with arrays of low-gain resonant antennas, other deployments are possible, e.g., conformal arrays on the facades of skyscrapers or arrays on the faces of water tanks in rural locations. Moreover, the same massive-MIMO principles that govern the use of collocated arrays of antennas applyalso to distributed deployments in which a college campus or an entire city could be covered with a multitude of distributed antennas that collectively serve many users (in this framework, the centralized baseband concept presented in Section II is an important architectural enabler).While very promising, massive-MIMO still presents a number of research challenges. Channel estimation is critical and currently it represents the main source of limitations. User motion imposes a finite coherence interval during which channel knowledge must be acquired and utilized, and consequently there is a finite number of orthogonal pilot sequences that can be assigned to the devices. Reuse of pilot sequences causes pilot contamination and coherent interference, which grows with the number of antennas as fast as the desired signals. The mitigation of pilot contamination is an active research topic. Also, there is still much to be learned about massive-MIMO propagation, although experiments thus far support the hypothesis of channel quasi-orthogonality. From an implementation perspective, massive-MIMO can potentially be realized with modular low-cost low-power hardware with each antenna functioning semi-autonomously, but a considerable development effort is still required to demonstrate the cost-effectiveness of this solution. Note that, at the microwave frequencies considered in this section, the cost and the energy consumption of ADCs/DACs are sensibly lower than at mmWave frequencies (cf. Section III).From the discussion above, we conclude that the adoption of massive-MIMO for 5G could represent a major leap with respect to today’s state-of-the-art in system and component design. To justify these major changes, massive-MIMO proponents should further work on solving the challenges emphasized above and on showing realistic performance improvements by means of theoretical studies, simulation campaigns, and testbed experiments.V.SMARTER DEVICESEarlier generations of cellular systems were built on the design premise of having complete control at the infrastructure side. In this section, we discuss some of the possibilities that can be unleashed by allowing the devices to play a more active role and, thereafter, how 5G’s design should account for an increase in device smartness. We focus on three different examples of technologies that could be incorporated into smarter devices, namely D2D, local caching, and advanced interference rejection.V.1 D2DIn voice-centric systems it was implicitly accepted that two parties willing to establish a call would not be in close proximity. In the age of data, this premise might no longer hold, and it could be common to have situations where several co-located devices would like to wirelessly share content (e.g., digital pictures) or interact (e.g., video gaming or social networking). Handling these communication scenarios via simply connecting through the network involves gross inefficiencies at various levels:1.Multiple wireless hops are utilized to achieve what requires, fundamentally, a single hop. This entails a multifold waste of signaling resources, and also a higher latency. Transmit powers of a fraction of a Watt (in the uplink) and several Watts (in the downlink) are consumed to achieve what requires, fundamentally, a few milliWatts. This, in turn, entails unnecessary levels of battery drain and of interference to all other devices occupying the same signaling resources elsewhere.2.Given that the pathlosses to possibly distant base stations are much stronger than the direct-link ones, the corresponding spectral efficiencies are also lower. While it is clear that D2D has the potential of handling local communication more efficiently, local high-data-rate exchanges could also be handled by other radio access technologies such as Bluetooth or Wi-Fi direct. Use cases requiring a mixture of local and nonlocal content or a mixture of low-latency and high- data-rate constraints (e.g., interaction between users via augmented reality), could represent more compelling reasons for the use of D2D. In particular, we envision D2D as an important enabler for applications requiring low-latency 3 , especially in future network deployments utilizing baseband centralization and radio virtualization (cf. Section I).From a research perspective, D2D communication presents relevant challenges:1.Quantification of the real opportunities for D2D. How often does local communication occur? What is the main use case for D2D: fast local exchanges, low-latency applications or energy saving?2.Integration of a D2D mode with the uplink/downlink duplexing structure.3.Design of D2D-enabled devices, from both a hardware and a protocol perspective, by providing the needed flexibility at both the PHY and MAC layers.4.Assessing the true net gains associated with having a D2D mode, accounting for possible extra overheads for control and channel estimation.5.Finally, note that, while D2D is already being studied in 3GPP as a 4G add-on2, the main focus of current studies is proximity detection for public safety [15]. What wediscussed here is having a D2D dimension natively supported in 5G.V.2 Local CachingThe current paradigm of cloud computing is the result of a progressive shift in the balance between data storage and data transfer: information is stored and processed wherever it is most convenient and inexpensive because the marginal cost of transferring it has become negligible, at least on wireline networks [2]. For wireless devices though, this cost is not always negligible. The understanding that mobile users are subject to sporadic ‘abundance’ of connectivity amidst stretches of ‘deprivation’ is hardly new, and the natural idea of opportunistically leveraging the former to alleviate the latter has been entertained since the 1990s [3]. However, this idea of caching massive amounts of data at the edge of the wireline network, right before the wireless hop, only applies to delay-tolerant traffic and thus it made little sense in voice-centric systems. Caching might finally make sense now, in data-centric systems [4]. Thinking ahead, it is easy to envision mobile devices with truly vast amounts of memory. Under this assumption, and given that a substantial share of the data that circulates wirelessly corresponds to the most popular audio/video/social content that is in vogue at a given time, it is clearly inefficient to transmit such content via unicast and yet it is frustratingly impossible to resort to multicast because the demand is asynchronous. We hence see local caching as an important alternative, both at the radio access network edge (e.g., at small cells) and at the mobile devices, also thanks to enablers such as mmWave and D2D.V.3 Advanced Interference RejectionIn addition to D2D capabilities and massive volumes of memory, future mobile devices may also have varying form factors. In some instances, the devices mightaccommodate several antennas with the consequent opportunity for active interference rejection therein, along with beamforming and spatial multiplexing. A joint design of transmitter and receiver processing, and proper control and pilot signals, are critical to allow advanced interference rejection. As an example, in Fig. 5 we show the gains obtained by incorporating the effects of nonlinear, intra and inter-cluster interference awareness into devices with 1, 2 and 4 antennas.While this section has been mainly focused on analyzing the implications of smarter devices at a component level, in Section II we discussed the impact at the radio access network architecture level. We regard smarter devices as having all the characteristic of a disruptive technology (cf. Section I) for 5G, and therefore we encourage researchers to further explore this direction.VI.NATIVE SUPPORT FOR M2M COMMUNICATIONWireless communication is becoming a commodity, just like electricity or water [13]. This commoditization, in turn, is giving rise to a large class of emerging services with new types of requirements. We point to a few representative such requirements, each exemplified by a typical service:1.A massive number of connected devices. Whereas current systems typically operate with, at most, a few hundred devices per base station, some M2M services might require over 104 connected devices. Examples include metering, sensors, smart grid components, and other enablers of services targeting wide area coverage.2.Very high link reliability. Systems geared at critical control, safety, or production, have been dominated by wireline connectivity largely because wireless links did not offer the same degree of confidence. As these systems transition from wireline to wireless, it becomes necessary for the wireless link to be reliably operational virtually all the time.3.Low latency and real-time operation. This can be an even more stringent requirement than the ones above, as it demands that data be transferred reliably within a given time interval. A typical example is Vehicle-to-X connectivity, whereby traffic safety can be improved through the timely delivery of critical messages (e.g., alert and control).Fig. 5 provides a perspective on the M2M requirements by plotting the data rate vs. the device population size. This cartoon illustrates where systems currently stand and how the research efforts are expanding them. The area R1 reflects the operating range of today’s systems, outlining the fact that the device data rate decreases as its population increases. In turn, R2 is the region that reflects current research aimed at improving the spectral efficiency. Finally, R5 indicates the region where operation is not feasible due to fundamental physical and information-theoretical limits.Regions R3 and R4 correspond to the emerging services discussed in this section:R3 refers to massive M2M communication where each connected machine or sensor transmits small data blocks sporadically. Current systems are not designed to simultaneously serve the aggregated traffic accrued from a large number of such devices. For instance, a current system could easily serve 5 devices at 2 Mbps each, but not 10000 devices each requiring 1 Kbps. R4 demarks the operation of systems that require high reliability and/or low latency, but with a relatively low average rate per device. The complete description of this region requires additional dimensions related to reliability and latency.There are services that pose simultaneously more than one of the above requirements, but the common point is that the data size of each individual transmission is small, going down to several bytes. This profoundly changes the communication paradigm for the following reasons:Existing coding methods that rely on long codewords are not applicable to very short data blocks. Short data blocks also exacerbate the inefficiencies associated with control and channel estimation overheads. Currently, the control plane is robust but suboptimal as it represents only a modest fraction of the payload data; the most sophisticated signal processing is reserved for payload data transmission. An optimized design should aim at a much tighter coupling between the data and control planes.As mentioned in Section II, the architecture needs a major redesign, looking at new types of nodes. At a system level, the frame-based approaches that are at the heart of 4G need rethinking in order to meet the requirements for latency and flexible allocation of resources to a massive number of devices. From the discussion above, and from the related architectural consideration in Section II, and referring one last time to the Henderson-Clark model, we conclude that a native support of M2M in 5G requires radical changes at both the node and the architecture level. Major research work remains to be done to come up with concrete and interworking solutionsenabling ‘M2M-inside’ 5G systems.VII.CONCLUSIONThis paper has discussed five disruptive research directions that could lead to fundamental changes in the design of cellular networks. We have focused on technologies that could lead to both architectural and component design changes: device-centric architectures, mmWave, massive-MIMO, smarter devices, and native support to M2M. It is likely that a suite of these solutions will form the basis of 5G. REFERENCES[1] A. Afuah, Innovation Management: Strategies, Implementation and Profits, Oxford University Press, 2003.[2] J. Zander and P. Mähönen, “Riding the data tsunami in the cloud: myths and challenges in future wireless access,” IEEE Comm. Magazine, V ol. 51, No. 3, pp. 145-151, Mar. 2013.[3] D. Goodman, J. Borras, N. Mandayam, R. D. Yates, “Infostations: A new system model for data and messaging services,” in Proc. IEEE Veh. Techn. Conf. (VTC), vol. 2, pp. 969–973, Rome, Italy, May 1997.[4] N. Golrezaei, A. F. Molisch, A. G. Dimakis and G. Caire, “Femtocaching and device-to-device collaboration: A new architecture for wireless video distribution,” IEEE Comm. Magazine, V ol. 51, No. 1, pp.142-149, Apr. 2013.[5] J. Andrews, “The seven ways HetNets are a paradigm shift,” IEEE Comm. Magazine, V ol. 51, No. 3, pp.136-144, Mar. 2013.[6] Y. Kishiyama, A. Benjebbour, T. Nakamura and H. Ishii, “Future steps of LTE-A: evolution towards integration of local area and wide area systems,” IEEE Wireless Communications, V ol. 20, No. 1, pp.12-18, Feb. 2013.[7] “C-RAN: The road towards green RAN,” China Mobile Res. Inst., Beijing, China, White Paper, ver. 2.5, Oct. 2011.[8] A. Lozano, R. W. Heath Jr., J. G. Andrews, “Fundamental limits of cooperation,” IEEE Trans. Inform. Theory, V ol. 59, No. 9, pp. 5213-5226, Sep. 2013.[9] C. D. T. Thai, P. Popovski, M. Kaneko, and E. de Carvalho, “Multi-flow scheduling for coordinated direct and relayed users in cellular systems,” IEEE Trans. Comm., V ol. 61, No. 2, pp. 669-678, Feb. 2013.[10] Z. Pi and F. Khan, “An introduction to millimeter-wave mobile broadband systems,” IEEE Comm. Magazine, V ol. 49, No. 6, pp. 101 –107, Jun. 2011.[11] T. Rappaport and et al, “Millimeter wave mobile communications for 5G cellular: It will work!” IEEE Access, vol. 1, pp. 335–349, 2013.[12] R. W. Heath Jr., “What is the Role of MIMO in Future Cellular Networks: Massive? Coordinated? mmWave?” ICC Workshop Plenary: Beyond LTE-A, Budapest, Hungary. Slides available at: /~rheath/presentations/2013/Future_of_MIMO_Plenary_He ath.pdf[13] Mark Weiser, “The Computer for the 21st Century,” Scientific American, Sept. 1991.。
5G无线通信基础英文论文 A Brief Introduction About 5G Network
A Brief Introduction About 5G Network JiaAbstractWith the rapid development of wireless technologies, theconcept of the Fifth Generation (5G) wireless communication system started to emerge. But most people know little about 5G，including some aspects of 5G wireless communication networks ,just like what 5G is about: what are the building blocks of core 5G system concept, what are the main challenges and how to tackle them. Besides,A number of countries and organizations working on 5G, 5G development situation in China is of concern to everyone, China also needs to have its own place in such a competitive environment. Keywords:5G Network, history,Core concept, Challenges, Solutions, In chinaTable of Content1. Introduction................................................................................................................. - 3 -2. Research and development history ............................................................................. - 3 -3. Core Concept .............................................................................................................. - 4 -4. Challenges and Solutions............................................................................................ - 5 - 4.1 5G Transport Challenge ........................................................................................ - 6 - 4.2 5G Transport Challenge and some Solutions........................................................ - 7 - 4.3 Machine to Machine Communication................................................................... - 7 - 4.3 Core Network Virtualisation ................................................................................. - 8 -4.4 Summary............................................................................................................... - 8 -5. 5G In China................................................................................................................. - 9 - 5.5.1 White paper........................................................................................................ - 9 - 5.5.2 5G standards ...................................................................................................... - 9 - 5.5.3 China communications companies .................................................................... - 9 -5.5.4 Summary.......................................................................................................... - 10 -6. Conlusion.................................................................................................................. - 10 -7. Acronyms.................................................................................................................. - 11 -8. References................................................................................................................. - 11 -1. Introduction5G (Fifth-generation mobile communications) is a new generation of mobile communication mobile communication systems for 2020, with high spectral efficiency and low power consumption, in terms of transfer rate and resource utilization improvement over 4G system 10 times, its wireless coverage performance and user experience will be significantly improved. 5G will be closely integrated with other wireless mobile communication technology, constitute a new generation of ubiquitous mobile information network, to meet future mobile Internet traffic 1000x development needs in 10 years.[1]In this paper I will show you some latest research and development history,what are the building blocks of core 5G system concept, what are the main challenges and how to tackle them firstly. In the rest of paper I will show how 5G development in China in recent years and my conclusion after research literature.2. Research and development historyFebruary 2013, the EU announced that it would grant 50 million euros to accelerate the development of 5G mobile technology, plans to launch a mature standard in 2020. [2][3]May 13,2013,South Korea's Samsung Electronics Co., Ltd. announced that it has successfully developed the 5th generation mobile communication (5G) core technology, which is expected to begin in 2020 to commercialization. The technology can transmit data at ultra-high frequency 28GHz to 1Gbps per second speed, and the maximum transmission distance of up to 2 km. In contrast, the current fourth generation Long Term Evolution (4GLTE) and services of only the transmission rate 75Mbps. Prior to the transmission bottleneck is widely believed that a technical problem, while Samsung Electronics is the use of 64 adaptive array antenna elements transmission technology to crack this problem. Compared with the transmission speed of 4G technology in South Korea, 5G technology is hundreds of times faster. Using this technique, download a high-definition (HD) movie just need 10 seconds.Back in 2009, Huawei has launched the early research related technologies, and to show the prototype of the 5G base in later years.In November 6, 2013,Huawei announced that it would invest $600 million in 2018 for the 5G technology development and innovation, and predicted that users will enjoy 20Gbps commercial 5G mobile networks in 2020. May 8, 2014, the Japanese telecom operator NTT DoCoMo announced officially, Ericsson ,Nokia, Samsung and other six manufacturers to work together, began testing override 1000 times than existing 4G networks the carrying capacity of the high-speed network 5G network, the transmission speed is expected to 10Gbps. Outdoor testing scheduled to commence in 2015, and expects to begin operations in 2020.[3]March 1, 2015, the British "Daily Mail" reported that the British 5G network has successfully developed and tested for data transmission within 100 meters per second data transfer of up to 125GB, is 6.5 times the 4G network, in theory, a 30 seconds to download movies, adding that investment in public test in 2018, 2020 officially put into commercial use.[4]February 11, 2015 in the afternoon news, IMT-2020 (5G) to promote the group (hereinafter referred to as "advance group") held a conference in Beijing 5G concept of white paper. White Paper from the mobile Internet and networking composed mainly of application scenarios, business needs and challenges of starting summed continuous wide area coverage, high reliability of the four major technology 5G scene of high capacity, low power consumption and low latency connection. Meanwhile, the combination of core technologies and key capabilities 5G and 5G concept proposed by the "flag sexuality index + a set of key technologies" common definition.March 3,2015,the European Economic and Social Commission for Digital Furusawa Ottinge officially announced the EU's vision of public-private partnerships 5G, and strive to ensure that the right to speak in the next generation of mobile technology in Europe in the global standard.Ottinger said that, 5G vision of public-private partnership involves not only fiber, wireless or satellite communications network integrated with each other, will also use the software-defined networking (SDN), network functions virtualization (NFV), Mobile Edge computing (MEC) and Fog Computing technology. In the spectrum, the EU's vision of public-private partnership will be designated 5G hundreds of megahertz to improve network performance, 60 GHz and higher frequency bands will also be taken into account.A number of countries and organizations announced, 5G network will be operational between 2020 ~ 2025.3. Core ConceptWhat is 5G? I believe many people will be so questionable when see 5G. Judging from the word meaning, 5G refers to the fifth generation of mobile communications. However, how should it define? Currently, the global industry for 5G concept not yet agreed. China IMT-2020 (5G) group released the White Paper considers the concept 5G, 5G integrated key capabilities and core technology, 5G concept by "important targets" and "a group of key technologies" to a common definition. Among them, the flag indicators "Gbps rate user experience" is a set of key technologies, including large-scale antenna array, ultra-dense networking, new multi-site, full-spectrum access and new network architectures.Recalling the course of development of mobile communications, each generation ofmobile communication systems can be defined by sexual performance indicators and signs of key technologies. Wherein, 1G using FDMA, only analog voice services; 2G mainly using TDMA, can provide voice and low -speed digital data services; 3G to CDMA technology is characterized by user peak rate of 2Mbps to reach tens of Mbps, support multimedia data services; 4G OFDMA technology as the core, the user peak rate of up to 100Mbps ~ 1Gbps, can support a variety of mobile broadband data services.5G key competencies richer than previous generations of mobile communications, user experience, speed, density of connections, end to end delay, the peak rate and mobility and so will be the 5G key performance indicators. However, unlike the case in the past only to emphasize different peak rate, the industry generally believe that the rate of the user experience is the most important performance indicators, it truly reflects the real data rate available to the user, and the user experience is the closest performance. Based on the technology needs of the main scene 5G, 5G user experience rate should reach Gbps magnitude.Faced with diverse scenes of extreme performance demands differentiation, 5G cannot have solutions for all scenarios. In addition, the current wireless technology innovation has diversified development trend, in addition to the new multi -access technology, large -scale antenna array, ultra -dense network, the whole spectrum access, the new network architecture, also is considered to be the main technical direction.5G can play a key role in the major technology scene. [5]4. Challenges and SolutionsIn this part I outline some observed research challengesand directions in the mobile network development and show some may become the future trends and solutions that may lead to improved network performance while meeting the constantly increasing user demands. the new network architecture Gbps user exerperience rate Ultra -dense network Large -scale antenna array New multi -access technology The new network architecture Figure 1 - 5G Concept4.1 5G Transport ChallengeIn order to understand the 5G transport challenges one must understand how 5G may evolve the radio access segment.Among the various initiatives that are looking into 5G, we can defines 5G in terms of scenarios which the next generation wireless access networks will have to support. [6]A total of five future scenarios have been defined,namely amazingly fast (users want to enjoy instantaneous network connectivity), great service in a crowd, ubiquitous things communicating (i.e., effective support to Internet of Things), super real time and reliable connections, and best experience follows you. Each of these scenarios introduces a challenge .Three of these challenges (i.e., very high data rate, very dense crowds of users and mobility) are more traditional in the sense that they are related to continued enhancement of user experience and supporting increasing traffic volumes and mobility. Two emerging challenges, very low latency and very low energy, cost and massive number of devices, are associated with the application of wireless communications to new areas. Future applications may be associated with one or several of these scenarios imposing different challenges to the network. In METIS twelve specific test cases were defined and mapped onto the five scenarios. The selected test cases essentially sample the space of future applications. Once technical enablers that fulfill there quirements for these test cases are defined, it is expected that other applications subject to the same fundamental challenges, will successfully be supported. As a consequence, defining technical enablers for the 5G test cases means also defining technical solutions to the 5G challenges.While METIS[7] is focused on wireless access, the challenges defined for 5G are expected to impact also the transport. Support for very high data rates will require both higher capacity radio access nodes as well as a densification of radio access sites. This, in turn, translates into a transport network that needs to support more sites and higher capacity per site, i.e. huge traffic volumes. The great service in a crowd scenario will put requirements on the transport network to provide very high capacity on-demand to specific geographical locations. In addition, the best experience follows you scenario, suggests a challenge in terms of fast reconfigurability of the transport resources. On the contrary, the other 5G challenges are not expected to play as important role for shaping the transport, as for example the case of very low latency and very low energy, cost and massive number of devices. A properly dimensioned transport network based on modern wireless and/or optical technologies is already today able to provide extremely low latency, i.e., the end-to-end delay contribution of the transport network is usually almost negligible. In addition, while a huge number of connected machines and devices will create a challenge for the wireless network, it will most probably not significantly impact the transport. This is due to the fact that the traffic generated by a large number of devices over a geographical area will already be aggregated in the transport. The three scenarios for the transport network described above are summarized along with their corresponding challenges and test cases. Note that does not report all the original test cases but only those that pose challenges to the transport network. This information will be used later inthe paper to identify the appropriate transport technologies.4.2 5G Transport Challenge and some SolutionsThis section provides an overview of a number of transportoptions for 5G wireless networks. A 5G transport network can be divided in two different segments, i.e., small cell transportand metro/aggregation (Fig. 2). The small cell transport segment aggregates the traffic to/from the wireless small cells towards the metro/aggregation segment. Different solutions in terms of technology (e.g., optics, wireless) and topology (e.g., tree, ring, mesh) are possible depending on the specific wireless access scenario. The metro/aggregation segment, on the other hand, connects different site types (i.e., macro and/or small cells) among themselves and to the core network, the latter via the service edge (service node for the interconnection among different network domains).For the metro/aggregation segment one promising solution is represented by a dense-wavelength-division multiplexing (DWDM)[8] -centric network. In such a network, packet aggregation takes place at the edges of the network (e.g., at small/macro cells sites and at the service edge), while at center (i.e., between access and metro rings) switching is done completely in the optical domain thanks to active optical elements such as wavelength selective switches (WSSs) and reconfigurable optical add-drop multiplexers (ROADMs). It has already been demonstrated that DWDM-centric solutions have the potential to offer high capacity (in the order of tens to hundreds of Gbps) and lower energy consumption than their packet-centric counterparts (i.e., with packet aggregation at the center of the network). [9] For this reason the DWDM-centric metro/aggregation concept may represent a good candidate for future 5G transport networks.[10]4.3 Machine to Machine CommunicationMachine to Machine Communication Besides network evolution, we observe also device evolution that become more and more powerful. The future wireless landscape will serve not only mobile users through such devices as smartphones, tablets or game consoles but also a tremendous number of any other devices, such as cars, smart grid terminals, health monitoring devices and household appliances that would soon require a connection to the Internet. The number of connected devices will proliferate at a very high speed. It is estimated that the M2M traffic will increase 24-fold between 2012 and 2017 .[11]M2M communication is already today often used in fleet monitoring or vehicle tracking. Possible future usage scenarios include a wide variety of e-health applications and devices, for instance new electronic and wireless apparatus used to address the needs of elderly people suffering from diseases like Alzheimer’s, or wearable heart monitors. Suchsensors would enable patient monitoring and aid doctors to observe patients constantly and treat them in a better way. It will also reduce the costs of treatment, as it can be done remotely, without the need of going to a hospital.Remote patient monitoring using a Body Area Network (BAN), where a number of wireless sensors, both on-skin and implanted, record the patient’s health parameters and sends reports to a doctor, will soon become a reality and an important part of 5G paradigm. Therefore, in order to offer e-health services, 5G will need to provide high bandwidth, meet extremely high Quality of Service (QoS) requirements, e.g., ultra low latency and lossless video compression for medical purposes, and implement enhanced security mechanisms. Furthermore, extended work will need to be done to efficiently manage radio resources, due to high diversity of traffic types, ranging from the reports sent periodically by the meters, to high quality medical video transmission.4.3 Core Network VirtualisationMoving towards 5G imposes changes not only in the Radio Access Network (RAN) but also in the Core Network (CN), where new approaches to network design are needed to provide connectivity to growing number of users and devices. The trend is to decouple hardware from software and move the network functions towards the latter one. Software Defined Networking (SDN) being standardised by Open Networking Foundation (ONF) assumes separation of the control and data plane[12]. Consequently, thanks to centralization and programmability, configuration of forwarding can be greatly automated.Moreover, standardisation efforts aiming at defining Network Functions Virtualisation (NFV) are conducted by multiple industrial partners including network operators and equipment vendors within ETSI.[13] Introducing a new software based solution is much faster than installing an additional specialised device with a particular functionality. Both solutions would improve the network adaptability and make it easily scalable. As a result of simpler operation, one can expect more dynamic and faster deployment of new network features.4.4 SummaryI only list a partial of the challenges of 5G networks and possible solutions , in fact, before making a formal universal 5G are still many problems to be overcome, it also requires effort frontline researchers.5. 5G In China5.5.1 White paperFebruary 11, 2015，China released White paper about concept of 5G.It instantly make more people are concerned about 5G. People eager to 5G network as soon as possible. The White Paper published, the concept from various angles, core competencies, technical characteristics of 5G defined and interpreted. At the same time, this is the IMT-2020 (5G) to promote the group last year after the publication of the White Paper 5G vision and needs another masterpiece. The foreseeable future, as the Chinese government pay more attention to the development of 5G and adopt a more open attitude, with the joint efforts of the industry, and China will play an increasingly important role in the global 5G development, global industry will also be unified 5G standard stride forward.5.5.2 5G standardsChina will actively participate in the development of 5G standards, will help China to further enhance the patent position in international communication standards, escort for our mobile phone manufacturing.China is a big manufacturing country, the state has proposed the creation of a strategic shift to China, 3G and 4G standards successful experience will help us win more patents in the development of 5G standard time, to achieve the transformation of China to create the goal.5.5.3 China communications companiesFebruary 12, 2015, the International Telecommunication Union standard 5G start research work, and clearly the IMT-2020 work plan: will complete the IMT-2020 international standard preliminary studies in 2015, 2016 will be carried out 5G technical performance requirements and evaluation methods Research, by the end of 2017 to start collecting 5G candidate to complete standards by the end of 2020.It is worth noting that, in the 5G standards, Huawei, ZTE and other Chinese telecommunications companies such as Ericsson veteran communications companies also play an important role, in which Huawei from between 2013 to 2018, five years is ho throw $ 600 million 5G conduct research and innovation.Recently, ZTE 5G key technologies to achieve new progress. Following the end of the year to complete Massive MIMO antenna array massive field test, ZTE independently developed the proposed super dense network UDN, multiple users to share access to Multi-User Shared Access and other core technologies through demonstration, in Pre5G phase is expected to be applied.[14]Huawei CEO HuHouKun rotation, said in 2015, the company will spend the equivalent of about 10% in 2014 research and development budget, or $ 60 million, the development of 5G technology. Overall, the company's commitment in the next few years, $ 600 million investment in 5G technology. 5G is a next-generation mobile communications standard, is expected early in the next decade and put into use.[15]5.5.4 SummaryChina needs to have its own place in the 5G market, China's communications companies are also very hard, believe in the future, China's R & D level 5G will lead other countries.6. ConlusionIn this paper，I presented a summary of the concept,chanlleges,solusions and 5G in china.For 2020 and the future of the mobile Internet and networking business needs, 5G will focus on supporting the continuous wide area coverage, hot high-capacity, low power consumption and low latency connection highly reliable four main technical scenario, the use of large scale antenna array , ultra-dense networking, new multi-site, full-spectrum access and new network architectures, such as the core technology, through the evolution of new 4G air interface and two technical routes to achieve Gbps rate user experience, and to ensure consistency in service under a variety of scenarios .5G network to achieve real business there are a lot of unresolved issues. Also faced include how to design network architecture, including many technical challenges. Compared with previous generations of communications technology, 5G era biggest challenge is not how to increase the rate, but the user experience with traffic density, the number of terminals from a series of interwoven problems. As much as possible while also reducing user costs. This is the 5G network must be solved.5G study conducted in China are enthusiastic, China needs to accelerate the pace of its own 5G technology to get rid of dependence on foreign companies.5G study conducted in China are enthusiastic, China needs to accelerate the pace of its own 5G technology to get rid of dependence on foreign companies. 5G accelerate the development is conducive to China stand at the forefront of the competition in the next wave of data, a competitive advantage.7. Acronyms5G - Fifth-generation mobile communicationsSDN - software-defined networkingNFV - network functions virtualizationMEC - Mobile Edge computingFDMA - Frequency Division Multiple AccessTDMA - Time Division Multiple AccessCDMA - Code Division Multiple AccessOFDMA - Orthogonal Frequency Division Multiple AccessDWDM - dense-wavelength-division multiplexingBAN - Body Area NetworkQoS - Quality of ServiceRAN - Radio Access Network8. References[1]Chen Si ,Li Hua Sheng,”5G technology trends and challenges for radio management”, /news/41/a888991.html[2]”Samsung developed 5G technology”，/link?url=m_HOSi6QF36L7im-m0NRBaQggvikTgV0GLWBNy vN1OllSGp6_nYwU2B_fXsl6tEnyO0lXAw4Fnk0Ku0vtPSBMq#reference-[2]-764107 0-wrap[3] C114 China Communication Network,(Shanghai) ,March2015 ,”The EU announced 5G Vision: To guarantee the right to speak of global standards”/15/0311/10/AKE0JHMD000915BE.html[4]People’s Posts and Telecommunications News (PPTN),March,2015,”Bell Labs: 5G urgent task is to be completed as soon as possible standardization”/info/2015-03/11/c_134058306.htm[5] Baidu Encyclopedia，”5G network”/view/6220993.htm”[6] METIS deliverable D1.1, ”Scenarios, requirements and KPIs for 5G mobile and wireless system”, April 2013.[7] METIS deliverable D6.1, ”Simulation guidelines”, October 2013.[8] Shuqiang Zhang, Ming Xia, S. Dahlfort, ”Fiber routing, wavelength assignment and multiplexing for DWDM-centric converged metro/aggregation networks,” in Proc. of ECOC, Sept. 2013.[9] B. Skubic, I. Pappa, ”Energy consumption analysis of converged networks:Node consolidation vs metro simplification,” in Proc. of OFC,March 2013.[10] Matteo Fiorani,”Challenges for 5G Transport Networks”,IEEE,2014[11]Cisco, “Global Mobile Data Traffic Forecast Update,2012-2017,” Feb. 2013, White Paper.[12]Open Networking Foundation, “SDN Architecture Overview,” Dec. 2013.[13]ETSI, “Network Functions Virtualisation,” Oct. 2012, White Paper.[14]”ZTE 5G MUSA and UDN developed key technologies to achieve new progresss”/news/127/a892565.html[15]”Huawei will invest $ 600 million R & D 5G”/2015-04/02/content_543144.htm。
通信工程移动通信中英文对照外文翻译文献
中英文翻译(文档含英文原文和中文翻译)附件1：外文资料翻译译文通用移动通信系统的回顾1.1 UMTS网络架构欧洲/日本的3G标准，被称为UMTS。
UMTS是一个在IMT-2000保护伞下的ITU-T 批准的许多标准之一。
随着美国的CDMA2000标准的发展，它是目前占主导地位的标准，特别是运营商将cdmaOne部署为他们的2G技术。
在写这本书时，日本是在3G 网络部署方面最先进的。
三名现任运营商已经实施了三个不同的技术：J - PHONE 使用UMTS，KDDI拥有CDMA2000网络，最大的运营商NTT DoCoMo正在使用品牌的FOMA（自由多媒体接入）系统。
FOMA是基于原来的UMTS协议，而且更加的协调和标准化。
UMTS标准被定义为一个通过通用分组无线系统（GPRS）和全球演进的增强数据技术（EDGE）从第二代GSM标准到UNTS的迁移，如图。
这是一个广泛应用的基本原理，因为自2003年4月起，全球有超过847万GSM用户，占全球的移动用户数字的68％。
重点是在保持尽可能多的GSM网络与新系统的操作。
我们现在在第三代（3G）的发展道路上，其中网络将支持所有类型的流量：语音，视频和数据，我们应该看到一个最终的爆炸在移动设备上的可用服务。
此驱动技术是IP协议。
现在，许多移动运营商在简称为2.5G的位置，伴随GPRS的部署，即将IP骨干网引入到移动核心网。
在下图中，图2显示了一个在GPRS网络中的关键部件的概述，以及它是如何适应现有的GSM基础设施。
SGSN和GGSN之间的接口被称为Gn接口和使用GPRS隧道协议（GTP的，稍后讨论）。
引进这种基础设施的首要原因是提供连接到外部分组网络如，Internet或企业Intranet。
这使IP协议作为SGSN和GGSN之间的运输工具应用到网络。
这使得数据服务，如移动设备上的电子邮件或浏览网页，用户被起诉基于数据流量，而不是时间连接基础上的数据量。
5G无线通信网络中英文对照外文翻译文献
5G无线通信网络中英文对照外文翻译文献(文档含英文原文和中文翻译)翻译：5G无线通信网络的蜂窝结构和关键技术摘要第四代无线通信系统已经或者即将在许多国家部署。
然而，随着无线移动设备和服务的激增，仍然有一些挑战尤其是4G所不能容纳的，例如像频谱危机和高能量消耗。
无线系统设计师们面临着满足新型无线应用对高数据速率和机动性要求的持续性增长的需求，因此他们已经开始研究被期望于2020年后就能部署的第五代无线系统。
在这篇文章里面，我们提出一个有内门和外门情景之分的潜在的蜂窝结构，并且讨论了多种可行性关于5G无线通信系统的技术，比如大量的MIMO技术，节能通信，认知的广播网络和可见光通信。
面临潜在技术的未知挑战也被讨论了。
介绍信息通信技术（ICT）创新合理的使用对世界经济的提高变得越来越重要。
无线通信网络在全球ICT战略中也许是最挑剔的元素，并且支撑着很多其他的行业，它是世界上成长最快最有活力的行业之一。
欧洲移动天文台（EMO）报道2010年移动通信业总计税收1740亿欧元,从而超过了航空航天业和制药业。
无线技术的发展大大提高了人们在商业运作和社交功能方面通信和生活的能力无线移动通信的显著成就表现在技术创新的快速步伐。
从1991年二代移动通信系统(2G)的初次登场到2001年三代系统（3G）的首次起飞，无线移动网络已经实现了从一个纯粹的技术系统到一个能承载大量多媒体内容网络的转变。
4G无线系统被设计出来用来满足IMT-A技术使用IP面向所有服务的需求。
在4G系统中，先进的无线接口被用于正交频分复用技术（OFDM），多输入多输出系统（MIMO）和链路自适应技术。
4G无线网络可支持数据速率可达1Gb/s的低流度，比如流动局域无线访问，还有速率高达100M/s的高流速，例如像移动访问。
LTE系统和它的延伸系统LTE-A，作为实用的4G系统已经在全球于最近期或不久的将来部署。
然而，每年仍然有戏剧性增长数量的用户支持移动宽频带系统。
5G的详细的介绍及前景展望(英文版)
Why does the vision of 5G emerge？
5G will make information break through the limitation of time and space, providing excellent interactive experience and immersive information feast for the user. Through the seamless fusion way, 5G will close the distance of all things, realize the intelligent interconnection between man and all things on earth.
converged
network
03 A green energy network
Besides the speed upgrade, 5G will also meet the requirements of large bandwidth, super high capacity, super dense site, super high reliability and whenever and wherever possible access.
In order to cope with the future of mobile data traffic explosive growth, the connection of massive device, the continuous emergence of various new services and applications scene, the fifth generation mobile communication (5G) system will emerge as times require.
关于5g英文作文素材高中
关于5g英文作文素材高中1. 5G is the latest innovation in wireless technology. It promises faster internet speeds and more reliable connections. With 5G, we can download movies in seconds and stream high-definition videos without any buffering. It's like having the world at our fingertips, with information available instantly.2. One of the key advantages of 5G is its low latency. Latency refers to the time it takes for data to travel from one point to another. With 5G, latency is significantly reduced, which means faster response times. This is crucial for applications like autonomous vehicles, where split-second decisions can make a difference between life and death.3. Another exciting aspect of 5G is its ability to support a massive number of devices. In the era of the Internet of Things (IoT), where everyday objects are connected to the internet, this is a game-changer. Imaginea world where your refrigerator can order groceries whenit's running low, or your wearable device can monitor your health in real-time. 5G makes this hyper-connected future possible.4. 5G also opens up new possibilities for industries like healthcare and education. Remote surgeries and telemedicine become more viable with the high-speed andlow-latency connections provided by 5G. Students in remote areas can access quality education through online courses and virtual classrooms. The potential for innovation and progress is immense.5. However, with every advancement comes concerns about privacy and security. As 5G connects more devices and collects more data, there is a need for robust cybersecurity measures. Ensuring the protection of personal information and preventing cyberattacks becomes paramount. It's important for governments and organizations to invest in cybersecurity infrastructure to safeguard against potential threats.6. The deployment of 5G networks also requiressignificant infrastructure upgrades. New towers and antennas need to be installed to support the increased data traffic. This may lead to debates about the placement of these structures, as some communities may have concerns about the potential health effects of increased exposure to electromagnetic radiation.7. Despite these challenges, the potential benefits of5G are undeniable. It has the power to transform industries, improve our daily lives, and drive economic growth. As we embrace this new era of connectivity, it's crucial to address the concerns and ensure that the benefits of 5G are accessible to all, bridging the digital divide and creating a more inclusive society.8. In conclusion, 5G is not just an upgrade to our current wireless technology, but a revolution that will shape the future. It brings faster speeds, lower latency, and the ability to connect a massive number of devices. However, it also raises concerns about privacy, security, and infrastructure. As we navigate this new frontier, it'simportant to strike a balance between innovation and responsibility, ensuring that 5G benefits everyone and creates a better world.。
无线通信G介绍英文论文ABrief Introduction About G Network
A Brief Introduction About 5G NetworkJiaAbstractWith the rapid development of wireless technologies, theconcept of the Fifth Generation (5G) wireless communication system started to emerge. But most people know little about 5G，including some aspects of 5G wireless communication networks ,just like what 5G is about: what are the building blocks of core 5G system concept, what are the main challenges and howto tackle them. Besides,A number of countries and organizations working on 5G, 5G development situation in China is of concern to everyone, China also needs to have its own place in such a competitive environment.Keywords:5G Network, history,Core concept, Challenges, Solutions, In chinaTable of Content1. Introduction5G (Fifth-generation mobile communications) is a new generation of mobile communication mobile communication systems for 2020, with high spectral efficiency and low power consumption, in terms of transfer rate and resource utilization improvement over 4G system 10 times, its wireless coverage performance and user experience will be significantly improved. 5G will be closely integrated with other wireless mobile communication technology, constitute a new generation of ubiquitous mobile information network, to meet future mobile Internet traffic 1000x development needs in 10 years.[1]In this paper I will show you some latest research and development history,what are the building blocks of core 5G system concept, what are the main challenges and how to tackle them firstly.In the rest of paper I will show how 5G development in China in recent years and my conclusion after research literature.2. Research and development historyFebruary 2013, the EU announced that it would grant 50 million euros to accelerate the development of 5G mobile technology, plans to launch a mature standard in 2020. [2][3]May 13,2013,South Korea's Samsung Electronics Co., Ltd. announced that it has successfully developed the 5th generation mobile communication (5G) core technology, which is expected to begin in 2020 to commercialization. The technology can transmit data at ultra-high frequency28GHz to 1Gbps per second speed, and the maximum transmission distance of up to 2 km. In contrast, the current fourth generation Long Term Evolution (4GLTE) and services of only the transmission rate 75Mbps. Prior to the transmission bottleneck is widely believed that a technical problem, while Samsung Electronics is the use of 64 adaptive array antenna elements transmission technology to crack this problem. Compared with the transmission speed of 4G technology in South Korea, 5G technology is hundreds of times faster. Using this technique, download a high-definition (HD) movie just need 10 seconds.Back in 2009, Huawei has launched the early research related technologies, and to show the prototype of the 5G base in later November 6, 2013,Huawei announced that it would invest $600 million in 2018 for the 5G technology development and innovation, and predicted that users will enjoy 20Gbps commercial 5G mobile networks in 2020.May 8, 2014, the Japanese telecom operator NTT DoCoMo announced officially,Ericsson ,Nokia, Samsung and other six manufacturers to work together, began testing override 1000 times than existing 4G networks the carrying capacity of the high-speed network 5G network, the transmission speed is expected to 10Gbps. Outdoor testing scheduled to commence in 2015, and expects to begin operations in 2020.[3]March 1, 2015, the British "Daily Mail" reported that the British 5G network has successfully developed and tested for data transmission within 100 meters per second data transfer of up to 125GB, is times the 4G network, in theory, a 30 seconds to download movies, adding that investment in public test in 2018, 2020 officially put into commercial use.[4]February 11, 2015 in the afternoon news, IMT-2020 (5G) to promote the group (hereinafter referred to as "advance group") held a conference in Beijing 5G concept of white paper. White Paper from the mobile Internet and networking composed mainly of application scenarios, business needs and challenges of starting summed continuous wide area coverage, high reliability of the four major technology 5G scene of high capacity, low power consumption and low latency connection. Meanwhile, the combination of core technologies and key capabilities5G and 5G concept proposed by the "flag sexuality index + a set of key technologies" common definition.March 3,2015,the European Economic and Social Commission for Digital Furusawa Ottinge officially announced the EU's vision of public-private partnerships 5G, and strive to ensure that the right to speak in the next generation of mobile technology in Europe in the global said that, 5G vision of public-private partnership involves not only fiber, wireless or satellite communications network integrated with each other, will also use the software-defined networking (SDN), network functions virtualization (NFV), Mobile Edge computing (MEC) and Fog Computing technology. In the spectrum, the EU's vision of public-private partnership will bedesignated 5G hundreds of megahertz to improve network performance, 60 GHz and higher frequency bands will also be taken into account.A number of countries and organizations announced, 5G network will be operational between 2020 ~ 2025.3. Core ConceptWhat is 5G? I believe many people will be so questionable when see 5G. Judging from the word meaning, 5G refers to the fifth generation of mobile communications. However, how should it define? Currently, the global industry for 5G concept not yet agreed. China IMT-2020 (5G) group released the White Paper considers the concept 5G, 5G integrated key capabilities and core technology, 5G concept by "important targets" and "a group of key technologies" to a common definition. Among them, the flag indicators "Gbps rate user experience" is a set of key technologies, including large-scale antenna array, ultra-dense networking, new multi-site,full-spectrum access and new network architectures.Recalling the course of development of mobile communications, each generation of mobile communication systems can be defined by sexual performance indicators and signs of key technologies. Wherein, 1G using FDMA, only analog voice services; 2G mainly using TDMA, can provide voice and low-speed digital data services; 3G to CDMA technology is characterized by user peak rate of 2Mbps to reach tens of Mbps, support multimedia data services; 4G OFDMA technology as the core, the user peak rate of up to 100Mbps ~ 1Gbps, can support a variety of mobile broadband data services.5G key competencies richer than previous generations of mobile communications, user experience, speed, density of connections, end to end delay, the peak rate and mobility and so will be the 5G key performance indicators. However, unlike the case in the past only to emphasize different peak rate, the industry generally believe that the rate of the user experience is the most important performance indicators, it truly reflects the real data rate available to the user, and the user experience is the closest performance. Based on the technology needs of the main scene 5G, 5G user experience rate should reach Gbps magnitude.Faced with diverse scenes of extreme performance demands differentiation, 5G cannot have solutions for all scenarios. In addition, the current wireless technology innovation has diversified development trend, in addition to the new multi-access technology, large-scale antenna array, ultra-dense network, the whole spectrum access, the new network architecture, also is considered to be the main technical can play a key role in the major technology scene. [5]Figure 1 - 5G Concepteffective support to Internet of Things), super real time and reliable connections, and best experience follows you. Each of these scenarios introduces a challenge .Three of these challenges ., very high data rate, very dense crowds of users and mobility) are more traditional in the sense that they are related to continued enhancement of user experience and supporting increasing traffic volumes and mobility. Two emerging challenges, very low latency and very low energy, cost and massive number of devices, are associated with the application of wireless communications to new areas. Future applications may be associated with one or several of these scenarios imposing different challenges to the network. In METIS twelve specific test cases were defined and mapped onto the five scenarios. The selected test cases essentially sample the space of future applications. Once technical enablers that fulfill there quirements for these test cases are defined, it is expected that other applications subject to the same fundamental challenges, will successfully be supported. As a consequence, defining technical enablers for the 5G test cases means also defining technical solutions to the 5G challenges.While METIS[7] is focused on wireless access, the challenges defined for 5G are expected to impact also the transport. Support for very high data rates will require both higher capacity radio access nodes as well as a densification of radio access sites. This, in turn, translates into a transport network that needs to support more sites and higher capacity per site, . huge traffic volumes. The great service in a crowd scenario will put requirements on the transport network to provide very high capacity on-demand to specific geographical locations. In addition, the best experience follows you scenario, suggests a challenge in terms of fast reconfigurability of the transport resources. On the contrary, the other 5G challenges are not expected to play as important role for shaping the transport, as for example the case of very low latency and very low energy, cost and massive number of devices. A properly dimensioned transport network based on modern wireless and/or optical technologies is already today able to provide extremely low latency, ., the end-to-end delay contribution of the transport network is usually almost negligible. In addition, while a huge number of connected machines and devices will create a challenge for the wireless network, it will most probably not significantly impact the transport. This is due to the fact that the traffic generated by a large number of devices over a geographical area will already be aggregated in the transport. The three scenarios for the transport network described above are summarized along with their corresponding challenges and test cases. Note that does not report all the original test cases but only those that pose challenges to the transport network. This information will be used later in the paper to identify the appropriate transport technologies.5G Transport Challenge and some SolutionsThis section provides an overview of a number of transportoptions for 5G wireless networks. A 5G transport network can be divided in two different segments, ., small cell transportandmetro/aggregation (Fig. 2). The small cell transport segment aggregates the traffic to/from the wireless small cells towards the metro/aggregation segment. Different solutions in terms of technology ., optics, wireless) and topology ., tree, ring, mesh) are possible depending on the specific wireless access scenario. The metro/aggregation segment, on the other hand, connects different site types ., macro and/or small cells) among themselves and to the core network, thelatter via the service edge (service node for the interconnection among different network domains).For the metro/aggregation segment one promising solution is represented by adense-wavelength-division multiplexing (DWDM)[8] - centric network. In such a network, packet aggregation takes place at the edges of the network ., at small/macro cells sites and at the service edge), while at center ., between access and metro rings) switching is done completely in the optical domain thanks to active optical elements such as wavelength selective switches (WSSs) and reconfigurable optical add-drop multiplexers (ROADMs). It has already been demonstrated that DWDM-centric solutions have the potential to offer high capacity (in the order of tens to hundreds of Gbps) and lower energy consumption than their packet-centric counterparts ., with packet aggregation at the center of the network). [9] For this reason the DWDM-centric metro/aggregation concept may represent a good candidate for future 5G transport networks.[10]Machine to Machine CommunicationMachine to Machine Communication Besides network evolution, we observe also device evolution that become more and more powerful. The future wireless landscape will serve not only mobile users through such devices as smartphones, tablets or game consoles but also a tremendous number of any other devices, such as cars, smart grid terminals, health monitoring devices and household appliances that would soon require a connection to the Internet. The number of connected devices will proliferate at a very high speed. It is estimated that the M2M traffic will increase 24-fold between 2012 and 2017 .[11]M2M communication is already today often used in fleet monitoring or vehicle tracking. Possible future usage scenarios include a wide variety of e-health applications and devices, for instance new electronic and wireless apparatus used to address the needs of elderly people suffering from disease s like Alzheimer’s, o r wearable heart monitors. Such sensors would enable patient monitoring and aid doctors to observe patients constantly and treat them in a better way. It will also reduce the costs of treatment, as it can be doneremotely, without the need of going to a hospital.Remote patient monitoring using a Body Area Network (BAN), where a number of wireless sensors, both on-skin and implanted, record the patient’s health parameter s and sends reports to a doctor, will soon become a reality and an important part of 5G paradigm. Therefore, in order to offer e-health services, 5G will need to provide high bandwidth, meet extremely high Quality of Service (QoS) requirements, ., ultra low latency and lossless video compression for medical purposes, and implement enhanced security mechanisms. Furthermore, extended work will need to be done to efficiently manage radio resources, due to high diversity of traffic types, ranging from the reports sent periodically by the meters, to high quality medical video transmission. Core Network VirtualisationMoving towards 5G imposes changes not only in the Radio Access Network (RAN) but also in the Core Network (CN), where new approaches to network design are needed to provide connectivity to growing number of users and devices. The trend is to decouple hardware from software and move the network functions towards the latter one. Software Defined Networking (SDN) being standardised by Open Networking Foundation (ONF) assumes separation of thecontrol and data plane[12]. Consequently, thanks to centralization and programmability, configuration of forwarding can be greatly automated.Moreover, standardisation efforts aiming at defining Network Functions Virtualisation (NFV) are conducted by multiple industrial partners including network operators and equipment vendors within ETSI.[13] Introducing a new software based solution is much faster than installing an additional specialised device with a particular functionality. Both solutions would improve the network adaptability and make it easily scalable. As a result of simpler operation, one can expect more dynamic and faster deployment of new network features.SummaryI only list a partial of the challenges of 5G networks and possible solutions , in fact, before making a formal universal 5G are still many problems to be overcome, it also requires effort frontline researchers.5. 5G In ChinaWhite paperFebruary 11, 2015，China released White paper about concept of 5G.It instantly make more people are concerned about 5G. People eager to 5G network as soon as possible.The White Paper published, the concept from various angles, core competencies, technical characteristics of 5G defined and interpreted. At the same time, this is the IMT-2020 (5G) to promote the group last year after the publication of the White Paper 5G vision and needs another masterpiece. The foreseeable future, as the Chinese government pay more attention to the development of 5G and adopt a more open attitude, with the joint efforts of the industry, and China will play an increasingly important role in the global 5G development, global industry will also be unified 5G standard stride forward.5G standardsChina will actively participate in the development of 5G standards, will help China to further enhance the patent position in international communication standards, escort for our mobile phone manufacturing.China is a big manufacturing country, the state has proposed the creation of a strategic shift to China, 3G and 4G standards successful experience will help us win more patents in the development of 5G standard time, to achieve the transformation of China to create the goal. China communications companiesFebruary 12, 2015, the International Telecommunication Union standard 5G start research work, and clearly the IMT-2020 work plan: will complete the IMT-2020 international standard preliminary studies in 2015, 2016 will be carried out 5G technical performance requirements and evaluation methods Research, by the end of 2017 to start collecting 5G candidate to complete standards by the end of 2020.It is worth noting that, in the 5G standards, Huawei, ZTE and other Chinese telecommunications companies such as Ericsson veteran communications companies also play an important role, in which Huawei from between 2013 to 2018, five years is ho throw $ 600 million 5G conduct research and innovation.Recently, ZTE 5G key technologies to achieve new progress. Following the end of the year to complete Massive MIMO antenna array massive field test, ZTE independently developed the proposed super dense network UDN, multiple users to share access to Multi-User Shared Accessand other core technologies through demonstration, in Pre5G phase is expected to be applied.[14]Huawei CEO HuHouKun rotation, said in 2015, the company will spend the equivalent of about 10% in 2014 research and development budget, or $ 60 million, the development of 5G technology. Overall, the company's commitment in the next few years, $ 600 million investment in 5G technology. 5G is a next-generation mobile communications standard, is expected early in the next decade and put into use.[15]SummaryChina needs to have its own place in the 5G market, China's communications companies are also very hard, believe in the future, China's R & D level 5G will lead other countries.6. ConlusionIn this paper，I presented a summary of the concept,chanlleges,solusions and 5G in 2020 and the future of the mobile Internet and networking business needs, 5G will focus on supporting the continuous wide area coverage, hot high-capacity, low power consumption and low latency connection highly reliable four main technical scenario, the use of large scale antenna array , ultra-dense networking, new multi-site, full-spectrum access and new network architectures, such as the core technology, through the evolution of new 4G air interface and two technical routes to achieve Gbps rate user experience, and to ensure consistency in service under a variety of scenarios .5G network to achieve real business there are a lot of unresolved issues. Also faced include how to design network architecture, including many technical challenges. Compared with previous generations of communications technology, 5G era biggest challenge is not how to increase the rate, but the user experience with traffic density, the number of terminals from a series of interwoven problems. As much as possible while also reducing user costs. This is the 5G network must be solved.5G study conducted in China are enthusiastic, China needs to accelerate the pace of its own 5G technology to get rid of dependence on foreign companies.5G study conducted in China are enthusiastic, China needs to accelerate the pace of its own 5G technology to get rid of dependence on foreign companies. 5G accelerate the development is conducive to China stand at the forefront of the competition in the next wave of data, a competitive advantage.7. Acronyms5G - Fifth-generation mobile communicationsSDN - software-defined networkingNFV - network functions virtualizationMEC - Mobile Edge computingFDMA - Frequency Division Multiple AccessTDMA - Time Division Multiple AccessCDMA - Code Division Multiple AccessOFDMA - Orthogonal Frequency Division Multiple AccessDWDM - dense-wavelength-division multiplexingBAN - Body Area NetworkQoS - Quality of ServiceRAN - Radio Access Network8. References[1]Chen Si ,Li Hua Sheng,”5G technology trends and challenges for radio management”,[2]”Samsung developed 5G technology”，[3] C114 China Communication Network,(Shanghai) ,March2015 ,”The EU announced 5G Vision: To guarantee the right to speak of global standards”[4]People’s Posts and Telecommunications News (PPTN),March,2015,”Bell Labs: 5G urgent task is to be completed as soon as possible standardization”[5] Baidu Encyclopedia，”5G network”[6] METIS deliverable , ”Scenario s, requirements and KPIs for 5G mobile and wireless system”, April 2013.[7] METIS deliverable , ”Simulation guidelines”, October 2013.[8] Shuqiang Zhang, Ming Xia, S. Dahlf ort, ”Fiber routing, wavelength assignment and multiplexing for DWDM-centric converged metro/aggregation networks,” in Proc. of ECOC, Sept. 2013.[9] B. Skubic, I. Pappa, ”Energy consumption analysis of converged networks:Node consolidation vs metro simplification,” in Proc. of OFC,March 2013.[10] Matteo Fiorani,”Challenges for 5G Transport Networks”,IEEE,2014[11]Cisco, “Global Mobil e Data Traffic Forecast Update,2012-2017,” Feb. 2013, White Paper.[12]Open Net working Foundation, “SD N Architecture Overview,” Dec. 2013.[13]ETSI, “Network Functions Virtualisation,” Oct. 2012, White Paper.[14]”ZTE 5G MUSA and UDN developed key technologies to achieve new progresss”[15]”Huawei will invest $ 600 million R & D 5G”。
关于5g的英文文献
关于5g的英文文献When it comes to English literature on 5G, there is a vast amount of research and scholarly articles available.5G, the fifth generation of wireless communication technology, has attracted significant attention from researchers, engineers, and industry professionals worldwide. Below, I will provide a comprehensive overview of the various aspects related to 5G that have been covered in the English literature.1. Introduction to 5G: Many articles focus on providinga general introduction to 5G technology, discussing its key features, potential applications, and the challenges it brings. These papers often examine the evolution from previous generations of wireless communication andhighlight the improvements and advancements brought about by 5G.2. Technical Aspects: Numerous papers delve into the technical details of 5G, exploring topics such as networkarchitecture, radio access technologies, spectrum allocation, massive multiple-input multiple-output (MIMO), beamforming, and advanced modulation schemes. Thesearticles provide in-depth analysis and evaluation of the underlying technologies that enable 5G networks.3. Performance Evaluation: Researchers often conduct performance evaluations of 5G networks, comparing them with previous generations or alternative technologies. These evaluations may include metrics such as data rate, latency, energy efficiency, coverage, and reliability. The findings help in understanding the capabilities and limitations of 5G and provide insights for further improvements.4. Applications and Use Cases: Many articles discuss the potential applications and use cases of 5G technology across various industries, including healthcare, transportation, smart cities, agriculture, industrial automation, and virtual reality. These papers explore how 5G can revolutionize these sectors and enable innovative services and solutions.5. Security and Privacy: Given the increasedconnectivity and data exchange in 5G networks, security and privacy concerns are of paramount importance. Researchers have published articles addressing these concerns, discussing potential vulnerabilities, and proposingsecurity mechanisms and protocols to safeguard 5G networks and user data.6. Standardization and Regulation: Standardization bodies, such as the 3rd Generation Partnership Project(3GPP), play a crucial role in defining the specifications and requirements for 5G. Many articles discuss the ongoing standardization efforts, regulatory aspects, and the collaboration among different stakeholders to ensure the successful deployment and interoperability of 5G networks globally.7. Future Trends and Challenges: As 5G continues to evolve, researchers speculate on future trends and challenges that may arise. These articles explore topics such as the integration of 5G with emerging technologieslike Internet of Things (IoT), artificial intelligence (AI),and edge computing. They also discuss the potential impact of 5G on society, economy, and the environment.In conclusion, the English literature on 5G is extensive and covers a wide range of topics, including technical aspects, performance evaluation, applications, security, standardization, and future trends. Researchers and industry experts have produced a wealth of knowledge that contributes to the understanding and advancement of 5G technology.。
什么是5G, 它是如何工作的英文作文400字
什么是5G, 它是如何工作的英文作文400字For most people 5g must have been heard even if they didn't understand it. But isn't the 4G era just a few years old? Is it a little early to say the next generation of wireless communication technology? It's true but time flies technology development is not waiting for people. 5g mobile communication may come to us soon. It's good to know some knowledge in advance.Maybe you can see some business opportunities in this article. Let's start with some terms. There is no long descxxxxription of wordiness here. You can take it at ease.First let's browse a few key words with Lei Feng's IOT Technology Review: 3G:the third generation mobile communication network. If you don't want to expose your age don't admit that you have come allthe way from "my site" because 3G was born after that era and its representative NOUN is HSPA or HSPA +. 4G: speaking of 4G network you must be familiar with the term LTE. In fact LTE LTE advanced and LTE advanced Pro all belong to 4G. They all have one characteristic - speed.5g: in fact it's a term used in the industry to describe the next generation of wireless communication network but the industry has not yet set relevant standards for it but the speedis 10 times faster than 4G. Millimeter wave: millimeter wave refers to the electromagnetic wave with the wavelength of millimeter and its frequency is generally above 6GHz. Nowadays the commonly used frequency band below 5GHz is very crowded. Where to find new spectrum resources? All major manufacturers come up with the same idea of using millimeter wave technology. Mbps / Gbps: these two terms represent network speed. 4G network must reach 100Mbps 5g requires 1Gbps. However these two standards have little effect on end users because they are only ideal values. Wireless operator: it's easy to explain. As long as it can provide wireless network it's a wireless operator. In China it's mobile Unicom and Telecom.Spectrum: that is electromagnetic spectrum in Hertz including radio microwave VHF UHF etc. Delay: that is the propagation speed of information between two points. In the age of 5g the delay will be further reduced (less than 1ms). Internet of things (IOT): another lousy term. As the name suggests IOT is the Internet connected with things. However from smart phones to refrigerators to smart bracelets to cars it will become apart of the Internet of things.。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
5G无线通信网络中英文对照外文翻译文献(文档含英文原文和中文翻译)翻译：5G无线通信网络的蜂窝结构和关键技术摘要第四代无线通信系统已经或者即将在许多国家部署。
然而，随着无线移动设备和服务的激增，仍然有一些挑战尤其是4G所不能容纳的，例如像频谱危机和高能量消耗。
无线系统设计师们面临着满足新型无线应用对高数据速率和机动性要求的持续性增长的需求，因此他们已经开始研究被期望于2020年后就能部署的第五代无线系统。
在这篇文章里面，我们提出一个有内门和外门情景之分的潜在的蜂窝结构，并且讨论了多种可行性关于5G无线通信系统的技术，比如大量的MIMO技术，节能通信，认知的广播网络和可见光通信。
面临潜在技术的未知挑战也被讨论了。
介绍信息通信技术（ICT）创新合理的使用对世界经济的提高变得越来越重要。
无线通信网络在全球ICT战略中也许是最挑剔的元素，并且支撑着很多其他的行业，它是世界上成长最快最有活力的行业之一。
欧洲移动天文台（EMO）报道2010年移动通信业总计税收1740亿欧元,从而超过了航空航天业和制药业。
无线技术的发展大大提高了人们在商业运作和社交功能方面通信和生活的能力无线移动通信的显著成就表现在技术创新的快速步伐。
从1991年二代移动通信系统(2G)的初次登场到2001年三代系统（3G）的首次起飞，无线移动网络已经实现了从一个纯粹的技术系统到一个能承载大量多媒体内容网络的转变。
4G无线系统被设计出来用来满足IMT-A技术使用IP面向所有服务的需求。
在4G系统中，先进的无线接口被用于正交频分复用技术（OFDM），多输入多输出系统（MIMO）和链路自适应技术。
4G无线网络可支持数据速率可达1Gb/s的低流度，比如流动局域无线访问，还有速率高达100M/s的高流速，例如像移动访问。
LTE系统和它的延伸系统LTE-A，作为实用的4G系统已经在全球于最近期或不久的将来部署。
然而，每年仍然有戏剧性增长数量的用户支持移动宽频带系统。
越来越多的人渴望更快的网络访问速度，时髦的手机，总的来说就是更快地与他人通信或信息访问。
如今更多功能强大小巧的手机和便捷电脑可以满足先进的多媒体功能变得越来越受欢迎。
这就造成了无线移动设备和服务的激增。
EMO指出自从2006年起，移动宽频每年有92%的增长。
无线世界研究论坛（WWRF）预言到2017年会有七万亿的无线设备来服务七十亿的人口；也就是说无线网络连接设备的数量将会是世界人口数量的1000倍。
随着越来越多的设备无线化许多研究难题需要被解决。
最重要的难题之一就是蜂窝通信中射频光谱分配的物质缺乏。
蜂窝频率把极高频带用于蜂窝手机，一般来讲范围可从几百兆赫兹到几千兆赫兹。
这些频谱被严重的使用以至于对操作员更多的获取造成困难。
另一个难题就是先进无线技术的部署面临高能量消耗的费用。
无线通信系统中高能消耗的增长间接造成了二氧化碳排放量的增长，后者被视为当前生态环境的主要威胁。
此外，据手机运营商反映基站的能源消耗贡献了超过70%的电力账单。
事实上，节能通信并不是4G 无线系统中的最初需求之一，但是它在之后的舞台上被作为问题所提及。
其他的难题，例如平均频谱效率、高传输率和高迁移率、无缝覆盖、多样化的服务质量请求以及分散的用户体验（不同无线设备/接口的不兼容和异构网络），仅仅提及一点点。
以上所有问题正给手机服务提供商带来更多压力，他们正面临着有更高传输率、更大的网络容量、更高的频谱效率、更高的能源利用率和更高的利用率规定的新型无线应用的持续增长需求。
另一方面，在当前的技术条件下，4G网络在传输率方面几乎已经达到了理论上的限制，因此并不能充分的解决以上难题。
从这层意义上来说，我们需要开创性的无线技术来解决以上由数万亿无线设备造成的问题，并且研究员们已经着手研究超4G（B4G）或者5G无线技术。
中英科学桥工程：B4G无线移动通信(chinab4g. /)可能是世界上着手B4G 研究的首批项目之一，其中的一些潜在的B4G技术已经被确定了。
欧洲和中国也已经开始了一些5G项目，比如由欧盟支持的METIS 2020(https://www.metis2020. com/)和由中国科学院支持的在5G方面的国家863重点工程。
诺基亚西门子通信公司描述通过对比2010年的通信水准今后十年潜在的无线接入技术可以被进一步开发用来支持多大超过一千倍的通信量。
三星公司展示了一个运用微波技术使传输率在两千米的范围内超过1Gb/s的无线系统。
5G网络，预期大约在2020年被标准化，究竟是什么呢？由于现在太早以至于不能确切地定义。
广泛的认同是与4G网络相比，5G网络应该达到1000倍的系统容量，10倍的频谱利用率、能源利用率和传输率（低流动性下最高传输率为10Gb/s，高流动性下最高传输率为1Gb/s）还有25倍平均系统吞吐量。
5G网络的目标在于连接整个世界以及实现任何人之间（人与人），任何事物之间（人与机器，机器与机器）的无缝的、无处不在的通信，无论他们在哪，无论他们什么时候需要，也无论他们用什么电子设备/服务/网络。
这就意味着5G网络应该能够支持一些4G网络所不能支持的特殊情况（例如乘坐高铁的用户）。
高铁车速可轻松达到350到500km/h，然后4G网络所能支持通信的情况是250km/h。
本篇文章中，我们提出了一个潜在的5G蜂窝结构并且讨论有希望的技术用来部署以便满足5G的需求。
这篇文章剩下的安排如下。
我们提出了一个潜在的5G蜂窝结构。
我们描述一些可行性的关键技术可以被5G系统采用。
未来的挑战是显著的，最终我们会得出结论。
潜在的5G无线蜂窝结构为了解决以上难题并且满足5G系统的需求，我们需要在蜂窝结构的设计上做个戏剧性的改变。
我们知道无线用户80%的时间都是待在户内，待在户外的仅仅约有20%。
当前常见的蜂窝结构通常是为移动用户在蜂窝通信中间建立一个露天基站，这样就不用管他们实在户内还是户外。
对于户内用户与户外基站间的通信，信号不得不穿过建筑墙，造成很高的穿透损耗，从而显著损伤无线传输的传输速率、频谱利用率、能源利用率。
设计5G蜂窝结构的中心思想就是分开户内和户外的情况这样穿透损耗经过建筑墙后可以在某种意义上来说避免掉。
这些将会由分布式天线系统（DAS）和大量的MIMO技术来实现,即在地面上部署由几十个或几百个天线单组成的分布式天线阵。
然而目前最主流的MIMO系统使用两个或四个天线，大量使用MIMO 系统的目的是为了开发尽可能大的容量效益以提升更大的天线阵。
户外基站将会装备由一些天线单元（也有大阵列天线）组成的大阵列天线，这些大阵列天线分布在覆盖区周围，通过光纤连接基站，从而从DAS和大量的MIMO技术中都能受益。
户外手机用户通常配备有限数量的天线单元，但是他们可以通过互相合作形成一个虚拟的大阵列天线，连同基站天线阵将会构造虚拟的大规模MIMO链接群。
大阵列天线也将被安装在每个建筑的外面以便与户外基站群或者拥有分布式天线单元的基站群相互通信，与可见组件通信也是有可能的。
大阵列天线用电缆连接到能与户内用户之间通信的建筑内部的无线接入点。
这样必定会在短时间内提高基础设备的花费最终显著提升覆盖区平均生产力，频谱效率，能源效率还有蜂窝系统传输率。
采用这样的蜂窝结构，户内用户仅需要使用安装在户外建筑的大阵列天线便可与户内无线接入点通信，很多的技术可以被利用以便适用高数据速率进行的短程通信。
举一些例子包括WiFi，毫微微蜂窝，超宽频（UWB），毫米波通信（3——300GHz），还有可见光通信(VLC)（400——490THz）。
值得说明的是毫米波和VLC技术使用更高的频率并不适用传统的蜂窝通信。
这些高频波并不能很好地穿透固体材料并且很容易就会被气体，雨水还有植物吸收或分散。
因此，很难将这些波用于户外和远距离应用。
然而，随着宽频带的实现，毫米波和VLC技术可以大大提高在户内情况下的数据传输速率。
为了解决频谱缺乏问题，并且找到新的不为传统无线服务（例如毫米波通信和VLC）所用的频带，我们可以尽力提高现有无线频谱的频谱利用率，比如取道认识的无线网络。
5G蜂窝结构同样应该是一种有宏蜂窝，微蜂窝，小基站和继电器组成的混杂结构。
为了适应高机动性用户比如乘车和乘高铁的用户，我们已经提出了超小型移动基站的概念，即结合移动中继和超小型基站的概念。
超小型移动基站位于车辆内部可以和位于车内的用户通信，而大阵列天线位于车辆外面和户外的基站通信。
一个超小型移动基站和它关联的用户都被基站看作一个单元。
从用户的角度来看，超小型移动基站被看作正式的基站。
这和上面区分户内（车辆内部）和户外情况的观点非常相似。
已经能表明的是用户使用超小型移动基站在享受高数据速率的服务的同时减少信令开销。
以上提出的5G混杂蜂窝结构在图1阐明。
有前景的5G无线网络的关键技术在这一部分，基于以上提出的混杂式蜂窝结构，我们讨论了一些有前景的无线网络关键技术使之能够满足5G无线网络的性能要求。
发展这些技术的目的是通过有效利用所有可能的资源以适应戏剧性的容量增长。
基于著名的香农定理，C可以近似的表示为系统的总容量sum⎪⎪⎭⎫ ⎝⎛+≈∑∑p i i sum N P B 1log C 2通道网路 （1） 其中i B 是第i 条信道的带宽，i P 是第i 条信道的信号功率，p N 表示噪声功率。
从公式1可以看出系统总容量sum C 等于所有子通道和网路容量之和。
为了增加sum C ，我们可以提高网络覆盖范围（通过使用含有宏蜂窝，微蜂窝，小基站，继电器，超小型移动基站的网络），子通道的数量（通过使用大量的MIMO 技术，空间调整，协作式MIMO ，DAS,管理干涉等等），带宽（通过CR 网络，毫米波通信，VLC ，多标准系统等等）还有功率（能源利用率和绿色通信）。
在下文中，我们重点聚焦于一些关键技术。
外文原文：ABSTRACTThe fourth generation wireless communica- tion systems have been deployed or are soon to be deployed in many countries. However, with an explosion of wireless mobile devices and ser- vices, there are still some challenges that cannot be accommodated even by 4G, such as the spec- trum crisis and high energy consumption. Wire- less system designers have been facing the continuously increasing demand for high data rates and mobility required by new wireless applications and therefore have started research on fifth generation wireless systems that are expected to be deployed beyond 2020. In this article, we propose a potential cellular architec- ture that separates indoor and outdoor scenar- ios, and discuss various promising technologies for 5G wireless communication systems, such as massive MIMO, energy-efficient communica- tions, cognitive radio networks, and visible lightcommunications. Future challenges facing these potential technologies are also discussed. INTRODUCTIONThe innovative and effective use of information and communication technologies (ICT) is becoming increasingly important to improve the economy of the world [1]. Wireless communica- tion networks are perhaps the most critical ele- ment in the global ICT strategy, underpinning many other industries. It is one of the fastest growing and most dynamic sectors in the world. The European Mobile Observatory (EMO) reported that the mobile communication sector had total revenue of €174 billion in 2010, there- by bypassing the aerospace and pharmaceutical sectors [2]. The development of wireless tech- nologies has greatly improved people’s ability to communicate and live in both business opera- tions and social functions.The phenomenal success of wireless mobile communications is mirrored by a rapid pace of technology innovation. From the second genera-tion (2G) mobile communication system debuted in 1991 to the 3G system first launched in 2001, the wireless mobile network has transformed from a pure telephony system to a network that can transport rich multimedia contents. The 4G wireless systems were designed to fulfill the requirements of International Mobile Telecom- munications-Advanced (IMT-A) using IP for all services [3]. In 4G systems, an advanced radio interface is used with orthogonal frequency-divi- sion multiplexing (OFDM), multiple-input multi- ple-output (MIMO), and link adaptation technologies. 4G wireless networks can support data rates of up to 1 Gb/s for low mobility, such as nomadic/local wireless access, and up to 100 Mb/s for high mobility, such as mobile access. Long-Term Evolution (LTE) and its extension, LTE-Advanced systems, as practical 4G systems, have recently been deployed or soon will be deployed around the globe.However, there is still a dramatic increase inthe number of users who subscribe to mobilebroadband systems every year. More and morepeople crave faster Internet access on the move,trendier mobiles, and, in general, instant com-munication with others or access to information.More powerful smartphones and laptops arebecoming more popular nowadays, demandingadvanced multimedia capabilities. This hasresulted in an explosion of wireless mobiledevices and services. The EMO pointed out thatthere has been a 92 percent growth in mobilebroadband per year since 2006 [2]. It has beenpredicted by the Wireless World ResearchForum (WWRF) that 7 trillion wireless deviceswill serve 7 billion people by 2017; that is, thenumber of network-connected wireless deviceswill reach 1000 times the world’s population [4].As more and more devices go wireless, manyresearch challenges need to be addressed.One of the most crucial challenges is thephysical scarcity of radio frequency (RF) spectraallocated for cellular communications. Cellularfrequencies use ultra-high-frequency bands forcellular phones, normally ranging from several hundred megahertz to several gigahertz. These frequency spectra have been used heavily, mak- ing it difficult for operators to acquire more. Another challenge is that the deployment of advanced wireless technologies comes at the cost of high energy consumption. The increase of energy consumption in wireless communication systems causes an increase of CO 2 emission indi- rectly, which currently is considered as a major threat for the environment. Moreover, it has been reported by cellular operators that the energy consumption of base stations (BSs) con- tributes to over 70 percent of their electricity bill [5]. In fact, energy-efficient communication was not one of the initial requirements in 4G wire- less systems, but it came up as an issue at a later stage. Other challenges are, for example, aver- age spectral efficiency, high data rate and high mobility, seamless coverage, diverse quality of service (QoS) requirements, and fragmented user experience (incompatibility of differentwireless devices/interfaces and heterogeneous networks), to mention only a few.All the above issues are putting more pres-sure on cellular service providers, who are facing continuously increasing demand for higher data rates, larger network capacity, higher spectral efficiency, higher energy efficiency, and higher mobility required by new wireless applications.On the other hand, 4G networks have just about reached the theoretical limit on the data ratewith current technologies and therefore are not sufficient to accommodate the above challenges.In this sense, we need groundbreaking wireless technologies to solve the above problems causedby trillions of wireless devices, and researchers have already started to investigate beyond 4G(B4G) or 5G wireless techniques. The projectUK-China Science Bridges: (B)4G Wireless Mobile Communications (chinab4g. /) is perhaps one of the first projects in the world to start B4G research, where some potential B4G technologies were identified. Europe and Chinahave also initiated some 5G projects, such asMETIS 2020 (https://www.metis2020. com/) sup-ported by EU and National 863 Key Project in5G supported by the Ministry of Science andTechnology (MOST) in China. Nokia SiemensNetworks described how the underlying radioaccess technologies can be developed further tosupport up to 1000 times higher traffic volumescompared to 2010 travel levels over the next 10years [6]. Samsung demonstrated a wireless sys-tem using millimeter (mm) wave technologieswith data rates faster than 1 Gb/s over 2 km [7].What will the 5G network, which is expectedto be standardized around 2020, look like? It isnow too early to define this with any certainty.However, it is widely agreed that compared tothe 4G network, the 5G network should achieve1000 times the system capacity, 10 times thespectral efficiency, energy efficiency and datarate (i.e., peak data rate of 10 Gb/s for lowmobility and peak data rate of 1 Gb/s for highmobility), and 25 times the average cell through-put. The aim is to connect the entire world, and achieve seamless and ubiquitous communica- tions between anybody (people to people), any- thing (people to machine, machine to machine), wherever they are (anywhere), whenever they need (anytime), by whatever electronicdevices/services/networks they wish (anyhow). This means that 5G networks should be able to support communications for some special sce- narios not supported by 4G networks (e.g., for high-speed train users). High-speed trains can easily reach 350 up to 500 km/h, while 4G net- works can only support communication scenarios up to 250 km/h. In this article, we propose a potential 5G cellular architecture and discuss some promising technologies that can be deployed to deliver the 5G requirements.The remainder of this article is organized as follows. We propose a potential 5G cellular architecture. We describe some promising key technologies that can be adopted in the 5G sys- tem. Future challenges are highlighted. Finally,conclusions are drawn.A POTENTIAL 5G WIRELESSCELLULAR ARCHITECTURETo address the above challenges and meet the5G system requirements, we need a dramatic change in the design of cellular architecture. We know that wireless users stay indoors for about 80 percent of time, while only stay ourdoors about 20 percent of the time [8]. The current conventional cellular architecture normally uses an outdoor BS in the middle of a cell communi- cating with mobile users, no matter whether they stay indoors or outdoors. For indoor users com- municating with the outdoor BS, the signals have to go through building walls, and this causes very high penetration loss, which significantly dam- ages the data rate, spectral efficiency, and ener- gy efficiency of wireless transmissions.One of the key ideas of designing the 5G cel- lular architecture is to separate outdoor and indoor scenarios so that penetration loss through building walls can somehow be avoided. This willbe assisted by distributed antenna system (DAS)and massive MIMO technology [9], where geo-graphically distributed antenna arrays with tensor hundreds of antenna elements are deployed.While most current MIMO systems utilize twoto four antennas, the goal of massive MIMO systems is to exploit the potentially large capacitygains that would arise in larger arrays of anten-nas. Outdoor BSs will be equipped with largeantenna arrays with some antenna elements (alsolarge antenna arrays) distributed around the celland connected to the BS via optical fibers, bene-fiting from both DAS and massive MIMO tech-nologies. Outdoor mobile users are normallyequipped with limited numbers of antenna ele-ments, but they can collaborate with each otherto form a virtual large antenna array, whichtogether with BS antenna arrays will constructvirtual massive MIMO links. Large antennaarrays will also be installed outside of everybuilding to communicate with outdoor BSs ordistributed antenna elements of BSs, possiblywith line of sight (LoS) components. Large anten- na arrays have cables connected to the wireless access points inside the building communicating with indoor users. This will certainly increase the infrastructure cost in the short term while signifi- cantly improving the cell average throughput, spectral efficiency, energy efficiency, and data rate of the cellular system in the long run.Using such a cellular architecture, as indoor users only need to communicate with indoor wireless access points (not outdoor BSs) with large antenna arrays installed outside build- ings, many technologies can be utilized that are suitable for short-range communications with high data rates. Some examples include WiFi, femtocell, ultra wideband (UWB), mm-wave communications (3–300 GHz) [7], and visible light communications (VLC) (400–490 THz) [10]. It is worth mentioning that mm-wave and VLC technologies use higher frequencies not traditionally used for cellular communications. These high-frequency waves do not penetratesolid materials very well and can readily be absorbed or scattered by gases, rain, and foliage. Therefore, it is hard to use these waves for outdoor and long distance applications. However, with large bandwidths available, mm- wave and VLC technologies can greatly increase the transmission data rate for indoor scenarios. To solve the spectrum scarcity prob- lem, besides finding new spectrum not tradi- tionally used for wireless services (e.g.,mm-wave communications and VLC), we can also try to improve the spectrum utilization of existing radio spectra, for example, via cogni- tive radio (CR) networks [11].The 5G cellular architecture should also be a heterogeneous one, with macrocells, microcells, small cells, and relays. To accommodate high- mobility users such as users in vehicles and high- speed trains, we have proposed the mobile femtocell (MFemtocell) concept [12], which combines the concepts of mobile relay and fem- tocell. MFemtocells are located inside vehiclesto communicate with users within the vehicle, while large antenna arrays are located outside the vehicle to communicate with outdoor BSs. An MFemtocell and its associated users are all viewed as a single unit to the BS. From the user point of view, an MFemtocell is seen as a regu- lar BS. This is very similar to the above idea of separating indoor (inside the vehicle) and out- door scenarios. It has been shown in [12] that users using MFemtocells can enjoy high-data-rate services with reduced signaling overhead.The above proposed 5G heterogeneous cellular architecture is illustrated in Fig. 1.PROMISING KEY5G WIRELESS TECHNOLOGIES In this section, based on the above proposed heterogeneous cellular architecture, we discuss some promising key wireless technologies that can enable 5G wireless networks to fulfill perfor- mance requirements. The purpose of developing these technologies is to enable a dramatic capac- ity increase in the 5G network with efficient uti-lization of all possible resources. Based on the well-known Shannon theory, the total system capacity C sum can be approximately expressed by ⎪⎪⎭⎫ ⎝⎛+≈∑∑p i i sum N P B 1log C 2通道网路 (1) where B i is the bandwidth of the ith channel, P i is the signal power of the ith channel, and N p denotes the noise power. From Eq. 1, it is clear that the total system capacity C sum is equivalent to the sum capacity of all subchannels and het-erogeneous networks. To increase C sum , we can increase the network coverage (via heteroge- neous networks with macrocells, microcells,small cells, relays, MFemtocell [12], etc.), num- ber of subchannels (via massive MIMO [9], spa- tial modulation [SM] [13], cooperative MIMO, DAS, interference management, etc.), bandwidth (via CR networks [11], mm-wave communica- tions, VLC [10], multi-standard systems, etc.), and power (energy-efficient or green communi- cations). In the following, we focus on some of the key technologies.。