volte信令流程详解8个步骤

volte信令流程详解8个步骤
英文回答：
VoLTE Signalling Procedure.
VoLTE (Voice over LTE) is a technology that allows voice calls to be made over an LTE (Long Term Evolution) network. It uses IP Multimedia Subsystem (IMS) for signalling and control, and Media Gateway Control Function (MGCF) for media handling.
The VoLTE signalling procedure involves the following steps:
1. Registration: The User Equipment (UE) registers with the LTE network and obtains an IP address from the Packet Data Network Gateway (PDN GW).
2. IMS Registration: The UE registers with the IMS network and obtains an IMS public user identity (IMPI).
3. Call Establishment: When the UE initiates a call, it sends a SIP INVITE message to the IMS core network.
4. Call Setup: The IMS core network forwards the INVITE message to the MGCF, which sets up the media session and sends a SIP 200 OK message back to the UE.
5. Media Exchange: The UE and the MGCF exchange media streams, such as voice and video.
6. Call Termination: When the call is terminated, the UE sends a SIP BYE message to the IMS core network.
7. IMS Deregistration: The UE deregisters from the IMS network.
8. LTE Deregistration: The UE deregisters from the LTE network.
中文回答：
VoLTE信令流程。

VoLTE（Voice over LTE）是一种允许在LTE（长期演进）网络上进行语音通话的技术。

它使用IP多媒体子系统（IMS）进行信令和控制，并使用媒体网关控制功能（MGCF）进行媒体处理。

VoLTE信令流程涉及以下步骤：
1. 注册，用户设备（UE）在LTE网络上注册，并从分组数据网络网关（PDN GW）获取IP地址。

2. IMS注册，UE在IMS网络上注册，并获取IMS公用用户标识（IMPI）。

3. 呼叫建立，当UE发起呼叫时，它向IMS核心网络发送SIP INVITE消息。

4. 呼叫建立，IMS核心网络将INVITE消息转发到MGCF，后者建立媒体会话并向UE发送SIP 200 OK消息。

5. 媒体交换，UE和MGCF交换媒体流，例如语音和视频。

6. 呼叫终止，当呼叫终止时，UE向IMS核心网络发送SIP BYE 消息。

7. IMS注销，UE从IMS网络注销。

8. LTE注销，UE从LTE网络注销。