VoLTE基本呼叫流程

VoLTE基本呼叫流程

文档名称：VoLTE基本呼叫流程

文档密级：未标明

VoLTE基本呼叫场景

VoLTE基本呼叫场景包括四种状态，主被叫都是VoLTE用户，且主被叫用户区分状态：

1.主叫是Connect状态，被叫是Connect状态；

2.主叫是Connect状态，被叫是Idle状态；

3.主叫是Idle状态，被叫是Connect状态；

4.主叫是Idle状态，被叫是Idle状态。

VoLTE呼叫建立流程详解

语音专有承载的建立时刻是由IMS的配置决定的。如果在振铃（180ringring）之后建立语音专有承载（即通常所说的早振铃），呼叫时延会更短，用户感受会好一些，但是接通后

需要等待一段时间才能听到声音。如果QCI1建立失败，会出现“鬼振铃”。如果是在XXX之前建立语音专有承载（即通常所说的晚振铃），呼叫时延会增长，但是接通后能够立即听到声音。

VoLTE主被叫用户都是Connect状态

在此场景下，如果是早振铃，建立语音专有承载的流程如下：

Caller（主叫）拨打被叫号码，eNodeB向MMESGW+PGWUPCCIMS发起Invite请求；

Callee（被叫）接收Invite请求，并向eNodeB回复100

Trying；

eNodeB向MMESGW+PGWUPCCIMS发送PRACK请求；

XXX回复180 Ringing，表示XXX；

eNodeB向MMESGW+PGWUPCCIMS发送AAR请求；

MMESGW+PGWUPCCIMS向XXX发送Invite请求；

Callee回复100 Trying；

MMESGW+PGWUPCCIMS向Callee回复200 OK；

Callee回复200 OK with SDP；

MMESGW+PGWUPCCIMS向eNodeB回复200 OK with

SDP；

eNodeB向MMESGW+PGWUPCCIMS发送RAA请求；

MMESGW+PGWUPCCIMS向XXX发送ACK请求；

Callee按接听键，建立QCI=1的语音专有承载；

被叫XXX；

MMESGW+PGWUPCCIMS向XXX发送RAR请求；

eNodeB向MMESGW+PGWUPCCIMS回复RAR请求；

eNodeB向MMESGW+PGWUPCCIMS发送E-RAB Setup

Request请求；

MMESGW+PGWUPCCIMS向eNodeB回复E-RAB Setup

Response；

MMESGW+PGWUPCCIMS向eNodeB发送Activate

Dedicated EPS Bearer Context Request请求；

eNodeB向MMESGW+PGWUPCCIMS回复Activate

Dedicated EPS XXX；

MMESGW+PGWUPCCIMS向eNodeB发送CCR请求；

eNodeB向MMESGW+PGWUPCCIMS回复CCAQCI=1的语音专有承载资源分配成功；

主叫QCI=1的语音专有承载建立，流程和被叫的相同。

如果是晚振铃，建立语音专有承载的流程与早振铃相同，只是在180 Ringing之前建立语音专有承载。

以上就是VoLTE基本呼叫流程的详细解析。

During the call。the dedicated EPS bearer for voice with

QCI=1 of the caller is released。following the same process as the

release of the dedicated EPS bearer with QCI=1 of the callee.

After the call。the XXX indicate the end of the n.

The call XXX.

XXX XXX.

The callee receives the XXX Trying message.

XXX XXX.

XXX.

The AAA server XXX EPS bearer.

XXX XXX.

XXX Trying message.

XXX.

The AAA server XXX EPS bearer.

XXX with an E-RAB Setup Response message.

The AAA server XXX.

XXX EPS bearer.

XXX for voice.

The callee's phone rings with a 180 Ringing message.

XXX Trying message.

XXX to ring with a 180 Ringing message.

XXX 180 Ringing message.

XXX to ring with a 180 Ringing message.

XXX 180 Ringing message.

XXX button on their phone.

XXX with a 200 OK message with SDP.

XXX exchange AAR and RAR messages to update the

dedicated EPS bearer.

XXX Request messages to modify the dedicated EPS bearer.

Modify EPS XXX:

The process for updating the QCI=1 voice dedicated bearer

for the calling party is the same as for the called party。Once the

update is complete。a 200 OK message with SDP is sent。followed by an ACK message。During the call。RTCP sender

reports are sent。When the call ends。the calling party's QCI=1

XXX using the same process as for the called party。A Deactivate

EPS XXX message is sent。followed by a BYE message。Finally。a RAA message is XXX.

Update Bearer Response:

The update process for the QCI=1 voice dedicated bearer for

the calling party is the same as for the called party。Once the

update is complete。a 200 OK message with SDP is sent。followed by an ACK message。During the call。RTCP sender

reports are sent。When the call ends。the calling party's QCI=1

XXX using the same process as for the called party。A Deactivate

EPS XXX message is sent。followed by a BYE message。Finally。a RAA message is XXX.

Delete Bearer Request:

When the call ends。the QCI=1 voice dedicated bearer

resources for both the calling and called XXX。This is done using

a Delete Bearer Request message。followed by an E-RAB Release

Command message。A Deactivate EPS Bearer Context Request

message is then sent。followed by an E-RAB Release Response

message and a Delete Bearer Response message。Finally。a BYE

message is sent to indicate the end of the call.

2.2 XXX Connect State。Called User IDLE State 2.2.1 Early

Ringing:

When the calling party dials the called party。an Invite

message is sent to the eNodeB。The SBC forwards the Invite

message to the PGW on the called party side。which sends a DDN

message to the MME to initiate paging of the called party。Once

the called party is located。a Downlink Data n message is sent to

the PGW。which forwards it to the SBC。An Invite message is

then sent to the called party's IMS core。and a 100 Trying

message is sent back to the calling party。If the called party is

available。a 180 Ringing message is sent to the calling party.

The following is a corrected n of the text:

180 Ringing

180 Ringing

180 Ringing

XXX 180 Ringing message.

The callee responds with a 200 OK message with SDP (n n

Protocol) to establish the call.

AAR (Access n Request) and RAR ( Access Request)

messages are XXX resources for the call.

XXX sends a Create Bearer Request message to the MME

(Mobility Management Entity) to set up the dedicated EPS

(Evolved Packet System) bearer context.

XXX with an E-RAB (EPS。Access Bearer) Setup Request

message。which is accepted by the eNodeB with an E-RAB Setup

Response message.

XXX XXX Response message to the MME to XXX.

RAA ( Access Acknowledgement) and CCR (Charging

Control Request) XXX.

The QCI (Quality of Service Class Identifier) for the voice

call is set to the resources for the call are XXX.

XXX。and the caller hears the ringing tone.

AAA (n。n。and Accounting) XXX.

XXX with QCI=1 for voice traffic.

The call ends with a BYE message from either party。and the

dedicated EPS XXX with a Delete Bearer Request message.

RTCP (Real-Time Control Protocol) Sender Report messages

are exchanged to report on the quality of the call.

XXX callee hangs up。and the n is XXX.

This process XXX (2.2.2).

Document name: IMS (IP Multimedia Subsystem)

Document n: XXX Confidential。XXX.

E-RAB Setup Response:

After receiving the E-RAB Setup Request from the UE。the

ork sends an E-RAB Setup Response to confirm the XXX bearers.

XXX:

XXX message is sent by the MME to the UE to confirm the

XXX.

Create Bearer Response:

The Create Bearer Response message is sent by the SGW to

the MME to confirm the XXX.

RAA。CCR。CCA:

These messages are part of the call control signaling een the

UE and the ork。The RAA message is sent by the UE to

acknowledge the receipt of a RAR message from the ork。The

CCR message is sent by the SGW to the PCRF to request the XXX.

PGW收到RAR消息后发送XXX创建专有承载，XXX收到后发现被叫是IDLE态，发Paging消息寻呼被叫:

When the PGW receives a RAR message。it XXX that the

UE is in IDLE mode。it XXX.

AAR。AAA。Invite:

These messages are part of the SIP signaling een the UE and

the ork for setting up a voice call。The AAR message is sent by

the UE to initiate the call。The AAA message is sent by the ork to

XXX the UE。The Invite message is sent by the UE to invite the

called party to the call.

QCI=1的语音专有承载资源分配成功:

The n of resources for the QCI=1 dedicated voice bearer is

successful.

Downlink Data n。Downlink Data n ACK:

These messages are used to notify the UE of ing data.

RAAPaging:

This message is sent by the MME to locate the UE in XXX.

Service Request。Initial Context Setup Request。Initial

Context Setup Response。Modify Bearer Request。Modify

Bearer Response:

These messages are part of the signaling een the UE and the

ork for XXX.

被叫XXX。PRACK。200 OK:

These messages are part of the SIP signaling een the UE and

the ork for establishing a voice call。The 180 XXX indicate that

the called party is ringing。The PRACK message is sent by the

UE to confirm the receipt of the 180 Ringing message。The 200

OK message is sent by the called party to indicate that the call has

been answered.

被叫按接听键200 OK with SDP:

The 200 OK with SDP message is sent by the called party to

confirm the XXX of the voice call.

Update Bearer Request。Update Bearer Response:

These messages are used to modify the EPS bearer context。The Update Bearer Request is sent by the UE to request the n。and

the Update Bearer Response is sent by the ork to XXX.

主叫QCI=1的语音专有承载更新过程，流程和被叫的更新过程相同:

The process for updating the QCI=1 dedicated voice bearer

for the caller is the same as the process for the called party.

In this document。we see several messages exchanged during

a VoLTE voice call。The call starts with an "Initial Context Setup

Request" from the caller's node to the XXX "Invite" message to the

callee。If the callee is in the "Connect" state。the call proceeds

normally。If the callee is in the "Idle" state。the caller sends a

"Service Request" to establish a n。Once the call is established。the parties exchange several messages such as "200 OK with

SDP," "ACK," "BYE," and "RTCP Sender Report." When the call

ends。the parties release the resources used for the call with

messages like "Delete Bearer Request" and "Deactivate EPS

XXX." Finally。the parties indicate the end of the n with messages

like "STR" and "STA."

Create Bearer Response: This message is sent by the ork to

the UE to XXX.

Activate Dedicated EPS XXX: This message is sent by the

UE to request the n of a dedicated EPS XXX.

Activate Dedicated EPS XXX: This message is sent by the

ork to the UE to confirm the n of a dedicated EPS XXX.

CCAQCI=1 voice exclusive: This message indicates that a

voice call with QCI=1 has been established and the resources have

been XXX.

Called party answers: This message indicates that the called

party has pressed the answer key and the call is in progress.

Called party rings: This message indicates that the called

party's phone is ringing.

AAA: This message is sent by the UE to request XXX.

RAR: This message is sent by the ork to the UE to request

XXX.

200 OK with SDP: This message is sent by the ork to the UE

to confirm the XXX of a voice call with QCI= process is the

same as for the called party.

ACK: This message is sent by both the UE and the ork to

XXX.

Main and called party voice call: This message indicates that

a voice call is in progress een the main and called parties.

XXX: This message is sent by either party to XXX call.

Delete Bearer Request: This message is sent by the UE to

request the XXX.

E-RAB Release Command: This message is sent by the ork to

release an E-RAB.

E-RAB Release Response: This message is sent by the UE to

confirm the release of an E-RAB.

Delete Bearer Response: This message is sent by the ork to

XXX.

RTCP Sender Report: This message is sent by the ork to

provide n about the quality of service.

200 OK: This message is sent by the ork to confirm the

release of a QCI=1 voice exclusive bearer。following the same

process as for the called party.

STR: This message indicates that the called party has hung up.

STA: This message indicates that the n has ended.

Deactivate EPS XXX: This message is sent by the UE to

request the XXX.

Deactivate EPS XXX: This message is sent by the ork to

XXX.

Flowchart: XXX of the call setup process.

Service Request: This message is sent by the UE to request a

service from the ork.

Initial XXX Request/Response: These messages are

exchanged een the UE and the ork to XXX for the call.

Invite: This message is sent by the calling party to invite the

called party to a call.

SGW+PGWUPCCIMSCalleeInvite: This message indicates

that the calling party has dialed the called party and the RRC n has

been established through the Service Request process.

XXX Request/Response: These messages are sent by the UE

and the ork to modify a bearer.

100 Trying: This message is sent by the ork to indicate that

the call is being processed.

Create Bearer Request: This message is sent by the UE to

request the XXX.

AAR: This message is sent by the UE to request the XXX.

E-RAB Setup Request: This message is sent by the UE to

request the setup of an E-RAB.

本文介绍了VoLTE主被叫用户在XXX状态下进行通话的过程。在通话开始前，主叫用户需要发送Activate Dedicated

EPS Bearer Context Request和E-RAB Setup Response消息，被叫用户则需要发送Activate Dedicated EPS XXX和Create

Bearer Response消息。在承载资源分配成功后，被叫用户会建立QCI=1的语音专有承载，流程和主叫的相同。通话开始时，主叫用户发送Invite消息，被叫用户会振铃并发送100 Trying和180 Ringing消息。主被叫用户之间的通话过程中，会发送PRACK、200 OK和ACK消息。通话结束时，主被叫用户需

要发送BYE消息，并释放承载资源。在通话过程中，如果需要更新承载资源，主被叫用户可以发送Update Bearer Request和Modify EPS Bearer Context Request消息。通话完毕后，被叫用户按挂机，指示会话终止。

2022年4月28日，XXX发布了一份保密文件，共计12页，禁止未经授权的扩散。该文件名为“XXX服务请求”，其中包含了一些通信流程和相关指令。

在通信过程中，主叫先拨打被叫号码，由于主叫处于空闲状态，通过RRC连接建立，进入CONNECT状态。同时，Service Request流程也开始了。

接着，进行Modify Bearer请求和响应。被叫处于空闲状态，通过下行数据触发Paging被叫，找到被叫并进入CONNECT状态。然后进行Downlink Data n和ACK等操作。

XXX将Invite转发给PGW，对于PGW来说，这个Invite就是用户报文。接着，进行Service Request、Initial Context

Setup请求和响应，以及100 Trying、180 Ringing等操作。最

后，被叫XXX并进行PRACK、200 OK等操作，完成通信流程。

这份保密文件包含了一些关键信息，需要妥善保管，未经授权禁止扩散。

Activate Dedicated EPS XXX EPS bearer for the voice call。The QCI value for the voice call is set to 1.

XXX。and the called party answers the call by XXX。

n。n。and Accounting (AAA) res are performed to verify the

identity of the calling and called parties。

After the AAA res are completed。the Resource n Request

(RAR) message is sent from the eNodeB to the MME。and the

Resource n Answer (RAA) message is sent back to the eNodeB。

The 200 OK with SDP message is exchanged een the calling

and called XXX the voice call。

The voice call is established with a dedicated EPS bearer with

QCI value of 1 for both the calling and called parties。

The ACK messages are exchanged een the calling and called

XXX of the voice call。

During the voice call。the RTCP Sender Report is sent

dically to report the quality of the voice call。

When the called party hangs up。the call is terminated。and

the Deactivate EPS XXX

XXX Request and Response messages are exchanged to

modify the QCI value of the dedicated EPS bearer during the call。

The XXX the EPS bearer for the voice call。

The call setup process is initiated by the caller。who sends a

Service Request message to the eNodeB。

The Initial Context Setup Request and Response messages are

XXX for the call。

XXX XXX the voice call。

The 100 XXX indicate that the call setup process has started。

The Create Bearer Request message is XXX the EPS bearer

for the voice call.

Activate Dedicated EPS Bearer Context Request。E-RAB

Setup Response。Activate Dedicated EPS Bearer Context Accept。Create Bearer Response。CCR。CCA。RAA。RAR。RAA。AAR。AAA。Invite。和 QCI=1的语音专有承载资源分配成功是与LTE网络相关的一些通信协议。在这些协议中，RAR用于请求无线资源，PGW收到RAR消息后发送XXX来创建专有承载。如果XXX发现被叫是IDLE态，它会发送Paging消息进行寻呼，并找到被叫并进入CONNECT状态。

Downlink Data n和Downlink Data n ACK用于向UE发送数据。Service Request和Initial Context Setup Request用于建立

初始上下文。Modify Bearer Request和Modify Bearer Response用于修改承载。E-RAB Setup Request和E-RAB Setup

Response用于建立E-RAB。Invite和AAR用于呼叫建立。Activate Dedicated EPS Bearer Context Request和Activate

Dedicated EPS XXX用于激活专用承载。Update Bearer Request和AAA用于更新承载。Modify EPS Bearer Context Request和Modify EPS XXX用于修改EPS承载。

在通信过程中，100 Trying和180 Ringing用于呼叫建立的信令。PRACK用于确认接收到的中间信令。200 OK和200

OK with SDP用于呼叫建立的确认信令。被叫按接听键后，200 OK用于确认接听。

Update Bearer Response:

在主叫QCI=1的语音专有承载更新过程中，更新流程与被叫更新过程相同。收到200 OK with SDP响应后，发送ACK确认消息。这是主叫和被叫语音通话的开始。通话结束后，通过BYE消息释放资源，释放流程与被叫QCI=1的专有承载释放过程相同。最后，收到Delete Bearer Response响应。

RAR:

RAR消息是用于在LTE网络上分配无线资源的消息。在该消息中，包含了所需的无线资源信息，例如频率和时间间隔等。这个消息通常由基站向移动设备发送。

Deactivate EPS XXX:

Deactivate EPS Bearer Context Request是一条用于释放EPS承载的消息。当一个通话结束时，这个消息会被发送来释放资源。

E-RAB Release Response:

E-RAB Release Response是一个用于释放E-RAB的响应消息。当一个通话结束时，这个消息会被发送来释放资源。

Delete Bearer Response:

Delete Bearer Response是一个用于删除承载的响应消息。当一个通话结束时，这个消息会被发送来释放资源。

RTCP Sender Report:

RTCP发送者报告是一种用于监测网络质量的报告。在通话结束时，这个报告会被发送来评估通话的质量。

2022-4-28XXX保密信息，未经授权禁止扩散第11页，共12页文档名称文档密级3VoLTE基本呼叫建立时延统计方法:

在VoLTE通话建立过程中，呼叫建立时延是一个重要的性能指标。它由两个部分组成：主叫侧统计的从拨打电话到听到XXX的时间和被叫侧统计的摘机时延。这个指标会影响到通话的质量，不同的运营商对它的关注点也不同。