CN100459739C

Movatterモバイル変換

Info

Publication number: CN100459739C
Application number: CNB2005100678078A
Authority: CN
Inventors: 刘振华
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2005-04-26
Filing date: 2005-04-26
Publication date: 2009-02-04
Anticipated expiration: 2025-04-26
Also published as: CN1856131A

Abstract

A multimedia backdrop processing method, including: sets the function unit of the video gateway on the media gateway of the mobile exchange centre in wireless network, which is used to disassemble the H.324 multimedia code flow from the wireless network user into the video code flow and the audio code flow that is needed by the IP terminal user of the NGN network; sends the multimedia backdrop request to the mobile exchange centre that set the video gateway function unit by the NGN network side or the wireless network side; the mobile exchange centre enforces the multimedia backdrop process according to the prescriptive protocol by other side of the NGN network side and the wireless network side. The invention changes the traditional VIG to the wireless network ISUP signaling into the BICC signaling by inner wedge the VIG into the wireless MSC, achieve to backdrop to voice mode smoothly during the video communication of the IP video terminal and the video terminal of the wireless network.

Description

Translated fromChinese

一种多媒体回落的处理方法A processing method for multimedia fallback

技术领域technical field

本发明涉及在下一代网络(NGN：Next Generation Network)和IP网络中的多媒体通信技术，尤其涉及一种可以处理无线网络如第三代移动通信(3G)终端与网络协议(IP-Internet Protocol)终端在视频通话中的回落的方法，当无线网络的移动终端用户(以下简称3G用户)不能进行视频通话时，可以使3G用户和IP视频用户之间进行语音通话。The present invention relates to the multimedia communication technology in next generation network (NGN: Next Generation Network) and IP network, relate in particular to a kind of can handle wireless network such as the third generation mobile communication (3G) terminal and network protocol (IP-Internet Protocol) The method for the fallback of the terminal during the video call can make the voice call between the 3G user and the IP video user when the mobile terminal user of the wireless network (hereinafter referred to as the 3G user) cannot carry out the video call.

背景技术Background technique

窄带低速率多媒体通信框架(H.324M)视频业务是3G的亮点业务，随着下一代网络和IP网络的不断发展，3G视频终端与基于IP的多媒体通信框架(H.323)视频终端、会话开始协议(SIP：Session Initiate Protocol)视频终端的互通将成为重要的应用。通常由一个转换设备例如视频网关(VIG：Video Internet Gateway)完成3G终端的H.324M与IP网络的视频业务互通转换。Narrowband and low-rate multimedia communication framework (H.324M) video service is the highlight service of 3G. With the continuous development of next-generation networks and IP networks, 3G video terminals and IP-based multimedia communication framework (H.323) video terminals, conversations The intercommunication of video terminals based on SIP (Session Initiate Protocol) will become an important application. Usually, a conversion device such as a video gateway (VIG: Video Internet Gateway) completes the interworking and conversion of video services between H.324M and IP networks of 3G terminals.

由于漫游、网络质量或其他原因，在3G视频用户与IP视频用户通话时，如果该3G视频用户突然漫游到一个不能提供视频通话、只能提供语音通话的区域，视频业务就会中断，这个时候如果3G视频终端及其中间的承载(如VIG)能回落到语音模式，则通话就不会中断。这就被称为多媒体回落。现有3G R5网络内部手机到手机之间的通话使用TS23172规范定义的过程可以支持多媒体回落，但手机与NGN终端之间的回落问题不能解决。Due to roaming, network quality or other reasons, when a 3G video user talks with an IP video user, if the 3G video user suddenly roams to an area where video calls cannot be provided but only voice calls can be provided, the video service will be interrupted. If the 3G video terminal and its intermediate bearer (such as VIG) can fall back to voice mode, the call will not be interrupted. This is known as multimedia fallback. The process defined by TS23172 standard can support multimedia fallback for calls between mobile phones in the existing 3G R5 network, but the problem of fallback between mobile phones and NGN terminals cannot be solved.

现有的VIG设备是独立的设备。在其与移动交换中心(MSC：MobileSwitching Center)之间，承载采用TDM(Time Division Multiplex：时分复用)，信令传递则使用ISUP即ISDN用户部分的信令协议(ISDN：Integrated Service Digital Network综合业务数字网)。这样，利用TDM的承载和ISUP信令就无法在通话过程中从视频业务回落到语音模式，导致3G视频用户与IP视频用户的视频通话中断。Existing VIG devices are stand-alone devices. Between it and the Mobile Switching Center (MSC: MobileSwitching Center), the bearer adopts TDM (Time Division Multiplex: Time Division Multiplexing), and the signaling transfer uses ISUP, which is the signaling protocol of the ISDN user part (ISDN: Integrated Service Digital Network Integrated Business Digital Network). In this way, the TDM bearer and ISUP signaling cannot fall back from the video service to the voice mode during the call, resulting in the interruption of the video call between the 3G video user and the IP video user.

产生上述问题的根本原因是现有ISUP信令协议不允许在通话过程中对业务承载内容作修改。在宽带码分多址移动通信系统(WCDMA：Wideband Code Division Multiple Access)中，根据R4之后的版本，电路域(CS)采用与承载无关的呼叫控制协议(BICC：Bearer Independent CallControl Protocol)或SIP信令后，手机到手机之间通话中的视频回落就可以解决。CDMA2000系统的IOS5.0版本也可以解决手机到手机之间通话中的视频回落问题。但是它们都无法利用现有的VIG设备解决3G视频终端与IP网络视频终端在视频通话中从视频通话回落到语音通话的问题。The root cause of the above problems is that the existing ISUP signaling protocol does not allow modification of the service bearer content during a call. In the wideband code division multiple access mobile communication system (WCDMA: Wideband Code Division Multiple Access), according to the version after R4, the circuit domain (CS) adopts the bearer-independent call control protocol (BICC: Bearer Independent Call Control Protocol) or SIP signal After the order, the video fallback in the call between mobile phone and mobile phone can be solved. The IOS5.0 version of the CDMA2000 system can also solve the problem of video fallback in calls between mobile phones. But none of them can utilize the existing VIG equipment to solve the problem that the 3G video terminal and the IP network video terminal fall back from the video call to the voice call during the video call.

发明内容Contents of the invention

为解决现有技术的上述问题，本发明的目的在于提供一种多媒体回落的处理方法，用于解决3G终端与IP终端在视频通话中的回落问题，当3G终端与IP终端之间不能进行视频通话时，本发明可以使3G用户和IP视频用户之间进行语音通话。In order to solve the above-mentioned problems in the prior art, the purpose of the present invention is to provide a processing method for multimedia fallback, which is used to solve the problem of fallback in video calls between 3G terminals and IP terminals. During the conversation, the present invention can make the voice conversation between the 3G user and the IP video user.

为实现上述目的，本发明提供的多媒体回落的处理方法包括：在3G网络的移动交换中心的媒体网关上增加VIG功能单元，用于将来自无线网络用户的H.324多媒体码流分解成为NGN网络IP终端用户需要的视频RTP(实时传输协议)码流和音频RTP码流；1)在无线网络的移动交换中心的媒体网关上设置视频网关功能单元，用于将来自无线网络用户的H.324多媒体码流分解成为NGN网络IP终端用户需要的视频码流和音频码流；2)所述NGN网络侧和所述无线网络侧任一方对所述设置有视频网关功能单元的所述移动交换中心发出多媒体回落请求；3)所述移动交换中心根据所述NGN网络侧和所述无线网络侧中的另一方所规定的协议，执行多媒体回落过程。In order to achieve the above object, the processing method of the multimedia fallback provided by the present invention includes: adding a VIG functional unit on the media gateway of the mobile switching center of the 3G network, for decomposing the H.324 multimedia code stream from the wireless network user into an NGN network The video RTP (real-time transport protocol) code stream and the audio RTP code stream that IP terminal users need; The multimedia code stream is decomposed into the video code stream and the audio code stream required by the NGN network IP terminal user; 2) either side of the NGN network side and the wireless network side is provided with the mobile switching center of the video gateway functional unit Sending a multimedia fallback request; 3) The mobile switching center executes a multimedia fallback process according to the protocol stipulated by the other side of the NGN network side and the wireless network side.

在上述方法中，MSC在用户面与其他MSC采用分组(ATM或IP)传送媒体流，与NGN网络采用IP传送。In the above method, the MSC transmits media streams with other MSCs in packets (ATM or IP) on the user plane, and transmits media streams with the NGN network using IP.

本发明的优点在于：通过将VIG功能单元内嵌于关口移动交换中心，将原来的VIG到无线网络的ISUP信令变成BICC信令，即支持承载修改的信令，从而解决了ISUP信令不能支持通话过程中的业务属性修改问题。从而实现了在IP视频终端与3G视频终端进行视频通话过程中可以平滑回落到语音模式。The advantage of the present invention is that by embedding the VIG functional unit in the gateway mobile switching center, the original ISUP signaling from the VIG to the wireless network is changed into BICC signaling, that is, signaling that supports bearer modification, thereby solving the problem of ISUP signaling It cannot support the modification of business attributes during a call. Therefore, it is possible to smoothly fall back to the voice mode during the video call between the IP video terminal and the 3G video terminal.

附图说明Description of drawings

图1为现有技术的3G视频用户与H.323IP终端用户的通信示意图；Fig. 1 is a schematic diagram of communication between a 3G video user and an H.323IP terminal user in the prior art;

图2为本发明的3G视频用户与H.323IP终端用户的通信示意图；Fig. 2 is the communication schematic diagram of 3G video user and H.323IP terminal user of the present invention;

图3为本发明的控制流程图，描述3G侧发起回落的过程；Fig. 3 is a control flowchart of the present invention, describing the process that the 3G side initiates a fallback;

图4为本发明的控制流程图，描述NGN侧发起回落的过程；Fig. 4 is the control flowchart of the present invention, describes the process that the NGN side initiates a fallback;

图5为本发明的数据流处理示意图，显示了3G的H.324视频业务流和NGN视频业务的互通；Fig. 5 is the data flow processing schematic diagram of the present invention, has shown the intercommunication of the H.324 video service flow of 3G and NGN video service;

图6为本发明的数据流处理示意图，显示了3G语音流和NGN语音业务互通。Fig. 6 is a schematic diagram of data stream processing in the present invention, showing the intercommunication between 3G voice stream and NGN voice service.

具体实施方式Detailed ways

下面结合附图，对本发明的实施例进行详细说明。Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

根据本发明，需要将常规的VIG功能单元设置于3G网络MSC的MGW中。根据本发明的实施方案，可以将VIG功能单元设置在GMSC的MGW上，或是在VMSC(访问MSC，就是通常所说的端局)上。出于成本考虑，当设置在GMSC中时，相当于将VIG功能单元集中放置，共享程度较大，可降低投资。但在3G运行初期，VMSC很少，因此可以将VIG直接内嵌于VMSC。无论设在端局还是关口局，其内部增加的VIG处理单元相当于一个IWF(interworking function：互通转换设备)处理模块。According to the present invention, conventional VIG functional units need to be set in the MGW of the MSC in the 3G network. According to the embodiment of the present invention, the VIG functional unit can be set on the MGW of the GMSC, or on the VMSC (visiting the MSC, which is commonly referred to as an end office). For cost considerations, when it is set in the GMSC, it is equivalent to placing the VIG functional units in a centralized manner, and the degree of sharing is large, which can reduce investment. But in the early stage of 3G operation, there are few VMSCs, so VIG can be directly embedded in VMSCs. Regardless of whether it is located in the end office or the gateway office, the VIG processing unit added inside is equivalent to an IWF (interworking function: interworking conversion device) processing module.

如图5所示，这个IWF处理模块从无线侧输入的是H.324M码流。该模块将H.324M的H.223层解复用后，提取出视频流和音频流，并将H.245控制流取出，可交给软交换处理。软交换可把这个H.245消息转变为H.323的H.245消息或SIP的呼叫信令(这些信令转变以及软交换对网关的控制可参考H.248标准及其附录，是现有的技术，因此不再赘述)。在NGN到3G网络的方向，该IWF模块将视频流、音频流和H.245控制流复用到H.324M的H.223层上，并对3G侧输出该H.223流。当呼叫是一个视频呼叫时，在通话处理中插入这个IWF处理模块，进行常规的VIG转换处理。当呼叫是一个语音呼叫时，不插入这个IWF处理模块，只插入语音TC(Transcoder，编解码转换器，可完成不同编码之间的转换)进行处理。As shown in Figure 5, the IWF processing module inputs the H.324M code stream from the wireless side. This module demultiplexes the H.223 layer of H.324M, extracts the video stream and audio stream, and extracts the H.245 control stream, which can be handed over to the soft switch for processing. The soft switch can convert this H.245 message into H.245 message of H.323 or call signaling of SIP (these signaling conversion and the control of the soft switch to the gateway can refer to the H.248 standard and its appendix, which are existing technology, so it will not be repeated here). In the direction from NGN to 3G network, the IWF module multiplexes video stream, audio stream and H.245 control stream to the H.223 layer of H.324M, and outputs the H.223 stream to the 3G side. When the call is a video call, this IWF processing module is inserted in call processing to perform conventional VIG conversion processing. When the call is a voice call, the IWF processing module is not inserted, and only the voice TC (Transcoder, codec converter, which can complete the conversion between different codes) is inserted for processing.

仍如图5所示，在视频模式下时，3G侧和NGN侧中间有一个IWF资源(即VIG功能单元)。当处于语音模式时，只需要把中间的IWF通道释放，插入一个语音TC即可(如图6所示)。Still as shown in FIG. 5 , in the video mode, there is an IWF resource (ie VIG functional unit) between the 3G side and the NGN side. When in voice mode, you only need to release the middle IWF channel and insert a voice TC (as shown in Figure 6).

如图2所示，在信令面上，嵌入了VIG功能单元的GMSC(或VMSC)与无线网络内部的其他VMSC服务器之间采用BICC信令、与NGN网络的软交换模块之间采用SIP信令，与H.323终端之间存在H.245信令。在用户面(媒体流传送)上，嵌入了VIG功能单元的GMSC(或VMSC)与其他VMSC采用分组(IP或ATM)传送的方式，与NGN网络采用IP传送的方式。As shown in Figure 2, on the signaling plane, BICC signaling is used between the GMSC (or VMSC) embedded with the VIG functional unit and other VMSC servers in the wireless network, and SIP signaling is used between the softswitch module of the NGN network. There is H.245 signaling between the H.323 terminal and the H.323 terminal. On the user plane (media stream transmission), the GMSC (or VMSC) embedded with the VIG functional unit adopts packet (IP or ATM) transmission mode with other VMSCs, and uses IP transmission mode with NGN network.

当IP终端与3G用户进行视频通话时，具有内嵌VIG功能单元的GMSC或VMSC将来自3G网络内部的H.324码流转换为NGN网络所要求的视频RTP流和音频RTP流。如果由于3G网络自身的原因，使得3G视频终端与IP网络终端的视频通话无法继续进行，则在3G网络内部会发起多媒体回落流程。这个流程遵守3GPP TS23172协议。具体步骤为：When an IP terminal makes a video call with a 3G user, the GMSC or VMSC with built-in VIG function unit converts the H.324 stream from the 3G network into the video RTP stream and audio RTP stream required by the NGN network. If the video call between the 3G video terminal and the IP network terminal cannot continue due to the reasons of the 3G network itself, a multimedia fallback procedure will be initiated within the 3G network. This process complies with the 3GPP TS23172 protocol. The specific steps are:

参考图3，以VIG内嵌于关口局为例。3G侧发起回落，通过BICC信令，按照3GPP TS23172协议向GMSC发起承载修改请求“APM(承载修改为语音)”。一旦GMSC收到了3G网络侧的BICC的承载修改请求后，就会对NGN的软交换单元发起SIP的重修改过程“Reinvite(修改会话为语音)”。NGN的软交换同意变更，返回200OK，GMSC收到200OK后，对无线网络发送APM确认同意修改，同时对NGN侧回ACK消息。在GMSC的NGN侧Reinvite过程中可以将IP终端的视频流关闭，只保留音频流，符合标准SIP协议。在GMSC的3G侧则完全符合TS23172。通过将NGN侧和3G侧的信令交互关联起来，实现了回落。当GMSC的两侧都完成回落过程后，其两侧处于语音模式下。在承载面上，也会同时删除IWF资源，并插入转变为语音的TC。Referring to Figure 3, take VIG embedded in the gateway office as an example. The 3G side initiates a fallback, and initiates a bearer modification request "APM (bearer modification to voice)" to the GMSC through BICC signaling in accordance with the 3GPP TS23172 protocol. Once the GMSC receives the bearer modification request from the BICC on the 3G network side, it will initiate the SIP re-modification process "Reinvite (modify the session to voice)" to the NGN softswitch unit. The softswitch of NGN agrees to change, and returns 200OK. After receiving 200OK, GMSC sends APM to the wireless network to confirm the modification, and returns ACK message to NGN side at the same time. During the Reinvite process on the NGN side of the GMSC, the video stream of the IP terminal can be closed, and only the audio stream is kept, which conforms to the standard SIP protocol. On the 3G side of GMSC, it fully complies with TS23172. The fallback is realized by associating the signaling interaction between the NGN side and the 3G side. When both sides of the GMSC complete the fallback process, both sides of the GMSC are in voice mode. On the bearer plane, IWF resources will also be deleted at the same time, and TCs converted to voice will be inserted.

图4是以VIG内嵌到关口局为例，说明NGN侧发起回落的过程。这时NGN软交换先发送reinvite过程，GMSC收到后对3G侧发送BICC的APM以修改业务。等到收到响应后，对NGN侧回200OK。在承载面上，也会同时删除IWF资源，并插入转变为语音的TC。GMSC在3G网络对外信令交换时完全依照3G规范。对NGN侧信令交换依照SIP规范。这样，通过将两侧信令流程关联起来完成了多媒体回落过程。Figure 4 takes VIG embedded in the gateway office as an example to illustrate the process of NGN side initiating fallback. At this time, the NGN softswitch sends the reinvite process first, and the GMSC sends the APM of the BICC to the 3G side to modify the service after receiving it. After receiving the response, return 200 OK to the NGN side. On the bearer plane, IWF resources will also be deleted at the same time, and TCs converted to voice will be inserted. GMSC fully complies with the 3G specification when exchanging external signaling in the 3G network. The signaling exchange on the NGN side follows the SIP specification. In this way, the multimedia fallback process is completed by associating the signaling processes of both sides.

对于在上述实施例中没有描述的NGN侧为H.323用户的情况，在实际的处理流程中，只要把SIP侧的reinvite用H.245的close logic channel(关闭逻辑信道)消息代替，将200OK用H.245的close logic channel ACK代替(这个消息不需要发送ACK)即可，其他部分与上面描述的过程完全相同。For the situation that the NGN side not described in the above-mentioned embodiment is an H.323 user, in the actual processing flow, as long as the reinvite of the SIP side is replaced with the close logic channel (close logic channel) message of H.245, the 200 OK Replace it with H.245 close logic channel ACK (this message does not need to send ACK), and the other parts are exactly the same as the process described above.

在本方案中，通过将VIG内嵌到无线MSC中，将传统VIG到无线网络的ISUP信令变成了BICC信令，即支持承载修改的信令后，解决了ISUP信令不能支持通话过程中的业务属性修改问题。从而实现了在IP终端与3G用户进行视频通话的过程中，可以平滑回落到语音模式下，改善用户的感受。In this solution, by embedding the VIG into the wireless MSC, the ISUP signaling from the traditional VIG to the wireless network is changed into BICC signaling, that is, after supporting the bearer modified signaling, it is solved that the ISUP signaling cannot support the call process The business attribute modification problem in . Therefore, it is realized that during the video call between the IP terminal and the 3G user, it can smoothly fall back to the voice mode, thereby improving the experience of the user.

以上所述仅为本发明的优选实施例，并非因此即限制本发明的专利范围。The above descriptions are only preferred embodiments of the present invention, and are not meant to limit the patent scope of the present invention.