CN101052154A

CN101052154A - IP multimedia sub system and its coding and decoding switching control method

Info

Publication number: CN101052154A
Application number: CN 200710027974
Authority: CN
Inventors: 欧阳振华; 任慧鹏
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2007-05-11
Filing date: 2007-05-11
Publication date: 2007-10-10
Anticipated expiration: 2027-05-11
Also published as: CN100539723C; WO2008138261A1

Abstract

The method comprises: pre-estimating the encode and decode type supported by the called user; according to the encode and decode type supported by the called user and the encode and decode type supported by the calling user, deciding if the session needs to be made with a encode and decode conversion; if there is an intersection between the said two encode and decode types, then continuing the session process; if there is no intersection between them, then the encode and decode type will be converted; controlling and negotiating the encode and decode type respectively supported by the calling and called users, and informing the encode and decode type respectively supported by both calling and called users to the media gateway.

Description

IP Multimedia System and coding/decoding conversion control method thereof

Technical field

The present invention relates to IP Multimedia System (IMS) technical field, in particular, the present invention relates to a kind of IMS system and coding/decoding conversion control method thereof.

Background technology

At present, trend in view of the Internet and telecommunications network fusion, International Standards Organization third generation partner program (3GPP) has introduced the IP Multimedia System (IMS) of supporting the all-IP business network framework of multimedia service on the basis of packet carrying network, the target of IMS is the user data according to personalization, the shielding user mode access, the degree of opening of control professional ability provides brand-new multimedia communication experiences.

Topmost functional entity comprises controlling call entity (CSCF) among the IMS, and CSCF has three types: serving CSCF (S-CSCF), proxy CSCF (P-CSCF), inquiry CSCF (I-CSCF).Wherein, S-CSCF is topmost operation controlling entity, and different S-CSCF is because application server (AS) difference that is connected can be finished different business functions.

In addition, in the IMS network, because the code/decode type that the calling and called user terminal is supported may be different, the medium code/decode type that caller is supported, called might the support; And the code/decode type of called support, caller then might not supported.Therefore in order to realize the session between calling and called, need network to have a kind of ability that can between calling and called, carry out the medium encoding and decoding conversion, guarantee that the Media Stream of calling and called both sides communication is the code/decode type that calling and called are supported.

At present, a kind of scheme that realizes encoding and decoding conversion between calling and called is provided in 3GPP 23218.740 agreements, it mainly is that configuration encoding and decoding AS carries out encoding and decoding conversion control in S-CSCF adopts based on the data of initial filter standard or norm (IFC), realize encoding and decoding conversion between the calling and called by media resource function controller (MRFC), but owing to can't dynamically know the code/decode type that the called subscriber supports, therefore all users need disposes the encoding and decoding AS that is correlated with and carry out encoding and decoding conversion in IFC, flexibility is not enough, maintenance cost is higher, and connecting time is longer.

Summary of the invention

The technical problem that the embodiment of the invention solves provides a kind of IMS system, IBCF, S-CSCF and coding/decoding conversion control method, to reduce maintenance cost, reduces connecting time, flexible realization encoding and decoding conversion.

For addressing the above problem, a kind of service call session control function entity of the specific embodiment of the invention includes:

The anticipation processing unit is used for the code/decode type that the anticipation called subscriber supports;

Encoding and decoding conversion judgment processing unit, be used for the code/decode type that the code/decode type supported according to the called subscriber of described anticipation processing unit anticipation and calling subscriber support and judge whether the session between the calling and called user need carry out encoding and decoding conversion, when there is not common factor in the code/decode type that the code/decode type of supporting the calling subscriber and the called subscriber of described anticipation support, judgement need be carried out encoding and decoding conversion, and indication encoding and decoding controller carries out encoding and decoding conversion control.

Correspondingly, a kind of Interconnection Border Control Function entity of the specific embodiment of the invention includes:

Control unit is consulted in media conversion, is used to control the code/decode type that negotiation calling and called user supports respectively;

The media conversion indicating member is notified media gateway with the code/decode type that the calling and called user who consults to determine supports respectively.

Correspondingly, a kind of IP Multimedia System of the specific embodiment of the invention comprises service call session control function entity and Interconnection Border Control Function entity, and described Interconnection Border Control Function entity includes:

The media conversion indicating member is notified media gateway with the code/decode type that the calling and called user who consults to determine supports respectively;

Described service call session control function entity includes:

Encoding and decoding conversion judgment processing unit, the code/decode type that code/decode type of supporting according to the called subscriber of described anticipation processing unit anticipation and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion, when there is not common factor in the code/decode type that the code/decode type of supporting the calling subscriber and called subscriber support, judgement need be carried out encoding and decoding conversion, and indication Interconnection Border Control Function entity carries out encoding and decoding conversion control.

Correspondingly, a kind of IP Multimedia System of the specific embodiment of the invention, include service call session control function entity, described IP Multimedia System comprises the encoding and decoding control application server of separate functional unit, is used to control media gateway and carries out encoding and decoding conversion;

Described service call session control function entity includes:

Encoding and decoding conversion judgment processing unit, the code/decode type that code/decode type of supporting according to the called subscriber of described anticipation processing unit anticipation and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion, when there is not common factor in the code/decode type that the code/decode type of supporting the calling subscriber and called subscriber support, judgement need be carried out encoding and decoding conversion, and indication encoding and decoding control application server carries out encoding and decoding conversion control.

Correspondingly, a kind of IP Multimedia System of the specific embodiment of the invention includes the Interconnection Border Control Function entity, and described Interconnection Border Control Function entity includes:

Encoding and decoding conversion judgment processing unit, the code/decode type that code/decode type of supporting according to the called subscriber of described anticipation processing unit anticipation and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion, when there is not common factor in the code/decode type that the code/decode type of supporting the calling subscriber and called subscriber support, judgement need be carried out encoding and decoding conversion, indicates described media conversion to consult control unit control and consults the code/decode type that the calling and called user supports respectively.

Correspondingly, a kind of service call session control function entity of the specific embodiment of the invention includes:

Encoding and decoding conversion judgment processing unit, the code/decode type that code/decode type of supporting according to the called subscriber of described anticipation processing unit anticipation and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion, when there is not common factor in the code/decode type that the code/decode type of supporting the calling subscriber and called subscriber support, judgement need be carried out encoding and decoding conversion, and the indication media conversion is consulted control unit control and consulted the code/decode type that the calling and called user supports respectively.

Correspondingly, a kind of IP Multimedia System of the specific embodiment of the invention includes service call session control function entity, and described service call session control function entity includes:

Correspondingly, a kind of coding/decoding conversion control method of the specific embodiment of the invention, this method mainly comprises:

The code/decode type that the anticipation called subscriber supports;

The code/decode type that code/decode type of supporting according to the called subscriber of anticipation and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion;

Occur simultaneously if the code/decode type that code/decode type that the calling subscriber supports and called subscriber support exists, then judge and need not carry out encoding and decoding conversion, continue session and handle;

If there is not common factor in the code/decode type that code/decode type that the calling subscriber supports and called subscriber support, then judge and to carry out encoding and decoding conversion, the code/decode type that the calling and called user supports is respectively consulted in control, notifies media gateway with the code/decode type that the calling and called user who consults to determine supports respectively.

After service call session control function entity receives that called subscriber that called subscriber equipment returns does not support caller code/decode type message, judge whether to consult the code/decode type that the calling and called user supports respectively, and in judged result for not the time, according to the codec type information that the called subscriber that carries in the described message of returning supports, the code/decode type notice media gateway that the code/decode type that the calling and called user supports respectively and the calling and called user that will consult to determine are again supported is respectively consulted in control again.

After service call session control function entity receives that called subscriber that called subscriber equipment returns does not support caller code/decode type message, judge whether to consult the code/decode type that the calling and called user supports respectively, and in judged result for not the time, according to the codec type information that the called subscriber that carries in the described message of returning supports, the code/decode type notice media gateway that the code/decode type that the calling and called user supports respectively and the calling and called user that will consult to determine are again supported is respectively consulted in the control of indication encoding and decoding controller again.

The Interconnection Border Control Function entity receives that the called subscriber that heterogeneous networks returns does not support caller code/decode type message, the code/decode type common factor information that the heterogeneous networks that the message of returning according to described priority is carried is supported, control are consulted the code/decode type notice media gateway that the code/decode type that the calling and called user supports respectively and the calling and called user that will consult to determine are again supported respectively again.

According to a particular embodiment of the invention, the code/decode type of supporting by anticipation called subscriber when the initiation session; The code/decode type that code/decode type of supporting according to the called subscriber of anticipation and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion; Occur simultaneously if the code/decode type that code/decode type that the calling subscriber supports and called subscriber support exists, then judge and need not carry out encoding and decoding conversion, continue session and handle; If there is not common factor in the code/decode type that code/decode type that the calling subscriber supports and called subscriber support, then judge and to carry out encoding and decoding conversion, the code/decode type that the calling and called user supports is respectively consulted in control, notify media gateway with the code/decode type that the calling and called user who consults to determine supports respectively, owing to need not in IFC, to carry out encoding and decoding conversion for encoding and decoding AS of each user's static configuration, can reduce maintenance cost, reduce connecting time, flexible realization encoding and decoding conversion.

Description of drawings

Fig. 1 is the main flow chart of a specific embodiment of coding/decoding conversion control method of the present invention;

Fig. 2 is the specific embodiment schematic diagram that encoding and decoding conversion is carried out in IBCF control of the present invention;

Fig. 3 is that initiation session of the present invention is rebuild a specific embodiment schematic diagram that immediately carries out encoding and decoding conversion by IBCF control;

Fig. 4 is the specific embodiment schematic diagram that IBCF of the present invention handles the encoding and decoding failure;

Fig. 5 is the first specific embodiment Message Processing flow chart of coding/decoding control method of the present invention;

Fig. 6 is the second specific embodiment Message Processing flow chart of coding/decoding control method of the present invention;

Fig. 7 is the 3rd a specific embodiment Message Processing flow chart of coding/decoding control method of the present invention;

Fig. 8 is the 4th a specific embodiment Message Processing flow chart of coding/decoding control method of the present invention;

Fig. 9 is the 5th a specific embodiment Message Processing flow chart of coding/decoding control method of the present invention;

Figure 10 is the first application scenarios schematic diagram of encoding and decoding control between IMS of the present invention territory;

Figure 11 is the second application scenarios schematic diagram of encoding and decoding control between IMS of the present invention territory;

Figure 12 is the 3rd an application scenarios schematic diagram of encoding and decoding control between IMS of the present invention territory;

Figure 13 is the 4th an application scenarios schematic diagram of encoding and decoding control between IMS of the present invention territory;

Figure 14 is the 5th an application scenarios schematic diagram of encoding and decoding control between IMS of the present invention territory;

Figure 15 is the 6th an application scenarios schematic diagram of encoding and decoding control between IMS of the present invention territory;

Figure 16 is the 7th an application scenarios schematic diagram of encoding and decoding control between IMS of the present invention territory;

Figure 17 is the 8th an application scenarios schematic diagram of encoding and decoding control between IMS of the present invention territory;

Figure 18 is the IMS of the present invention system first specific embodiment structural representation;

Figure 19 is the IMS of the present invention system second specific embodiment structural representation;

Figure 20 is IMS of the present invention system the 3rd a specific embodiment structural representation;

Figure 21 is IMS of the present invention system the 4th a specific embodiment structural representation.

Embodiment

With reference to figure 1, this figure is the main flow chart of a specific embodiment of coding/decoding conversion control method of the present invention, specifically mainly comprises the steps:

Step s101, the code/decode type that the anticipation called subscriber supports, during specific implementation, can be by the S-CSCF code/decode type that the anticipation called subscriber supports when session is set up, for example, S-CSCF can adopt following manner to obtain the code/decode type that the called subscriber supports after receiving the Invite message that initiation session is set up:

(1) based on number analysis result to Request URI, judge called subscriber place network type, and then the code/decode type of judgement called user terminal support, during specific implementation, for example can dispose territory, called subscriber place medium property table and realize, can obtain the code/decode type of called subscriber place network support by inquiring about local configuration at S-CSCF.

Preserve the P-Access-Network-Info header field that the user brings up when (2) S-CSCF registers,, judge the code/decode type that called user terminal is supported by the access network type at called subscriber place.

(3) by RFC3840, the described mode of RFC3841 agreement, UE brings S-CSCF with the coding/decoding capability of oneself supporting when registration, under S-CSCF preserves when registration, when calling out, obtain the code/decode type that called user terminal is supported by the inquiring user data, the priority of above-mentioned judgment mode can increase progressively successively, for example according to (1)＜(2)＜(3).

Need illustrate, during specific implementation, also can be by the code/decode type of Interconnection Border Control Function entity (IBCF) or other network entity anticipations called subscriber support, concrete anticipation called subscriber's code/decode type can adopt above-mentioned or other multiple modes, repeats no more here.

Step s102, the code/decode type that code/decode type of supporting according to the called subscriber of anticipation and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion, for example, when setting up according to session, the code/decode type that the code/decode type that the calling subscriber who carries in the session invitation message supports and the called subscriber of described anticipation support is whether decidable needs to carry out encoding and decoding conversion, during specific implementation, if above-mentioned steps s101 determines the code/decode type that the called subscriber supports by the S-CSCF anticipation, then this step continues to be determined whether to carry out encoding and decoding conversion by the S-CSCF judgement, if above-mentioned steps s101 determines the code/decode type that the called subscriber supports by the IBCF anticipation, then this step continues to be determined whether to carry out encoding and decoding conversion by the IBCF judgement.

In addition, at step s103, occur simultaneously in the present embodiment, then judge and need not carry out encoding and decoding conversion, can continue session and handle, repeat no more here if the code/decode type that code/decode type that the calling subscriber supports and called subscriber support exists;

In addition, in the present embodiment, at step s104, if there is not common factor in the code/decode type that code/decode type that the calling subscriber supports and called subscriber support, then judge and to carry out encoding and decoding conversion, may command is consulted the code/decode type that the calling and called user supports respectively, and the code/decode type that the calling and called user that will consult to determine supports is respectively notified media gateway, during specific implementation, for example can indicate IBCF control to consult the code/decode type that the calling and called user supports respectively by S-CSCF, and the code/decode type that the calling and called user that will consult to determine supports is respectively notified media gateway, a concrete example, for example S-CSCF constructs the expansion header field in Invite message, be used for indication and need carry out encoding and decoding conversion, and the Invite forwards that will carry the expansion header field that this indication need carry out encoding and decoding conversion gives IBCF, for example expand header field can for:

Called-Required-Codecs：CALLED-REQUIRED；audio-codec-list＝PCMA，PCMU，G729，AMR。

I.e. expression is carried information and is PCMA, PCMU, G729, AMR for the essential audio coding decoding type (codec) of called subscriber.

IBCF can by checking in the Invite message that S-CSCF sends whether contain the extension header domain information that indication need be carried out encoding and decoding conversion, for example IBCF detects and contains Called-Required-Codecs expansion header field in the Invite message that S-CSCF sends, then the IBCF judgement need be carried out encoding and decoding conversion, start and consult the code/decode type that the calling and called user supports, and the code/decode type that the calling and called that will consult to determine are supported is respectively notified media gateway.

With reference to figure 2, this figure is the specific embodiment schematic diagram that IBCF realizes encoding and decoding conversion control when session is set up, IBCF is as the IMS network boundary, can finish that network topology is hidden, the functions such as IP network intercommunication of IMS-ALG, medium control, service quality (QoS) management, SIP signaling filtering, introducing IWF and non-session initiation protocol (SIP), IBCF controls and carries out encoding and decoding conversion and mainly comprise following flow process in the present embodiment:

(1) whether contains the extension header domain information that need carry out encoding and decoding conversion in the Invite message that IBCF inspection S-CSCF sends, for example IBCF detects and contains Called-Required-Codecs expansion header field in the Invite message in the present embodiment, and then IBCF judges and need carry out encoding and decoding conversion;

(2) IBCF obtains the IP address ip 1 of medium and the code/decode type codec 1 that the calling subscriber supports from the Invite message SDP that S-CSCF sends, 2, send the Req message of the code/

decode type codec

1,2 that carries described IP1 and calling subscriber's support then to I-BGF.

(3) I-BGF returns Rsp message, wherein carries the IP address ip 3 after the conversion.

(4) address ip 3 returned according to I-BGF of IBCF is revised SDP message body of Invite message, with the codec among the expansion header field Called-Required-Codecs add among the SDP Offer corresponding m capable under the capable codec back of a, and deletion expansion header field, give the called subscriber according to the address in the Route header field with the Invite forwards, preserve the SDP in the Invite message simultaneously.

(5) IBCF receives 200 message that the called subscriber returns, and obtains the IP address ip 4 of medium and code/

decode type codec

3,4 information that the called subscriber supports from the SDP of described 200 message.

(6) IBCF sends to I-BGF and carries the code/decode type codec1 that described IP4 and calling subscriber support, and 2 and the Req message of code/

decode type codec

3,4 information supported of called subscriber.

(7) I-BGF returns Rsp message, carries the IP address ip 2 after the conversion, and at this moment, I-BGF has been known the coding/decoding capability that calling and called user both sides support respectively, can carry out encoding and decoding conversion between the calling and called user.

Above-mentioned IBCF carries out encoding and decoding conversion control in the process for session is set up, and under other scene, IBCF also can carry out encoding and decoding conversion control, for example:

With reference to figure 3, IBCF receives that the processing after the re-Invite message is as follows behind the call setup:

IBCF receives re-Invite message behind the call setup, if there is not Media Stream (" m " OK) increase and deletion, for example carried out the Media Stream (" m of encoding and decoding conversion " OK) link information (IP and port) or encoding and decoding variation has taken place, the more user of kainogenesis change and the media information of I-BGF of IBCF may command then; And if Media Stream (" m arranged " OK) increase, then the IBCF may command is carried out the processing of the encoding and decoding conversion that Media Stream increases; Perhaps, if Media Stream (" m is arranged " OK) deletion, i.e. port vanishing, the IBCF may command is carried out the encoding and decoding conversion of Media Stream deletion and is handled, and for example deletes link information.

Perhaps, with reference to figure 4, when session was set up, IBCF and RACS carried out encoding and decoding conversion control alternately, if after RACS returned AA response (AAA) message of encoding and decoding failure, then IBCF returned 4xx message to the calling subscriber and removes session.

In addition, need illustrate, under concrete applied environment, also can be by the code/decode type of S-CSCF anticipation called subscriber support, consult the code/decode type that the calling and called user supports respectively by S-CSCF indication encoding and decoding control AS control, and will consult the code/decode type notice media gateway that definite calling and called user supports respectively; Or the code/decode type of supporting by S-CSCF anticipation called subscriber, directly control the code/decode type that negotiation calling and called user supports respectively by S-CSCF, and the code/decode type that the calling and called user that will consult to determine supports is respectively notified media gateway, or the code/decode type of supporting by IBCF anticipation called subscriber, also will consult the code/decode type notice media gateway that definite calling and called user supports respectively by the code/decode type that IBCF control negotiation calling and called user supports respectively, give unnecessary details no longer one by one here.

In addition, also need to illustrate, under concrete applied environment, for example when initiation session is set up, if the session between S-CSCF anticipation calling and called user does not need to do encoding and decoding conversion, and the session invitation message is not sent to IBCF, but directly be transmitted to callee side, after if S-CSCF receives that called subscriber that called subscriber equipment returns does not support caller code/decode type message, for example, when receiving 488/606 response message that the called subscriber returns, S-CSCF can at first judge whether to consult the code/decode type that the calling and called user supports respectively, and in judged result for not the time, codec type information according to called subscriber's support of carrying in the described message of returning, directly the code/decode type notice media gateway that the code/decode type that the calling and called user supports respectively and the calling and called user that will consult to determine are again supported is respectively consulted in control again, or indication encoding and decoding controller (described encoding and decoding controller can be that IBCF also can be that encoding and decoding application server or other can be realized the functional entity of encoding and decoding control) is consulted the code/decode type notice media gateway that the code/decode type that the calling and called user supports respectively and the calling and called user that will consult to determine are again supported respectively again.

In addition, also need to illustrate, under concrete applied environment, for example, when initiation session is set up, if the session between S-CSCF anticipation calling and called user need be done encoding and decoding conversion, the session invitation message is sent to IBCF, because the local policy inspection of heterogeneous networks, may forbid that some encoding and decoding passes through, IBCF may receive successively that the network that heterogeneous networks returns do not support caller code/decode type message, then the common factor information of the code/decode type that can support according to described heterogeneous networks, the code/decode type that the calling and called user supports is respectively consulted in control again, notifies media gateway with the code/decode type that the calling and called user who consults again to determine supports respectively.

In addition, also need to illustrate, under concrete applied environment, for example, when initiation session is set up, session when between anticipation calling and called user need be done encoding and decoding conversion, the code/decode type that the calling and called user supports is respectively consulted in control, if the code/decode type of being supported that the called subscriber returns is identical with calling subscriber's support, be need not make encoding and decoding conversion between calling and called, the code/decode type notice media gateway (in such cases, the code/decode type that the calling and called user supports is identical) that the calling and called user can be supported respectively equally, media gateway is not made encoding and decoding conversion to the medium between calling and called.

Be elaborated with the process of concrete application scenarios below to encoding and decoding conversion control.

With reference to figure 5, this figure is the first specific embodiment process chart of coding/decoding conversion control method of the present invention.

The calling and called user is the IMS intra domain user in the present embodiment, but the calling and called user terminal is not supported identical code/decode type, need the IMS network that encoding and decoding conversion is provided, S-CSCF, IBCF, RACS, I-BGF by called subscriber's side in the present embodiment finish encoding and decoding conversion, and concrete handling process is as follows:

Step s201: the essential code/decode type of terminating S-CSCF anticipation called subscriber side (is codec 4 in the present embodiment, 5) code/decode type supported of the calling subscriber that SDP Offer carries in the Invite message that sends with the calling subscriber that receives (is codec 1 in the present embodiment, 2,3) compare, need not carry out encoding and decoding conversion if do not exist common factor then to judge; S-CSCF (is codec 4 in the present embodiment with the code/decode type of called subscriber's support of anticipation, 5) add (the code/decode type codec 4 that called subscriber described in the present embodiment supports in the Invite message to, the 5 expansion header field Called-Required-Codecs by Invite message carry), be transmitted to IBCF.

Carry expansion header field Called-Required-Codecs in the Invite message that step s202:IBCF discovery S-CSCF sends, judgement need be done encoding and decoding conversion, send AA request (AAR) message to RACS, carry the code/decode type codec 1 that the medium IP address ip 1 obtained and calling subscriber support in the described AAR message from the SDP of Invite message, 2,3.

Step s203:RACS is this territory and the foreign lands ID of the IP address ip 1 in the AAR message, SDP Direction, medium, and the code/decode type codec that supports of calling

subscriber

1,2,3 sends to I-BGF by Add Termination.

Step s204:I-BGF is according to this territory and the foreign lands ID of the SDP Direction in the Add Termination message, medium, the IP address ip 3 in application purpose territory returns to RACS by Reply message, preserve the code/

decode type codec

1,2,3 that IP address ip 1 and calling subscriber support simultaneously.

Step s205:RACS returns AAA message according to the IP address ip 3 that obtains to IBCF from Reply message.

Step s206:IBCF is according to the IP address ip 3 that obtains from AAA message, and the code/decode type codec 4 that supports of the called subscriber who is used for indicating the expansion header field Called-Required-Codecs that carries out encoding and decoding conversion to carry in the S-CSCF Invite message of sending, 5 revise SDP, code/decode type codec1 with calling subscriber's support, 2,3 and the code/decode type codec 4 of called support, 5

synthetic codes

1,2,3,4,5 add in the SDP message body, and delete described expansion header field Called-Required-Codecs and give the called subscriber with the Invite forwards, and the called subscriber consults to pass through, return and carry the code/decode type codec4 that the called subscriber supports, 5 1xx/2xx message.

Step s207:IBCF receives the 1xx/2xx message that the called subscriber returns, from the SDP of described 1xx/2xx message, obtain the IP address ip 2 of medium and the code/decode type codec4 that the called subscriber supports, 5, send AAR message to RACS, carry the code/decode type Codec 1 of described IP address ip 2, calling subscriber's support in the described AAR message, 2,3 and the code/decode type codec4 that supports of called subscriber, 5.

The code/decode type Codec 1 that step s208:RACS supports according to the IP address ip 2 that obtains from AAR message, SDP Direction, local this territory of medium of preserving, territory ID, calling subscriber, 2,3 and the code/decode type codec 4,5 that supports of called subscriber send Add Termination to I-BGF.

Step s209:I-BGF is according to SDP Direction that obtains from Add Termination message and local this territory of medium and the foreign lands ID that preserves, the IP address ip 4 in application purpose territory, return to RACS by Reply message, preserve the code/decode type Codec 1 that the calling subscriber supports simultaneously, 2,3 and the code/decode type codec 4,5 that supports of called subscriber.

Step s210:RACS returns AAA message according to the IPv4 address ip 4 that obtains to IBCF from Reply message.

Step s211:IBCF revises SDP message body according to the code/

decode type codec

1,2,3 of the IP address ip 4 that obtains and calling subscriber's support from AAA message, with 200 message forward pass, finally be transmitted to the calling subscriber by S-CSCF.

With reference to figure 6, this figure is the second specific embodiment process chart of coding/decoding conversion control method of the present invention.

The calling and called user is the IMS intra domain user in the present embodiment, but the calling and called terminal is not supported identical code/decode type, need the IMS network that the encoding and decoding conversion business is provided, same S-CSCF in the present embodiment by called subscriber's side, IBCF, RACS, I-BGF finishes encoding and decoding conversion, after wherein terminating S-CSCF receives that initial session is invited Invite message, judging does not need to do encoding and decoding conversion, follow-up terminating S-CSCF receives that called subscriber that called user terminal returns does not support 488/606 response message of calling subscriber's code/decode type, carried the code/decode type that the called subscriber supports in the response message, S-CSCF wherein, IBCF, RACS, I-BGF finishes the process and first specific embodiment similar (being step s302-s311) of encoding and decoding conversion, itself and the different step s301 that are of the first specific embodiment maximum, the called subscriber that terminating S-CSCF returns according to called user terminal does not support 488/606 response message of calling subscriber's code/decode type, the code/decode type that the called subscriber who carries in described 488/606 response message is supported (is codec 4 in the present embodiment, 5) add in the Called-Required-Codecs expansion header field of Invite message, be transmitted to IBCF.

With reference to figure 7, this figure is the 3rd a specific embodiment process chart of coding/decoding conversion control method of the present invention.

The calling and called user is the IMS intra domain user in the present embodiment, but the calling and called terminal does not have identical code/decode type, need the IMS network that the encoding and decoding conversion business is provided, same S-CSCF in the present embodiment by called subscriber's side, IBCF, RACS, I-BGF finishes encoding and decoding conversion, wherein IBCF successively receives 488/606 response message (having carried the code/decode type that first network allows in this response message) and second 488/606 response message (having carried the code/decode type of second network support in this response message) that network returns that first network returns, and concrete handling process is as follows:

Step s401: terminating S-CSCF judges and need carry out encoding and decoding conversion, and the code/decode type (codec 4,5) that the called subscriber of anticipation is supported adds among the expansion header field Called-Required-Codecs of Invite message, is transmitted to IBCF.

Carry expansion header field Called-Required-Codecs in the Invite message that step s402:IBCF detection discovery S-CSCF sends, judgement need be done encoding and decoding conversion, send AAR message to RACS, carry the code/decode type codec 1 that the medium IP address ip 1 obtained and calling subscriber support in the described AAR message from the SDP of Invite message, 2,3.

Code/decode type codec that step s403:RACS supports the IP address ip 1 in the AAR message, SDP Direction and calling

subscriber

1,2,3 sends to I-BGF by Add Termination.

Step s404:I-BGF is according to the IP address in the Add Termination message, this territory of SDPDirection and medium and foreign lands ID, the IP address ip 3 of the media domain in application purpose territory, return to RACS by Reply message, the code/decode type codec 1 that the calling subscriber is supported simultaneously, 2,3 preserve.

The IP address ip 3 that step s405:RACS obtains from Reply message is returned AAA message to IBCF.

Step s406:IBCF is according to the IP address ip 3 that obtains from AAA message, revise SDP message body, the code/decode type codec1 that the calling subscriber is supported simultaneously, 2,3 and the

synthetic codes

1,2 of code/decode type codec 4,5 of called support, 3,4,5 add in the SDP message body, and deletion expansion header field Called-Required-Codecs gives the called subscriber with the Invite forwards, because the local policy inspection of heterogeneous networks, may forbid that some encoding and decoding passes through, IBCF receives that 488/606 response message that first network returns (has carried the code/decode type codes2 that this first network allows, 3 in this response message, 4,5), the back receives that again 488/606 response message that second network returns (carries the code/

decode type codes

3,4 of second network support in this response message, 5,6.

Step s407:IBCF is according to the code/decode type codec2 of first network support of successively returning, 3,4, the code/decode type codec 3 of 5 and second network supports, 4,5,6

common factor codec

3,4,5 revise SDP, give the called subscriber with the message forward pass, and the called subscriber consults to pass through, return 183 message of the code/decode type codec 4,5 that carries called subscriber's support.

Obtain the IP address ip 2 of medium and the code/decode type codec 4 that the called subscriber supports the SDP of 183 message that step s408:IBCF returns from the called subscriber, 5, send AAR message to RACS, carry the code/decode type Codec1 of described IP address ip 2, calling subscriber's support in the described AAR message, 2,3 and the code/decode type codec 4,5 that supports of called subscriber.

The code/decode type codec 1 that step s409:RACS supports according to the IP address ip 2 that obtains from AAR message, SDP Direction, local this territory of medium of preserving, foreign lands ID, calling subscriber, 2,3 and the code/decode type codec4 that supports of called subscriber, 5 send Add Termination to I-BGF.

Step s410:I-BGF is according to SDP Direction that obtains from Add Termination message and local this territory of medium and the foreign lands ID that preserves, the IP address ip 4 in application purpose territory, return to RACS by Reply message, preserve the code/decode type codec 1 that the calling subscriber supports simultaneously, 2,3 and the code/decode type codec 4,5 that supports of called subscriber.

Step s411:RACS returns AAA message according to the IP address ip 4 that obtains to IBCF from Reply message.

The code/

decode type codec

1,2,3 that IP address ip 4 that step s412:IBCF basis obtains from AAA message and the calling subscriber who obtains before support revises SDP message body, with 200 message forward pass, finally is transmitted to the calling subscriber by S-CSCF.

With reference to figure 8, this figure is the 4th a specific embodiment process chart of coding/decoding conversion control method of the present invention.

The calling and called user is the IMS intra domain user in the present embodiment, but the calling and called terminal is not supported identical code/decode type, need the IMS network that the encoding and decoding conversion business is provided, S-CSCF, RACS, I-BGF by called subscriber's side in the present embodiment finish encoding and decoding conversion, and concrete handling process is as follows:

Step s501: terminating S-CSCF receives that the session that the calling subscriber sends sets up Invite message, the essential code/decode type of anticipation called subscriber side (is codec 4 in the present embodiment, 5) code/decode type supported of the calling subscriber that SDP Offer carries in the Invite message that sends with the calling subscriber that receives (is codec 1 in the present embodiment, 2,3) compare, need not carry out encoding and decoding conversion if do not exist common factor then to judge; Send AAR message to RACS, carry the code/

decode type codec

1,2,3 that the IP address ip 1 obtained and calling subscriber support in the described AAR message from Invite message SDP.

Code/decode type codec that step s502:RACS supports the IP address ip 1 in the AAR message, SDP Direction and calling

subscriber

1,2,3 sends to I-BGF by Add Termination.

Step s503:I-BGF is according to the IP address ip 1 in the Add Termination message, this territory of SDPDirection and medium and foreign lands ID, the IP address ip 3 of the media domain in application purpose territory, return to RACS by Reply message, preserve the code/decode type codec 1 that IP address ip 1 and calling subscriber support simultaneously, 2,3.

The IP address ip 3 that step s504:RACS obtains from Reply message is returned AAA message to S-CSCF.

Step s505:S-CSCF revises SDP message body according to the address ip 3 that RACS returns, simultaneously with codec 4,5 and

codec

1,2,3

synthetic codes

1,2,3,4,5 add in the SDP message body, give the called subscriber with Invite message forward pass, and the called subscriber consults to pass through, return and carry the code/decode type codec4 that the called subscriber supports, 5 1xx/2xx message.

Obtain the IP address ip 2 of medium and the code/decode type codec4 that the called subscriber supports the SDP of the 1xx/2xx message that step s506:S-CSCF returns from the called subscriber, 5, send AAR message to RACS, carry the IP address ip 2 of described medium, the code/decode type codec 1 that the calling subscriber supports in the described AAR message, 2,3 and the code/decode type codec 4,5 that supports of called subscriber.

The code/decode type codec 1 that step s507:RACS supports according to the IP address ip 2 that obtains from AAR message, SDP Direction, local this territory of medium of preserving, foreign lands ID, calling subscriber, 2,3 and the code/decode type codec 4,5 that supports of called subscriber send Add Termination to I-BGF.

Step s508:I-BGF is according to SDP Direction that obtains from Add Termination message and local this territory of medium and the foreign lands ID that preserves, the IP address ip 4 in application purpose territory, return Reply message to RACS, preserve the code/decode type codec 1 that the calling subscriber supports simultaneously, 2,3 and the code/decode type codec 4,5 that supports of called subscriber.

Step s509:RACS returns AAA message according to the IP address ip 4 that obtains to S-CSCF from Reply message.

The code/

decode type codec

1,2,3 that IP address ip 4 that step s510:S-CSCF basis obtains from AAA message and the calling subscriber who obtains before support revises SDP message body, gives the calling subscriber with 200 message forward pass.

Need illustrate, only setting up S-CSCF in the process with session in the present embodiment directly carries out encoding and decoding conversion and is controlled to be example and describes, other S-CSCF anticipations do not need to do encoding and decoding conversion, after receiving the message of not supporting calling subscriber's code/decode type that the called subscriber returns, again the scene and the present embodiment that directly carry out encoding and decoding conversion control are similar, repeat no more here.

With reference to figure 9, this figure is the 5th a specific embodiment process chart of coding/decoding control method of the present invention.

The calling and called user is the IMS intra domain user in the present embodiment, but the calling and called user terminal is not supported identical code/decode type, need the IMS network that the encoding and decoding conversion business is provided, session is set up in the process by the S-CSCF of called subscriber's side, encoding and decoding control AS, MRFC and is finished encoding and decoding conversion, specifically comprises the steps:

Step s601:S-CSCF receives and triggers the Invite message that finishes, and has carried the code/decode type that the calling subscriber supports (being

codec

1,2 in the present embodiment) among the described Invite message SDP.

The code/decode type that step s602:S-CSCF anticipation called subscriber supports (is codec3 in the present embodiment, 4), and judge whether to carry out encoding and decoding conversion, do not support identical code/decode type owing to the calling and called user in the present embodiment, S-CSCF judges need carry out encoding and decoding conversion, the expansion header field Called-Required-Codecs that the code/decode type codec 4,5 that the called subscriber of anticipation is supported adds Invite message to carries; For example, expansion header field Called-Required-Codecs:CALLED-REQUIRED; Audio-codec-list=3,4.

Step s603:S-CSCF gives described Invite forwards of carrying expansion header field Called-Required-Codecs the encoding and decoding control AS of configuration, wherein the route header field of Invite message is following form: route:Transcoding AS, next jumps network element, promptly requires message to be routed directly to next by encoding and decoding control AS and jumps network element.

Step s604: contain expansion header field Called-Required-Codecs in the Invite message that encoding and decoding control AS inspection discovery S-CSCF sends, then encoding and decoding control AS writes down this and calls out the sign for Transcoding, if type is CALLED-REQUIRED, then the code/

decode type codec

3,4 that the called subscriber in the Called-Required-Codecs header field is supported adds among the SDP Offer of Inivite message.

Step s605: the expansion header field of encoding and decoding control AS deletion Invite message, with

codec

3,4 and codec1,2

synthetic codes

1,2,3,4 add in the SDP message body, give the called subscriber according to the Route header field with the Invite forwards.

Step s606: after the called subscriber consulted to pass through, the code/

decode type codec

3,4 that the called subscriber is supported returned to encoding and decoding control AS.

Step s607: the code/

decode type codec

3,4 that code/

decode type codec

1,2 that encoding and decoding control AS supports according to the calling subscriber and called subscriber support set up by MRFC and calling and called between encoding and decoding conversion.

Step s608: it is same as the prior art that subsequent session is set up flow process, repeats no more here.

Need illustrate, only setting up S-CSCF in the process with session in the present embodiment inserts encoding and decoding control AS and carries out encoding and decoding conversion and be controlled to be example and describe, other S-CSCF anticipations do not need to do encoding and decoding conversion, after receiving the message of not supporting calling subscriber's code/decode type that the called subscriber returns, again the scene and the present embodiment that insert encoding and decoding control AS negotiation carrying out encoding and decoding conversion control are similar, repeat no more here.

Need illustrate, above-mentioned coding/decoding conversion control method both can carry out encoding and decoding conversion control in the IMS territory, also can be between the IMS territory or other scenes carry out encoding and decoding conversion, for example, with reference to Figure 10, caller IMS network can provide the encoding and decoding conversion business, the calling and called user is IMS user, but the calling and called user is not in same IMS territory, and the calling and called user terminal does not have identical code/decode type, caller IMS network can provide the encoding and decoding conversion business, and the called IMS network can not provide the encoding and decoding conversion business.Under this scene, caller IMS network can provide the scene of encoding and decoding control in encoding and decoding conversion business and the previously described IMS territory similar, specifically with reference to above stated specification, repeats no more here.

Perhaps, with reference to Figure 11, the called IMS network can provide the encoding and decoding conversion business, the calling and called user is IMS user, but the calling and called user is not in same IMS territory, and the calling and called user terminal does not have identical code/decode type, and caller IMS network can not provide the encoding and decoding conversion business, and the called IMS network can provide the encoding and decoding conversion business.Under this scene, the called IMS network can provide the scene of encoding and decoding control in encoding and decoding conversion business and the previously described IMS territory similar, specifically with reference to above stated specification, repeats no more here.

Perhaps, with reference to Figure 12, IMS user is caller, the non-IMS SIP network user is called, when IMS user and non-IMS SIP network user intercommunication, IMS user is caller, and the non-IMS SIP network user is called, and the calling and called user terminal does not have identical code/decode type, needs the IMS network that the encoding and decoding conversion business is provided.Under this scene, the IMS network provides the scene of encoding and decoding control in encoding and decoding conversion business and the previously described IMS territory similar, specifically with reference to above stated specification, repeats no more here.

Perhaps, with reference to Figure 13, IMS user is called, the non-IMS SIP network user is caller, when IMS user and non-IMS SIP network user intercommunication, IMS user is called, and the non-IMS SIP network user is caller, and the calling and called user terminal does not have identical code/decode type, needs the IMS network that the encoding and decoding conversion business is provided.Under this scene, the IMS network provides the scene of encoding and decoding control in encoding and decoding conversion business and the previously described IMS territory similar, specifically with reference to above stated specification, repeats no more here.

Perhaps, with reference to Figure 14, IMS user is caller, H.323 the IP network user of network or other non-SIP is called, IMS user and H.323 IP network user's intercommunication of network or other non-SIP, IMS user is caller, H.323 the IP network user of network or other non-SIP is called, and the calling and called user terminal does not have identical code/decode type, needs the IMS network that the encoding and decoding conversion business is provided.Under this scene, the IMS network provides the scene of encoding and decoding control in encoding and decoding conversion business and the previously described IMS territory similar, specifically with reference to above stated specification, repeats no more here.

Perhaps, with reference to Figure 15, IMS user is called, H.323 the IP network user of network or other non-SIP is caller, IMS user and H.323 IP network user's intercommunication of network or other non-SIP, IMS user is called, H.323 the IP network user of network or other non-SIP is caller, and the calling and called user terminal does not have identical code/decode type, needs the IMS network that the encoding and decoding conversion business is provided.Under this scene, the IMS network provides the scene of encoding and decoding control in encoding and decoding conversion business and the previously described IMS territory similar, specifically with reference to above stated specification, repeats no more here.

Perhaps, with reference to Figure 16, IMS user is called, the CS territory user of PSTN/ISDN user or PLMN is caller, CS territory user's intercommunication of IMS user and PSTN/ISDN user or PLMN, IMS user is called, the CS territory user of PSTN/ISDN user or PLMN is caller, and the calling and called user terminal does not have identical code/decode type, needs the IMS network that the encoding and decoding conversion business is provided.Under this scene, the IMS network provides the scene of encoding and decoding control in encoding and decoding conversion business and the previously described IMS territory similar, specifically with reference to above stated specification, repeats no more here.

Perhaps, with reference to Figure 17, caller is the CS territory user of PSTN/ISDN user or PLMN, through the IMS junction network, called is IMS or non-IMS SIP or other IP network user, the IMS network is as junction network, caller is the CS territory user of PSTN/ISDN user or PLMN, through the IMS junction network, called is IMS or non-IMS SIP or other IP network user, provide the encoding and decoding conversion business by called IMS or non-IMS SIP or other IP network, wherein can provide the encoding and decoding conversion business with reference to the called IMS network, repeat no more here for called scene for IMS user.

The following describes explanation on the other hand.

With reference to Figure 18, this figure is the first specific embodiment structural representation of IMS of the present invention system.

The entity that the IMS system relates to encoding and decoding conversion control in the present embodiment mainly includes S-CSCF 1 and IBCF 2, and wherein said S-CSCF 1 can include:

Anticipation processing unit 11, the processing unit of anticipation described in the present embodiment 11 are mainly used in the code/decode type that the anticipation called subscriber supports, concrete anticipation mode can repeat no more here with reference to above stated specification;

Encoding and decoding conversion judgment processing unit 12, the conversion of decoding described in present embodiment judgment processing unit 12 is mainly used in according to the code/decode type of called subscriber's support of described anticipation processing unit 11 anticipations and the code/decode type that the calling subscriber supports judges whether the session between the calling and called user need carry out encoding and decoding conversion, when promptly there is not common factor in the code/decode type supported of the code/decode type of supporting the calling subscriber and called subscriber, judgement need be carried out encoding and decoding conversion, indication IBCF 2 carries out encoding and decoding conversion control, indicating mode can adopt in S-CSCF 1 and IBCF 2 interactive messages by expansion header field (for example Called-Required-Codecs) sign, specifically can be with reference to above stated specification, here repeat no more, in addition, when there is common factor in the code/decode type that the code/decode type that described encoding and decoding conversion judgment processing unit 12 is supported the calling subscriber and called subscriber support, can not judge and need carry out encoding and decoding conversion that indication continues session and handles.

During specific implementation, described S-CSCF 1 also can comprise message parse processing

unit

13,12 judgements need not carried out encoding and decoding conversion in described encoding and decoding conversion judgment processing unit, after continuing the session processing, if receive that called subscriber equipment returns the called subscriber and do not support caller code/decode type message, then indicate encoding and decoding controller (present embodiment is IBCF) to carry out encoding and decoding conversion control, described IBCF carries out encoding and decoding conversion control and can repeat no more here with reference to above stated specification.

And described IBCF 2 can include:

Control unit 21 is consulted in media conversion, and media conversion described in the present embodiment is consulted control unit 21 and is mainly used in the code/decode type that control negotiation calling and called user supports respectively;

Media conversion indicating member 22, the indicating member of media conversion described in the present embodiment 22 are mainly used in will consult the code/decode type notice media gateway that definite calling and called user supports respectively.

With reference to Figure 19, this figure is the second specific embodiment structural representation of IMS of the present invention system.

What the IMS system related to encoding and decoding conversion control in the present embodiment mainly includes S-CSCF 1, the encoding and decoding control AS 3 that also comprises separate functional unit in the described in addition IMS system, be used to control media gateway and carry out encoding and decoding conversion, encoding and decoding control AS 3 control media gateway are carried out encoding and decoding conversion and can be repeated no more here with reference to prior art;

Wherein said S-CSCF 1 includes:

Anticipation processing unit 21, the processing unit of anticipation described in the present embodiment 21 are mainly used in the code/decode type that the anticipation called subscriber supports, concrete anticipation mode can repeat no more here with reference to above stated specification;

Encoding and decoding conversion judgment processing unit 22, the code/decode type that code/decode type that the judgment processing of encoding and decoding conversion described in present embodiment unit 22 is mainly supported according to the called subscriber of described anticipation processing unit 21 anticipations and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion, if existing, the code/decode type that code/decode type that the calling subscriber supports and called subscriber support occurs simultaneously, then judge and need not carry out encoding and decoding conversion, continue session and handle; If there is not common factor in the code/decode type that code/decode type that the calling subscriber supports and called subscriber support, judge then and need carry out encoding and decoding conversion that indication encoding and decoding control AS 3 carries out encoding and decoding conversion control.

In addition, described S-CSCF 1 also can comprise:

Message parse processing unit 23, the processing unit of message parse described in the present embodiment 23 is mainly used in encoding and decoding conversion judgment processing unit 22 and judges and need not carry out encoding and decoding conversion, after continuing the session processing, if receive that called subscriber equipment returns the called subscriber and do not support caller code/decode type message, then indicate encoding and decoding controller (being encoding and decoding control AS 3 in the present embodiment) to carry out encoding and decoding conversion control.

With reference to Figure 20, this figure is the 3rd a specific embodiment structural representation of IMS of the present invention system.

The entity that the IMS system relates to encoding and decoding conversion control in the present embodiment mainly includes IBCF 2, and wherein said IBCF 2 includes:

Anticipation processing unit 31, the processing unit of anticipation described in the present embodiment 31 are mainly used in the code/decode type that the anticipation called subscriber supports, concrete anticipation mode can repeat no more here with reference to above stated specification;

Control unit 32 is consulted in media conversion, and media conversion described in the present embodiment is consulted control unit 32 and is mainly used in the code/decode type that control negotiation calling and called user supports respectively;

Media conversion indicating member 33, the indicating member of media conversion described in the present embodiment 33 are mainly used in will consult the code/decode type notice media gateway that definite calling and called user supports respectively;

Encoding and decoding conversion judgment processing unit 34, the code/decode type that code/decode type that the judgment processing of encoding and decoding conversion described in present embodiment unit 34 is mainly supported according to the called subscriber of described anticipation processing unit 31 anticipations and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion, if existing, the code/decode type that code/decode type that the calling subscriber supports and called subscriber support occurs simultaneously, then judge and need not carry out encoding and decoding conversion, continue session and handle; If there is not common factor in the code/decode type that code/decode type that the calling subscriber supports and called subscriber support, then judge and need carry out encoding and decoding conversion, indicate described media conversion to consult control unit 32 controls and consult the code/decode type that the calling and called user supports respectively.

In addition, described IBCF 2 also can comprise:

Message parse processing unit 35, the processing unit of message parse described in the present embodiment 35 is mainly used in is successively receiving that network and called subscriber equipment return the called subscriber and do not support caller code/decode type message, then indicates media conversion to consult control unit control and consults the code/decode type that the calling and called user supports respectively again.

With reference to Figure 21, this figure is the 4th a specific embodiment structural representation of IMS of the present invention system.

The entity that the IMS system relates to encoding and decoding conversion control in the present embodiment mainly includes S-CSCF 1, and wherein said S-CSCF 1 includes:

Anticipation processing unit 41 is used for the code/decode type that the anticipation called subscriber supports, concrete anticipation mode can repeat no more here with reference to above stated specification;

Control unit 42 is consulted in media conversion, is used to control the code/decode type that negotiation calling and called user supports respectively;

Media conversion indicating member 43 is notified media gateway with the code/decode type that the calling and called user who consults to determine supports respectively;

Encoding and decoding conversion judgment processing unit 44, the code/decode type that code/decode type of supporting according to the called subscriber of described anticipation processing unit anticipation and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion, if existing, the code/decode type that code/decode type that the calling subscriber supports and called subscriber support occurs simultaneously, then judge and need not carry out encoding and decoding conversion, continue session and handle; If there is not common factor in the code/decode type that code/decode type that the calling subscriber supports and called subscriber support, judge then and need carry out encoding and decoding conversion that the indication media conversion is consulted control unit 42 controls and consulted the code/decode type that the calling and called user supports respectively.

In addition, S-CSCF 1 also can comprise:

Message parse processing unit 45, need not carry out encoding and decoding conversion in described encoding and decoding conversion judgment processing unit judges, after continuing the session processing, if receive that the called subscriber that called subscriber equipment returns does not support caller code/decode type message, then indicate media conversion to consult control unit control and consult the code/decode type that the calling and called user supports respectively again.

The above only is the specific embodiment of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims

1, a kind of service call session control function entity is characterized in that, includes:

2, service call session control function entity according to claim 1 is characterized in that, also comprises:

The message parse processing unit, need not carry out encoding and decoding conversion in encoding and decoding conversion judgment processing unit judges, after continuing the session processing,, then indicate the encoding and decoding controller to carry out encoding and decoding conversion control if receive that called subscriber equipment returns the called subscriber and do not support caller code/decode type message.

3, a kind of Interconnection Border Control Function entity is characterized in that, includes:

4, Interconnection Border Control Function entity according to claim 3 is characterized in that, also comprises:

Encoding and decoding conversion judgment processing unit, the code/decode type that code/decode type of supporting according to the called subscriber of described anticipation processing unit anticipation and calling subscriber support judges whether the session between the calling and called user need carry out encoding and decoding conversion, when there is not common factor in the code/decode type that the code/decode type of supporting the calling subscriber and the called subscriber of described anticipation support, judgement need be carried out encoding and decoding conversion, and the indication media conversion is consulted control unit control and consulted the code/decode type that the calling and called user supports respectively.

5, Interconnection Border Control Function entity according to claim 4 is characterized in that, also comprises:

The message parse processing unit if successively receive that network and called subscriber equipment return the called subscriber and do not support caller code/decode type message, is then indicated media conversion to consult control unit control and is consulted the code/decode type that the calling and called user supports respectively again.

6, a kind of IP Multimedia System comprises service call session control function entity and Interconnection Border Control Function entity, it is characterized in that, described Interconnection Border Control Function entity includes:

Described service call session control function entity includes:

7, a kind of IP Multimedia System includes service call session control function entity, it is characterized in that, described IP Multimedia System comprises the encoding and decoding control application server of separate functional unit, is used to control media gateway and carries out encoding and decoding conversion;

Described service call session control function entity includes:

8, a kind of IP Multimedia System includes the Interconnection Border Control Function entity, it is characterized in that, described Interconnection Border Control Function entity includes:

9, a kind of service call session control function entity is characterized in that, includes:

10, service call session control function entity according to claim 9 is characterized in that, also comprises:

The message parse processing unit, need not carry out encoding and decoding conversion in described encoding and decoding conversion judgment processing unit judges, after continuing the session processing, if receive that the called subscriber that called subscriber equipment returns does not support caller code/decode type message, then indicate media conversion to consult control unit control and consult the code/decode type that the calling and called user supports respectively again.

11, a kind of IP Multimedia System includes service call session control function entity, it is characterized in that, described service call session control function entity includes:

12, a kind of coding/decoding conversion control method is characterized in that, comprising:

The code/decode type that the anticipation called subscriber supports;

13, coding/decoding conversion control method according to claim 12 is characterized in that, the code/decode type that described anticipation called subscriber supports in the following way:

Judge the code encoding/decoding mode that the called subscriber supports according to called subscriber place network type; Or

Code encoding/decoding mode according to called subscriber place access network type decision called subscriber support; Or

IP Multimedia System log-on message according to the called subscriber is judged the code encoding/decoding mode that the called subscriber supports.

14, coding/decoding conversion control method according to claim 12, it is characterized in that, by the code/decode type of service call session control function entity anticipation called subscriber support, also will consult the code/decode type notice media gateway that definite calling and called user supports respectively by the code/decode type that service call session control function entity indication Interconnection Border Control Function entity control negotiation calling and called user supports respectively.

15, coding/decoding conversion control method according to claim 12, it is characterized in that, by the code/decode type of service call session control function entity anticipation called subscriber support, also will consult the code/decode type notice media gateway that definite calling and called user supports respectively by the code/decode type that service call session control function entity indication encoding and decoding control application server controls negotiation calling and called user supports respectively.

16, coding/decoding conversion control method according to claim 12, it is characterized in that, by the code/decode type that Interconnection Border Control Function entity anticipation called subscriber supports, also will consult the code/decode type notice media gateway that definite calling and called user supports respectively by the code/decode type that Interconnection Border Control Function entity control negotiation calling and called user supports respectively.

17, coding/decoding conversion control method according to claim 12, it is characterized in that, by the code/decode type that service call session control function entity anticipation called subscriber supports, also will consult the code/decode type notice media gateway that definite calling and called user supports respectively by the code/decode type that service call session control function entity control negotiation calling and called user supports respectively.

18, a kind of coding/decoding conversion control method is characterized in that, comprising:

19, a kind of coding/decoding conversion control method is characterized in that, comprising:

20, coding/decoding conversion control method according to claim 19 is characterized in that, described encoding and decoding controller is Interconnection Border Control Function entity or encoding and decoding control application server.

21, a kind of coding/decoding conversion control method is characterized in that, comprising: