CN101815270B

CN101815270B - Processing method and device for calling

Info

Publication number: CN101815270B
Application number: CN201010128281.0A
Authority: CN
Inventors: 杨强; 王忱; 唐飞
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2010-03-05
Filing date: 2010-03-05
Publication date: 2014-04-09
Anticipated expiration: 2030-03-05
Also published as: CN101815270A; WO2011107001A1

Abstract

The invention discloses processing method and device for calling. In the method, a network element receives a call request which carries a call waiting service identifier from a service-call session control functional entity (S-CSCF) or an application server (AS), wherein the identifier is used for indicating whether the called subscriber of the call request supports the call waiting service or not; the network element determines whether to trigger the call waiting service of the called subscriber or not according to the identifier and the state information of the called subscriber; and the network element replies a call failure response to the S-CSCF or the AS when not to trigger the call waiting service of the called subscriber is determined; and otherwise, the network element triggers the call waiting service of the called subscriber. By the invention, the network processing performance and efficiency are improved.

Description

Processing method and the device called out

Technical field

The present invention relates to the communications field, relate in particular to a kind of processing method and device of calling.

Background technology

IP Multimedia System (IP Multimedia Core Network Subsystem, referred to as IMS) be by third generation partner program (3rd Generation PartnershipProject, referred to as 3GPP) a kind of IP-based network architecture that proposes of tissue, built an opening and service environment flexibly, support multimedia application, and provide abundant multimedia service for user.

Public switched telephone network/integrated services digital network simulation subsystem (Public SwitchedTelephone Network/Integrated Services Digital,, PSTN/ISDNEmulation Subsystem, referred to as PES) be telecommunications and the Internet converged services and a kind of IP-based network architecture of high-level network protocol (Telecommunications and Internet converged Services andProtocols for Advanced Networking, referred to as TISPAN) to the proposition of conventional terminal access to IMS network.

European telecommunications standards institute (European Telecommunication StandardsInstitute, referred to as ETSI) 183 043 for legacy user (for example, H.248 user), ETSI 183 0436 defines respectively for the call waiting of IMS network for isdn user, 3GPP TS 24.615, and has relevant realization flow.The purposes of this call waiting is in the situation that user is busy, allows new calling incoming call.As for select with the user's communication of new incoming call or with the user's communication that enters conversation state, by call waiting user, with associative operation, selected to determine.

ETSI 183 043, the principle that in ETSI 183 0436, call waiting is realized is: application server (Application Server, referred to as AS) can not judge (or, some AS does not have ability judgement) whether user in busy condition, and calling is mail to AGCF (Access Gateway Control Function, referred to as AGCF), Proxy Call Session Control Function (Proxy-Call Session Control Function, referred to as P-CSCF), the voice transfer gateway of IP based network (Voice over InternetProtocol, it is voip gateway, referred to as VGW), ISDN terminal or conversation initialized protocol (Session Initiation Protocol, referred to as SIP) terminal, and judge whether available free terminal by these network elements.For example, AGCF with H.248 user in busy condition and while allowing it to use fork spring business, realize Call Waiting flow process (for example, put stand by tone to H.248 user, user can hooking carries out Call Transfer etc.); User in busy condition and while not allowing it to use fork spring business, by AGCF to service call conversation control function (Serving-Call Session Control Function, referred to as S-CSCF) the busy failure response (for example, 486 message) of transmission user.If user has divert when busy business, S-CSCF/AS, after receiving 486 message, triggers divert when busy business.

Fig. 1 is that as shown in Figure 1, this flow process mainly comprises following processing (step S101-step S107) according to the called subscriber busy of the AGCF band of correlation technique and the call flow diagram of not support call latency services:

Step S101, user terminal A, user terminal B enter talking state.

Step S102, the user terminal C caller party terminal A of IMS network, the network elements such as S-CSCF by user terminal C place are sent out session invitation to the AS/S-CSCF at user terminal A place.

Step S103, the AS/S-CSCF at user terminal A place sends out session invitation to the AGCF at user terminal A place.

Step S104, AGCF, in the situation that confirming user in busy condition and supporting hook switch operation, is put stand by tone to user terminal A.

Step S105, when putting stand by tone to user terminal A, (for example return ring response message to the AS/S-CSCF at user terminal A place, 180 message), and in ring response message, carry Call Waiting sign (for example, carrying Alert-Info:urn:service:call-waiting in 180 message).

Step S106, AS/S-CSCF receives after the ring response message with Call Waiting sign, can be according to the business information of user's registration, learn that user can not use call waiting, so the network elements such as S-CSCF by user terminal C place are sent out failure response message to user terminal C, to remove the AS of user terminal C establishment and the session between user terminal C.

Step S107, AS/S-CSCF, when sending out failure response to user terminal C, sends out release message to the AGCF at user terminal A place, to discharge the AS that created by user terminal C and the A-C session between AGCF.

That is to say, realize AS and judge in calling, whether triggered Call Waiting flow process and done corresponding processing, just necessarily having required AGCF must carry the information that AGCF triggers call waiting in 180 message of replying or other Temporary Response message according to the ring response message received.Otherwise, S-CSCF or AS cannot learn that whether user is in busy condition, will allow and originally not have the AGCF user of call waiting to use call waiting (, do not have to process according to user's expectation, but force user to use call waiting, and then cannot realize user's divert when busy or the requirement of call release).

And, even in the situation that carried the information that AGCF triggers call waiting in 180 message that AGCF returns or other Temporary Response message, also still require S-CSCF or AS after receiving this message, do special processing.For example, initiate to discharge or divert when busy flow process, this does not conform to the general processing to 18x Temporary Response message.

Fig. 1 just take that to be with H.248 agreement user under AGCF be example, brief description correlation technique because of AGCF erroneous trigger Call Waiting flow process, and the inconvenience of bringing to the subsequent treatment of AGCF and AS.For example, whether AS, when receiving the ring response message identifying with Call Waiting, need to have call waiting to do different call flows in conjunction with user and control; And may trigger wrong customer service (for example, putting stand by tone to user).If clapped immediately hook switch after user hears stand by tone, can produce more, not expected flow process controls (for example, media switching etc.).In existing standard and technology, H.248 there is above defect and deficiency with the user of other type in that not only for AGCF, is with, and, for ISDN, MGCP (Media Gateway Control Protocol, referred to as MGCP), the various users under P-CSCF/VGW have similar defect too, do not repeat them here.

Therefore, due to correlation technique AGCF/P-CSCF not recording user whether have call waiting, and AS or I/S-CSCF can not (for example carry out in the situation of effectively judgement user's busy-idle condition, by AGCF, access the corresponding a plurality of D passages of an ISDN number and B passage or the T1/E1 of IMS network), cannot realize the priority of user's divert when busy and call waiting is effectively processed, so that may allow user's use call waiting of going beyond one's commission, or bring user undesirable business service.If adopt the modes such as subscription to allow AGCF/P-CSCF obtain user's the business information such as Call Waiting, AGCF/P-CSCF can record more business information as AGCF so, and, for the obtaining and upgrade of business, also need some functions of the extra support of AGCF/P-CSCF or interacting message.

Summary of the invention

Main purpose of the present invention is to provide a kind of processing scheme of calling, at least one of to address the above problem.

To achieve these goals, according to an aspect of the present invention, provide a kind of processing method of calling.

According to the processing method of calling of the present invention, comprise the following steps: network element receives from the call request that carries call waiting sign of service call session control function entity S-CSCF or application server AS transmission, whether the called subscriber that wherein, this sign is used to indicate call request support call latency services; Network element determines whether to trigger called subscriber's call waiting according to this sign and called subscriber's state information; And in the situation that determine the call waiting do not trigger called subscriber, to S-CSCF or AS callback failure response; Otherwise, triggering called subscriber's call waiting.

Preferably, according to this sign and called subscriber's state information, determine whether that the call waiting that triggers called subscriber comprises: in the situation that this service state that is designated support call latency services and called subscriber is busy, determine the call waiting that triggers called subscriber.

Preferably, according to this sign and called subscriber's state information, determine whether that the call waiting that triggers called subscriber comprises: in the situation that this is designated not support call latency services, determine the call waiting that does not trigger called subscriber.

Preferably, triggering called subscriber's call waiting comprises: in the situation that network element is access gateway control function entity AGCF, to called subscriber, send stand by tone.

Preferably, triggering called subscriber's call waiting also comprises: in the situation that network element is proxy call conversation control function entity P-CSCF, to called subscriber, send call request, called subscriber returns to ring and responds to P-CSCF.

Preferably, after triggering called subscriber's call waiting, said method also comprises: the transmit leg to call request returns ring response message, wherein, carries this sign in ring response message.

Preferably, network element below one of at least: the voice transfer gateway VGW of AGCF, P-CSCF, IP based network, Session initiation protocol SIP terminal.

To achieve these goals, according to a further aspect in the invention, provide a kind of AGCF.

According to AGCF of the present invention, comprising: receiver module, for receiving the call request of the sign that carries call waiting sending from S-CSCF or AS, wherein, whether the called subscriber that this sign is used to indicate call request support call latency services; Determination module, for determining whether to trigger called subscriber's call waiting according to this sign and called subscriber's state information; And processing module, for be designated not support call latency services at this in the situation that, to S-CSCF or AS callback failure response; In the situation that this service state that is designated support call latency services and called subscriber is busy, to called subscriber, send stand by tone.

Preferably, determination module, in the situation that being designated not support call latency services, is determined the call waiting that does not trigger called subscriber; In the situation that be designated support call latency services and called subscriber's service state, be busy, determine the call waiting that triggers called subscriber.

To achieve these goals, according to a further aspect in the invention, provide a kind of P-CSCF.

According to P-CSCF of the present invention, comprise: receiver module, for receiving from the call request that carries call waiting sign of service call session control function entity S-CSCF or application server AS transmission, whether the called subscriber that wherein, sign is used to indicate call request support call latency services; Determination module, for determining whether to trigger called subscriber's call waiting according to this sign and called subscriber's state information; And processing module, in the situation that determine the call waiting do not trigger called subscriber, to S-CSCF or AS callback failure response; Otherwise, to called subscriber, send call request.

Preferably, determination module, in the situation that this is designated not support call latency services, is determined the call waiting that does not trigger called subscriber; In the situation that this service state that is designated support call latency services and called subscriber is busy, determine the call waiting that triggers called subscriber.

By the present invention, the mode of call waiting sign is carried in employing in call request, having solved AGCF/P-CSCF in correlation technique does not have recording user whether to open the information of call waiting and causes the problem of system to the mistake processing of call flow, has improved network processes performance and efficiency.

Accompanying drawing explanation

Accompanying drawing described herein is used to provide a further understanding of the present invention, forms the application's a part, and schematic description and description of the present invention is used for explaining the present invention, does not form inappropriate limitation of the present invention.In the accompanying drawings:

Fig. 1 is according to the called subscriber busy of the AGCF band of correlation technique and the call flow diagram of not support call latency services;

Fig. 2 is according to the flow chart of the processing method of the calling of the embodiment of the present invention;

Fig. 3 is according to the structured flowchart of the AGCF of the embodiment of the present invention;

Fig. 4 is according to the structured flowchart of the P-CSCF of the embodiment of the present invention;

Fig. 5 is according to the called subscriber busy of the AGCF band of the preferred embodiment of the present invention one and the call flow diagram of not support call latency services;

Fig. 6 is according to the called subscriber busy of the AGCF band of the preferred embodiment of the present invention two and the call flow diagram of support call latency services;

Fig. 7 is according to the VGW of the P-CSCF band of the preferred embodiment of the present invention three or the flow chart of sip terminal Call Waiting.

Embodiment

Hereinafter with reference to accompanying drawing, also describe the present invention in detail in conjunction with the embodiments.It should be noted that, in the situation that not conflicting, embodiment and the feature in embodiment in the application can combine mutually.

In the present embodiment, provide a kind of processing method of calling, Fig. 2 is according to the flow chart of the processing method of the calling of the embodiment of the present invention, and as shown in Figure 2, the method comprises the following steps:

Step S202, network element receives the call request that carries call waiting sign sending from S-CSCF or AS, and wherein, whether the called subscriber that this sign is used to indicate call request support call latency services.

Step S204, said network element determines whether to trigger called subscriber's call waiting according to this sign and called subscriber's state information.Wherein, called subscriber's state information refers to this user's service state, that is, and and " free time " or " hurrying " etc.

Step S206, in the situation that determine the call waiting do not trigger called subscriber, to described S-CSCF or described AS callback failure response; Otherwise, triggering called subscriber's call waiting.

By above-mentioned steps S202 to step S206, the mode of call waiting sign is carried in employing in call request, (for example on AGCF/P-CSCF, realize terminal, H.248 and ISDN terminal) call waiting, having solved AGCF/P-CSCF in correlation technique does not have recording user whether to open the information of call waiting and causes the problem of system to the mistake processing of call flow, make system can be better compatible with busy call business, strengthen the adaptive capacity to call flow business, improved network processes performance and efficiency.

Before step S202, can to AGCF/P-CSCF, be made a call by S-CSCF or AS, and when calling out, carry call waiting indication.

Preferably, in step S204, in the situation that this service state that is designated support call latency services and called subscriber is busy, determine the call waiting that triggers called subscriber.Thereby improved the practicality of system.

In addition, in the situation that this is designated not support call latency services, determine the call waiting that does not trigger called subscriber.For example, the INVITE of supporting for noncall latency services, if user is busy, gives CSCF reuse family busy failure response message (for example, 486 message).The method has improved the control function of call flow and the disposal ability of system, has increased user's experience.

Preferably, in step S206, the call waiting that triggers called subscriber can comprise: in the situation that said network element is AGCF, to called subscriber, send stand by tone; In the situation that said network element is P-CSCF, to called subscriber, send call request, called subscriber returns to ring and responds to P-CSCF.So the method can improve the adaptive capacity of system, strengthened the flexibility of system.

Preferably, after step S206, to the transmit leg of call request, return ring response message, wherein, in ring response message, carry this sign, so that network element is identified which user in which group and by registration, improved the performance that call flow is controlled.

It should be noted that, said network element can be following one of at least: AGCF, P-CSCF, VGW, sip terminal.That is, the embodiment of the present invention is not only applicable to AGCF/P-CSCF, is applicable to too VGW or common sip terminal.

Corresponding to above-mentioned method, a kind of AGCF is also provided in the present embodiment, and Fig. 3 is according to the structured flowchart of the AGCF of the embodiment of the present invention, as shown in Figure 3, this AGCF comprises: receiver module 302, determination module 304, processing module 306, be elaborated to this structure below.

Receiver module 302, for receiving the call request that carries call waiting sign sending from S-CSCF or AS, wherein, whether the called subscriber that this sign is used to indicate call request support call latency services; Determination module 304 is connected to receiver module 302, for determine whether to trigger called subscriber's call waiting according to this sign and called subscriber's state information; And processing module 306 is connected to determination module 304, for be designated not support call latency services at this in the situation that, to S-CSCF or AS callback failure response; In the situation that this service state that is designated support call latency services and called subscriber is busy, to called subscriber, send stand by tone.

Preferably, determination module 304, in the situation that this is designated not support call latency services, is determined the call waiting that does not trigger called subscriber; In the situation that this service state that is designated support call latency services and called subscriber is busy, determine the call waiting that triggers called subscriber.

By above-mentioned AGCF, this embodiment adopts the mode of carrying call waiting sign in call request, overcome ISDN or other types user and cannot judge whether the defect in busy condition by S-CSCF or AS, strengthen the adaptive capacity to call flow business, improved network processes performance and efficiency.

Corresponding to above-mentioned method, a kind of P-CSCF is also provided in the present embodiment, and Fig. 4 is according to the structured flowchart of the P-CSCF of the embodiment of the present invention, as shown in Figure 4, this P-CSCF comprises: receiver module 402, determination module 404, processing module 406, be elaborated to this structure below.

Receiver module 402, for receiving the call request that carries call waiting sign sending from S-CSCF or AS, wherein, whether the called subscriber that this sign is used to indicate call request support call latency services; Determination module 404 is connected to receiver module 402, for determine whether to trigger called subscriber's call waiting according to this sign and called subscriber's state information; And processing module 406 is connected to determination module 404, in the situation that determine the call waiting that does not trigger called subscriber, to S-CSCF or AS callback failure response; Otherwise, to called subscriber, send call request.

Preferably, determination module 404, in the situation that this is designated not support call latency services, is determined the call waiting that does not trigger called subscriber; In the situation that this service state that is designated support call latency services and called subscriber is busy, determine the call waiting that triggers called subscriber.

By above-mentioned P-CSCF, this embodiment adopts the mode of carrying call waiting sign in call request, business information is stored in to S-CSCF/AS, make at AGCF/P-CSCF not under the prerequisite of the business information such as recording user Call Waiting, call waiting can be compatible with busy call business better, improved network processes performance and efficiency.

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are described, should be appreciated that preferred embodiment described herein, only for description and interpretation the present invention, is not intended to limit the present invention.

Preferred embodiment one

In this preferred embodiment, the user of the not support call latency services under AGCF has mainly been described in a session, there is again new calling incoming call, the call flow of the system in new calling when called, Fig. 5 is according to the called subscriber busy of the AGCF band of the preferred embodiment of the present invention one and the call flow diagram of not support call latency services, as shown in Figure 5, comprise the following steps:

Step S501, user terminal A, user terminal B enter talking state.

Step S502, the user terminal C calling party A of IMS network, the network elements such as S-CSCF by user terminal C place are sent out session invitation to the AS/S-CSCF at user terminal A place.

Step S503, the AS/S-CSCF at user terminal A place sends out session invitation to the AGCF at user terminal A place.In sending to the session invitation message of AGCF, (or divert when busy business is registered and activated to user terminal A with user terminal A, there is no call waiting, and in the high situation of the priority of the priority ratio call waiting of divert when busy business) be foundation, carry the sign that there is no call waiting, with notice AGCF, user terminal A cannot be used call waiting.

Step S504, AGCF is judging that user is in busy condition, but, due in the session invitation message of receiving identifying subscriber terminal A cannot use call waiting, for example, so AGCF returns the busy failure response message (, 486 message in Session Initiation Protocol) causing because of party A-subscriber to the AS/S-CSCF at party A-subscriber place.

Follow-up flow process, according to existing techniques in realizing (for example, step S505, the AS/S-CSCF at party A-subscriber place is after receiving the failure response message causing because party A-subscriber is busy of AGCF, if user is registration or activation divert when busy business not, by the network elements such as S-CSCF at user terminal C place, to user terminal C, send out failure response message; If party A-subscriber registers and activate divert when busy business, trigger divert when busy flow process).

Preferred embodiment two

In this preferred embodiment, the user of the support call latency services under AGCF has mainly been described in a session, there is again new calling incoming call, the call flow of the system in new calling when called, Fig. 6 is according to the called subscriber busy of the AGCF band of the preferred embodiment of the present invention two and the call flow diagram of support call latency services, comprises the following steps:

Step S601, user terminal A, user terminal B enter talking state.

Step S602, the user terminal C caller party terminal A of IMS network, the network elements such as S-CSCF by user terminal C place are sent out session invitation to the AS/S-CSCF at party A-subscriber place.

Step S603, the AS/S-CSCF at user terminal A place sends out session invitation to the AGCF at user terminal A place.Simultaneously, (and user terminal A does not activate divert when busy business with user terminal A, to have call waiting, or the priority of the priority ratio divert when busy business of call waiting is high) be foundation, in issuing the session invitation message of AGCF, carry call waiting sign, with notice AGCF, user terminal A can be used call waiting.

Step S604, AGCF judgement user in busy condition, still, due in the session invitation message of receiving identifying subscriber terminal A can use call waiting, to user, put stand by tone.

Step S605, when putting stand by tone to user, (for example return ring response message to the AS/S-CSCF at party A-subscriber place, 180 message), and carry Call Waiting sign (for example, carrying Alert-Info:urn:service:call-waiting in 180 message) at ring response message.

Step S606, by the ring response message of receiving, the S-CSCF by user C place is transmitted to user C to AS/S-CSCF.AS/S-CSCF, when forwarding ring response message, can, according to the Call Waiting sign in message, put holding tone to user C.The flow process of follow-up relevant call waiting, existing standard and technology, do not describe at this.

Preferred embodiment three

In this preferred embodiment, the VGW of P-CSCF band, the Call Waiting flow process of sip terminal have mainly been described, Fig. 7 is according to the VGW of the P-CSCF band of the preferred embodiment of the present invention three or the flow chart of sip terminal Call Waiting, as shown in Figure 7, comprises the following steps:

Step S701, user terminal A, user terminal B, enter talking state.

Step S702, the user terminal C of IMS network calls out with terminal family A, and the network elements such as S-CSCF by user terminal C place are sent out session invitation to the AS/S-CSCF at party A-subscriber place.

Step S703, the AS/S-CSCF at user terminal A place sends out session invitation to the P-CSCF at user terminal A place.Simultaneously, (and user terminal A does not activate divert when busy business with user terminal A, to have call waiting, or the priority of the priority ratio divert when busy business of call waiting is high) be foundation, in issuing the session invitation message of P-CSCF, carry call waiting sign, with notice P-CSCF, user terminal A can be used call waiting.

Step S704, P-CSCF judgement user in busy condition but in due to the session invitation message of receiving identifying subscriber terminal A can use call waiting, send out session invitation to VGW or the corresponding sip terminal of party A-subscriber at party A-subscriber place.

Step S705, the corresponding sip terminal of the VGW at party A-subscriber place or party A-subscriber is sent out ring response message (for example, 180 message of Session Initiation Protocol) to the P-CSCF at party A-subscriber place.

Step S706, P-CSCF (for example forwards ring response message to the AS/S-CSCF at party A-subscriber place, 180 message), and at ring response message carry Call Waiting sign (for example, carrying Alert-Info:urn:service:call-waiting in 180 message).If P-CSCF can not judge its with user whether in busy condition, after receiving the session invitation message that comes from the network elements such as S-CSCF, send out session invitation to VGW or sip terminal.

Step S707, by the ring response message of receiving, the S-CSCF by user terminal C place is transmitted to user terminal C to AS/S-CSCF.AS/S-CSCF, when forwarding ring response message, can, according to the Call Waiting sign in message, put holding tone to user terminal C.The flow process of follow-up relevant call waiting, existing standard and technology, do not describe at this.

It should be noted that, AGCF in embodiment, P-CSCF, S-CSCF, AS, user terminal (User Equipmen, referred to as UE) network element and the message between them, in order clearly to represent the thought of IMS network support AGCF station camp-on business realizing, in concrete realization, be not limited to these network elements and message.If need to consider the priority of user's Call Waiting and divert when busy, and the priority of the priority ratio call waiting of divert when busy is high.In the situation that user has divert when busy business, in issuing the INVITE of AGCF/P-CSCF, do not carry call waiting sign, allow AGCF/P-CSCF think that user does not have call waiting.Concrete logic judgement is realized as required by network elements such as AS, S-CSCF.

In sum, the embodiment of the present invention adopts the mode that business information is stored in to S-CSCF/AS, having solved AGCF/P-CSCF in correlation technique does not have recording user whether to open the information of call waiting and causes the problem of system to the mistake processing of call flow, overcome in correlation technique ISDN or other types user and cannot judge whether the defect in busy condition by S-CSCF or AS, strengthen the adaptive capacity to call flow business, improved network processes performance and efficiency.

Obviously, those skilled in the art should be understood that, above-mentioned each module of the present invention or each step can realize with general calculation element, they can concentrate on single calculation element, or be distributed on the network that a plurality of calculation elements form, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in storage device and be carried out by calculation element, and in some cases, can carry out shown or described step with the order being different from herein, or they are made into respectively to each integrated circuit modules, or a plurality of modules in them or step are made into single integrated circuit module to be realized.Like this, the present invention is not restricted to any specific hardware and software combination.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., within all should being included in protection scope of the present invention.

Claims

1. a processing method for calling, is characterized in that, comprises the following steps:

Network element receives from the call request that carries call waiting sign of service call session control function entity S-CSCF or application server AS transmission, whether the called subscriber that wherein, described sign is used to indicate described call request support call latency services;

Described network element determines whether to trigger described called subscriber's described call waiting according to described sign and described called subscriber's state information; And

In the situation that determine the described call waiting do not trigger described called subscriber, to described S-CSCF or described AS callback failure response; Otherwise, trigger described called subscriber's described call waiting.

2. method according to claim 1, it is characterized in that, according to described sign and described called subscriber's state information, determine whether that the call waiting that triggers described called subscriber comprises: the service state that is designated support call latency services and described called subscriber in the situation that described is busy, determine the described call waiting that triggers described called subscriber.

3. method according to claim 1, it is characterized in that, according to described sign and described called subscriber's state information, determine whether that the call waiting that triggers described called subscriber comprises: described, be designated not support call latency services in the situation that, determine the described call waiting that does not trigger described called subscriber.

4. method according to claim 1 and 2, is characterized in that, the described call waiting that triggers described called subscriber comprises: in the situation that described network element is access gateway control function entity AGCF, to described called subscriber, send stand by tone.

5. method according to claim 1 and 2, it is characterized in that, the described call waiting that triggers described called subscriber comprises: in the situation that described network element is proxy call conversation control function entity P-CSCF, to described called subscriber, send described call request, described called subscriber returns to ring and responds to described P-CSCF.

6. method according to claim 1 and 2, it is characterized in that, after triggering described called subscriber's described call waiting, described method also comprises: the transmit leg to described call request returns ring response message, wherein, in described ring response message, carry described sign.

7. method according to claim 1, is characterized in that, described network element comprise following one of at least: the voice transfer gateway VGW of AGCF, P-CSCF, IP based network, Session initiation protocol SIP terminal.

8. an access gateway control function entity, is characterized in that, comprising:

Receiver module, for receiving from the call request of the sign that carries call waiting of service call session control function entity S-CSCF or application server AS transmission, whether the called subscriber that wherein, described sign is used to indicate described call request support call latency services;

Determination module, for determining whether to trigger described called subscriber's described call waiting according to described sign and described called subscriber's state information; And

Processing module, for described be designated not support call latency services in the situation that, to described S-CSCF or described AS callback failure response; The service state that is designated support call latency services and described called subscriber in the situation that described is busy, to described called subscriber, sends stand by tone.

9. access gateway control function entity according to claim 8, is characterized in that, described determination module be designated not support call latency services in the situation that, is determined the described call waiting that does not trigger described called subscriber described; The service state that is designated support call latency services and described called subscriber in the situation that described is busy, determines the described call waiting that triggers described called subscriber.

10. a proxy call conversation control function entity, is characterized in that, comprising:

Receiver module, for receiving from the call request that carries call waiting sign of service call session control function entity S-CSCF or application server AS transmission, whether the called subscriber that wherein, described sign is used to indicate described call request support call latency services;

Processing module, in the situation that determine the described call waiting do not trigger described called subscriber, to described S-CSCF or described AS callback failure response; Otherwise, to described called subscriber, send described call request.

11. proxy call conversation control function entities according to claim 10, is characterized in that, described determination module be designated not support call latency services in the situation that, is determined the described call waiting that does not trigger described called subscriber described; The service state that is designated support call latency services and described called subscriber in the situation that described is busy, determines the described call waiting that triggers described called subscriber.