CN101137096A - Method for implementing non-reachable forwarding in IMS centralized control service - Google Patents

Abstract

This method includes steps: Step 402 ICCF sends the Calling Side Start Call Request to L-CAAF-n; Step 404 L-CAAF-n starts paging to seach the called party (CP); Step 406 After paging, L-CAAF-n finds that CP cannot be reached, then sends the message of Called Party Not Reach (CPNR) to ICCF via conversation control path; Step 408 ICCF sends to TAS the SIP response message, which means CPNR. According to SIP message, TAS controls to trigger the service of Forward When CPNR. This invention enables IMS domain to realize the Forward CPNR traditional service, one of the IMS centralized control services, on non-ICS terminal without obtaining the User Not Reach State when non-ICS UE accesses the CS domain.

Description

The implementation method of user's Call Forwarding on mobile subscriber Not Reachable in the IMS centralized control business

Technical field

The present invention relates to the communications field, and especially, relate to a kind of IP Multimedia System (IP Multimedia Core Network Subsystem, IMS) implementation method of user's Call Forwarding on mobile subscriber Not Reachable in the centralized control business.

Background technology

IP (procotol, Internet Protocol, be called for short IP) IP multimedia subsystem, IMS (IPMultimedia Core Network Subsystem, be called for short IMS) be by third generation partner program (3rd Generation Partnership Project, abbreviation 3GPP) a kind of IP-based network framework that proposes, it has made up an opening and service environment flexibly, supports multimedia application, and provides abundant multimedia service for the user.

IMS is based on the communication network framework of IP, irrelevant with access technology, except being GPRS (General Packet Radio Service, GPRS), WLAN (wireless local area network) (Wireless Local Area Network, grouping exchange (PacketSwitched such as WLAN), abbreviation PS) access network provides outside the business, can also be global system for mobile communications (Global System for Mobile communications, GSM), (Universal Mobile Telecommunications System UMTS) waits mobile cellular network to provide professional to unified mobile communcations system.

Mobile cellular network such as GSM, UMTS adopts circuit-switched technology, be called circuit switching (Circuit Switched, be called for short CS) territory (hereinafter it being called circuit domain), it can be for the user provides basic speech business, and based on the supplementary service of speech business.When IMS is inserted in the CS territory, can develop into a kind of access way, business provides by IMS is unified fully, and this technology is called IMS centralized traffic (IMS Centralized Service is called for short ICS).

The IMS centralized traffic has the following advantages:

(1) IMS provides consistent business for access waies such as circuit commutative field, packet-switched domains, and network enabled merges;

(2) support the CS network to the evolution of IMS network;

(3) not only support to have ICS ability subscriber equipment, also support the existing subscriber equipment that does not possess the ICS ability, non-ICS subscriber equipment is also referred to as traditional subscriber equipment.

Fig. 1 is that legacy user terminals is passed through the Organization Chart that realization IMS centralized control business is inserted in the CS territory, comprises following network element:

User terminal (User Equipment, be called for short UE) 101, adaption function (Local CS Access Adaptation Function-network equivalent is called for short L-CAAF-n) 102 is inserted in the local circuit territory, Visited Mobile Switching Center (Visited Mobile SwitchCenter, be called for short VMSC) 103, home subscriber server (Home Subscriber Server, be called for short HSS) 104, MGCF (Media Gateway Control Function is called for short MGCF) 105, media gateway (Media Gateway, be called for short MGW) 106, IMS circuit domain control function (IMS CS Control Function, be called for short ICCF) 107, CSCF (Call Session Control Function, be called for short CSCF) 108, and telecommunication application server (Telecom Application Server is called for short TAS) 109.

As shown in Figure 1, when practical business was realized, UE101 set up 3 paths via L-CAAF-n102 to the ICCF107 in IMS territory: session control path, carrying control path and bearer path.

Wherein, the session control path is carried on the CS territory, UE101 adopts the CS control signaling of standard to insert L-CAAF-n102, L-CAAF-n102 is if adopt conversation initialized protocol (Session initiation Protocol on the IP bearer path, be called for short SIP) the transmission session control messages, ICCF107 is inserted through CSCF108 in this path so.L-CAAF-n102 is if adopt unstructured supplementary service data (Unstructured Supplementary Service Data is called for short USSD) transmission session control messages on the circuit domain bearer path, ICCF107 is inserted through HSS104 in this path so.

Carrying control path UE101 adopts the CS control signaling of standard to insert L-CAAF-n102 and VMSC103, and L-CAAF-n102 both can separate also and can merge with VMSC103, was linked into IMS by MGCF105 then, arrived ICCF107 by CSCF108 at last.

Bearer path is by being that UE101 is linked into IMS by VMSC103 and MGW106, and sets up medium with the remote user equipment of this session and be connected.

The IMS centralized traffic is utilized the interactive sessions control information between UE101 and ICCF107 of session control path, and sets up and the control media bearer by carrying control path, and ICCF107 serves as the IMS user agent, replaces subscriber equipment to insert IMS.

The TAS109 server can provide multiple supplementary services such as calling out maintenance, calling transfer, number demonstration, Call Forwarding for the user, therefore is called supplementary business server again.

In this professional implementation procedure, so-called user's Call Forwarding on mobile subscriber Not Reachable business is meant: after called subscriber B had contracted user's Call Forwarding on mobile subscriber Not Reachable business of user C, calling subscriber A called out B, switch calling user B, user B is unreachable, forwards user C before switch makes a call to.

ICS must support the unreachable Call Forwarding services of non-ICS user as the business in a kind of telecommunication system.But do not have relevant flow process to realize non-ICS user's Call Forwarding on mobile subscriber Not Reachable business at present in the IMS centralized control business, need the attainable flow process of service definition for this reason.

Fig. 2 is IMS user A conversation procedure process chart when calling out the traditional non-ICS mobile subscriber B that inserts from the CS territory.Wherein, ICCF utilizes the roaming number of user B to make a call to the called subscriber and sets up process, and this process is called called process, and flow process is divided following step:

201, CSCF receives called SIP (Session Initiation Protocol, the conversation initialized protocol) conversation request message that Calling Side user A initiates to callee side user B; CSCF with the session request be routed to the telecommunication application server of being responsible for Call Forwarding services (Telecom Aplication Server, TAS); The called conversation request message of TAS route is to ICCF;

202, ICCF uses the SIP session, or use USSD on the circuit domain bearer path by the session control path on the IP bearer path, to the called request of L-CAAF-n initiation session, carry information such as calling number and called number in the called request;

203, ICCF obtains the roaming number of user B, and the roaming number of utilization acquisition is routed to MGCF with calling subscriber's SIP conversation request through CSCF then;

204, MGCF to VMSC send out ISUP (ISDN User Part, ISDNYong Hubufen) initial address message (initial address message, IAM);

205, VMSC makes a call to set up to L-CAAF-n and asks, and L-CAAF-n issues user B with setup requests, initiates paging to user B, and user B begins ring;

206, user B carries out follow-up conversation procedure.

Fig. 3 is the process chart of IMS user A conversation procedure when calling out the traditional non-ICS user B that inserts from the CS territory.Wherein, L-CAAF-n uses the address of ICCF to make a call to ICCF and sets up process, and this process is called the caller process, and as shown in Figure 3, this calling procedure can divide following step:

301, CSCF receives the called SIP conversation request message that Calling Side user A initiates to callee side user B; CSCF is routed to the session request TAS that is responsible for Call Forwarding services; The called conversation request message of TAS route is to ICCF;

302, ICCF distributes an ICCF address for user B, by the session control path, uses the SIP session on the IP bearer path, or use USSD on the circuit domain bearer path, to the called request of L-CAAF-n initiation session, carries the ICCF address in the request message;

303, after L-CAAF-n receives conversation request message, immediately called number is used as in the ICCF address, make a call to set up to ICCF and ask;

304, ICCF responds this conversation request, sends out ALERTING message to L-CAAF-n, and L-CAAF-n initiates paging to user B, carries out session with user B and sets up process, and L-CAAF-n notifies user B ring then;

305, user B carries out follow-up conversation procedure.

In the prior art be: to called subscriber's distributing paging,, judge that by switch the user is unreachable when network side and called subscriber carry out call setup if can not paging arrive the called subscriber to the unreachable method of judging of user.In the mode of setting up of the professional called flow of the described IMS centralized control of Fig. 2 and Fig. 3 as can be seen, L-CAAF-n needs to carry out paging to the called subscriber in caller process and the called process, L-CAAF-n can judge that the user is unreachable, but prior art is subject to the MGCF physical capabilities, the MGCF entity can not be converted to sip response message with the ISUP release message that carries the unreachable cause value of user, therefore can't be implemented in the supplementary service of CS legacy user Call Forwarding on mobile subscriber Not Reachable in the centralized control business of IMS territory by prior art, need be in IMS centralized control business, for user's Call Forwarding on mobile subscriber Not Reachable defines attainable flow process.

Summary of the invention

Consider the problems referred to above and make the present invention, for this reason, main purpose of the present invention is to provide the implementation of user's Call Forwarding on mobile subscriber Not Reachable in a kind of IMS centralized control business, to solve the problem that can't be implemented in the supplementary service of CS legacy user Call Forwarding on mobile subscriber Not Reachable in the centralized control business of IMS territory in the prior art.

According to embodiments of the invention, provide the implementation method of user's Call Forwarding on mobile subscriber Not Reachable in a kind of IMS centralized control business.

This method comprises: step S402, and the called request message that IMS circuit domain control function entity is initiated Calling Side is sent to the local circuit territory and inserts the adaption function entity;

Step S404, the local circuit territory is inserted the adaption function entity and is initiated paging to the called subscriber;

Step S406 under the untouchable situation of affirmation called subscriber, sends the unreachable message of user by the session control path to IMS circuit domain control function entity after the local circuit territory is inserted the adaption function entity to initiate paging; And

Step S408, IMS circuit domain control function entity will represent that the untouchable conversation initialized protocol response message of called subscriber sends to telecommunication application server, and telecommunication application server is controlled the triggering of called subscriber's Call Forwarding on mobile subscriber Not Reachable business according to conversation initialization protocol message.

Wherein, in step S402, may further include: step S402-2, call conversation control function entity receives the called request message that Calling Side sends; Step S402-4, call conversation control function entity is sent to IMS circuit domain control function entity with called request message via telecommunication application server according to initial filter standard or norm.

In addition, in step S406, adopt in the session control path under the situation of circuit domain carrying, use unstructured supplementary service data transmission MAP error response message, the MAP error response message represents that the called subscriber is unreachable, and wherein carries the untouchable cause value of called subscriber.

In this case, in step S408, IMS circuit domain control function entity is mapped as the conversation initialized protocol response message with the MAP error response message, and the conversation initialized protocol response message of mapping is sent to telecommunication application server.

In addition, adopt in the session control path under the situation of IP carrying, utilize the conversation initialized protocol response message to represent that the called subscriber is unreachable, and the session initialization protocol message is sent to telecommunication application server.

In addition, in step S408, the conversation initialized protocol response message can be untouchable conversation initialized protocol 503 message of expression called subscriber.

In step S408, IMS circuit domain control function entity can send to telecommunication application server via call conversation control function entity with session initializtion protocol response message.

By technique scheme of the present invention, the unreachable state of user when making the IMS territory not need to obtain non-ICS UE to insert in the CS territory just can be realized user's Call Forwarding on mobile subscriber Not Reachable business of non-ICS terminal traditional in the IMS centralized control business.

Description of drawings

Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.In the accompanying drawings:

Fig. 1 is the block diagram according to the system of the realization IMS centralized control business of correlation technique;

Fig. 2 be in the IMS centralized control business of correlation technique when ICCF and called subscriber's conversation procedure adopts called process non-ICS user realize the process chart of Call Forwarding;

Fig. 3 be in the IMS centralized control business of correlation technique when ICCF and called subscriber's conversation procedure adopts the caller process non-ICS user realize the process chart of Call Forwarding;

Fig. 4 is the flow chart according to the implementation method of the unreachable Call Forwarding of user in the IMS centralized control business of the embodiment of the invention;

Fig. 5 is the flow chart according to the processing example 1 of the method for the embodiment of the invention; And

Fig. 6 is the flow chart according to the processing example 2 of the method for the embodiment of the invention.

Embodiment

In the present embodiment, provide the implementation method of user's Call Forwarding on mobile subscriber Not Reachable in a kind of IMS centralized control business (ICS), wherein, the preceding commentaries on classics of mentioning in the following description is meant Call Forwarding.

As shown in Figure 4, implementation method according to user's Call Forwarding on mobile subscriber Not Reachable in the IMS centralized control business (ICS) of present embodiment comprises: step S402, and the called request message that IMS circuit domain control function entity (ICCF) is initiated Calling Side is sent to the local circuit territory and inserts adaption function entity (L-CAAF-n); Step S404, L-CAAF-n initiates paging to the called subscriber; Step S406 confirms to send the unreachable message of user by the session control path to ICCF under the untouchable situation of called subscriber after L-CAAF-n initiates paging; And step S408, ICCF will represent that the untouchable conversation initialized protocol of called subscriber (SIP) response message sends to telecommunication application server (TAS), TAS controls the triggering of called subscriber's Call Forwarding on mobile subscriber Not Reachable business according to sip message.

Wherein, in step S402, may further include: step S402-2, call conversation control function entity receives the called request message that Calling Side sends; Step S402-4, call conversation control function entity is sent to ICCF with called request message via TAS according to initial filter standard or norm.

In addition, in step S406, adopt in the session control path under the situation of circuit domain carrying, use unstructured supplementary service data (USSD) transmission MAP error response message, the MAP error response message represents that the called subscriber is unreachable, and wherein carry the untouchable cause value of called subscriber (for example, can be user's absence).

In this case, in step S408, ICCF is mapped as sip response message with the MAP error response message, and the sip response message of mapping is sent to TAS.

In addition, adopt in the session control path under the situation of IP carrying, utilize sip response message to represent that the called subscriber is unreachable, and sip message is sent to TAS.

In addition, in step S408, sip response message can be the untouchable SIP503 message of expression called subscriber.

In step S408, ICCF can send to TAS via call conversation control function entity with session initiation protocol response message.

Describe the present invention in detail below with reference to instantiation.

In the following example that will describe, after called request message sent to the CSCF entity, the CSCF entity sent to ICCF entity with called request message through TAS according to initial filter standard or norm; The ICCF entity is issued L-CAAF-n by the session control path with called request message; L-CAAF-n carries out paging to the called subscriber, confirm that the called subscriber is unreachable, L-CAAF-n passes to ICCF by the session control path with the untouchable message of user, ICCF passes to TAS with the unreachable message of user user, finally triggers user's Call Forwarding on mobile subscriber Not Reachable operation flow by TAS.

L-CAAF-n passes to ICCF by the session control path with the unreachable message of user dual mode, a kind of is to use USSD when circuit domain is carried, the MAP error response message of carrying the unreachable cause value of user is passed to the ICCF entity, and the ICCF entity is mapped as the unreachable message of SIP503 user with it and passes to TAS.Another kind is to use the SIP session when IP carries, and will represent that the untouchable SIP503 message of user passes to the ICCF entity, and ICCF passes to TAS again.Below both of these case will be described respectively.

Example 1

As shown in Figure 5, in this example, the circuit domain bearer path is used in the session control path, and can comprise following processing this moment:

Step 501, CSCF receives the called request message that Calling Side is initiated to CS territory tradition called subscriber, and CSCF issues TAS according to initial filter standard or norm (iFC) with called request message;

Step 502, TAS is sent to ICCF with called request message through CSCF;

Step 503, it is the called request message of USSD that ICCF changes called request message, described called request message carries dialing number information, called number information and ICCF information, and the called request message of USSD is sent to L-CAAF-n through HSS;

Step 504, L-CAAF-n according to called number to called subscriber UE-B distributing paging;

Step 505, L-CAAF-n finds and can not paging arrive called subscriber UE-B, determines that the user is unreachable;

Step 506, L-CAAF-n passes through USSD on the session control path, send the MAP error response message to ICCF, described MAP error response message is carried the unreachable cause value of user, the untouchable error reason of the unreachable cause value indication user of user can be the absent subscriber;

Step 507, the MAP error response message that ICCF will carry the unreachable cause value of user is mapped as sip response message, and the expression user is unreachable, and by CSCF this sip response message is passed to TAS; Wherein, this sip response message can be SIP503 message;

Step 508, TAS carries out follow-up user's Call Forwarding on mobile subscriber Not Reachable flow process according to the triggering of sip response message control user Call Forwarding on mobile subscriber Not Reachable business.

Example 2

As shown in Figure 6, in this example, the IP bearer path is used in the session control path, at this moment, can comprise following processing procedure:

Step 601, CSCF receives the called request message that Calling Side is initiated to CS territory tradition called subscriber, and CSCF issues TAS according to initial filter standard or norm (iFC) with called request message;

Step 602, TAS is sent to ICCF with called request message through CSCF.

Step 603, ICCF initiates SIP conversation request message to L-CAAF-n by the CSCF route on session control path, CS territory, and wherein, conversation request message is carried dialing number information, called number information and ICCF information etc.;

Step 604, L-CAAF-n according to called number to called subscriber UE-B distributing paging;

Step 605, L-CAAF-n finds and can not paging arrive called subscriber UE-B, determines that the user is unreachable;

Step 606, L-CAAF-n by the CSCF route, sends sip response message to ICCF on the session control path, and the expression user is unreachable, and described sip response message can be SIP503 message;

Step 607, ICCF is passed to TAS by the CSCF route with this sip response message;

Step 608, TAS carries out follow-up user's Call Forwarding on mobile subscriber Not Reachable flow process according to the triggering of sip response message control user Call Forwarding on mobile subscriber Not Reachable business.

In sum, by means of technical scheme of the present invention, the unreachable state of user when making the IMS territory not need to obtain non-ICS UE to insert in the CS territory just can be realized user's Call Forwarding on mobile subscriber Not Reachable business of non-ICS terminal traditional in the IMS centralized control business.

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

Claims (7)

1. the implementation method of user's Call Forwarding on mobile subscriber Not Reachable in the IMS centralized control business is characterized in that, comprising:

Step S402, the called request message that IMS circuit domain control function entity is initiated Calling Side is sent to the local circuit territory and inserts the adaption function entity;

Step S404, described local circuit territory is inserted the adaption function entity and is initiated paging to the called subscriber;

Step S406 under the untouchable situation of the described called subscriber of affirmation, sends the unreachable message of user by the session control path to IMS circuit domain control function entity after described local circuit territory is inserted the adaption function entity to initiate described paging; And

Step S408, described IMS circuit domain control function entity will represent that the untouchable conversation initialized protocol response message of described called subscriber sends to telecommunication application server, and described telecommunication application server is controlled the triggering of described called subscriber's Call Forwarding on mobile subscriber Not Reachable business according to described conversation initialization protocol message.

2. 1 described method as requested is characterized in that, in described step S402, further comprises:

Step S402-2, call conversation control function entity receives the described called request message that Calling Side sends;

Step S402-4, described call conversation control function entity is sent to described IMS circuit domain control function entity with described called request message via described telecommunication application server according to initial filter standard or norm.

3. 1 described method as requested, it is characterized in that, in described step S406, adopt in described session control path under the situation of circuit domain carrying, use unstructured supplementary service data transmission MAP error response message, described MAP error response message represents that described called subscriber is unreachable, and wherein carries the untouchable cause value of described called subscriber.

4. 3 described methods as requested, it is characterized in that, in step S408, described IMS circuit domain control function entity is mapped as described conversation initialized protocol response message with described MAP error response message, and the described conversation initialized protocol response message that will shine upon is sent to described telecommunication application server.

5. 1 described method as requested, it is characterized in that, adopt in described session control path under the situation of IP carrying, utilize described conversation initialized protocol response message to represent that described called subscriber is unreachable, and described conversation initialization protocol message is sent to described telecommunication application server.

6. each described method in 1 to 5 as requested is characterized in that in step S408, described conversation initialized protocol response message is untouchable conversation initialized protocol 503 message of the described called subscriber of expression.

7. each described method in 1 to 5 as requested, it is characterized in that, in step S408, described IMS circuit domain control function entity sends to described telecommunication application server with described conversation initialized protocol response message via described call conversation control function entity.

Images