CN101848443A

CN101848443A - Communication service switching method, network system and interworking function entity

Info

Publication number: CN101848443A
Application number: CN200910081004A
Authority: CN
Inventors: 陈中平; 吴问付
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2009-03-27
Filing date: 2009-03-27
Publication date: 2010-09-29
Anticipated expiration: 2029-03-27
Also published as: WO2010108420A1; CN101848443B

Abstract

The embodiment of the invention discloses a communication service switching method, a network system and an interworking function entity. The method comprises the following steps: receiving a first registration request message transmitted by a user terminal at the source network, thereby completing the registration of the service IWF from a user terminal to a user terminal; receiving a second registration request message transmitted by the user terminal at the source network, and transmitting the second registration request message to a source service MME of the user terminal, so that the user terminal completes the registration to the source service MME; and receiving a switching request message from the user terminal at the source network, and forwarding the switching request message to the source service MME, so that the source service MME executes the switching procedure and switches the user terminal to a target network. The embodiment of the invention realizes switching from GERAN/UTRAN to E-UTRAN in CS domain services, thereby avoiding service interruption in the CS domain service switching process.

Description

Communication service switching method, network system and interworking function entity

Technical field

The present invention relates to the communication technology, especially a kind of communication service switching method, network system and interworking function entity.

Background technology

Circuit switching (Circuit Switched, hereinafter to be referred as: CS) the main processed voice business in territory.The signaling plane controlled entity in CS territory be mobile switching center (Mobile Switch Center/Visitor Location Register, hereinafter to be referred as: MSC/VLR).GSM/ enhanced data rates for gsm evolution wireless access network (GSM/EDGE Radio Access Network, hereinafter to be referred as: GERAN), wireless access network element base station controller (Base Station Controller, hereinafter to be referred as: BSC) with the base station (Base Transceiver Station, hereinafter to be referred as: BTS) be connected with MSC by the A interface.Universal mobile telecommunications system (Universal Mobile Telecommunications System, hereinafter to be referred as: UMTS) land radio access web (UMTS Territorial Radio Access Network, hereinafter to be referred as: UTRAN), the wireless access network element radio network controller (Radio Network Controller, hereinafter to be referred as: RNC) be connected with MSC by the Iu interface with base station (NodeB).

In order to tackle the challenge of wireless broad band technology, keep the leading superiority of 3GPP network, 3GPP will have formulated Long Term Evolution in the end of the year 2004, and (Long Term Evolution is hereinafter to be referred as LTE) plan.This LTE defined in the works evolution packet network (evolved packet system, hereinafter to be referred as: EPS).The EPS core net mainly comprises mobile management entity (Mobility Management Entity, hereinafter to be referred as: MME), gateway (Serving Gateway, hereinafter to be referred as: S-GW), (Packet Data Network Gateway is hereinafter to be referred as P-GW) three logic function bodies for grouped data network gateway.Wherein, MME is mainly used in and realizes Access Layer (Access Stratum, hereinafter to be referred as: AS) signaling and Non-Access Stratum (Non Access Stratum, hereinafter to be referred as: NAS) signaling is encrypted and roaming, is followed the tracks of, and distributing user temporary identity sign, safety function etc.S-GW is mainly used in and realizes the local mobility anchor point and the mobility anchor point of 3GPP internal system, and Lawful Interception relevant information function.P-GW is mainly used in the implementation strategy execution and charges, and Lawful Interception relevant information function.

Along with improving constantly of development of Communication Technique and communication service demand, communication service often need GERAN or UTRAN (hereinafter to be referred as: GERAN/UTRAN) be the evolution of Access Network in the LTE system the Universal Mobile Telecommunications System land radio access web (Evolved UMTS Terrestrial Radio Access Network, hereinafter to be referred as: switch E-UTRAN).But, in realizing process of the present invention, the inventor finds: because wireless access network element evolution base station (the Evolved NodeB among the existing E-UTRAN, hereinafter to be referred as: eNB) can't handle the signaling process in CS territory, therefore, still can't realize that GERAN/UTRAN switches to the CS territory of E-UTRAN is professional at present.

Summary of the invention

The purpose of the embodiment of the invention is: a kind of communication service switching method, network system and interworking function entity are provided, realize the switching of CS territory business from GERAN/UTRAN to E-UTRAN.

A kind of communication service switching method that the embodiment of the invention provides comprises:

Receive user terminal in first login request message that source network sends, finish of the registration of described user terminal to the service-interworking functional entity IWF of described user terminal;

Receive second login request message that described user terminal sends at described source network, Mobility Management Entity MME is served in the source that described second login request message is sent to user terminal, so that described user terminal is accomplished to the registration of described source serving MME;

Receive the handoff request message of described user terminal, and give described source serving MME,, described user terminal is switched to objective network so that described source serving MME is carried out switching flow with described handoff request forwards at described source network.

A kind of interworking function entity that the embodiment of the invention provides comprises:

The registration receiving element is used to receive user terminal in first login request message that source network sends, and finishes the registration of described user terminal to the service IWF of described user terminal;

Retransmission unit, be used to receive second login request message that described user terminal sends at described source network, and described second login request message is forwarded to the source serving MME of described user terminal, so that described user terminal is accomplished to the registration of described source serving MME;

The handover trigger unit is used to receive the handoff request message of user terminal at described source network, and gives described source serving MME with described handoff request forwards, so that described source serving MME is carried out switching flow, described user terminal is switched to objective network.

A kind of mobile switching centre that the embodiment of the invention provides comprises:

Receiving element is used for the handoff request message of the user terminal that the access network element of reception sources network sends;

Determining unit, the handoff request message that is used for receiving according to described receiving element are determined the service-interworking functional entity IWF of described terminal;

Transmitting element is used for described handoff request message is sent to the service IWF that described determining unit is determined.

A kind of Mobility Management Entity that the embodiment of the invention provides comprises:

Receiving element is used to receive the handoff request message of the user terminal that the IWF of user terminal sends;

Switch unit is used for user terminal is switched to objective network from source network.

A kind of network system that the embodiment of the invention provides comprises the source serving MME of the service IWF and the user terminal of MSC, user terminal, wherein

Described MSC is used for the handoff request message of the user terminal that the access network element of reception sources network sends, and determines the service IWF of described user terminal according to described handoff request message, and described handoff request message is sent to described definite service IWF;

Described service IWF is used to receive user terminal in first login request message that described source network sends, and finishes the registration of described user terminal to the service IWF of described user terminal; Receive second login request message that described user terminal sends at described source network, and described second login request message is forwarded to the source serving MME of described user terminal, so that described user terminal is accomplished to the registration of described source serving MME; Receive the handoff request message of described user terminal, and give described source serving MME,, described user terminal is switched to objective network so that described source serving MME is carried out switching flow with described handoff request forwards at described source network;

Described source serving MME is used to receive the handoff request message of the user terminal that described service IWF sends, and described user terminal is switched switch to described objective network from described source network.

The communication service switching method that provides based on the above embodiment of the present invention, network system and interworking function entity, UE can be registered to IWF by GERAN/UTRAN, and be registered to serving MME by this service IWF, like this, the CS territory service needed of follow-up UE is when GERAN/UTRAN switches to E-UTRAN, service IWF can be used as the target access network network element among the E-UTRAN, be registered to the source serving MME information of storing in the process of serving MME according to UE, the indication serving MME is carried out the switching flow of CS territory business to E-UTRAN, solve the target access network network element eNB among the E-UTRAN and can't handle CS domain signaling flow process problem, ensure GERAN/UTRAN to professional normally the carrying out of switching in the CS territory of E-UTRAN, thereby guaranteed the user's communications quality of service.

Below by drawings and Examples, technical scheme of the present invention is described in further detail.

Description of drawings

Fig. 1 is a networking structure schematic diagram of GERAN, UTRAN, E-UTRAN and EPS core net;

Fig. 2 a is the flow chart of an embodiment of communication service switching method of the present invention;

Fig. 2 b is the flow chart of another embodiment of communication service switching method of the present invention;

The flow chart that Fig. 3 is registered to service IWF and is registered to a serving MME embodiment in source by this service IWF for UE of the present invention;

The flow chart that Fig. 4 is registered to service IWF and is registered to source another embodiment of serving MME by this service IWF for UE of the present invention;

Fig. 5 is the service IWF of MSC addressing UE of the present invention, and sends the flow chart of an embodiment of handoff request message;

Fig. 6 is the service IWF of MSC addressing UE of the present invention, and sends the flow chart of another embodiment of handoff request message;

Fig. 7 is the service IWF of MSC addressing UE of the present invention, and sends the flow chart of another embodiment of handoff request message;

Fig. 8 is the flow chart of another embodiment of communication service switching method of the present invention;

Fig. 9 serves IWF sends flow chart from an embodiment of handoff request message to the source serving MME for the present invention.

Figure 10 is the structural representation of an embodiment of IWF of the present invention;

Figure 11 is the structural representation of an embodiment of MSC of the present invention;

Figure 12 is the structural representation of an embodiment of MME of the present invention;

Figure 13 is the structural representation of the unified embodiment of network system of the present invention.

Embodiment

Because a lot of communication services that operator provides all operate in the CS territory, for existing C S is provided in the LTE network business, prior art is connected to the CS domain core net with the EPS core net.As shown in Figure 1, for the Universal Mobile Telecommunications System land radio access web of GERAN, UTRAN, evolution (Evolved UMTS Terrestrial Radio Access Network, hereinafter to be referred as: E-UTRAN) with a networking structure schematic diagram of EPS core net.According to Fig. 1, user terminal (User Equipment, hereinafter to be referred as: UE) by interworking function entity (Interworking Function, hereinafter to be referred as: IWF) MSC with the CS core net is connected.IWF possesses the ability of Simulation with I u-CS/A interface, can dispose Iu-CS/A interface corresponding protocols stack on IWF.When UE communicates by letter with MSC, at first send message to IWF.IWF converts thereof into the signaling format on the Iu-CS/A interface, and sends to MSC after receiving the message that UE sends, thereby finishes communicating by letter of UE and MSC.In like manner, IWF can pass through MSC the forwards of Iu-CS/A interface transmission to UE.Sv is the reference point between MME and the IWF, when the LTE network when GERAN/UTRAN switches, MME by Sv to the IWF request message that switches.Z1 is the reference point between UE and the IWF, can be used as the IP tunnel between IWF and the UE.

Fig. 2 a is the flow chart of an embodiment of communication service switching method of the present invention, and it comprises:

S1, reception user terminal are finished the registration of described user terminal to the service-interworking functional entity IWF of described user terminal in first login request message that source network sends;

Second login request message that S2, the described user terminal of reception send at source network, Mobility Management Entity MME is served in the source that described second login request message is sent to described user terminal, so that described user terminal is accomplished to the registration of described source serving MME;

S3, receive the handoff request message at source network of user terminal, and give described source serving MME,, described user terminal is switched to objective network so that described source serving MME is carried out switching flow with described handoff request forwards.

Wherein, described source network can be networks such as GERAN, UTRAN, and described objective network can be E-UTRAN etc.The method that the embodiment of the invention provided, UE can be registered to service IWF by GERAN/UTRAN, and by the service IWF be registered to the source serving MME, when the CS territory of described UE business when the GERAN/UTRAN network switches to E-UTRAN, described MSC gives described source serving MME by service IWF with the handoff request forwards of described UE, indicates described source service IWF to finish the service switchover in described CS territory.Among the S2, described second login request message is sent to before the source service Mobility Management Entity MME of user terminal, can also comprises: the source serving MME of determining described user terminal.

Fig. 2 b is the flow chart of another embodiment of communication service switching method of the present invention.Shown in Fig. 2 b, the communication service switching method of this embodiment may further comprise the steps:

Step 101, UE is registered to IWF by GERAN/UTRAN, and is registered to the MME of UE by this service IWF.IWF wherein is the service IWF of UE, and MME is the source serving MME of UE.

Step 102, the access network elements of GERAN/UTRAN transmits the handoff request message of UE to MSC, and (identifier is hereinafter to be referred as ID) information to comprise target access network network element ID among CS territory handover information and the E-UTRAN in this handoff request message.

Particularly, the access network elements of GERAN/UTRAN specifically can be BSC or RNC.The target access network network element specifically can be eNB among the E-UTRAN.

Step 103, the service IWF of MSC addressing UE, and to service IWF forwarding handoff request message.

Step 104, service IWF is according to being registered to the source serving MME information of storing in the process of source serving MME by service IWF, and indication source serving MME is carried out the switching flow of CS territory business to E-UTRAN.

Step 105, service IWF sends to switch to MSC and finishes notification message after UE inserts E-UTRAN, so that MSC is delivered to service IWF with Business Stream, and the carrying that triggers among the E-UTRAN sets up flow process, so that Business Stream is delivered to UE by service IWF.

UE can be registered to IWF by GERAN/UTRAN, and be registered to serving MME by this service IWF, like this, the CS territory service needed of follow-up UE is when GERAN/UTRAN switches to E-UTRAN, service IWF can be used as the target access network network element among the E-UTRAN, be registered to the source serving MME information of storing in the process of serving MME according to UE, the indication serving MME is carried out the switching flow of CS territory business to E-UTRAN, solve the target access network network element eNB among the E-UTRAN and can't handle CS domain signaling flow process problem, ensure GERAN/UTRAN to professional normally the carrying out of switching in the CS territory of E-UTRAN, thereby guaranteed the user's communications quality of service.

The communication service switching method of the embodiment of the invention goes for any communication service, especially speech business.Below of the present invention, among some embodiment, be that example describes, for other professional same being suitable for the speech business.

In step 101 embodiment illustrated in fig. 2, UE specifically can take following dual mode, is registered to IWF by GERAN/UTRAN, and is registered to the MME of this UE by this service IWF:

A kind of UE of being is registered to the service IWF of UE by the CS territory of GERAN/UTRAN, and is registered to the source serving MME of UE by service IWF.Particularly, UE finishes after the CS territory adheres to, and can be registered to the service IWF of UE by the CS territory of GERAN/UTRAN by the professional UE that triggers in CS territory, and this is equivalent to UE and initiatively triggers the service IWF that is registered to UE.In addition, when UE will carry out the network switching, the access network elements of GERAN/UTRAN also can notify UE to register to IWF.This is equivalent to the service IWF that the passive triggering of UE is registered to UE.

Another kind is that UE is registered to the service IWF of UE by the packet switching PS territory of GERAN/UTRAN, and is registered to the source serving MME of UE by service IWF.Particularly, UE finishes after the PS territory adheres to, and can be registered to the service IWF of UE by the PS territory of GERAN/UTRAN by the professional UE that triggers in CS territory, and this is equivalent to UE and initiatively triggers the service IWF that is registered to UE.In addition, when UE will carry out the network switching, the access network elements of GERAN/UTRAN also can notify UE to register to IWF.This is equivalent to the service IWF that the passive triggering of UE is registered to UE.

The flow chart that Fig. 3 is registered to service IWF and is registered to a serving MME embodiment in source by this service IWF for UE of the present invention.Among this embodiment, UE is registered to the service IWF of UE by the CS territory of GERAN/UTRAN, and is registered to the source serving MME of UE by service IWF.UE is registered to before its service IWF, sets up the passage between UE and its service IWF earlier, so that carry out Signalling exchange or data interaction by this passage between UE and the IWF.According to one embodiment of present invention, UE can and its service IWF between can pass through unstructured supplementary data traffic (Unstructured Supplementary Service Data, hereinafter to be referred as: USSD) mode is set up the USSD tunnel, as the passage between UE and its service IWF.In the USSD mode, IWF can regard the USSD server as.As shown in Figure 3, the flow process of this embodiment specifically may further comprise the steps:

Step 201, service IWF receives first login request message that UE sends by the USSD tunnel, for example: UE-IWF-RC REGISTER REQUEST.This first login request message sends to service IWF through access network elements BSC/RNC and the MSC of GERAN/UTRAN successively by UE, be used for request registration to service IWF, comprise user ID and the UE current location information in GERAN/UTRAN in first login request message.User ID wherein specifically can be international mobile subscriber identity (International Mobile SubscriberIdentification Number, hereinafter to be referred as: IMSI), the current location information of UE in GERAN/UTRAN specifically can be current location area identification (the Location Area Identity of UE in GERAN/UTRAN, hereinafter to be referred as: LAI), Routing Area Identifier (Routing Area Identity, hereinafter to be referred as: RAI) or cellular global identity (Cell Global Identifier, hereinafter to be referred as: CGI).

Step 202, service IWF handles first login request message.

Step 203, service IWF returns first registration through the access network elements BSC/RNC of MSC and GERAN/UTRAN to UE successively and accepts message, for example: UE-IWF-RC REGISTER ACCEPT.

Step 204, service IWF receives second login request message that UE sends by the USSD tunnel, this second login request message sends to service IWF through access network elements BSC/RNC and the MSC of GERAN/UTRAN successively by UE, be used for request registration to the source serving MME, specifically can be Attach Request message Attach Request, also can be tracing section updating request message TAURequest, can be included in UE and serve among the IWF interactive messages UE-IWF UL DIRECT TRANSFER.

Step 205, service IWF is that UE selects the source serving MME, and transmits second login request message to the source serving MME of selecting.Particularly, if second login request message is included in UE and serves among the IWF interactive messages UE-IWF UL DIRECT TRANSFER, after then serving IWF and receiving message UE-IWF UL DIRECT TRANSFER, resolve earlier, obtain second login request message that UE sends.

Particularly, service IWF can comprise for UE selects the source serving MME in the following manner:

Service IWF detects in second login request message that receives whether comprise MME information.

If do not comprise MME information in second login request message, service IWF selects to satisfy pre-conditioned MME as the source serving MME from the MME tabulation according to preestablishing, and this MME tabulation can be kept on the service IWF.Wherein can comprise and preestablish service IWF after receiving second login request message according to preestablishing, in MME tabulation arbitrarily MME of selection as the source serving MME; Perhaps preestablish service IWF after receiving second login request message, the little MME of load of selection is as the source serving MME in MME tabulation; Also can bore the then source serving MME of described user terminal according to predefined other strategy.

If comprise MME information in second login request message, whether the MME that service IWF inquires about the MME message identification that comprises in second login request message is present in the MME tabulation of storage in advance.If be present in the MME tabulation, service IWF selects the MME of the MME message identification that comprises in second login request message as the source serving MME.If be not present in the MME tabulation, service IWF selects to satisfy pre-conditioned MME as the source serving MME from the MME tabulation according to preestablishing.When the MME information that is comprised in second login request message was not in described MME tabulation, service IWF selected the processing that the process of source serving MME can be when not comprising MME information in second login request message.

Concrete, MME information can be global unique temporary identity (Globally Unique Temporary Identity is hereinafter to be referred as GUTI) or MME ID.

Step 206, the source serving MME is handled second login request message, and return second registration to described service IWF and accept message, it specifically can be to adhere to accept message Attach Accept that message is accepted in this second registration, also can be that tracing section updating is accepted message TAU Accept.

Step 207, service IWF returns second registration through the access network elements BSC/RNC of MSC and GERAN/UTRAN to UE successively and accepts message, and source serving MME information is kept in the context of UE, so that in follow-up flow process, the source serving MME that service IWF addressing is served for this UE.Particularly, second registration is accepted message Attach Accept/TAU Accept and can be included among UE and the service IWF interactive messages UE-IWF DL DIRECT TRANSFER.

So far, UE finishes the registration to IWF by GERAN/UTRAN, and then is accomplished to the registration of MME by service IWF.

In addition, in step 201, service IWF can also obtain the current cell information of UE, also promptly: the current location information of UE in GERAN/UTRAN according to first login request message of UE transmission.Accordingly, in the step 204, after service IWF receives second login request message of UE transmission, can also carry out following operation: service IWF is according to the transformational relation that sets in advance, the UE current location information is converted to the positional information of E-UTRAN, and the positional information of this E-UTRAN is sent to the source serving MME.Perhaps, service IWF as the positional information of UE at E-UTRAN, sends to the source serving MME with the positional information of pre-configured E-UTRAN, so that subsequent movement association or session association flow process are used.

Because in the E-UTRAN network, the passage between UE and its service IWF is based on IP, for IWF, needs the IP address of record UE, and passes through above-mentioned embodiment shown in Figure 3, and the passage between UE and its service IWF is the USSD tunnel, right and wrong IP's.Therefore, after UE is accomplished to the registration of source serving MME, also need to rebulid the IP tunnel of UE, provide its IP address information to IWF to its service IWF, that is: UE again to its service IWF registration, provides IP address information by register flow path to its service IWF in the EPS network.If in GERAN/UTRAN, carried out the registration of UE before to its service IWF, before carrying out the flow process that is accomplished to service IWF registration by the EPS network, UE need carry out the registration of going to service IWF at GERAN/UTRAN, initiates to be accomplished to by the EPS network flow process of service IWF registration then.At this moment, its service IWF be exactly before service IWF among the GERAN/UTRAN.That is to say, after the step 207 of flow process shown in Figure 3, also comprise: the source serving MME is set up the Internet protocol IP tunnel of UE to IWF; Service IWF receives the IP address information of the UE of UE transmission.

Wherein, the source serving MME is set up UE and is comprised to the Internet protocol IP tunnel of IWF:

The packet data network that source serving MME reception UE sends (Packet Data Network, hereinafter to be referred as: PDN) connection request message PDN Connectivity Request.The APN that uses in this PDN connection request message (APN Access Point Name, hereinafter to be referred as: APN) information can be default APN, also can be other APN.UE can initiate this PDN connection request in the process of attach to network, also can initiate this PDN connection request later at attach to network;

The source serving MME sends to S-GW/P-GW and creates default bearer request Create Default Bearer Request;

Create carrying between S-GW/P-GW and the source serving MME, and return establishment default bearer response Create Default Bearer Response to the source serving MME;

The source serving MME is returned PDN to UE and is accepted message PDN Connectivity Accept.

Above-mentioned PDN establishment of connection flow process, be actually in advance the passage of carrying out the CS business in the EPS network is ready to, the PDN establishment of connection is that UE sets up an IP tunnel to its service IWF, after setting up the professional relevant PDN in CS territory in the EPS network and connect by above-mentioned flow process, UE just can realize Signalling exchange or data interaction by this IP tunnel with its service IWF, so that UE is accomplished to the registration of its service IWF, in addition, UE also can obtain the IP address of CS territory business in the follow-up EPS of the carrying out network.Help follow-up switching flow.

The IP address information that service IWF receives the UE of UE transmission comprises:

Service IWF receives the 3rd login request message that UE sends by IP tunnel, and for example: UE-IWF-RC REGISTER REQUEST comprises the IP address information of UE in the 3rd login request message;

The IP address information of service IWF storage UE, and return the 3rd registration to UE and accept message, for example: UE-IWF-RC REGISTER ACCEPT.

So far, UE finishes to the IP tunnel foundation in advance between its service IWF in the EPS network.

The packet switching PS territory of UE by GERAN/UTRAN is registered to before its service IWF, sets up UE earlier to the IP tunnel between its service IWF, so that carry out Signalling exchange or data interaction by this IP tunnel between UE and the IWF.According to one embodiment of present invention, UE can and its service IWF between can set up GPRS Tunnel Protocol (GPRS Tunneling Protocol is hereinafter to be referred as GTP) tunnel, as the IP tunnel between UE and its service IWF.As shown in Figure 4, specifically can between UE and its service IWF, set up GTP tunnel by following flow process:

Step 30A, UE is by the access network elements BSC/RNC of GERAN/UTRAN, to GPRS serving GPRS support node (Serving GPRS Support Node, hereinafter to be referred as SGSN) transmission PDP activation request message Activate PDP Context Request, this PDP activates the APN information of carrying in the request message, can be default APN, also can be other APN.

Step 30B, SGSN send to S-GW/P-GW and create PDP request message Create PDP Context Request, and the carrying between this SGSN and the S-GW/P-GW is created in request.

Step 30C creates carrying between S-GW/P-GW and the SGSN, and returns establishment PDP response message Create PDP Context Response to SGSN.

Step 30D, SGSN reply the PDP activation to UE and accept message Activate PDP Context Accept by the access network elements BSC/RNC of GERAN/UTRAN.

The flow chart that Fig. 4 is registered to service IWF and is registered to source another embodiment of serving MME by this service IWF for UE of the present invention.Set up after the GTP tunnel between UE and its service IWF, UE is registered to the service IWF of UE by the PS territory of GERAN/UTRAN, and is registered to the source serving MME of UE by service IWF.As shown in Figure 4, the flow process of this embodiment specifically may further comprise the steps:

Step 301, service IWF receives first login request message that UE sends by GTP tunnel, for example: UE-IWF-RC REGISTER REQUEST.This first login request message sends to service IWF through access network elements BSC/RNC and the SGSN of GERAN/UTRAN successively by UE, be used for request registration to service IWF, comprise user ID and the UE current location information in GERAN/UTRAN in first login request message.User ID wherein specifically can be IMSI, and the current location information of UE in GERAN/UTRAN specifically can be current LAI, RAI or the CGI of UE in GERAN/UTRAN.

Step 302, service IWF handles first login request message.

Step 303, service IWF returns first registration through the access network elements BSC/RNC of SGSN and GERAN/UTRAN to UE successively and accepts message, for example: UE-IWF-RC REGISTER ACCEPT.

Step 304, service IWF receives second login request message that UE sends by GTP tunnel, this second login request message sends to service IWF through access network elements BSC/RNC and the SGSN of GERAN/UTRAN successively by UE, be used for request registration to the source serving MME, specifically can be Attach Request message Attach Request, also can be tracing section updating request message TAURequest, can be included in UE and serve among the IWF interactive messages UE-IWF UL DIRECT TRANSFER.

Step 305, service IWF is that UE selects the source serving MME, and transmits second login request message to the source serving MME of selecting.Particularly, if second login request message is included in UE and serves among the IWF interactive messages UE-IWF UL DIRECT TRANSFER, after then serving IWF and receiving message UE-IWF UL DIRECT TRANSFER, resolve earlier, obtain second login request message that UE sends.

Particularly, service IWF is that UE selects the method for source serving MME can refer step 205.

Step 306, the source serving MME is handled second login request message, and return second registration to described service IWF and accept message, it specifically can be to adhere to accept message Attach Accept that message is accepted in this second registration, also can be that tracing section updating is accepted message TAU Accept.

Step 307, service IWF returns second registration through the access network elements BSC/RNC of SGSN and GERAN/UTRAN to UE successively and accepts message, and source serving MME information is kept in the context of UE, so that in follow-up flow process, the source serving MME that service IWF addressing is served for this UE.Particularly, second registration is accepted message Attach Accept/TAU Accept and can be included among UE and the service IWF interactive messages UE-IWF DL DIRECT TRANSFER.

Because GTP tunnel has been the IP pattern,, can not need rebulid the IP tunnel of UE to its service IWF by flow process embodiment illustrated in fig. 4.Follow-up execution GERAN/UTRAN to the E-UTRAN network, be that is to say by the GERAN/UTRAN Network Synchronization that when E-UTRAN switches when E-UTRAN carried out the network switching, the IP address of UE was constant by the GERAN/UTRAN network.

By above-mentioned Fig. 3 and flow process shown in Figure 4, UE finishes the registration to service IWF at GERAN/UTRAN, and then be accomplished to the registration of source serving MME by service IWF, just can set up the passage of UE in advance by this source serving MME to service IWF, thereby can reduce the professional time delay for switching in follow-up CS territory, improve communication quality and user's business experience.

Be accomplished to by IWF in the process of MME registration at UE, in fact service IWF has carried out the interface function of eNB, that is: service IWF need dispose the respective protocol stack of S1 interface, so just can communicate by letter with the source serving MME.By step 202 or step 302, after UE was accomplished to the registration of service IWF, service IWF can create the context of this UE for UE.Therefore, in step 104 embodiment illustrated in fig. 2, service IWF indication source serving MME is carried out CS territory business when the switching flow of E-UTRAN, needs whether set up S1 between the target access network network element at first the detection resources serving MME and E-UTRAN and is connected.Connect if set up S1, then serve IWF and directly indicate the source serving MME to carry out the switching flow of CS territory business to E-UTRAN.Connect if set up S1, then serve IWF trigger the source serving MME set up with the target access network network element between S1 is connected, and after setting up S1 and connecting, indicate the switching flow of serving MME execution CS territory, source business to E-UTRAN.

In the prior art, when the switching of CS territory took place, the access network elements BSC/RNC of source GERAN/UTRAN only can report target access network NE ID information to source MSC.Therefore, switch for the CS territory, a difficulty in treatment of prior art is that MSC can associate with the service IWF of UE when how to guarantee to switch, so that the service IWF of MSC addressing UE, rather than associate with target access network network element eNB among the E-UTRAN.Fig. 5 is the service IWF of MSC addressing UE of the present invention, and sends the flow chart of an embodiment of handoff request message.As shown in Figure 5, this embodiment may further comprise the steps:

Step 401, the access network elements BSC/RNC of GERAN/UTRAN receives the handover measurement report that UE reports, and comprises the metrical information of E-UTRAN and the metrical information of the service IWF that UE registers in this handover measurement report.

In the embodiment of the invention, during the UE reporting measurement reports, can identify the metrical information of E-UTRAN and the metrical information of IWF.According to the sign of UE, access network elements can be discerned the metrical information of the E-UTAN that UE reports and the metrical information of IWF.Wherein, the metrical information of IWF derives from the discovery and registration process of UE execution IWF, the IWF system information that the IWF of registration provides to UE.

Step 402, when the access network elements BSC/RNC of GERAN/UTRAN initiates switching flow according to the metrical information decision-making of the service IWF of the metrical information of E-UTRAN and UE registration, send handoff request message to MSC, comprise the relevant information of serving IWF in this handoff request message, the metrical information of the relevant information corresponding with service IWF of service IWF.

Step 403, MSC is according to the service IWF of relevant information addressing UE of service IWF, and sends handoff request message to this service IWF.

Particularly, in the step 401, the metrical information of service IWF can be the cell information of service IWF, for example: frequency channel numbers (Absolute Radio Frequency Channel Number, hereinafter to be referred as: ARFCN), base station identity code (base station identity code, hereinafter to be referred as: BSIC), in the step 403, the relevant information of service IWF is specially target identification/target cell information of service IWF.Accordingly, before the step 402, also comprise: the cell information that the access network elements of GERAN/UTRAN will be served IWF is mapped as cellular global identity CGI, and, obtain the target identification/target cell information corresponding with CGI according to the correspondence relationship information between the CGI that sets in advance and the target identification/Target cell.Step 403 is specially: MSC is according to the target identification/Target cell of service IWF and the correspondence relationship information between the IWF, the service IWF of addressing UE.

The metrical information of service IWF also can be specially the address information of serving IWF with the relevant information of service IWF, for example: sequence number.Accordingly, in the step 403, MSC to the address information of service IWF carry out domain name system (Domain Name System, hereinafter to be referred as: DNS) resolve, obtain serving the address of IWF, and according to addressing of address service IWF of this service IWF.

Fig. 6 is the service IWF of MSC addressing UE of the present invention, and sends the flow chart of another embodiment of handoff request message.Among this embodiment, the service IWF of UE with oneself be registered to home subscriber server (Home Subscriber Server, hereinafter to be referred as: HSS), carry out network when switching, MSC finds that the objective network that UE switches is E-UTRAN, then to HSS request IWF address information.As shown in Figure 6, this embodiment may further comprise the steps:

Step 501, service IWF receives first login request message that UE sends, for example: UE-IWFREGISTER REQUEST.

Step 502, service IWF sends the 4th login request message to the HSS of UE, for example: Update Location Request.Comprise the relevant information of serving IWF in the 4th login request message, for example: IWF ID, root of hair can the corresponding IWF of addressing according to this IWF ID.In addition, the 4th login request message also comprises UE user's IMSI.

Step 503, HSS registers service IWF, and returns the 4th registration reply message to service IWF.

Step 504, service IWF returns the 4th registration reply message to UE, and for example: GA-RCREGISTER ACCEPT comprises the IWF system information in the registration reply message.

Step 505, UE reports the handover measurement report to the access network elements BSC/RNC of GERAN/UTRAN.

Step 506, the access network elements BSC/RNC of GERAN/UTRAN sends handoff request message to MSC, for example: Handover CS to VoIP bearer.

Step 507, MSC sends the IWF address request to HSS, for example: IWF Request, comprising the MSC ID of this MSC and UE user's IMSI, to the IWF address information of HSS request UE registration.

Step 508, HSS returns the IWF address response message to MSC, and for example: (IWF ID IMSI), returns the IWF address information of UE registration to IWF Response to MSC.

Step 509, MSC is according to the service relevant information of IWF and the correspondence relationship information between the IWF, the service IWF of addressing UE, and send handoff request message to this service IWF.

Fig. 7 is the service IWF of MSC addressing UE of the present invention, and sends the flow chart of another embodiment of handoff request message.Among this embodiment, IWF will oneself be registered among the HSS, and HSS can initiatively intercut the IWF address to MSC as CAMEL-Subscription-Information.As shown in Figure 7, this embodiment may further comprise the steps:

Step 601, service IWF receives first login request message that UE sends, for example: UE-IWFREGISTER REQUEST.

Step 602, service IWF sends the 4th login request message to the HSS of UE, for example: Update Location Request.Comprise the relevant information of serving IWF in the 4th login request message, for example: IWF ID, root of hair can the corresponding IWF of addressing according to this IWF ID.In addition, the 4th login request message also comprises UE user's IMSI.

Step 603, HSS registers service IWF, and returns registration reply message to service IWF.

Step 604, service IWF returns registration reply message to UE, and for example: GA-RCREGISTER ACCEPT comprises the IWF system information in the registration reply message.

Step 605, when HSS upgraded in the relevant information of service IWF, to the subscription data of MSC insertion UE, this subscription data comprised the relevant information of the service IWF of renewal.

IWF information can be used as the subscription data of UE, when finding subscription data, HSS changes, also promptly: during the IWF information updating, for example: in the step 602, when service IWF sends login request message, HSS is to the network element of finishing the service UE of registration, for example: MSC, insert subscription data and carry associated IWF address information.

Step 606, MSC replys response message to HSS.

Wherein, step 605-606 and step 603-604 can carry out not according to above-mentioned time sequencing, and step 605-606 also can carry out with step 603-604 or carry out prior to step 603-604 simultaneously.

Step 607, MSC is according to the relevant information of service IWF and the correspondence relationship information between the IWF, the service IWF of the UE of the relevant information correspondence of the service IWF that addressing is upgraded.

Wherein, step 607 also can be carried out with step 606 or be carried out prior to step 606 simultaneously.

Fig. 8 is the flow chart of another embodiment of communication service switching method of the present invention.The communication service switching method of this embodiment is that example describes with the speech business, stands good for other business.As shown in Figure 8, it may further comprise the steps:

Step 701, UE is registered to IWF by GERAN/UTRAN, and is registered to the MME of UE by this service IWF.IWF wherein is the service IWF of UE, and MME is the source serving MME of UE.

Particularly, this step 701 can realize by Fig. 3 or flow process embodiment illustrated in fig. 4.

Step 702, UE is to the access network elements BSC/RNC of GERAN/UTRAN, that is: access network elements BSC/RNC in source reports handover measurement report Measurement Reports, comprises the metrical information of E-UTRAN and the metrical information of the service IWF that UE registers in this handover measurement report.

Step 703, source access network elements BSC/RNC initiates switching flow according to the metrical information decision-making of the service IWF of the metrical information of E-UTRAN and UE registration.

Step 704, source access network elements BSC/RNC sends handoff request message Handover Required to MSC, and notice MSC carries out the CS territory and switches.

Step 705, the service IWF of MSC addressing UE as the target access network network element, sends handoff request message Handover Request to this service IWF with it, notifies this service IWF to prepare resource.Comprise target access network NE ID information among CS territory handover information and the E-UTRAN in the handoff request message.

Step 706, service IWF knows that according to the target access network NE ID objective network of switching is E-UTRAN, according to the source serving MME information of the UE that writes down before, sends handoff request message Handover Required to this source serving MME.

According to one embodiment of present invention, when service IWF sends handoff request message to this source serving MME, if UE does not set up eNB in the E-UTRAN network when being connected the S1 connection with signaling between the serving MME of source, service IWF at first triggers the S1 connection building process and sets up the S1 connection, sends handoff request message then to the source serving MME.

Step 707, source serving MME send to target MME and transmit replacement request message Forward Relocation Request, give target MME with the context transfer of UE.

Step 708, according to relevant informations such as the load of relevant information such as the position of UE and the S-GW of service before, energy, if Fu Wu S-GW can't continue service before, target MME reselects S-GW, and sends establishment bearing request message Create Bearer Request to the S-GW that selects.

Step 709, the S-GW of selection returns to target MME and creates bearing response message Create Bearer Response, and sets up carrying between the target MME.

Step 710, the target eNB of target MME in E-UTRAN send handoff request message Handover Request.

Step 711, target eNB is replied switching request acknowledgement message Handover Request Ack to target MME.

In the reciprocal process of step 710-711 target MME and target eNB, the UE context that target MME also passes over according to the source serving MME, notice eNB sets up carrying.

Step 712, target MME replys to the source serving MME and transmits replacement response message Forward Relocation Response, and the handoff preparation phase among the notification target network E-UTRAN is finished.

Step 713, the source serving MME sends switching command Handover Command to service IWF, and the handoff preparation phase among the notification target network E-UTRAN is finished.

Step 714, service IWF finishes resource and prepares between this service IWF and MSC, reply switching request acknowledgement message Handover Ack to MSC.

Step 715, MSC replys switching command Handover Command to source access network elements BSC/RNC, and the notice handoff preparation phase is finished.

Step 716, source access network elements BSC/RNC sends switching command Handover Command to UE, and notice UE switches to objective network.Carry the relevant information of objective network E-UTRAN in this switching command message.

Step 717, UE carries out E-UTRAN network insertion process according to the relevant information of objective network E-UTRAN, afterwards, sends handoff completion message Handover Complete to target access network network element eNB.

Step 718, target access network network element eNB sends to switch to target MME and finishes notification message Handover Notify.

Step 719, target MME sends the forwarding replacement to the source serving MME and finishes message Forward Relocation Complete, the notification source serving MME, UE has inserted E-UTRAN.

Step 720, the source serving MME is replied the forwarding replacement to target MME and is finished acknowledge message Forward Relocation Complete Ack.

Step 721, target MME sends to S-GW and upgrades bearing request message Update Bearer Request.

Step 722, S-GW sends to P-GW and upgrades bearing request message Update Dedicated Bearer Request.

Step 723, new bearer more between P-GW and the S-GW, and return to S-GW and to upgrade bearing response message Update Dedicated Bearer Response.

Step 724, S-GW replys to target MME and upgrades bearing response message Update Dedicated Bearer Response.

Step 725, UE initiating updating of tracking area flow process TAU Procedure finishes the registration of target MME to HSS.

Step 726, UE replys handoff completion message Handover Complete to service IWF.

Step 727, service IWF replys handoff completion message Handover Complete to MSC, and speech business stream switches to service IWF from source, that is: and MSC is delivered to service IWF with speech business stream.

Step 728, service IWF triggers the carrying of speech business stream and sets up flow process.

Step 729, service IWF is to strategy and charging regulation function entity (Policy and Charging Rules Function, hereinafter to be referred as: PCRF) provide the relevant information of speech business, trigger the dedicated bearing activation process Dedicated Bearer Activation Procedure that PCRF initiates speech business.PCRF to P-GW strategy is provided and the control of chargeing (Policy Charging Control, hereinafter to be referred as: PCC) information, P-GW initiates dedicated bearing and sets up flow process. dedicated bearing is set up and is finished, and speech business stream switches to E-UTRAN from the CS territory of GERAN/UTRAN.

Fig. 2 of the present invention has mainly handled the switching of CS territory business to embodiment shown in Figure 8.If the CS territory is professional switch in, also have ongoing PS territory service needed to switch to E-UTRAN from GERAN/UTRAN, that is: finish the switching of the CS territory of carrying out simultaneously among the GERAN/UTRAN and PS territory business to E-UTRAN., can or hang up to embodiment shown in Figure 8 according to Fig. 2, that is: preferentially guarantee the smooth switching of CS territory business the professional cut-out in ongoing PS territory.

According to another embodiment of the invention, the CS territory is professional to switch to E-UTRAN with PS territory service needed from GERAN/UTRAN if having simultaneously, in the step 102 of embodiment shown in Figure 1, also comprise PS territory handover information in the handoff request message, with the SGSN address information or the trigger message of UE registration, SGSN address information or trigger message are used to trigger the source serving MME is obtained UE from SGSN context.Corresponding business stream is CS territory Business Stream and PS territory Business Stream.Because the access network elements of GERAN/UTRAN only sends handoff request to MSC, and do not send handoff request, when the objective network that the access network elements perception of GERAN/UTRAN is switched is E-UTRAN, only trigger the switching in CS territory to SGSN.In subsequent step 103 and the step 104, MSC and service IWF do not resolve PS territory handover information, mainly are to pass to the source serving MME by service IWF.Accordingly, in the step 104, indication source serving MME is carried out CS territory business when the switching flow of E-UTRAN, and also comprise: indication source serving MME is carried out the switching flow of PS territory business to E-UTRAN.

Particularly, indication source serving MME execution PS territory business comprises to the switching flow of E-UTRAN: service IWF transmits handoff request message to the source serving MME; Source serving MME addressing SGSN, and, obtain the context of UE from SGSN according to SGSN address information or trigger message; The source serving MME is carried out the switching flow of PS territory business to E-UTRAN.

In addition, if the source serving MME does not have the SGSN address information of UE registration, obtain from SGSN before the context of UE according to trigger message, can also comprise: service IWF obtains the SGSN address information of UE registration, and this SGSN address information is offered the source serving MME; Perhaps, the source serving MME is obtained the SGSN address information of UE registration from HSS; Perhaps, UE is by the NAS signaling, and the SGSN address information that UE is registered sends to the source serving MME.NAS signaling wherein is specially Attach Request message, TAU request message or PDN connection request message.

Particularly, the SGSN address information that service IWF obtains UE registration can be: UE with the information interactive process of service IWF in, IWF sends the SGSN address information to service; Perhaps, UE is receiving Packet Temporary Mobile Subscriber Identity sign (the Packet Temporary Mobile Subscriber Identity that SGSN redistributes, hereinafter to be referred as: P-TMSI) with Routing Area Identifier (Routing Area Identity, hereinafter to be referred as: in the time of RAI), IWF sends the SGSN address information to service.

Fig. 9 serves IWF sends flow chart from an embodiment of handoff request message to the source serving MME for the present invention.As shown in Figure 9, this embodiment may further comprise the steps:

Step 801, service IWF sends handoff request message to the source serving MME, comprise target access network NE ID information among CS territory handover information, PS territory handover information, the E-UTRAN in this handoff request message, with the SGSN address information or the trigger message of UE registration, SGSN address information or trigger message are used to trigger the source serving MME is obtained UE from SGSN context.

Step 802, the service SGSN of source serving MME addressing UE, and to this service SGSN transmission UE context request message Context Request, the context of request UE.

Step 803, service SGSN returns UE context response information Context Response to the source serving MME, comprising the context of UE.

Step 804, the source serving MME is returned UE context acknowledgement message Context Ack to service SGSN.

Particularly, in the step 802, the source serving MME can be by the service SGSN of following three kinds of mode addressing UE:

First kind of mode is: service IWF obtains the SGSN address information of UE registration, and this SGSN address information is offered the source serving MME.UE can with the reciprocal process of IWF in, the SGSN address information of registration is offered IWF.

As an embodiment, at UE in the process of IWF registration or register update, for example: UE is registered to IWF for the first time or service IWF changes, UE re-registers in the process of new IWF, and UE can carry the SGSN address information in UE-IWF DISCOVERY REQUEST message from register flow path to IWF that initiate or UE-IWF REGISTER REQUEST message or UE-IWF REGISTER UPDATE UPLINK message.Perhaps, in other reciprocal process of UE and IWF, will be with the SGSN address information to be carried at and send to IWF in the related news.

As another embodiment, if UE has been registered to service IWF, if UE receives P-TMSI and RAI information that SGSN redistributes, for example: when SGSN changes, UE sends message, for example: UE-IWF REGISTER UPDATE UPLINK, give service IWF, carry the SGSN address information of renewal in this message.That is: when UE carried out RAU at every turn in GERAN/UTRAN, UE provided SGSN address information P-TMSI and RAI information to service IWF.

As another embodiment, UE also can not adopt the mode of Signalling exchange, but will serve IWF as the destination, the SGSN address information is placed on passes to service IWF in the packet.IWF resolves this packet can obtain serving the SGSN address information.

The second way is: when the source serving MME need be obtained the SGSN address information of UE registration, the source serving MME was obtained the SGSN address information of UE registration from HSS.

Particularly, the source serving MME can send SGSN address request SGSNRequest to HSS, the SGSN address information of acquisition request UE registration.The IMSI that comprises source serving MME ID and UE user in the SGSN address request.After HSS receives the SGSN address request, return SGSN address response message SGSN Response, return the SGSN address information of UE registration, comprising SGSN ID and UE user's IMSI to the source serving MME.

The third mode is: UE is by the NAS signaling, and the SGSN address information that UE is registered sends to the source serving MME.NAS signaling wherein is specially Attach Request message Attach Request, TAU request message TAU Request or PDN connection request message PDN Connectivity Request etc.In addition, can also transmit the SGSN address information of UE registration by increasing a new NAS message.If UE receives P-TMSI and RAI information that SGSN redistributes, for example: the situation that SGSN changes, UE can carry renewal in NAS message SGSN address information sends to the source serving MME.That is: when UE carries out RAU at every turn in GERAN/UTRAN, provide SGSN address information P-TMSI and RAI information to the source serving MME.

Figure 10 is the structural representation of an embodiment of IWF of the present invention.The IWF of this embodiment can be used as the service IWF of UE, realizes the corresponding function of service IWF in the above embodiment of the present invention.As shown in figure 10, the IWF of this embodiment comprises registration receiving element 901, retransmission unit 902, handover trigger unit 903 etc.

Wherein, registration receiving element 901 is used to receive user terminal in first login request message that source network sends, and finishes the registration of described user terminal to the service IWF of described user terminal;

Retransmission unit 902, be used to receive second login request message that described user terminal sends at source network, and described second login request message is forwarded to the source serving MME of described user terminal, so that described user terminal is accomplished to the registration of described source serving MME;

Handover trigger unit 903 is used to receive the handoff request message at source network of user terminal, and gives described source serving MME with described handoff request forwards, so that described source serving MME is carried out switching flow, described user terminal is switched to objective network.

In another one embodiment of the present invention, described retransmission unit, also be used for determining the source service IWF of described user terminal, when in described second login request message, not comprising MME information, from the MME tabulation, select to satisfy pre-conditioned MME as described source serving MME; Perhaps

When in described second login request message, comprising MME information, inquire about the MME that the MME information that comprises in described second login request message identified and whether be present in the described MME tabulation; If be present in the described MME tabulation, the MME that then selects the MME message identification that comprises in described second login request message is as described source serving MME; If be not present in the described MME tabulation, from the MME tabulation, select to satisfy pre-conditioned MME as described source serving MME.Wherein said MME tabulation can be kept on the service IWF.

In another one embodiment of the present invention, described service IWF can also comprise:

The register requirement unit also is used for after described registration receiving element is finished the registration of user terminal, sends the home subscriber server HSS of the 4th login request message to user terminal, and request is accomplished to the registration of described HSS.

In the foregoing description, source network can be GERAN, UTRAN etc., and objective network can be E-UTRAN etc.UE can be registered to IWF by GERAN/UTRAN, and be registered to serving MME by this service IWF, like this, the CS territory service needed of UE is when GERAN/UTRAN switches to E-UTRAN, service IWF can be used as the target access network network element among the E-UTRAN, be registered to the source serving MME information of storing in the process of serving MME according to UE, the indication serving MME is carried out the switching flow of CS territory business to E-UTRAN, solve the target access network network element eNB among the E-UTRAN and can't handle CS domain signaling flow process problem, ensure GERAN/UTRAN to professional normally the carrying out of switching in the CS territory of E-UTRAN, thereby guaranteed the user's communications quality of service.

Figure 11 is the structural representation of an embodiment of MSC of the present invention, and it comprises receiving element 1001, determining unit 1002 and transmitting element 1003, wherein:

Receiving element 1001 is used for the user terminal handoff request message that the access network element of reception sources network sends;

Determining unit 1002 is used for determining according to the handoff request message that described receiving element 1001 receives the service-interworking functional entity IWF of described terminal;

Transmitting element 1003 is used for described handoff request message is sent to the service IWF that described determining unit 1002 is determined.

In another one embodiment of the present invention, when comprising the relevant information of serving IWF in the described handoff request message, after described determining unit 1002 receives the user terminal handoff request message of access network element transmission at described receiving element, according to described address from the relevant information of IWF to HSS inquiry service IWF that serve; Perhaps

When the relevant information of service IWF is upgraded, the subscription data that HSS will comprise the relevant information of described service IWF sends to described moving exchanging center MSC, after described determining unit 1002 receives the user terminal handoff request message of access network element transmission at described receiving element, determine the service IWF of described user terminal according to the relevant information of service IWF.

In the foregoing description, source network can be GERAN, UTRAN etc., and objective network can be E-UTRAN etc.The MSC that the embodiment of the invention provided, the handoff request of user terminal in the source network can be transmitted to service IWF handles, solve the target access network network element eNB among the E-UTRAN and can't handle CS domain signaling flow process problem, ensure GERAN/UTRAN to professional normally the carrying out of switching in the CS territory of E-UTRAN, thereby guaranteed the user's communications quality of service.

Figure 12 is the structural representation of an embodiment of MME of the present invention, and it comprises receiving element 1101 and switch unit 1102, wherein:

Receiving element 1101 is used to receive the handoff request message of the user terminal that the service-interworking functional entity IWF of user terminal sends;

Switch unit 1002 is used for user terminal is switched to objective network from source network.

In another one embodiment of the present invention, described Mobility Management Entity also comprises:

First sets up the unit, is used to set up the Internet protocol IP tunnel of user terminal to interworking function entity IWF.

Simultaneously, in another one embodiment of the present invention, described Mobility Management Entity also comprises:

Second sets up the unit, and when being used for determining that not setting up S1 between described source serving MME and the described target access network network element is connected, foundation is connected with S1 between the described target access network network element.

Acquiring unit is used to obtain the address information of GPRS serving GPRS support node SGSN, and obtains described terminal use's context from SGSN.

In the foregoing description, source network can be GERAN, UTRAN etc., and objective network can be E-UTRAN etc.The mobile management entity that the embodiment of the invention provided can be served the switching indication that IWF sends in the reception sources network, the business of described user terminal is switched to objective network from source network, solve the target access network network element eNB among the E-UTRAN and can't handle CS domain signaling flow process problem, ensure GERAN/UTRAN to professional normally the carrying out of switching in the CS territory of E-UTRAN, thereby guaranteed the user's communications quality of service.

Figure 13 is the structural representation of the unified embodiment of network system of the present invention, and it comprises the service-interworking functional entity IWF 1202 of moving exchanging center MSC 1201, user terminal and the source service Mobility Management Entity 1203 of user terminal, wherein

Described MSC1201, the handoff request message that is used for the user terminal that the access network element of reception sources network sends, determine the service IWF1202 of described terminal according to described handoff request message, and described handoff request message is sent to described definite service IWF1202;

Described service IWF1202 is used to receive user terminal in first login request message that source network sends, and finishes the registration of described user terminal to the service IWF1202 of described user terminal; Receive second login request message that described user terminal sends at source network, and described second login request message is forwarded to described source serving MME 1203, so that described user terminal is accomplished to the registration of described source serving MME 1203; Receive the handoff request message at source network of user terminal, and give described source serving MME 1203,, described user terminal is switched to objective network so that described source serving MME 1203 is carried out switching flow with described handoff request forwards;

Described source serving MME 1203 is used to receive the handoff request message of the user terminal that service IWF1202 sends, and user terminal is switched switch to objective network from source network.

In addition, described source service IWF1202 also is used for determining the service IWF of described user terminal.

In another one embodiment of the present invention, when comprising in the described handoff request message that the CS territory is professional, when described service IWF determines that not setting up S1 between described source serving MME and the described target access network network element is connected, described service IWF trigger described source serving MME set up with described target access network network element between S1 be connected.

One of ordinary skill in the art will appreciate that: all or part of step that realizes said method embodiment can be finished by the relevant hardware of program command, aforesaid program can be stored in the computer read/write memory medium, this program is carried out the step that comprises said method embodiment when carrying out; And aforesaid storage medium comprises: various media that can be program code stored such as ROM, RAM, magnetic disc or CD.

The embodiment of the invention provides communication service, especially speech business, switch to the processing method of E-UTRAN from the CS territory of GERAN/UTRAN, when the user adheres at GERAN/UTRAN, be accomplished to the registration of IWF by GERAN/UTRAN after, when follow-up generation network switches, IWF handles switching flow as the target access network network element, solved the problem that eNB can't handle CS domain signaling flow process, ensured that GERAN/UTRAN to normally carrying out that switch in the CS territory of E-UTRAN, has guaranteed communication quality and user's business experience.Further, UE can also be accomplished to the registration of MME and set up UE in advance to the transmission channel between the IWF by MME by service IWF.In follow-up handoff procedure, owing to set up UE to the transmission channel between the IWF before, after service IWF receives the CS territory Business Stream of MSC transmission, can smoothly CS territory Business Stream be passed to UE, be not attached to the EPS network and set up the flow process of UE and do not need to carry out to the transmission channel between the IWF at the EPS network, reduce the professional time delay for switching in CS territory, improved communication quality and user's business experience.

It should be noted last that: above embodiment is only in order to illustrating technical scheme of the present invention, but not the present invention is made restrictive sense.Although the present invention is had been described in detail with reference to above-mentioned preferred embodiment, those of ordinary skill in the art is to be understood that: it still can make amendment or be equal to replacement technical scheme of the present invention, and this modification or be equal to the spirit and scope that replacement does not break away from technical solution of the present invention.

Claims

1. a communication service switching method is characterized in that, comprising:

2. method according to claim 1 is characterized in that, described second login request message is sent to before the source service Mobility Management Entity MME of user terminal, also comprises:

Determine the source serving MME of described user terminal.

3. method according to claim 2 is characterized in that, determines that the source serving MME of described user terminal comprises:

If do not comprise MME information in described second login request message, described service IWF selects to satisfy pre-conditioned MME as described source serving MME from the MME tabulation; Perhaps

If comprise MME information in described second login request message, whether described service IWF inquires about the MME that the MME information that comprises in described second login request message identified and is present in the MME tabulation;

If be present in the described MME tabulation, described service IWF selects the MME of the MME message identification that comprises in described second login request message as described source serving MME; Perhaps

If be not present in the described MME tabulation, described service IWF selects to satisfy pre-conditioned MME as described source serving MME from the MME tabulation;

Wherein said MME tabulation is kept on the service IWF.

4. method according to claim 1, it is characterized in that, if described second login request message sends to described service IWF by unstructured supplementary data traffic USSD tunnel, then described second login request message is forwarded to after the serving MME of described source, also comprise:

Described source serving MME is set up the Internet protocol IP tunnel of described user terminal to described service IWF;

Described service IWF receives the 3rd login request message that user terminal sends by IP tunnel, and described service IWF stores the IP address information that comprises in described the 3rd request message;

Service IWF receives the IP address information of the described user terminal of described user terminal transmission.

5. method according to claim 1 is characterized in that, receives described user terminal and draws together in the handoff request message of described source network:

Described user terminal sends to moving exchanging center MSC by the access network element of source network with described handoff request message, described MSC determines the service IWF of described user terminal according to described handoff request message, and described handoff request is sent to described service IWF.

6. method according to claim 5 is characterized in that, the access network element of described source network sends to MSC with described handoff request message and comprises:

Described access network element receives the measurement report of described user terminal, and described measurement report comprises the metrical information of described objective network and the metrical information of the service IWF that described user terminal is registered;

When described access network element is determined to initiate switching flow according to the measurement report of described user terminal, send handoff request message, comprise the relevant information of described service IWF in the described handoff request message to described MSC.

7. method according to claim 6, it is characterized in that, when the relevant information of described service IWF is target identification or the target cell information of service IWF, when the metrical information of service IWF is the cell information of service IWF, described MSC determines to comprise the service IWF of described user terminal according to described handoff request message:

Described access network elements is mapped as cellular global identity CGI with the cell information of described service IWF, and according to the correspondence relationship information between the CGI that sets in advance and the target identification/Target cell, obtain the target identification/target cell information corresponding, and the target identification/target cell information corresponding with described CGI sent to MSC with described CGI;

Described MSC determines the service IWF of described CGI corresponding user terminal according to the correspondence relationship information between described target identification/Target cell and the IWF.

8. method according to claim 5 is characterized in that, described reception user terminal comprises in first login request message that source network sends: described service IWF receives first login request message that described user terminal sends;

Described service IWF receives after first login request message of described user terminal transmission, and also comprise: described service IWF sends the 4th login request message to the home subscriber server HSS of described user terminal, and request is accomplished to the registration of HSS.

9. method according to claim 8 is characterized in that, described MSC determines to comprise the service IWF of described user terminal according to described handoff request message:

After described MSC receives the user terminal handoff request message of described access network element transmission, obtain the address of service IWF from described HSS according to the relevant information of described service IWF; Perhaps

When described HSS upgrades in the relevant information of described service IWF, insert the subscription data of described user terminal to described MSC, this subscription data comprises the relevant information of the service IWF of renewal, after described MSC receives the user terminal handoff request message of described access network element transmission, determine the service IWF of described user terminal according to the relevant information of described service IWF.

10. method according to claim 1 is characterized in that, when comprising circuit switching field service information in the described handoff request message, also comprises:

When described service IWF did not set up S1 and is connected between the access network elements of described source serving MME and described objective network, the S1 that triggers between the access network elements of the serving MME foundation of described source and described objective network was connected.

11. according to any described method of claim 1 to 10, it is characterized in that, when comprising packet switch domain service information in the described handoff request message, give described source serving MME with described handoff request forwards, so that carrying out switching flow, described source serving MME comprises:

Described source serving MME receives the handoff request message that described service IWF transmits;

Obtain the address information of GPRS serving GPRS support node SGSN, and obtain the context of described user terminal from this SGSN after, carry out the switching flow of packet switch domain service.

12. method according to claim 11 is characterized in that, the address information of the described SGSN of obtaining comprises:

Described service IWF obtains the SGSN address information of described user terminal registration, and this SGSN address information is offered described source serving MME; Perhaps

Described source serving MME is obtained the SGSN address information of described user terminal registration from HSS; Perhaps

Described user terminal is by Non-Access Stratum NAS signaling, and the SGSN address information that described user terminal is registered sends to described source serving MME.

13. an interworking function entity is characterized in that, comprising:

14. interworking function entity according to claim 13, it is characterized in that, described retransmission unit, also be used for determining the source service IWF of described user terminal, when not comprising MME information in described second login request message, from the MME tabulation, select to satisfy pre-conditioned MME as described source serving MME; Perhaps

When comprising MME information in described second login request message, inquire about the MME that the MME information that comprises in described second login request message identified and whether be present in the described MME tabulation; If be present in the described MME tabulation, the MME that then selects the MME message identification that comprises in described second login request message is as described source serving MME; If be not present in the described MME tabulation, from the MME tabulation, select to satisfy pre-conditioned MME as described source serving MME; Wherein said MME tabulation is kept on the service IWF.

15. interworking function entity according to claim 13 is characterized in that, also comprises:

The register requirement unit is used for after described registration receiving element is finished the registration of described user terminal, sends the home subscriber server HSS of the 4th login request message to described user terminal, and request is accomplished to the registration of described HSS.

16. a mobile switching centre is characterized in that, comprising:

17. mobile switching centre according to claim 16, it is characterized in that, when comprising the relevant information of serving IWF in the described handoff request message, described determining unit is inquired about the address of described service IWF to HSS according to the relevant information of described service IWF after described receiving element receives described access network element transmission handoff request message; Perhaps

When the relevant information of described service IWF is upgraded, the subscription data that described HSS will comprise the relevant information of described service IWF sends to MSC, after described determining unit receives the handoff request message of described access network element transmission at described receiving element, determine the service IWF of described user terminal according to the relevant information of described service IWF.

18. a Mobility Management Entity is characterized in that, comprising:

19. Mobility Management Entity according to claim 18 is characterized in that, also comprises:

First sets up the unit, is used to set up the IP tunnel of user terminal to described IWF.

20. Mobility Management Entity according to claim 18 is characterized in that, also comprises:

Second sets up the unit, when being used between source serving MME and described objective network target access network network element, not setting up S1 and being connected, set up with described target access network network element between S1 be connected.

21. according to any described Mobility Management Entity of claim 18 to 20, it is characterized in that, also comprise:

Acquiring unit is used to obtain the address information of SGSN, and obtains the context of described user terminal from this SGSN.

22. a network system is characterized in that, comprises the source serving MME of the service IWF and the user terminal of MSC, user terminal, wherein

23. network system according to claim 22 is characterized in that, described source service IWF also is used for determining the service IWF of described user terminal.