CN101394667B - Urgent session switching method - Google Patents

Abstract

The invention discloses an emergent session switching method. A user terminal establishes the bearer in a source access system and carries out emergence call service; when a target access system is discovered and the switching is determined, the user terminal firstly determines a session service type carried by the source access system; if the emergent session service is carried by the source access system, the user terminal initiates an emergent attach request to the target access system to trigger and complete the switch of the emergent session. In the emergent session switching method, the emergent attach request is initiated directly when the switching is conducted, thereby achieving the switch of the emergent session between a non-3GPP IP access system and a 3GPP access system, avoiding the target network system to forbid UE to access due to the roaming restriction or the access restriction of the UE, and resulting in the failing emergent session; meanwhile, the target network establishes the emergent bearer of the emergent session service, thereby ensuring the high QoS (Quality of Service) priority level required for the emergent session.

Description

Urgent session switching method

Technical field

The present invention relates to the communications field; Particularly; Relate to a kind of method of carrying out the emergent session switching for user terminal; Relate in particular to a kind of user terminal and between 3GPP (3rd Generation PartnershipProject, third generation partner program) Access Network and non-3 GPP access network, carry out the method that emergent session switches.

Background technology

In the existing network evolution; Development along with network architecture flattening; And the appearance that multiple high-speed wideband moves access way impels mobile communications network to propose the framework theory of future generation of LTE/SAE (Long term Evolution/System Architecture Evolution, Long Term Evolution/system architecture evolution), comprises making the wireless communication system of evolution that higher transmission rate can be provided; Shorter transmission delay; Lower cost is supported the mobility between the inner connecting system of 3GPP simultaneously, and the mobility between 3GPP connecting system and the non-3GPP connecting system or the like.LTE/SAE further is defined as EPS (Evolved Packet System according to the standard progress; Evolved packet system) network; The EPS network also as a kind of access means in IMS (IP Multimedia Subsystem, IP Multimedia System) territory, impels the IMS framework to be able to evolution and development.

3GPP evolved packet system (Evolved Packet system; Be called for short EPS) by E-UTRAN (Evolved Universal Terrestrial Radio Access Network; The universal land radio access web of evolution), MME (mobile management unit; Mobility Management Entity), S-GW (gateway, Serving GateWay), P-GW (Packet Data Network GateWay, data network gateway), HSS (home subscriber server; Home Subscriber Server), 3GPP aaa server (3GPP authentication and authorization charging server); PCRF (Policy and Charging RulesFunction, "Policy and Charging Rules Function), and other supporting network element device is formed.

E-UTRAN is follow-on wireless access network, and higher up-downgoing speed can be provided, lower transmission delay and reliable more wireless transmission.Wherein the main network entity of E-UTRAN is eNodeB.

MME is responsible for mobile management and storage UE (User Equipment; User terminal) context chain of command related works such as (such as UE/ ID, mobility management states, user security parameters etc.); For the user distributes temporary mark,, is responsible for UE this user is carried out authentication when quartering at this tracing area or this network.

Serving GW (be called for short S-GW), the user plane functions entity is mobile anchor point and the mobile anchor point between the E-UTRAN between EPS system and traditional 3GPP system.S-GW is the accessing gateway equipment that links to each other with E-UTRAN, between E-UTRAN and P-GW, transmits data, and is responsible for pending datas such as paging are carried out buffer memory.

PDN GW (being called for short P-GW), the user plane functions entity is responsible for user terminal and is transmitted functions such as data to the access of PDN, between EPS and PDN.User face data is carried out route handle, termination is in the downlink data of the UE of idle state, when the downlink data that mails to UE arrives, initiates paging.The context of management and storage UE is such as IP bearer service parameter and network internal routing iinformation etc.

PDN (Packet Data Network): packet data network is for the user packet-based service network to be provided.

HSS is a home subscriber server, the information such as user contracting data in management circuit territory (CS), packet domain (PS) territory and IMS territory.

PCRF is the "Policy and Charging Rules Function entity, and it obtains business information through Rx interface and operator's IP operation network interface; And link to each other with gateway device in the network through the S7/S7a/S7b/S7c interface, be responsible for initiating IP (Internet Protocol, Internet protocol) carrying strategic decision-making; Like foundation, the deletion of carrying; The QoS of business datum/carrying (Quality of Service, service quality) etc., and the control of chargeing.

EPS supports and the intercommunication of non-3GPP network, promptly supports the access of non-3GPP IP Access Network.The intercommunication of EPS and non-3GPP network realizes that through the S2a/b/c interface P-GW is 3GPP and the internetwork anchor point of non-3GPP.The system architecture diagram of EPS is as shown in Figure 1.Wherein non-3 GPP access network is divided into trusted non-3GPP IP Access Network and trustless non-3GPP IP Access Network.The non-3GPP IP of trusted Access Network can directly be connected with P-GW through the S2a interface; Trustless non-3GPP IP Access Network need pass through ePDG (Evolved Packet Data Gateway, the data gateway of evolution) and link to each other with P-GW, and the interface between ePDG and P-GW is the S2b interface.

In traditional 3GPP network; Strategy and charge execution function (Policy and chargingenforcement function; Be called for short PCEF) exist only among the P-GW; PCRF needs only the control that can accomplish all functions such as comprising QoS corresponding strategies and charging with the P-GW interface, passes through S7 interface exchange message between PCRF and P-GW.But after the 3GPP network provided the IWF with non-3GPP, the interface when between P-GW and S-GW was based on PMIP (Proxy Mobile IP; Proxy-mobile IP) time; Since the limitation of PMIP interface, the partial function of PCEF, the binding function that for example carries etc.; Moved among the S-GW, passed through S7c interface exchange message between S-GW and the PCRF.When non-3GPPIP system through between S2a/S2b interface and 3GPP system during the intercommunication access, the also function of resident part PCEF in the non-3 GPP system.When non-3 GPP system is connecting system trusty (the non-3GPP of trusted inserts), pass through information such as S7a interface exchange control strategy, charging between PCRF and non-3 GPP system; When non-3 GPP system is fly-by-night connecting system (trustless non-3GPP inserts), pass through information such as S7b interface exchange control strategy, charging between PCRF and non-3 GPP system.In the 3GPP system, business provides by carrying (bearer).Carrying has multiple attribute, such as bearer types, speed, priority etc.In the EPS system; UE (user terminal) is called default bearing (default bearer) with first carrying that certain P-GW sets up in attach (adhering to) process, the carrying of setting up for certain specific business later on is called dedicated bearing (dedicated bearer).Supporting dynamic strategy to charge in EPS system and the non-3 GPP access network of control, the strategy that the UE through non-3GPP access 3GPP system issues according to PCRF is set up the IAD dedicated bearing of UE and non-3GPP.

Fig. 2 has described UE and has been linked into the switching flow that non-3GPP inserts from 3GPP, and non-3GPP inserts and comprises that the non-3GPP of trusted inserts and trustless non-3GPP access.As shown in Figure 2, switching flow comprises following steps:

201:UE inserts EPS through the 3GPP connecting system, sets up default bearing; And PMIP or GTP tunnel have been set up between S-GW and P-GW;

202:UE finds non-3GPP connecting system and initiates to switch, and promptly UE is linked into non-3GPP connecting system by 3GPP connecting system (EPS network);

203:UE initiates access authentication through non-3GPP IP connecting system to HSS/AAA; The 3GPPAAA server carries out authentication and mandate to UE in the access of non-3GPP; 3GPP AAA inquiry HSS also returns the P-GW address and gives non-3GPP IP connecting system;

204:UE initiates attach request to non-3GPP IP connecting system;

205: non-3GPP IP connecting system and PCRF carry out IAD session control process, and non-3GPP IP connecting system gets access to QoS and policing rule, and carry out the binding of carrying with session;

206: non-3GPPIP connecting system sends agent binding update messages to P-GW, and original session port in the 3GPP connecting system is bound in application;

207:P-GW is to PCRF initiation session modify request messages, and PCRF returns the session modification acknowledge message to P-GW, comprises qos policy and charging regulation in the message, is carried out by P-GW;

208:P-GW and HSS/AAA carry out alternately UE being authorized;

209:P-GW handles agent binding update, sends proxy binding acknowledgment messages to non-3GPPIP connecting system;

210: non-3GPP IP connecting system sends to UE and adheres to completion message, sets up default bearing between UE and the non-3GPPIP connecting system simultaneously.

Step 210 is set up the PMIP tunnel between non-3GPP IP connecting system and P-GW after accomplishing, and the default bearing of UE is also set up completion; UE can insert through non-3GPP IP connecting system, and through P-GW transmission/reception IP packet, completion is switched in session.

Above-mentioned non-3GPP connecting system possibly comprise a plurality of network element devices, and wherein comprises the PCEF function relevant with carrying.Fig. 3 has described UE and has been linked into the switching flow that 3GPP inserts from non-3GPP, and non-3GPP inserts and comprises that the non-3GPP of trusted inserts and trustless non-3GPP access.As shown in Figure 3, switching flow comprises following steps:

301:UE is linked into P-GW through non-3GPP connecting system, and sets up default bearing; Set up the PMIP tunnel between non-3GPP connecting system and P-GW;

302:UE finds E-UTRAN connecting system (being the 3GPP connecting system) and decision initiation switching, and promptly UE is inserted session and switches to the 3GPP connecting system by current non-3GPP;

303:UE sends to MME through the E-UTRAN route with attach request, and MME carries out authentication to UE, and sets up NAS (Network Association Security) network security alliance;

304:MME sends position updating request to HSS/AAA, carries the sign of MME, the sign of UE in the message; HSS/AAA finds out the address of user data and the P-GW of UE according to the sign of UE, sends to MME;

MME receives user data, and whether inspection UE is allowed access to network, returns to HSS and receives user's response; If MME finds UE problems such as roaming restriction or access restriction are arranged, MME will forbid that UE adheres to, and notice HSS/AAA;

305:MME is that UE selects a S-GW, and to the request that default bearing is set up in its transmission, comprises information such as P-GW address and bearer types in the message;

306:S-GW sends the request set up default bearing to P-GW, in this request, comprises the information such as address, bearer types of S-GW;

307:P-GW is to PCRF initiation session modify request messages, and PCRF returns the session modification acknowledge message to P-GW, comprises qos policy and charging regulation in the message, is carried out by P-GW;

308:P-GW sets up the default bearing resource according to strategy and charging decision information that PCRF returns, and returns carrying to S-GW and set up response;

309:S-GW sends the response that default bearing is set up to MME, and indication S5 carries foundation and upgrades successfully;

310:MME sends attachment response to E-UTRAN, shows that the request that is attached to network of UE is received; Set up radio bearer between E-UTRAN and the UE, and realize between the S-GW that user plane inserts;

311:S-GW sends the bearer update request message to P-GW, comprises wireless access completion mark, and indication P-GW switches to the 3GPP connecting system from non-3GPP IP connecting system and removes the access data bag; P-GW confirms.

Step 311 is set up the PMIP/GTP tunnel after accomplishing between S-GW and P-GW, the wireless and access bearer between UE and E-UTRAN, the S-GW is also set up completion; UE can insert through the 3GPP connecting system, and through P-GW transmission/reception IP packet, completion is switched in session.

Above-mentioned non-3GPP connecting system possibly comprise a plurality of network element devices, and wherein comprises the PCEF function relevant with carrying.

In Fig. 2; When UE goes forward side by side guild's call business through 3GPP access network access EPS system; After UE finds the non-3 GPP access network network; UE can be according to the measurement report or the network notice of wireless signal, and decision is carried out session to non-3 GPP access network and switched, and promptly the current sessions business is carried by the 3GPP Access Network and switched to the non-3 GPP access network carrying.

In Fig. 3; UE is linked into P-GW through the non-3 GPP access network network; When going forward side by side guild's call business, after UE found the 3GPP access network, UE can be according to the measurement report or the network notice of wireless signal; Decision is carried out session to the 3GPP Access Network and is switched, and promptly the current sessions business is carried by non-3 GPP access network and switched to the carrying of 3GPP Access Network.

Supporting dynamic strategy to charge the EPS system of control when having sessions carry to switch with non-3 GPP access network, the sessions carry between 3GPP access network and the non-3 GPP access network network is switched the switching flow that will relate to the emergent session business.

Urgent call (Emergency Call) is distinctive a kind of voice service function in the GSM.Even be provided with the restriction exhalation and do not insert subscriber identification module (Subscriber IdentityModule at portable terminal; Abbreviation SIM) under the situation; As long as in mobile network's region covered; When the user dial emergency numbers as: 110, after 119,911 etc., calling can forward corresponding EC (PSAP) to like police office, fire brigade, first-aid centre etc., thereby to the masses 24 hours emergency assistance services is provided.The operation of whole system is by the completion of cooperating jointly of emergency services such as telecom operators and public security, fire-fighting, hospital.

Under the conventional situation, urgent call all is to be placed in the CS territory, and along with the progressively IPization of network, the PS territory also begins progressively to support emergence call service, and utilizes the IMS system to do call signaling control for emergent session.Current, the emergence call service that utilizes the IMS territory to provide can abbreviate the IMS urgent call as.The IMS urgent call need realize in non-3GPP IP connecting system or 3GPP connecting system that IP carries.Therefore, the session of non-3GPP IP connecting system and 3GPP connecting system needs to support that emergent session switches in switching.

In the above-mentioned existing switching flow, if UE can realize normally adhering in non-3GPP connecting system and 3GPP connecting system, that emergent session switches through Fig. 2, the described flow process of Fig. 3 can realize the session switching.If but UE has roaming restriction or inserts restriction in target access system, do not open reasons such as roaming or arrearage like the user, can authentification failure when the target access system authentication, cause adhering to and be rejected, finally cause the emergent session handoff failure.

The scene of emergent session handoff failure see Fig. 4; When non-3GPPIP connecting system was initiated the emergent session switching, non-3GPP IP connecting system and HSS/AAA were mutual, and UE is carried out authentication at the 3GPP connecting system; Information such as subscription data through UE; Non-3GPP IP connecting system judgement UE has the roaming restriction or inserts restriction and forbid access, and non-3GPP IP connecting system can be sent out refusal to UE and insert message in step 405, cause the emergent session handoff failure.

Two of the scene of emergent session handoff failure is seen Fig. 5; When the 3GPP connecting system was initiated the emergent session switching, MME and HSS/AAA were mutual, and UE is carried out authentication at non-3GPP IP connecting system; Information such as subscription data through UE; MME judgement UE has the roaming restriction or inserts restriction and forbid access, and MME can send out refusal to UE and insert message in step 506, cause the emergent session handoff failure.

Summary of the invention

The technical problem that the present invention will solve provides a provenance connecting system and realizes the method that emergent session switches to target access system; To solve in the prior art; Connecting system is when target access system is initiated the emergent session switching in the source; Target access system is carried out access authentication to UE, because UE has roaming restriction or access to limit and forbids inserting, causes the problem of emergent session handoff failure.

In order to address the above problem; The invention provides a kind of urgent session switching method, user terminal in the source connecting system set up and carry and carry out emergence call service, when finding that target access system and decision are switched; Said user terminal is at first judged the session service type that connecting system carries in said source; If what connecting system carried in said source is that emergent session is professional, said user terminal is initiated emergency attached request to said target access system, triggers and accomplishes emergent session and switch.

Further, said user terminal carries urgent sign in the emergency attached request message that said target access system is initiated, and is used to indicate that this attach request initiates is that emergent session is professional.

Further; Said target access system judges whether carry urgent sign in the said Attach Request message after receiving the attach request of said user terminal transmission, if having; The access of forbidding of then ignoring this user limits, and allows said user terminal to insert target access system.

Further, after said target access system was passed through the urgent access authentication of said user terminal, said target access system and home subscriber server/authentication and authorization charging server HSS/AAA obtained user data alternately; The address of the data network gateway P-GW that said HSS/AAA will connect with said source connecting system sends to target access system.

Further; After said target access system obtains the address of said P-GW; The emergency bearing request is set up to the P-GW transmission in address according to said P-GW, sets up and carries urgent sign in the emergency bearing request message, indicates this emergency bearing to be used for the emergent session business.

Further, said foundation also includes target access system access address and bearer types in the emergency bearing request message.

Further; Said P-GW receives that said target access system sends set up the emergency bearing request after; Send session modification request to "Policy and Charging Rules Function PCRF, carry urgent sign in the session modification request message, be used for indication and set up emergency bearing.

Further; After said PCRF receives the session modification request of said P-GW transmission; Judge and whether carry urgent sign in the session modification request message; If have, said PCRF sends the session modification acknowledge message to said P-GW, comprises in this message to serve emergent session professional QoS policy and charging regulation.

Further; After said P-GW receives said session modification acknowledge message,, set up emergency bearing resource according to being used for emergent session professional qos policy and charging regulation in this message; And return emergency bearing to said target access system and set up response, carry urgent sign in the response message;

Said target access system receives said emergency bearing and sets up response; According to the urgent sign indication in the response message; Set up wireless with said user terminal and P-GW and the access emergency bearing, the high QoS rank of serving urgency traffic is provided, said user terminal is realized urgent the access through said target access system; And through said P-GW transmission and reception IP packet, emergent session switches to be accomplished.

Further, said user terminal is judged the session service type that connecting system carries in said source through one of following dual mode:

Said user terminal judges whether calling number is the emergency telephone number of its storage, if then the session service type of this call setup is that emergent session is professional;

Said user terminal is after professional Control Network makes a call; Said professional Control Network judges whether the session service type of this call setup is that emergent session is professional; If it is that emergent session is professional that said professional Control Network is notified the session service type of said this call setup of user terminal.

Urgent session switching method of the present invention; When switching, directly initiate emergency attached request; Thereby the emergent session that can be implemented between non-3GPP IP connecting system and the 3GPP connecting system switches, and has avoided the objective network system because of the roaming of UE restriction or access restriction and has forbidden that UE inserts, and causes the scene of emergent session failure to take place; Set up emergency bearing at objective network simultaneously, ensured the high QoS priority that emergent session needs into the emergent session service.

Description of drawings

Fig. 1 is the system architecture sketch map of EPS access network;

Fig. 2 is under the prior art, and UE is linked into the session switching flow figure that non-3GPP IP inserts from 3GPP;

Fig. 3 is under the prior art, and UE is linked into the session switching flow figure that 3GPP inserts from non-3GPP IP;

Fig. 4 is under the prior art, and UE is linked into the scene of the emergent session handoff failure of non-3GPP IP access from 3GPP;

Fig. 5 is under the prior art, and UE is linked into the scene of the emergent session handoff failure of 3GPP access from non-3GPP IP;

Fig. 6 for UE of the present invention from the source connecting system to the emergent session switching flow figure of target access system;

Fig. 7 is linked into the flow chart of the embodiment that emergent session that non-3GPP IP inserts switches from 3GPP for UE of the present invention;

Fig. 8 is linked into the flow chart of the embodiment that emergent session that 3GPP inserts switches from non-3GPP IP for UE of the present invention.

Embodiment

The present invention mainly solves in the prior art; UE in the source connecting system (the source connecting system is meant the IP connecting system of current carrying UE session service; Can right and wrong 3GPP IP connecting system, also can be the 3GPP connecting system) in carry out emergent session when professional, when UE finds that (target access system is meant that session switches the IP connecting system of back carrying UE session to target access system; Can right and wrong 3GPP IP connecting system; Also can be the 3GPP connecting system) back decision initiation session is switched, but target access system has couple UE not enter restriction, causes the problem of session handoff failure.

In the 3GPP network, when UE carries out emergent session when professional through professional Control Network (like the IMS network), UE need judge whether it is urgent call, can relatively discern through emergency numbers of dialing and the emergency numbers that UE stores.If UE can't discern, it just makes a call to set up by the normal call flow process and asks, and after professional Control Network was received setup requests, needing to differentiate be urgent call or normal call, if urgent call, professional Control Network need be notified UE.

Learn that through above-mentioned analysis after UE set up emergent session, UE can know that current session is emergent session or common session through the mode that self discerns or network is notified.Therefore; When UE when finding that target access system and decision are switched; UE can directly initiate emergency attached in target access system, sets up emergency bearing, thereby has both guaranteed that emergent session switched to target access system; Emergent session is carried on the emergency bearing of high QoS priority, has greatly ensured the continuity of emergent session business and the high-quality and the high reliability of voice.

Below in conjunction with accompanying drawing and specific embodiment the present invention is described further so that those skilled in the art can better understand the present invention and implementing, but the embodiment that lifts not conduct to qualification of the present invention.

As shown in Figure 6, after UE carried realization emergent session business through the source connecting system, when UE found that target access system and decision are switched, UE elder generation judged whether session service is emergent session, carried out emergent session in target access system then and switched.Step is following:

S12:UE carries through the source connecting system and has realized that emergent session is professional; UE finds target access system and decision initiation switching, and promptly UE switches to target access system with session by current source connecting system;

S14:UE is before switching, and the conversation type of earlier connecting system in the source being carried judges that judgement is emergent session type or normal conversation type;

UE can know the emergent session type that connecting system carries in the source through dual mode.First method is UE when initiating urgent call, and UE can judge whether called number whether be that emergency numbers discerns is urgent call; Second method is after UE makes a call, and whether professional Control Network (like the IMS network) identification of having the ability is urgent call, and notice UE this be urgent call.

S16:UE judge the source connecting system carry be urgent call after, directly initiate emergency attached in target access system, and carry urgent sign and indicate;

S18: information such as target access system and HSS/AAA interactive user subscription data, UE is carried out urgent access authentication; Because of UE is an emergency attached, target access system is ignored roaming restriction or is inserted restriction and wait and do not enter restriction, allows UE to be linked into network, and returns to HSS/AAA and to accept the user and respond;

Target access system with the HSS/AAA information interaction in obtain the address information of P-GW.

S20: target access system is sent the request of setting up emergency bearing to P-GW, in this request, comprises information such as target access system access address, bearer types and urgent sign, sets up emergency bearing through urgent sign indication;

S22:P-GW is to PCRF initiation session modify request messages, and carrying urgent sign indication in the message is emergency bearing; PCRF returns the session modification acknowledge message to P-GW, is included as the qos policy and the charging regulation of emergency bearing service in the message, is carried out by P-GW; The qos policy and the charging decision information of the emergency bearing that S24:P-GW returns according to PCRF are set up emergency bearing resource, and return emergency bearing to target access system and set up response, carry urgent sign in the response message; S26: the urgent sign indication of target access system basis, set up wireless with UE, P-GW and the access emergency bearing, the high QoS rank of serving urgency traffic is provided; UE can realize urgent the access through target access system, and sends and receive the IP packet through P-GW, and emergent session switches to be accomplished.

First embodiment of the invention is as shown in Figure 7; In this embodiment; UE carries through 3GPP connecting system (EPS network) and has initiated emergent session; UE is through to the judgement of emergency numbers or from the notice of professional Control Network (like the IMS network), and what UE knew that the 3GPP connecting system carries is emergent session.When UE initiates emergent session when switching at non-3GPP IP connecting system, UE directly initiates emergency attached at non-3GPP IP connecting system, sets up emergency bearing, ensures the handover success of emergent session and the high QoS priority of emergency bearing.

Fig. 7 has described UE and has been linked into the emergent session switching flow that non-3GPP IP inserts from 3GPP, and non-3GPP inserts and comprises that the non-3GPP of trusted inserts and trustless non-3GPP access.As shown in Figure 7, the emergent session switching flow comprises following steps:

701:UE inserts EPS through the 3GPP connecting system, sets up default bearing or dedicated bearer; And PMIP or GTP tunnel have been set up between S-GW and P-GW;

702:UE finds non-3GPP IP connecting system and prepare to initiate switches, promptly UE by the EPS network insertion to non-3GPP connecting system;

703:UE judges that to the conversation type of carrying at the 3GPP connecting system judgement is emergent session type or normal conversation type earlier before switching; UE judge the 3GPP connecting system carry be urgent call after, directly initiate emergency attached at non-3GPP IP connecting system;

UE can know through dual mode whether what carry at the 3GPP connecting system is the emergent session type.First method is UE when initiating urgent call, and whether whether UE be that emergency numbers discerns be urgent call if having the ability to judge called number; Second method is after UE makes a call, and whether professional Control Network (like the IMS network) identification of having the ability is urgent call, and notice UE this be urgent call.

704:UE initiates urgent access authentication through non-3GPP IP connecting system to HSS/AAA, carries urgent sign in the message and indicates; The 3GPP aaa server carries out authentication to UE in the urgent access of non-3GPP, and the roaming of ignoring UE limits, access restriction etc. do not enter restriction, and access is authorized to UE; 3GPP AAA inquiry HSS also returns the P-GW address and gives non-3GPP connecting system;

705:UE initiates emergency attached request to non-3GPP IP connecting system, in emergency attached request, carries urgent sign and indicates;

706: non-3GPP IP connecting system and PCRF carry out IAD session control process, and carrying urgent sign indication in the interaction message is emergency bearing; PCRF can identify by identified emergency, and gives non-3GPP IP connecting system with the high QoS priority and the strategy rule downloading of emergency bearing, and non-3GPP IP connecting system is carried out the binding of emergency bearing and emergent session;

707: non-3GPP IP connecting system sends agent binding update messages to P-GW, and original session port in the 3GPP connecting system is bound in application, and carrying urgent sign indication in the message is emergency bearing;

708:P-GW is to PCRF initiation session modify request messages, and carrying urgent sign indication in the message is emergency bearing; PCRF returns the session modification acknowledge message to P-GW, is included as the qos policy and the charging regulation of emergency bearing service in the message, is carried out by P-GW; 709:P-GW and HSS/AAA carry out alternately UE promptly being authorized;

710:P-GW handles agent binding update, sends proxy binding acknowledgment messages to non-3GPP IP connecting system, carries urgent sign in the message, shows that emergency bearing sets up successfully;

711: non-3GPP IP connecting system sends emergency attached to UE and accomplishes message, sets up emergency bearing between non-3GPPIP connecting system and the UE simultaneously.

Step 711 is set up the PMIP tunnel that is used for emergency bearing after accomplishing between non-3GPP IP connecting system and P-GW, the emergency bearing of UE and 3GPP IP connecting system is also set up completion; UE can insert through non-3GPP IP connecting system, and sends and receive the IP packet through P-GW, and emergent session switches to be accomplished.

Above-mentioned non-3GPP connecting system possibly comprise a plurality of network element devices, and wherein comprises the PCEF function relevant with carrying.

Second embodiment of the invention is as shown in Figure 8; In this embodiment; UE carries through non-3GPP IP connecting system and has initiated emergent session; UE is through to the judgement of emergency numbers or from the notice of professional Control Network (like the IMS network), and what UE knew that non-3GPP IP connecting system carries is emergent session.When UE initiates emergent session when switching at 3GPP connecting system (EPS network), UE directly initiates emergency attached at the 3GPP connecting system, sets up emergency bearing, ensures the handover success of emergent session and the high QoS priority of emergency bearing.

Fig. 8 has described UE and has switched to the switching flow of 3GPP connecting system from non-3GPP IP connecting system, and non-3GPP inserts and comprises that the non-3GPP of trusted inserts with trustless non-3GPP and insert.As shown in Figure 8, switching flow comprises following steps:

801:UE is linked into P-GW through non-3GPP IP connecting system, and sets up default bearing or dedicated bearer; Set up the PMIP tunnel between non-3GPP IP connecting system and P-GW;

802:UE finds E-UTRAN connecting system (being the 3GPP connecting system) and decision initiation switching, and promptly UE switches to the 3GPP connecting system with session by current non-3GPP IP connecting system;

803:UE judges that to the conversation type of carrying at non-3GPP IP connecting system judgement is emergent session type or normal conversation type earlier before switching; UE judge non-3GPP IP connecting system carry be urgent call after, directly initiate emergency attached at 3GPP connecting system (EPS network);

UE can know the emergent session type of carrying at non-3GPP IP connecting system through dual mode.First method is UE when initiating urgent call, and whether whether UE be that emergency numbers discerns be urgent call if having the ability to judge called number; Second method is after UE makes a call, and whether professional Control Network (like the IMS network) identification of having the ability is urgent call, and notice UE this be urgent call.

804:UE initiates emergency attached request through the E-UTRAN route to MME, carries urgent sign in the request message and indicates;

805:MME carries out authentication to UE, and sets up NAS (Network Association Security) network security alliance;

806:MME sends position updating request to HSS/AAA, carries the sign of MME, the sign of UE in the message; HSS/AAA finds out the address of user data and the P-GW of UE according to the sign of UE, sends to MME;

MME receives user data, and because of UE is an emergency attached, MME ignores roaming restriction or inserts restriction and wait and do not enter restriction, allows UE to be linked into network, and returns to HSS and to receive the user and respond;

807:MME is that UE selects a S-GW, and to the request that emergency bearing is set up in its transmission, comprises information such as P-GW address, bearer types and urgent sign in the message, sets up emergency bearing through urgent sign indication;

808:S-GW sends the request of setting up emergency bearing to P-GW, in this request, comprises the information such as address, bearer types and urgent sign of S-GW, sets up emergency bearing through urgent sign indication;

809:P-GW is to PCRF initiation session modify request messages, and carrying urgent sign indication in the message is emergency bearing; PCRF returns the session modification acknowledge message to P-GW, is included as the Qos strategy and the charging regulation of emergency bearing service in the message, is carried out by P-GW;

The qos policy and the charging decision information of the emergency bearing that 810:P-GW returns according to PCRF are set up emergency bearing resource, and return emergency bearing to S-GW and set up response, carry urgent sign in the response message; 811:S-GW sends the response that emergency bearing is set up to MME, and indication S5 emergency bearing is set up and upgraded successfully, carries urgent sign in the response message;

812:MME sends the emergency attached response to E-UTRAN, carries urgent sign in the response message, shows that the emergency attached of UE is accepted to the request of network; Set up wireless emergency between E-UTRAN and the UE and carry, and realize between the S-GW that user plane inserts;

813:S-GW sends the emergency bearing update inquiry information to P-GW, carries urgent sign and wireless emergency in the message and carries the completion mark, and indication P-GW switches to the 3GPP connecting system from non-3GPP IP connecting system and removes the access data bag; P-GW confirms.

Step 813 is set up the PMIP/GTP tunnel for emergency bearing between S-GW and P-GW after accomplishing, and the wireless and access emergency bearing between UE and E-UTRAN, the S-GW is also set up completion; UE can promptly insert through the 3GPP connecting system, and through P-GW transmission/reception IP packet, emergent session switches to be accomplished.

From above description, can find out; Use the present invention; The emergent session that can be implemented between non-3GPP IP connecting system and the 3GPP connecting system switches, and has avoided the objective network system because of the roaming of UE restriction or access restriction and has forbidden that UE inserts, and causes the scene of emergent session failure to take place; Set up emergency bearing at objective network simultaneously, ensured the high QoS priority that emergent session needs into the emergent session service.

The above embodiment is the preferred embodiment that proves absolutely that the present invention lifts, and protection scope of the present invention is not limited thereto.Being equal to that the technical staff in present technique field is done on basis of the present invention substitutes or conversion, all within protection scope of the present invention.Protection scope of the present invention is as the criterion with claims.

Claims (10)

1. a urgent session switching method is characterized in that, user terminal in the source connecting system set up and carry and carry out emergence call service; When finding that target access system and decision are switched; Said user terminal is at first judged the session service type that in said source connecting system carries, if connecting system carries in said source is that emergent session is professional, said user terminal is initiated emergency attached request to said target access system; Set up emergency bearing, trigger and accomplish emergent session and switch; Wherein, said source connecting system is meant the IP connecting system of current carrying user terminal session service, and said target access system is meant the IP connecting system that carries the user terminal session service after session is switched.

2. the method for claim 1 is characterized in that, said user terminal carries urgent sign in the emergency attached request message that said target access system is initiated, and is used to indicate that this attach request initiates is that emergent session is professional.

3. method as claimed in claim 2; It is characterized in that; Said target access system judges whether carry urgent sign in the said Attach Request message after receiving the attach request of said user terminal transmission, if having; The access of forbidding of then ignoring this user limits, and allows said user terminal to insert target access system.

4. method as claimed in claim 3; It is characterized in that; After said target access system was passed through the urgent access authentication of said user terminal, said target access system and home subscriber server/authentication and authorization charging server HSS/AAA obtained user data alternately; The address of the data network gateway P-GW that said HSS/AAA will connect with said source connecting system sends to target access system.

5. method as claimed in claim 4; It is characterized in that; After said target access system obtains the address of said P-GW; The emergency bearing request is set up to the P-GW transmission in address according to said P-GW, sets up and carries urgent sign in the emergency bearing request message, indicates this emergency bearing to be used for the emergent session business.

6. method as claimed in claim 5 is characterized in that, said foundation also includes target access system access address and bearer types in the emergency bearing request message.

7. method as claimed in claim 5; It is characterized in that; Said P-GW receives that said target access system sends set up the emergency bearing request after; Send session modification request to "Policy and Charging Rules Function PCRF, carry urgent sign in the session modification request message, be used for indication and set up emergency bearing.

8. method as claimed in claim 7; It is characterized in that; Said PCRF judges whether carry urgent sign in the session modification request message after receiving the session modification request of said P-GW transmission, if having; Said PCRF sends the session modification acknowledge message to said P-GW, comprises in this message to serve emergent session professional QoS policy and charging regulation.

9. method as claimed in claim 8 is characterized in that,

After said P-GW receives said session modification acknowledge message; According to being used for emergent session professional qos policy and charging regulation in this message; Set up emergency bearing resource, and return emergency bearing to said target access system and set up response, carry urgent sign in the response message;

Said target access system receives said emergency bearing and sets up response; According to the urgent sign indication in the response message; Set up wireless with said user terminal and P-GW and the access emergency bearing, the high QoS rank of serving urgency traffic is provided, said user terminal is realized urgent the access through said target access system; And through said P-GW transmission and reception IP packet, emergent session switches to be accomplished.

10. like any described method in the claim 1～9, it is characterized in that said user terminal is judged the session service type that connecting system carries in said source through one of following dual mode:

Said user terminal judges whether calling number is the emergency telephone number of its storage, if then the session service type of this call setup is that emergent session is professional;

Said user terminal is after professional Control Network makes a call; Said professional Control Network judges whether the session service type of this call setup is that emergent session is professional; If it is that emergent session is professional that said professional Control Network is notified the session service type of said this call setup of user terminal.

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