CN101668280B

CN101668280B - Network switching method, management equipment, terminal and home location server

Info

Publication number: CN101668280B
Application number: CN2008102139615A
Authority: CN
Inventors: 陈中平; 吴问付; 张谦
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2008-09-01
Filing date: 2008-09-01
Publication date: 2012-07-04
Anticipated expiration: 2028-09-01
Also published as: WO2010022644A1; CN101668280A

Abstract

The invention discloses a network switching method, management equipment, a terminal and a home location server. In the embodiment of the invention, the network switching method comprises the following steps: receiving a network switching request sent by a terminal; indicating the terminal to register in a target network by the network switching request; and acquiring PGW information used by the terminal, and informing the PGW to switch the loading of the terminal to the target network so as to realize the network switching of a multi-mode multi-standby terminal. In addition, because the multi-mode multi-standby terminal is registered in the target network and keeps maintaining the communication relationships with the target network, when the network switching is carried out, the network switching request sent by the terminal carries a switching type identifier registered by the terminal in the target network so as to enable a network side to receive the switching type identifier without rebuilding context information on the target network but adopting the existing context information. Compared with the prior technical scheme, the network switching method can complete the switching more quickly, save the flow and improve the user experience.

Description

Method for switching network and management equipment, terminal and home location server

Technical field

The present invention relates to communication technical field, be specifically related to method for switching network and management equipment, terminal and home location server.

Background technology

Development along with new technology; The more and more mobile communication technology has appearred; As global system for mobile communications (Global System for Mobile Communications, GSM), code division multiple access insert (Code-Division Multiple Access, CDMA), global inserting of microwave (World Interoperability forMicrowave Access; WiMAX), Long Term Evolution plan (Long Term Evolution; LTE), (Wireless Local Area Network, WLAN) etc., various technology all have advantage and the weak tendency of oneself to WLAN.Operator can select one or more communication technologys that service is provided according to the needs of oneself, like this, because different operators possibly use the different communication technologys; Perhaps an operator uses the multiple communication technology; And network coverage also is not quite similar, still, the user use network the time; A kind of network access mode can only be supported in the terminal, can not the reasonable use Internet resources.

For addressing the above problem, prior art scheme one has appearred, and this technical scheme is to provide a kind of terminal to net the technical scheme of access to the user more; At least two User Recognition card of terminal inner setting; The user can insert two Subscriber Identity Modules and insert corresponding network, and (for example: GSM and cdma network) is in this scheme; Can realize that the terminal inserts a plurality of networks, and the terminal is separate in the communication of each network.In fact portable terminal in this scheme is equivalent to integrating of a plurality of independently terminals, only is the simple superposition of function, therefore can't realize professional fusion.

The network handover scheme that prior art two provides a kind of multimode singly to treat, the difference of this scheme and scheme one are that the user adopts unique user identity in a plurality of networks, to use (using a Subscriber Identity Module to get final product); When business is carried out; If terminal or network side find when providing professional network signal quality bad, and detect and have the better network coverage of signal, then can directly adopt said unique customer identity registration to the better network of signal through attachment flow; And proceed business; Realization switches to another network with ongoing business, and the shortcoming of prior art two is at one time, and a network carrying business can only be used in the terminal.

In research and practice process to prior art, inventor of the present invention finds, along with the appearance of multi-mode multi-standby terminal; Unique identity is adopted at the terminal, and the technology in a plurality of network attachment is ripe simultaneously, and the terminal can use a plurality of network carryings to carry out business simultaneously, still; Also there is the professional possibility of switching in multi-mode multi-standby terminal in process of service execution, for example: the network signal quality of current operation business is bad; Perhaps the better network coverage of performance has been found at the terminal in moving process; Then need carry out business and switch, and switch if adopt prior art two identical conventional attachment flow to realize, then can in handoff procedure, delete the contextual information at the existing said terminal of objective network and rebuild new contextual information for the network of multi-mode and multi-standby; Cause handoff procedure longer, reduce user's business experience.

Summary of the invention

The embodiment of the invention provides a kind of method for switching network and management equipment, terminal and home location server, can accelerate the network switching flow, improves user experience.

A kind of method for switching network that the embodiment of the invention provides comprises:

The network handoff request that receiving terminal sends; Said network handoff request indicates said terminal to register at objective network;

Obtain said terminal in the employed packet data network PDN of source network link information, and notify the PGW that uses in the corresponding source network of said PDN link information that the business data flow of this terminal source network is switched to objective network.

Register at source network and objective network at the terminal;

When said terminal from source network when objective network switches, send the network handoff request to the network side management equipment; Said network handoff request indicates said terminal to register at objective network;

The network side management equipment receives said network handoff request, obtain the PGW address of in source network, using at said terminal, and the PGW that uses in the notification source network switches to objective network with this terminal at the business data flow of source network;

After switching completion, said terminal uses the carrying of objective network to communicate.

A kind of network side management equipment that the embodiment of the invention provides comprises:

Receiving element is used for the network handoff request that receiving terminal sends; Said network handoff request indicates said terminal to register at objective network;

The gateway information acquiring unit is used to obtain the PGW information that use at said terminal;

The switching notice unit is used to notify said PGW that the carrying at this terminal is switched to objective network.

A kind of portable terminal that the embodiment of the invention provides comprises: the network registry unit is used for registering at source network and objective network;

Network handoff request unit is used for from source network when objective network switches, and sends the network handoff request to the network side management equipment; Said network handoff request indicates said terminal to register at objective network;

Communications processor element after being used for network hand-off process that network side carries out and accomplishing, uses the carrying of objective network to communicate;

PDN connects inspection unit; Be used for the PDN link information that preserve this locality is checked; Find that same APN exists PDN to be connected at source network and objective network; And the IP address that these two PDN connect corresponding terminal is identical, and the network handoff request that then said network handoff request unit sends is bearing resource request for allocation or the request of PDP secondary activating; Perhaps; Be used for the PDN link information that preserve this locality is checked; Find that same APN exists PDN to be connected at source network and objective network; And these two PDN connect that the IP address at corresponding terminal is different, and the network handoff request that then said network handoff request unit sends is that PDN connection request or PDP once activate request, and said PDN connection request or PDP once activate the sign that comprises said APN in the request and the said terminal IP address at source network; Perhaps; Be used for the PDN link information that preserve this locality is checked; Find that the PDN in the source network connects the APN that comprises does not have correspondence in objective network PDN connection; The network handoff request that then said network handoff request unit sends is that PDN connection request or PDP once activate request, and said PDN connection request or PDP once activate the sign that comprises said APN in the request and the said terminal IP address at source network.

The network handoff request of sending through receiving terminal in the embodiment of the invention; Said network handoff request indicates said terminal to register at objective network; Obtain the PGW information that use at said terminal, and notify said PGW that the carrying at this terminal is switched to objective network.The network of having realized multi-mode multi-standby terminal switches; And because multi-mode multi-standby terminal registered and keep the maintenance to the objective network correspondence at objective network, therefore carrying out network when switching, through the network handoff request carried terminal that sends at the terminal in the switching type sign of objective network registration; Network side is received said switching type sign; Then need not the contextual information of reconstructed object network, adopt existing contextual information to get final product, can accomplish switching faster with respect to the prior art scheme; Practice thrift flow process, improve user experience.

Description of drawings

Fig. 1 is the flow chart of the embodiment of the invention one method for switching network;

Fig. 2 is the flow chart of the method for the embodiment of the invention two network registries;

Fig. 3 is the flow chart that the embodiment of the invention three PDN connect the method for setting up;

Fig. 4 is the flow chart of the embodiment of the invention four network registering methods;

Fig. 5 is the flow chart of the embodiment of the invention five network registering methods;

Fig. 6 is the flow chart of the embodiment of the invention six network registering methods;

Fig. 7 is the flow chart of the embodiment of the invention seven method for switching network;

Fig. 8 is the flow chart of the embodiment of the invention eight method for switching network;

Fig. 9 is the flow chart of the embodiment of the invention nine method for switching network;

Figure 10 is the structural representation of the embodiment of the invention ten portable terminals;

Figure 11 is the structural representation of the embodiment of the invention 11 network equipments;

Figure 12 is the structural representation of the embodiment of the invention 12 network equipments;

Figure 13 is the structural representation of the embodiment of the invention 13 network equipments;

Figure 14 is the structural representation of the embodiment of the invention 14 home location servers.

Embodiment

The embodiment of the invention provides method for switching network, can accelerate the network switching flow, improves user experience.The embodiment of the invention also provides corresponding mobile terminal and network equipment, below is elaborated respectively.

Embodiment one, a kind of method for switching network, flow chart is as shown in Figure 1, comprising:

A1, the network handoff request that receiving terminal (UE) sends; Said network handoff request indicates said terminal to register at objective network;

It is understandable that, indicate said terminal to may be implemented in a variety of ways: in the present embodiment, comprise the said terminal of expression in the said network handoff request and identify at the switching type of objective network registration in the objective network registration; It is understandable that it is that request is carried out network and switched that said switching type sign is used to indicate the purpose of the request of this user terminal, the switching type sign is used for distinguishing the function of message.In the practical communication process; The network handoff request that send at the terminal can be passed through login request message, position updating request, packet data protocol (PDP) connection request, bearing resource allocation request message or PDP conventional message such as activation request and realize; Because carried the switching type sign in the message, then network side can learn that this request is request " network switching ".

Can also be through the message format of communicating pair agreement for the said terminal of indication in the mode of objective network registration; The fixed field sign; Modes such as bit-identify realize that concrete mode can have multiple mode according to communicating pair, do not constitute the restriction to invention.

A2 obtains said terminal in the employed PDN link information of source network;

In the present embodiment, obtain said terminal and comprise in the employed PDN link information of source network:

(Home Subscription Server HSS) initiates register requirement, and said register requirement comprises the sign of the PDN link information of the said terminal use that indication HSS only returns to home location server for said terminal;

Receive the said terminal PDN link information that HSS searches acquisition.

It is understandable that; The packet data network at said terminal (Packet Data Network; PDN) link information also possibly have preservation in the corresponding contextual information in terminal described in the objective network, so the embodiment of the invention can preserve from objective network is the PDN link information of obtaining the terminal the contextual information at terminal.Can also before the CAMEL-Subscription-Information of asking said terminal to HSS, check the PDN link information that whether comprises said terminal in the contextual information at the said terminal that objective network is preserved; If comprise, then can directly from said contextual information, obtain the PDN link information at terminal.

What the embodiment of the invention was stressed is; Switching to from source network the process of objective network; Grouped data network gateway (the Packet Data Network Gateway that use at the terminal; PGW) can not change, this be for guarantee professional handoff procedure continuously, can not cause the professional terminal or the interruption of session because of the switching of network.

A3 notifies the PGW that uses in the corresponding source network of said PDN link information that the business data flow of this terminal source network is switched to objective network.Be appreciated that notice PGW switching carrier can through send to said PGW create the request of carrying or more new bearer request realize, be to send to create the request of carrying or send more new bearer request and need choose according to actual conditions.Concrete:

If the access point that in source network, uses of said terminal (Access Point Name APN) does not have corresponding PDN to connect at objective network, then saidly notifies said PGW that the process that the source network business data flow at this terminal switches to objective network is comprised:

Send and create the default bearer request to the said PGW that in source network, uses, the request network side is created the carrying that the user uses; Carry in the said default bearer request and switch sign, the sign of APN and the IP address at terminal.

If said terminal exists PDN to connect at the employed APN of source network,, the PDN connection of said APN in objective network selected different PGW but connecting with the PDN of said APN in source network in objective network; The then said PGW that notifies said source network comprises the process that the source network business data flow at this terminal switches to objective network: send and create the default bearer request to the said PGW that in source network, uses, the request network side is created the carrying that the user uses; Carry the sign of switching sign, APN and terminal IP address in the said default bearer request at source network.

If said terminal exists PDN to connect in objective network at the employed APN of source network; The PDN connection of said APN in objective network simultaneously connects with the PDN of said APN in source network has selected identical PGW, but the PDN of terminal in objective network used the IP address different with source network in connecting; The then said PGW that notifies said source network comprises the process that the source network business data flow at this terminal switches to objective network: send and create the default bearer request to the said PGW that in source network, uses, the request network side is created the carrying that the user uses; Carry the sign of switching sign, APN and terminal IP address in the said default bearer request at source network.

If said terminal exists PDN to connect in objective network at the employed APN of source network, and the PDN of said APN in objective network connect with the PDN connection of said APN in source network in selected identical PGW, and the IP address at terminal is identical; Then send more new bearer request to said PGW, carry the sign of switching sign, APN and terminal IP address in the said more new bearer request at source network.

Can also comprise after the said steps A 3: PGW switches to objective network with the carrying at said terminal, and concrete handoff procedure can adopt the existing conventional mode to realize, does not do here and gives unnecessary details.

In the embodiment of the invention, PGW also comprises after the carrying at said terminal is switched to objective network:

(Policy and Charging Rule Function PCRF) obtains the charging regulation at said terminal to said PGW, and it is to charge in said terminal that parallel connection adds up to the expense server from the "Policy and Charging Rules Function entity.

The network handoff request of sending through receiving terminal in the embodiment of the invention one; Comprising the said terminal of expression in the said network handoff request identifies at the switching type of objective network registration; Obtain the PGW information that use at said terminal, and notify said PGW that the carrying at this terminal is switched to objective network.The network of having realized multi-mode multi-standby terminal switches; And because multi-mode multi-standby terminal registered and keep the maintenance to the objective network correspondence at objective network, therefore carrying out network when switching, through the network handoff request carried terminal that sends at the terminal in the switching type sign of objective network registration; Network side is received said switching type sign; Then need not the contextual information of reconstructed object network, adopt existing contextual information to get final product, can accomplish switching faster with respect to the prior art scheme; Practice thrift flow process, improve user experience.

In the embodiment of the invention carry out network switch before the terminal register at source network and objective network, and network side need connect preservation respectively to the PDN of terminal in heterogeneous networks in the process of registration, its basic process is:

Register at source network and objective network at the terminal;

HSS preserves source network respectively and objective network is the PDN link information that create at said terminal.

Said PDN link information comprises: the IP address at the APN sign that use at the terminal, PGW sign, wireless access type (RAT) sign and terminal.

In the embodiment of the invention, can expand the PDN link information for the terminal establishment of preserving simultaneously, the wireless access type of adding (RAT) sign, RAT is used to identify PDN and connects the network type of creating, and is convenient to PDN information is classified.As: distinguish 3GPP network or Non-3GPP network or other networks with the value of RAT.The purpose of doing like this is in order to realize that network provides support to the network switching of multi-mode multi-standby terminal.

In the prior art, different PDN connects corresponding different APN in the consolidated network, and an APN binds together one by one with a PGW and is kept among the HSS.But under the scene of multi-mode and multi-standby; Such problem may appear; The user uses same APN to select different PGW in two networks, carries out when going the HSS registration, and existing HSS only can preserve the binding relationship of an APN and PGW for same APN.When switch between 3GPP and Non-3GPP network at the terminal like this; Mobile management network element or Non-3GPP GW only obtain an APN and PGW address record from HSS; Mobile management network element or Non-3GPP GW can only initiate a PDN establishment of connection program at objective network like this; Can only set up a PDN at objective network connects; And other PDN that the terminal is set up in source network connects and will lose at objective network, and the business that causes using in these PDN connections can not re-use in objective network, influences the experience at terminal.That is to say; The terminal of dual-mode dual-standby; Under prior art; If same APN has activated the PDN connection in two heterogeneous networks, but selected different PGW, PDN connection that like this might the said APN of source network is corresponding under the scene that switches switches to objective network.

And in the embodiment of the invention; Because connecting, all preserves the PDN that network side is set up behind a plurality of network registries for the terminal; When occurring network is switched; Can obtain professional corresponding a plurality of PDN that source network carries out and connect and business data flow is switched to objective network, can better business experience be provided to the user, guarantee better in the handoff procedure professional continuously.

In network, carry out PDN foundation or renewal for the terminal, and the process that completion is preserved is with reference to following examples two to embodiment six in HSS.

Embodiment two, a kind of method of network registry, and flow chart is as shown in Figure 2, comprising:

S201: register requirement (Attach Request) message is sent to mobile management network element in the terminal;

For the GERAN/UTRAN network, the network side management equipment is meant SGSN, and for the E-UTRAN network, the network side management equipment is meant mobile management network element (MME).Be to be that example describes with MME in the present embodiment.

S202: carry out authorizing procedure between terminal, mobile management network element and the HSS;

S203: executing location is upgraded and is inserted the subscription data flow process between mobile management network element and the HSS, and in HSS, simultaneously, HSS is inserted into the subscription data at terminal in the mobile management network element with the address registration of mobile management network element;

S204: the default APN that mobile management network element uses according to the terminal selects PGW; Send and create the default bearer request message to gateway (Serving Gateway; SGW) carry out the establishment that default PDN connects, carry the PGW address and the APN information of selection in the message;

S205:SGW sends establishment default bearer request message or agent binding update messages arrives the PGW that selects, and carries APN information in the message;

If the interface protocol between SGW and the PGW uses the GTP agreement, then use and create the default bearer request message; If the interface protocol between SGW and the PGW uses the PMIP agreement, then use agent binding update messages.

S206:PGW returns the response of establishment default bearer or proxy binding acknowledgment messages arrives SGW;

If PGW for this PDN connects the distributing IP address, then carries this PDN and connects the IP address of using in the message.

S207:SGW returns and creates the default bearer response message to mobile management network element;

S208: mobile management network element returns to adhere to accepts message to the terminal;

S209: mobile management network element sends and upgrades location request message to HSS, the IP address information at APN, PGW identity (resolving the address information that this sign can obtain PGW), RAT and terminal that the default PDN that carried terminal uses in the message connects;

S210:HSS preserves the IP address at APN, PGW identity (resolving the address information that this sign can obtain PGW), RAT and the terminal of the PDN connection of using at the terminal.

Embodiment two is saved in HSS through register flow path with the PDN link information at terminal.

Embodiment three, and a kind of PDN connects the method for setting up, and flow chart is as shown in Figure 3, comprising:

S301: the terminal is sent PDN connection request message and is set up the PDN connection to the mobile management network element request, carries the employed APN of this PDN in the message;

S302: the APN that mobile management network element carries according to the terminal selects PGW, sends establishment default bearer request message and carries out the establishment that PDN connects to SGW, carries PGW address, the APN information of selection in the message.

S303:SGW sends establishment default bearer request message or agent binding update messages arrives the PGW that selects, and carries APN information in the message;

S304:PGW returns the response of establishment default bearer or proxy binding acknowledgment messages arrives SGW;

S305:SGW returns and creates the default bearer response message to mobile management network element;

S306: mobile management network element returns PDN and accepts message to the terminal;

S307: mobile management network element sends and upgrades location request message to HSS, the IP address information at APN, PGW identity (resolving the address information that this sign can obtain PGW), RAT and terminal that the default PDN that carried terminal uses in the message connects;

S308:HSS preserves the IP address information at APN, PGW identity (resolving the address information that this sign can obtain PGW), RAT and the terminal of the default PDN connection of using at the terminal.

Embodiment two sets up flow process through PDN the PDN link information at terminal is saved in HSS.

Embodiment four, a kind of network registering method, flow chart is as shown in Figure 4, comprising:

S401: carry out authentication and authentication between terminal, Non-3GPP GW, AAA Server, the HSS;

For wlan system, Non-3GPP GW be the evolution packet data gateway (Evolved PacketData Gateway, EPDG); For the Wimax system, Non-3GPP GW is access business network gateway (Access Service Network Gateway, ASN GW); For cdma system, Non-3GPP GW be IAD (Access Gateway, AGW).

S402: layer 3 login request message are sent to Non-3GPP GW in the terminal;

S403: if use the PMIP agreement in the Non-3GPP network, then Non-3GPP GW selects PGW according to the default APN of terminal use, sends agent binding update messages then and sets up default PDN connection to the PGW that selects, and carries APN information in the message;

S404:PGW sends and upgrades the PGW address message to AAA Server, and AAA Server sends renewal PGW address message and to HSS the information that this PDN connects is registered to HSS; Wherein, carry the IP address information at APN, PGW identity (resolving the address information that this sign can obtain PGW), RAT and the terminal of PDN connection in the message;

S405:PGW returns proxy binding acknowledgment messages to Non-3GPP GW;

S406:Non-3GPP GW transmission layer 3 adheres to accepts message to the terminal, carries the PDN connection identifier in the message.

Embodiment four is saved in HSS through register flow path with the PDN link information at terminal.

Embodiment five, a kind of network registering method, and flow chart is as shown in Figure 5, comprising:

S501: carry out authentication and authentication between terminal, Non-3GPP GW, AAA Server, the HSS;

S502: layer 3 login request message are sent to Non-3GPP GW in the terminal;

S503: if use the CMIP agreement in the Non-3GPP network, then Non-3GPP GW returns layer 3 and adheres to and accept message to the terminal;

S504: if use the CMIP agreement in the Non-3GPP network, then the terminal is sent binding update messages and is set up default PDN connection to PGW, carries APN information in the message;

S505:PGW sends and upgrades the PGW address message to AAA Server; AAA Server sends renewal PGW address message and to HSS the information that this PDN connects is registered to HSS; Wherein, carry the IP address information at APN, PGW identity (resolving the address information that this sign can obtain PGW), RAT and the terminal of this PDN connection in the message.

S506:PGW sends binding acknowledgement message to the terminal;

Embodiment five is saved in HSS through register flow path with the PDN link information at terminal.

Embodiment six, a kind of network registering method, and flow chart is as shown in Figure 6, comprising:

S601: if use the PMIP agreement in the Non-3GPP network, then PDN connection request message is sent to Non-3GPP GW in the terminal, carries this PDN in the message and connects the APN information of using;

S602:Non-3GPP GW selects PGW according to this APN, sends agent binding update messages then and sets up the PDN connection to the PGW that selects;

S603:PGW sends and upgrades the PGW address message to AAA Server; AAA Server sends renewal PGW address message and to HSS the information that this PDN connects is registered to HSS; Wherein, carry the IP address information at APN, PGW identity (resolving the address information that this sign can obtain PGW), RAT and the terminal of this PDN connection in the message;

S604:PGW returns proxy binding acknowledgment messages to Non-3GPP GW;

S605:Non-3GPP GW sends PDN and accepts message to the terminal;

Embodiment six is saved in HSS through new technological process more with the PDN link information at terminal.

From embodiment three, embodiment four, can find out that the employed PDN link information in terminal of preserving for MME, SGW, PGW, HSS, 3AAAServer, Non-3GPP GW (also can be called: PDN connection context or PDN contract context) should comprise that this PDN connects the IP address information at employed APN, PGWidentity (resolving the address information that this sign can obtain PGW), RAT (radio access technology types) and terminal.And the PDN link information that preserve at the terminal need comprise the IP address information that this PDN connects employed APN, RAT and terminal.

Embodiment seven, a kind of method for switching network, flow chart is as shown in Figure 7, comprising:

B1, register at source network and objective network at the terminal;

B2, when said terminal from source network when objective network switches, send the network handoff request to the network side management equipment; Said network handoff request indicates said terminal to register at objective network;

B3, the network side management equipment receives said network handoff request, obtain the PGW address of in source network, using at said terminal, and the PGW that uses in the notification source network switches to objective network with this terminal at the business data flow of source network;

B4, after switching was accomplished, said terminal used the carrying of objective network to communicate.

The embodiment of the invention two is handling processes of end side, and the terminal is comprising the switching type sign that has registered at objective network at the said terminal of expression in the present embodiment in network side transmission handoff request.Be appreciated that; Because the terminal obviously can judge whether this machine is registered at objective network according to self data and state before switching; If carried out registration; Then in the process that objective network switches, can directly use the contextual information of objective network, need not to rebulid context.Therefore, present embodiment through to the terminal after the handoff request that network side sends is expanded, can the indication network side when switching, keep the contextual information at this terminal, accelerate switching flow, improve user experience.

In the present embodiment; Said terminal can also comprise before the network side management equipment is sent the network handoff request: the PDN link information that preserve this locality at the terminal is checked; All exist PDN to be connected if find same APN at source network and objective network; And the IP address that these two PDN connect corresponding terminal is identical, and then said network handoff request of sending to the network side management equipment is: bearing resource request for allocation or the request of packet data protocol PDP secondary activating.

Said bearing resource request for allocation or the IP address of sending carried terminal in the request of PDP secondary activating;

The PGW address that said network side management equipment obtains in source network, to use at said terminal comprises:

Said network side management equipment obtains the PGW that use at this terminal according to the IP address at province terminal in source network.

Be appreciated that in the embodiment of the invention the also IP address of carried terminal not in the bearing resource request for allocation of said transmission or the request of packet data protocol PDP secondary activating.And the PGW information used of locating terminal in the following manner.

If said network handoff request of sending to the network side management equipment is the bearing resource request for allocation;

Said network side management equipment is according to the sign of the Network Service Access point in the said carrying handoff request (Linked EPS Bearer Id, LBI) the PND link information at said terminal, location; And from this PND link information, obtain the PGW that in source network, uses at terminal.

If said network handoff request of sending to the network side management equipment is the request of PDP secondary activating;

Said network side management equipment is according to packet domain research system bearing sign (the Network layer Service Access Point Identifier of the link in the request of said PDP secondary activating; NSAPI) locate the PND link information at said terminal, and from this PND link information, obtain the PGW that in source network, uses at terminal.

Carry out the network switching as if said through sending the bearing resource request for allocation; Among the then said step B3; The PGW that uses in the notification source network with this terminal in the process that the business data flow of source network switches to objective network can be: send the bearing resource request for allocation and give PGW, carry indication information handover indication P-GW switching carrier in the message.PGW is given in IP address that can carried terminal in the message, also can PGW according to the IP address that obtains the terminal in the PDN link information of bearing identification location.

If the result that the above-mentioned PDN link information that this locality is preserved is checked is:

The PDN link information that preserve this locality at the terminal is checked, all exists PDN to be connected if find same APN at source network and objective network, and these two PDN connect the IP address difference at corresponding terminal; Perhaps the PDN in the source network connects the APN that comprises does not have corresponding PDN to connect in objective network; Then said network handoff request of sending to the network side management equipment is: PDN connection request or PDP once activate request; Said PDN connection request or PDP once activate the sign that comprises said APN in the request and the said terminal IP address at source network.

Carry out the network switching as if said through sending the PDN connection request; Among the then said step B3; The PGW that uses in the notification source network with this terminal in the process that the business data flow of source network switches to objective network can be:; The network side management equipment send to be created the default bearer request to the PGW that comprises during the employed said PDN of above-mentioned source network connects; The request network side is created the carrying that the user uses, and carries indication information handover indication P-GW switching carrier in the message, in the message and carry APN information that this PDN connects and the IP address information of UE.

In the embodiment of the invention, said network side management equipment is MME or SGSN.

Below in conjunction with concrete application scenarios the method for the embodiment of the invention being described, is that example describes with the double-mode and double-standby terminal in following examples.

Embodiment eight, a kind of method for switching network, and in the present embodiment, source network is non-3GPP (Non-3GPP) network, objective network is the 3GPP network.

It is to adopt attachment flow to realize that before this flow process, user terminal is registered respectively at 3GPP network and Non-3GPP network that network in the present embodiment switches, and particular flow sheet is as shown in Figure 3, comprising:

C1, login request message is sent to mobile management network element (MME)/GPRS service support node (SGSN) in the terminal.

In the embodiment of the invention; It is that example describes to send register requirement that handoff request is sent at the terminal; It is understandable that; It can be that to detect the condition that network need switch with the terminal be triggering that handoff request is sent at said terminal, also can be that network side detects and needs the terminal to switch, and notice terminal execution in step C1 sends handoff request.In this process, if network side carries out the judgement that network switches, the terminal also can be after receiving the notice of network side, and whether decision-making need be carried out network and switch and carry out follow-up step.

In the present embodiment, the network handoff request that send at the terminal is a login request message, comprises the said terminal of expression in the said login request message and identifies at the switching type of objective network registration.

Owing to registered before the terminal at MME/SGSN; This moment, the state at the MME/SGSN record was the registration attitude; For avoiding MME/SGSN to receive once more that under the situation that the user has registered register requirement is used as abnormality processing; Avoid after MME/SGSN receives register requirement, delete the existing contextual information in this terminal and discharge the bearing resource that has existed.Therefore in login request message, increasing the said terminal of expression identifies at the switching type of objective network registration.

Increasing the said terminal of expression can perhaps adopt methods such as revising existing cell to realize through in login request message, adopting newly-increased cell in the switching type label manner of objective network registration.

For example: in login request message, the value of Attach Type cell is expanded.Attach Type cell after the expansion has following three values: 00 (Normal Attach shows that login request message is normal login request message); 01 (Handover Attach shows that login request message is to switch the login request message that causes); 03 (Registered handover attach shows that login request message is under the prerequisite of having registered, and switches the login request message cause.Value for Attach Type is 03, and then network side can learn that this terminal registers at objective network.

C2, (Home Subscription Server carries out authorizing procedure between HSS) for terminal, MME/SGSN, home location server.Concrete authentication process can adopt the existing conventional implementation, does not do here and gives unnecessary details.

C3, MME/SGSN obtain the PDN link information that the user uses.

Obtaining the PDN link information of user's use can pass through: following mode realizes:

The PDN link information of obtaining user's use can realize in the following manner:

Be designated as " Registered handover attach " if switch the value of sign; Can initiate registration process to HSS; PDN link information (PDN subscription context only) is only obtained in indication; HSS only intercuts the employed PDN link information of user (comprising that the PDN that the user uses connects corresponding APN, the IP address information that use at PGW identity, RAT and terminal) to MME/SGSN after receiving indication.

Be appreciated that; If dynamic PDN link information is used as the part of user contracting data; Register at MME/SGSN discovery terminal so, and have contextual information, also can not initiate registration process (because subscription data changes to HSS; HSS can initiatively intercut new subscription data to mobile management network element), directly from user's subscription data, obtain the PDN link information.

The type of MME/SGSN judges registration, if the type of user's registration is normal location registration process type, then MME is according to normal flow processing; If the type of user's registration is RegisteredHandover Attach; Then MME/SGSN checks the employed PDN link information of user of preserving, and the employed PDN connection of Non-3GPP network is connected with the PDN of 3GPP network use compare (can distinguish network type through the RAT in the PDN link information).

C4, MME/SGSN check APN and the corresponding PGW information that said terminal is related, send create the request of carrying or more new bearer request to said PGW;

Concrete is to send to create the request of carrying or send more new bearer request, and difference is as the case may be distinguished:

Protect certain APN that contains does not have identical APN correspondence in the 3GPP network PDN connection if find the employed PDN of Non-3GPP network in connecting; Then MME/SGSN sends and creates the default bearer request to above-mentioned P-GW; The request network side is created the carrying that the user uses; Carry indication information handover indication P-GW switching carrier in the message, in the message and carry the APN information that this PDN connects and the IP address information at terminal.Send out through SGW.The IP address at APN terminal.

Protect certain APN that contains has identical APN correspondence in the 3GPP network PDN connection if find the employed PDN of Non-3GPP network in connecting; Employed P-GW information inconsistency in P-GW address information that comprises during but the employed said PDN of Non-3GPP network connects and the said 3GPP network; Then MME/SGSN send to create the default bearer request to the P-GW that comprises during the employed said PDN of above-mentioned Non-3GPP network connects; The request network side is created the carrying that the user uses; Carry indication information handover indication P-GW switching carrier in the message, in the message and carry the APN information that this PDN connects and the IP address information at terminal.

Protect certain APN that contains has identical APN correspondence in the 3GPP network PDN connection if find the employed PDN of Non-3GPP network in connecting; And employed P-GW information is consistent in the P-GW address information that comprises during the employed said PDN of Non-3GPP network connects and the said 3GPP network; The employed IP address information in terminal is inconsistent in IP address information that use at the terminal that comprises during but the employed said PDN of Non-3GPP network connects and the said 3GPP network; Then MME/SGSN send to create the default bearer request to the P-GW that comprises during the employed said PDN of above-mentioned Non-3GPP network connects; The request network side is created the carrying that the user uses; Carry indication information handover indication P-GW switching carrier in the message, in the message and carry the APN information that this PDN connects and the IP address information at terminal.The IP address is different, the IP address of carrying source network.

Protect certain APN that contains has identical APN correspondence in the 3GPP network PDN connection if find the employed PDN of Non-3GPP network in connecting; Employed P-GW information is consistent in the P-GW address information that comprises during the employed said PDN of Non-3GPP network connects and the said 3GPP network; And the employed IP address information in terminal is all consistent in the IP address information that use at the terminal that comprises during the employed said PDN of Non-3GPP network connects and the said 3GPP network; MME/SGSN sends renewal (default) carrying and asks above-mentioned P-GW; Carry indication information handover indication P-GW switching carrier in the message, in the message and carry the APN information that this PDN connects and the IP address information at terminal.

C5, PGW initiates the network side switching flow current business in the Non-3GPP network is switched to the 3GPP network.

In the embodiment of the invention, obtain strategy and charging (PCC) rule that the user uses to PCRF if desired, then PGW transmission request strategy and charging regulation message are obtained the PCC rule that the user uses to PCRF, and the PCC that PCRF provides the user to use is regular to PGW.

In the present embodiment, realize that step C1 sends and carries the switching type sign that has registered at objective network at the said terminal of expression in the login request message through attachment flow; Make network side know that the terminal registers at objective network.And then to keep original contextual information be that user terminal provides network to switch.Be appreciated that; Network in the embodiment of the invention switches can also adopt existing other flow processs realizations; And represent that said terminal also can pass through other existing multiple message bearings in the switching type sign of objective network registration, concrete message format and type are not construed as limiting the invention.Describe for example below, below can expand the message of carrying the switching type sign only is to realize the present invention's giving an example under concrete protocol environment.

Realize through location update message that 1, the said terminal of said expression is carried to MME/SGSN through position updating request (TAU/RAU Request) in the switching type sign of objective network registration.The switching type sign can adopt newly-increased cell, also can adopt methods such as revising existing cell.

For example: can expand to the cell of Update Type in the said position updating request; Increase the value of Registered handover update (registered switching renewal); Value like Update Type is " 03 ", representes that then the terminal registers at objective network.Below several kinds of modes similar to the extended mode of message, repeat no more here.

Realize through the bearing resource allocation flow that 2, the said terminal of said expression sends to MME/SGSN in the switching type sign of objective network registration through bearing resource request for allocation (Request Bearer Resource Allocation).

3, activate request through PDP time and realize, the switching type sign that has registered at objective network at the said terminal of said expression activates request (Activate Secondary PDP Context Request) through PDP and sends to MME/SGSN.

Sending the bearing resource request for allocation for the terminal gives MME or sends the request of PDP secondary activating to SGSN.Indicate Handover in the message, and the indication that the PDN that need to switch connects (the IP address of generally can carried terminal using) need be carried in the terminal.Comprise (LBI in traditional bearing resource request for allocation; PTI, SDF QoS, TFT); LBI can navigate to the default bearer (SGSN carries through the NSAPI location) that concrete PDN connects; This moment is if switch and to be based on the PDN granularity, and cell SDFQoS so, TFT possibly just not need (because that be based on professional particle size fraction other).

Can also realize that the said terminal of said expression sends to MME/SGSN in the switching type sign of objective network registration through PDP connection request (PDN Connectivity Request) through PDP connection request flow process.

The employed PDN link information in terminal (the PDN connection context can be called the signatory context of PDN among the HSS) of preserving for MME, SGW, P-GW, HSS, 3AAA Server, non-3GPP GW comprise that this PDN connects the IP address information at employed APN, PGW identity (resolving the address information that this sign can obtain PW), RAT and terminal.

The PDN link information that preserve at the terminal need comprise the IP address information that this PDN connects employed APN, RAT and terminal.And the mode of switching flow can be selected to initiate according to the PDN link information that preserve this locality in the terminal.For example:

The terminal is according to the PDN information of oneself preserving; All exist PDN to be connected if find same APN at 3GPP network and Non-3GPP network; And the IP address of this moment is the same (in this case; The PGW of two network associates should be same PGW, because have only same PGW could guarantee that the IP address of two networks is consistent), the terminal is initiated resource allocation and is accomplished switching so.

The terminal is according to the PDN link information of oneself preserving; All exist PDN to be connected if find same APN at 3GPP network and non-3GPP network; But the IP address of this moment is the same; Perhaps certain PDN connects the APN that comprises does not have correspondence in objective network PDN connection in the source network, and terminal initiation PDN connection request is accomplished and switched so.

Embodiment nine, a kind of method for switching network, and in the present embodiment, source network is the 3GPP network, objective network is non-3GPP (Non-3GPP) network.

Flow process is as shown in Figure 9, comprising:

D1, the network handoff request is sent to the Non-3GPP gateway in the terminal; Comprising the said terminal of expression in the said network handoff request identifies at the switching type of objective network registration.

In the present embodiment, said network handoff request can be to insert request (Access Request) or resource allocation request or PDP connection request.

Owing to registered before the terminal at Non-3GPP; This moment, the state at the Non-3GPP record was the registration attitude; Receive that for keeping away Non-3GPP register requirement is used as abnormality processing under the situation that the user has registered once more; Avoid after Non-3GPP receives register requirement, delete the existing contextual information in this terminal and discharge the bearing resource that has existed.Therefore in login request message, increasing the said terminal of expression identifies at the switching type of objective network registration.

D2, if first the access carried out authorizing procedure between terminal, non-3GPP gateway, AAA Server, the HSS, concrete authentication process can adopt the existing conventional implementation, does not do here and gives unnecessary details.

D3, Non-3GPP GW obtain the PDN link information that the user uses.

Be appreciated that; If dynamic PDN connection context is also regarded the part of user contracting data as; Register at MME/SGSN discovery terminal so; And there is contextual information, also can not initiate registration process (because subscription data changes, HSS can initiatively intercut new subscription data to mobile management network element) to HSS.

D4, non-3GPP gateway check APN and the corresponding PGW information that said terminal is related, send agent binding update messages and give PGW.Indicate said PGW to create or new bearer more.So to create carrying still more new bearer, can be according among the step D3, the PDN of source network connected be connected the result who compares with the PDN of objective network and select.

Protect certain APN that contains does not have identical APN correspondence in the 3GPP network PDN connection if find the employed PDN of Non-3GPP network in connecting; Then MME/SGSN sends and creates the default bearer request to above-mentioned PGW; The request network side is created the carrying that the user uses; Carry indication information handover indication PGW switching carrier in the message, in the message and carry the APN information that this PDN connects and the IP address information at terminal.

Protect certain APN that contains has identical APN correspondence in the 3GPP network PDN connection if find the employed PDN of Non-3GPP network in connecting; Employed PGW information inconsistency in PGW address information that comprises during but the employed said PDN of Non-3GPP network connects and the said 3GPP network; Then MME/SGSN send to create the default bearer request to the PGW that comprises during the employed said PDN of above-mentioned Non-3GPP network connects; The request network side is created the carrying that the user uses; Carry indication information handover indication PGW switching carrier in the message, in the message and carry the APN information that this PDN connects and the IP address information at terminal.

Protect certain APN that contains has identical APN correspondence in the 3GPP network PDN connection if find the employed PDN of Non-3GPP network in connecting; And employed PGW information is consistent in the PGW address information that comprises during the employed said PDN of Non-3GPP network connects and the said 3GPP network; The employed IP address information in terminal is inconsistent in IP address information that use at the terminal that comprises during but the employed said PDN of Non-3GPP network connects and the said 3GPP network; Then MME/SGSN send to create the default bearer request to the PGW that comprises during the employed said PDN of above-mentioned Non-3GPP network connects; The request network side is created the carrying that the user uses; Carry indication information handover indication PGW switching carrier in the message, in the message and carry APN information that this PDN connects and terminal in the IP of source network address information.

Protect certain APN that contains has identical APN correspondence in the 3GPP network PDN connection if find the employed PDN of Non-3GPP network in connecting; Employed PGW information is consistent in the PGW address information that comprises during the employed said PDN of Non-3GPP network connects and the said 3GPP network; And the employed IP address information in terminal is all consistent in the IP address information that use at the terminal that comprises during the employed said PDN of Non-3GPP network connects and the said 3GPP network; MME/SGSN sends more, and new bearer request arrives above-mentioned PGW; Carry indication information handover indication PGW switching carrier in the message, in the message and carry the APN information that this PDN connects and the IP address information at terminal.

D5, PGW initiates the network side switching flow current business in the 3GPP network is switched to the Non-3GPP network.

One of ordinary skill in the art will appreciate that all or part of step in the whole bag of tricks of the foregoing description is to instruct relevant hardware to accomplish through program; This program can be stored in the computer-readable recording medium, and storage medium can comprise: ROM, RAM, disk or CD etc.

Embodiment ten, a kind of portable terminal 500, and structural representation is shown in figure 10, comprising: network registry unit 510, network handoff request unit 520, communications processor element 530;

Network registry unit 510 is used for registering at source network and objective network;

Network handoff request unit 520 is used for from source network when objective network switches, and sends the network handoff request to the network side management equipment; Said network handoff request indicates said terminal to register at objective network;

Communications processor element 530 after being used for network hand-off process that network side carries out and accomplishing, uses the carrying of objective network to communicate.

In the embodiment of the invention, said portable terminal can also comprise:

PDN connects inspection unit; Be used for the PDN link information that preserve this locality is checked; All exist PDN to be connected if find same APN at source network and objective network; And the IP address that these two PDN connect corresponding terminal is identical, and the network handoff request that then said network handoff request unit sends is bearing resource request for allocation or the request of PDP secondary activating.

All exist PDN to be connected if find same APN at source network and objective network, and the IP address at the terminal of these two PDN connection correspondences is different, perhaps the PDN in the source network connects the APN that comprises does not have corresponding PDN connection in objective network; The network handoff request that then said network handoff request unit sends is: PDN connection request or PDP once activate request; Said PDN connection request or PDP once activate the sign that comprises said APN in the request and the said terminal IP address at source network.

Embodiment 11, a kind of network equipment 600, and structural representation such as Figure 11 comprise: receiving element 610, gateway information acquiring unit 620, switching notice unit 630;

Receiving element 610 is used for the network handoff request that receiving terminal sends; Said network handoff request indicates said terminal to register at objective network;

Gateway information acquiring unit 620 is used for after receiving element 610 is received the network handoff request, obtaining the PGW information that use at said terminal;

Switching notice unit 630 is used to notify PGW that said gateway information acquiring unit 620 obtains that the carrying at this terminal is switched to objective network.

Embodiment 12, a kind of network equipment, and structural representation is shown in figure 12, comprising: receiving element 710, gateway information acquiring unit 720, switching notice unit 730; Gateway information acquiring unit 720 comprises: CAMEL-Subscription-Information request unit 721 and CAMEL-Subscription-Information receiving element 722;

Receiving element 710 is used for the network handoff request that receiving terminal sends; Said network handoff request indicates said terminal to register at objective network;

CAMEL-Subscription-Information request unit 721 is used for asking to HSS the CAMEL-Subscription-Information at said terminal;

CAMEL-Subscription-Information receiving element 722 is used to receive the CAMEL-Subscription-Information at the said terminal that HSS returns; Said CAMEL-Subscription-Information comprises the PGW information of this user current use in source network.

Switching notice unit 730 is used to notify said PGW that the carrying at this terminal is switched to objective network.

Embodiment 13, a kind of network equipment, and structural representation is shown in figure 13, comprising: receiving element 810, gateway information acquiring unit 820, switching notice unit 830; Gateway information acquiring unit 820 comprises: inspection unit 821, acquiring unit 822;

Receiving element 810 is used for the network handoff request that receiving terminal sends; Said network handoff request indicates said terminal to register at objective network;

Inspection unit 821 is used for checking whether the contextual information at the said terminal that objective network is preserved comprises the PGW information that use at said terminal;

Acquiring unit 822 is used for when said inspection unit check result is the PGW information of terminal use, from said contextual information, obtaining the PGW information that use at the terminal.

Switching notice unit 830 is used to notify said PGW that the carrying at this terminal is switched to objective network.

Embodiment 14, a kind of home location server 900, and structural representation is shown in figure 14, comprising:

Register requirement receiving element 910, being used to receive the network side management equipment is the register requirement that send at the terminal; Said register requirement comprises the sign of the PDN link information of the said terminal use that indication HSS only returns;

Search unit 920, be used for searching the PDN link information that use at said terminal according to said register requirement;

Transmitting element 930 is used for searching the PDN link information that the unit finds and returning to said network side management equipment said.

More than method for switching network and management equipment, terminal and home location server that the embodiment of the invention provided have been carried out detailed introduction; Used concrete example among this paper principle of the present invention and execution mode are set forth, the explanation of above embodiment just is used for helping to understand method of the present invention and core concept thereof; Simultaneously, for one of ordinary skill in the art, according to thought of the present invention, the part that on embodiment and range of application, all can change, in sum, this description should not be construed as limitation of the present invention.

Claims

1. a method for switching network is characterized in that, comprising:

2. the method for claim 1 is characterized in that, also comprises before the network handoff request that said receiving terminal sends:

Register at source network and objective network at the terminal;

Home location server HSS preserves source network respectively and objective network is the PDN link information that create at said terminal.

3. the method for claim 1, said PDN link information comprises: the IP address at the access point APN sign that use at the terminal, PGW sign, wireless access type sign and terminal.

4. method as claimed in claim 3; It is characterized in that; If the access point APN that in source network, uses of said terminal does not have corresponding PDN to connect at objective network, then saidly notify said grouped data network gateway PGW that the process that the source network business data flow at this terminal switches to objective network is comprised:

Send and create the default bearer request to the said PGW that in source network, uses, the request network side is created the carrying that the user uses; Carry the sign of switching sign, APN and terminal IP address in the said default bearer request at source network.

5. method as claimed in claim 3; It is characterized in that; If said terminal exists PDN to connect at the employed APN of source network,, the PDN connection of said APN in objective network selected different PGW but connecting with the PDN of said APN in source network in objective network; The then said PGW that uses in the corresponding source network of said PDN link information of notifying comprises the process that the business data flow of this terminal source network switches to objective network: send and create the default bearer request to the said PGW that in source network, uses, the request network side is created the carrying that the user uses; Carry the sign of switching sign, APN and terminal IP address in the said default bearer request at source network.

6. method as claimed in claim 3; It is characterized in that; If said terminal exists PDN to connect in objective network at the employed APN of source network; Simultaneously the PDN that in objective network, uses of said APN connect with said APN in source network, use PDN connect and selected identical PGW, but used the IP address different in the PDN connection of terminal in objective network with source network; Then notify the PGW that uses in the corresponding source network of said PDN link information that the process that the business data flow of this terminal source network switches to objective network is comprised: send and create the default bearer request to the said PGW that in source network, uses, the request network side is created the carrying that the user uses; Carry the sign of switching sign, APN and terminal IP address in the said default bearer request at source network.

7. method as claimed in claim 3; It is characterized in that; If said terminal exists PDN to connect in objective network at the employed APN of source network; And the PDN of said APN in objective network connect with the PDN connection of said APN in source network in selected identical PGW, and the IP address at terminal is identical; Then notifying the PGW that uses in the corresponding source network of said PDN link information that the business data flow of this terminal source network is switched to objective network comprises: send more new bearer request to said PGW, carry the sign of switching sign, APN and the terminal IP address at source network in the said more new bearer request.

8. the method for claim 1 is characterized in that, the said terminal of said acquisition comprises in the employed PDN link information of source network:

For initiating register requirement to HSS in said terminal, said register requirement comprises the sign of the PDN link information of the said terminal use that indication HSS only returns;

Receive the said terminal PDN link information that HSS searches acquisition.

9. the method for claim 1 is characterized in that, the said terminal of said acquisition comprises in the employed PDN link information of source network:

What preserve from objective network is the PDN link information of obtaining the terminal the contextual information at terminal.

10. like any described method of claim 1 to 3, it is characterized in that, saidly notify said PGW to comprise after the source network business data flow at this terminal is switched to objective network:

PGW switches to objective network with the source network business data flow at said terminal.

11. method as claimed in claim 10 is characterized in that, PGW also comprises after the carrying at said terminal is switched to objective network:

Said PGW obtains the charging regulation at said terminal from PCRF, and it is to charge in said terminal that parallel connection adds up to the expense server.

12. a method for switching network is characterized in that, comprising:

Register at source network and objective network at the terminal;

13. method as claimed in claim 12; It is characterized in that; Said terminal comprised before the network side management equipment is sent the network handoff request: the PDN link information that preserve this locality at the terminal is checked; All exist PDN to be connected if find same APN at source network and objective network; And the IP address that these two PDN connect corresponding terminal is identical, and then said network handoff request of sending to the network side management equipment is: bearing resource request for allocation or the request of packet data protocol PDP secondary activating.

14. method as claimed in claim 13 is characterized in that, said bearing resource request for allocation or the IP address of sending carried terminal in the request of PDP secondary activating;

Said network side management equipment obtains the PGW that use at this terminal according to the IP address at said terminal in source network.

15. method as claimed in claim 13 is characterized in that, if said network handoff request of sending to the network side management equipment is the bearing resource request for allocation;

The PGW address that then said network side management equipment obtains in source network, to use at said terminal comprises:

Said network side management equipment is located the PND link information at said terminal according to the sign of the Network Service Access point in said carrying handoff request LBI; And from this PND link information, obtain the PGW that in source network, uses at terminal.

16. method as claimed in claim 13 is characterized in that, if said network handoff request of sending to the network side management equipment is the request of PDP secondary activating;

Said network side management equipment is located the PND link information at said terminal according to the packet domain research system bearing sign NSAPI of the link in the request of said PDP secondary activating, and from this PND link information, obtains the PGW that in source network, uses at terminal.

17. method as claimed in claim 12; It is characterized in that; Said terminal comprised before the network side management equipment is sent the network handoff request: the PDN link information that preserve this locality at the terminal is checked; All exist PDN to be connected if find same APN at source network and objective network, and these two PDN connect the IP address difference at corresponding terminal; Perhaps the PDN in the source network connects the APN that comprises does not have corresponding PDN to connect in objective network; Then said network handoff request of sending to the network side management equipment is: PDN connection request or PDP once activate request; Said PDN connection request or PDP once activate the sign that comprises said APN in the request and the said terminal IP address at source network.

18., it is characterized in that said network side management equipment is MME or SGSN like any described method of claim 12 to 17.

19. a network side management equipment is characterized in that, comprising:

Receiving element is used for the network handoff request that receiving terminal sends, and said network handoff request indicates said terminal to register at objective network;

20. network side management equipment as claimed in claim 19 is characterized in that, said gateway information acquiring unit comprises:

The CAMEL-Subscription-Information request unit is used for asking to HSS the CAMEL-Subscription-Information at said terminal;

The CAMEL-Subscription-Information receiving element is used to receive the CAMEL-Subscription-Information at the said terminal that HSS returns; Said CAMEL-Subscription-Information comprises the PGW information of this user current use in source network.

21. network side management equipment as claimed in claim 20 is characterized in that, said gateway information acquiring unit comprises:

Inspection unit is used for checking whether the contextual information at the said terminal that objective network is preserved comprises the PGW information that use at said terminal;

Acquiring unit is used for when said inspection unit check result is the PGW information of terminal use, from said contextual information, obtaining the PGW information that use at the terminal.

22. a portable terminal is characterized in that, comprising: the network registry unit is used for registering at source network and objective network;