CN104349507B

CN104349507B - A kind of switching method and apparatus

Info

Publication number: CN104349507B
Application number: CN201310344563.8A
Authority: CN
Inventors: 侯云静
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2013-08-08
Filing date: 2013-08-08
Publication date: 2018-08-07
Anticipated expiration: 2033-08-08
Also published as: CN104349507A

Abstract

An embodiment of the present invention provides a kind of switching method and apparatus ensure that the continuity of the terminal traffic during terminal disconnects the AP being currently accessed and is linked into new AP.The method of the present invention includes：The TWAG that terminal currently connects receives the switching request of terminal transmission, and the switching request is for the handoff procedure to the TWAG initiating terminals currently connected between different AP；The handoff procedure for executing terminal, to be that the terminal establishes connection on the new TWAG of new AP connections；And send switching to terminal and reply, this switches back into the connection being multiplexed between the AP that instruction terminal disconnects and currently connects and is linked into new AP.Since terminal is before being linked into new AP, on the new TWAG of new AP connections connection is established for the terminal, to which during terminal disconnects the AP currently connected and is linked into new AP, terminal business currently in use will not interrupt, and ensure that the continuity of the terminal traffic.

Description

A kind of switching method and apparatus

Technical field

The present invention relates to field of communication technology, more particularly to a kind of user equipment (User Equipment, UE) is in difference Switching method and apparatus between access point (Access Point, AP).

Background technology

UE is connected to credible WLAN access nets (Trusted WLAN Access under the network architecture based on S2a Network, TWAN；Wireless Local Area Network, WLAN) when the network architecture it is shown in Figure 1. The logical construction of TWAN in Fig. 1 is shown in Figure 2, wherein：

WLAN accesses the set that network (WLAN Access Network, WLAN AN) is WLAN AP, including one or more A WLAN AP；

Believable WLAN access gatewaies (Trusted WLAN Access Gateway, TWAG) are acquiescence for UE Router and dynamic host configuration protocol (Dynamic Host Configuration Protocol, DHCP) server (Server)；When TWAN provides the service for the packet-based core networks (Evolved Packet Core, EPC) for accessing evolution for UE, TWAG is responsible for the data forwarding of UE to Packet Data Network (Packet Data Network, PDN) gateway (Gateway, GW)；

Believable WLAN authentication, authorization, accountings agency (Trusted WLAN AAA Proxy, TWAP) is responsible for roaming AAA information is forwarded in scene between WLAN AN and 3GPP aaa servers.

After UE establishes a plurality of connection, needs a kind of method that UE and TWAG are distinguished and belong to different connections The data of (PDN connections and/or non-seamless WLAN shunt (Non-Seamless WLAN Offload, NSWO)) connection.From logic From the point of view of, it needs to establish a virtual point-to-point link between UE and TWAG for every connection of UE.It is implementing In, TWAG is that each virtual point-to-point link distributes a unique mark, and UE and TWAG are sent connect relevant number with certain According to when, UE and TWAG are carried in data and are connect relevant unique mark with this.

Virtual point-to-point link model between UE and TWAG includes being based on virtual LAN (Virtual Local Area Network, VLAN) mark (Identifier, ID) virtual point-to-point link model and accessed based on TWAG media Control the virtual point-to-point link model of the address (Media Access Control, MAC).

Virtual point-to-point link model based on VLAN ID is shown in Figure 3.Every PDN connection of UE and NSWO connect It connects corresponding with a virtual point-to-point link respectively.Wherein, PDN connections are that the logic between UE and PDN GW connects It connects, the flow transmitted by PDN connections is required for the routing by EPC that can just be sent to external network or is sent to UE； The flow of NSWO connections transmission needs not move through EPC routings, directly can be sent to external network by wlan network.

In model shown in Fig. 3, virtual point-to-point link is used for transmission the stream of specific PDN connections or NSWO connections Amount, this is distributed only by the access point name (Access Point Name, APN) that TWAG is specific PDN connections or NSWO connections One VLAN ID are realized.These different VLAN ID are configured on TWAG interfaces, i.e. TWAG can be received from these 2 frame of layer of VLAN ID can also send 2 frame of layer to these VLAN ID.

From figure 3, it can be seen that virtual point-to-point link is sent to accordingly by the data for connecting PDN connections with NSWO VLAN in realize, mark in 2 frame of layer of encapsulation of data corresponding VLAN ID can be realized transmit data to it is corresponding VLAN.Model in the sides UE, each virtual point-to-point link is virtual interface, from Internet Protocol (Internet Protocol, IP) from the point of view of layer, each virtual interface is exactly a fixed address IPv4 and/or the addresses IPv6.Using journey Socket (socket) can be tied on specific virtual interface by sequence, it is achieved that by socket be tied to one it is specific PDN connections or NSWO connections.IP packet transmissions are as follows：

Uplink direction：All IP groupings (including ip multicast is grouped) transmitted by virtual interface are all encapsulated in one In 2 frame of a layer, the head of 2 frame of layer carries VLAN ID marks, which connect with the PDN bound in socket/ interfaces Or NSWO connections are related.In receiving terminal, the IP encapsulated in 2 frame of layer groupings are sent to phase by TWAG according to the VLAN ID in 2 frame of layer The PDN connections or NSWO connections answered.

Downlink direction：In downlink direction, when TWAG receives IP from PDN connections or NSWO connections to be grouped, IP groupings are encapsulated in 2 frame of layer by TWAG, and 2 frame of layer carrying is connect with above-mentioned PDN or the relevant VLAN ID of NSWO connections. Receiving side, UE judge the PDN connections belonging to the IP groupings in 2 frame of layer or NSWO connections, then according to the VLAN ID in 2 frame of layer UE is sent to IP layers using the IP groupings of corresponding virtual interface.

Virtual point-to-point link model based on layer 2TWAG MAC Address is shown in Figure 4.Every PDN connection of UE It is connected with NSWO corresponding with a virtual point-to-point link respectively.In the link model, virtual point-to-point link is used It is respectively that APN or NSWO connections safeguard one uniquely in the flow for transmitting specific PDN connections or NSWO connections, and by TWAG MAC Address realizes that these different addresses layer 2MAC are configured on TWAG interfaces.As shown in figure 4, virtual point-to-point link By the way that IP groupings to be encapsulated in 2 frame of layer for carrying TWAG MAC Address, the grouping of forwarding uplink downlink is realized.

From the point of view of UE, the model of each virtual point-to-point link is a virtual interface, which is presented to IP Layer is a fixed address IPv4 and/or IPv6.Socket can be tied to one and specifically virtually connect by application program On mouth, therefore it can realize and socket is tied to a specific PDN connection or NSWO connections.Packet transmission is as follows：

Uplink direction：All IP groupings (including ip multicast is grouped) transmitted by virtual interface are all encapsulated in one In 2 frame of a layer, the target MAC (Media Access Control) address of 2 frame of this layer is arranged to 2 unicast mac address of layer of TWAG, the MAC Address and socket/ The PDN connections or NSWO connections that interface is tied to are related.In receiving side, TWAG by searching for 2 frame of layer purpose TWAG MAC IP can be grouped and be sent to suitable PDN connections or NSWO connections by location.

Downlink direction：When TWAG receives IP groupings (including ip multicast grouping) from PDN connections or NSWO connections, IP groupings are encapsulated in 2 frame of layer by TWAG, and it is that above-mentioned PDN connections or NSWO connect that the source MAC of 2 frame of this layer, which is arranged to TWAG, Connect the TWAG MAC Address of distribution.In receiving side, UE judges that IP is grouped institute by searching for the 2 source unicast mac address of layer of data frame Then IP groupings are sent to IP layers by the PDN connections or NSWO connections of category by corresponding virtual interface.

Currently, when UE is moved between different TWAG, first, the company between UE disconnections and the TWAG currently connected It connects；Then, UE is interacted with new TWAG again, to be linked into new TWAG, it is seen then that UE established connections before the movement All off (including PDN connections are connected with NSWO), business all interruptions namely currently in use from the point of view of user, from And can not ensure the continuity of business, influence the service experience of user.

Invention content

An embodiment of the present invention provides a kind of switching method and apparatus, solve the above problem, ensure that terminal traffic Continuity.

An embodiment of the present invention provides a kind of switching methods of the sides TWAG, including：

The TWAG that terminal currently connects receives the switching request that the terminal is sent, and the switching request to described for working as The TWAG of preceding connection initiates handoff procedure of the terminal between different AP；

The TWAG currently connected executes the handoff procedure of the terminal, in the new TWAG of the new AP connections It is upper to establish connection for the terminal；

The TWAG currently connected sends switching to the terminal and replys, and described switch back into is used to indicate the terminal again It disconnects the connection between the AP that currently connects and is linked into the new AP.

In force, the TWAG currently connected executes handoff procedure, specifically includes：

The TWAG currently connected is according to the new TWAG carried in the MAC Address of itself and the switching request MAC Address, judge whether this switching can cause the TWAG for providing service for the terminal to change；

The TWAG currently connected executes different processing procedures according to judging result.

The first situation, this switching will not cause the TWAG for providing service for the terminal to change, then described to work as The TWAG of preceding connection executes following processing procedure：

The TWAG currently connected stores the TWAG currently connected and institute in the contextual information of the terminal State the information of the endpoint of a tunnel for the data transmission tunnel established between new AP.

The second situation, this switching can cause the TWAG for providing service for the terminal to change, then described current The TWAG of connection executes following processing procedure, specifically includes：

The TWAG currently connected sends handover resource allocation request, the handover resource allocation to the new TWAG Request is the terminal distribution resource for asking the new TWAG；

The TWAG currently connected receives the handover resource allocation that the new TWAG is returned and replys, the switchable resource It is to be sent to the TWAG's currently connected after the new TWAG completes the resource allocation process of the terminal that distribution, which is replied,.

In the embodiment of the present invention, the handover resource allocation request includes：

The contextual information for the terminal that the terminal MAC address, the TWAG currently connected are stored, the terminal Credible WLAN access characteristics based on S2a interfaces the supported and terminal is workable at the new TWAG is based on At least one of the credible WLAN access characteristics of S2a interfaces information；

Wherein, the contextual information of the terminal include the currently-established all connections of the terminal relevant information and At least one of the signing information of terminal information.

Based on above-mentioned the second situation, if carrying the terminal in the new TWAG in handover resource allocation request The workable credible WLAN access characteristics based on S2a interfaces are descended, then the TWAG currently connected is obtained according to following steps The terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG：

The TWAG currently connected by the interaction with the new TWAG, obtain that the new TWAG supports based on The credible WLAN access characteristics of S2a interfaces；The TWAG currently connected by the new TWAG support based on S2a interfaces The credible WLAN access characteristics based on S2a interfaces that credible WLAN access characteristics and the terminal are supported are sent to certification, award Power and charging aaa server, and the terminal that the reception aaa server returns are workable at the new TWAG Credible WLAN access characteristics based on S2a interfaces；

Alternatively,

The TWAG currently connected by the interaction with the new TWAG, obtain that the new TWAG supports based on The credible WLAN access characteristics of S2a interfaces；The TWAG currently connected is according to the new TWAG supports based on S2a interfaces Credible WLAN access characteristics, the terminal signing information and the terminal support the credible WLAN based on S2a interfaces Access characteristic determines the terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG.

Preferably, it is described before the TWAG currently connected sends handover resource allocation request to the new TWAG Method further includes：

The TWAG currently connected is based on workable for sending the terminal at the new TWAG to the terminal The credible WLAN access characteristics of S2a interfaces, to obtain the instruction the information whether terminal continues to execute this switching.

Specially：If the TWAG currently connected receive that the terminal returns for showing that the terminal continues to hold The instruction information of this switching of row, then the TWAG currently connected send handover resource allocation request to the new TWAG； If the TWAG currently connected receive that the terminal returns for showing that the terminal does not execute the instruction of this switching Information, then the TWAG currently connected terminates this handoff procedure, and continues as the terminal forwarding data.

Based on above-mentioned the second situation, if the terminal is not carried in handover resource allocation request described new The workable credible WLAN access characteristics based on S2a interfaces under TWAG, then the new TWAG is according to following steps acquisition institute State terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG：

The new TWAG obtain that the terminal supports from handover resource allocation request based on S2a interfaces can Believe WLAN access characteristics；Credible WLAN access characteristics based on S2a interfaces that the new TWAG supports itself and described The credible WLAN access characteristics based on S2a interfaces that terminal is supported are sent to aaa server, and receive the aaa server The terminal returned workable credible WLAN access characteristics based on S2a interfaces at the new TWAG；

Alternatively,

The new TWAG obtain that the terminal supports from handover resource allocation request based on S2a interfaces can Believe the signing information of WLAN access characteristics and the terminal；The new TWAG supported according to itself based on S2a interfaces The credible WLAN based on S2a interfaces that credible WLAN access characteristics, the signing information of the terminal and the terminal are supported connects Enter characteristic, determines the terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG.

Based on above-mentioned the second situation, in force, new TWAG executes following resource allocation process：

The new TWAG workable credible WLAN based on S2a interfaces at the new TWAG according to the terminal Access characteristic determines the type for the connection that the terminal can be established at the new TWAG；

The type for the connection that the new TWAG can be established according to the terminal at the new TWAG and described The currently-established all connections of terminal, execute the resource allocation process of the terminal.

Specifically include following three kinds of different resource allocation process：

One, the terminal can only establish NSWO connections at the new TWAG, and the new TWAG executes following resource Assigning process：

The new TWAG determines that NSWO connections have had been established in the terminal；

The new TWAG is established NSWO connections allocation identification information；

Wherein, the handover resource allocation carries the corresponding mark pair of established NSWO connections, the mark in replying To being the allocated identification information of established NSWO connections including the TWAG currently connected and the new TWAG is The newly assigned identification information of the established NSWO connections.

Two, the terminal can only establish PDN connections at the new TWAG, and the new TWAG executes following resource point With process：

The new TWAG determines that at least one PDN connections have had been established in the terminal；

The new TWAG is every established PDN connections allocation identification information；

Wherein, the handover resource allocation carries that every established PDN connection is corresponding to be identified pair in replying, Mei Gebiao Know to being an established allocated identification information of PDN connections including the TWAG currently connected and the new TWAG is The newly assigned identification information of the established PDN connections of this.

Three, the terminal can establish NSWO connections at the new TWAG but also establish PDN connections, described new TWAG executes following resource allocation process：

The new TWAG determines that NSWO connections and/or at least one PDN connections has had been established in the terminal；

The new TWAG is established NSWO connections and/or every PDN connection allocation identification information respectively；

Wherein, the handover resource allocation carried in replying established NSWO connections it is corresponding identify pair and every The corresponding mark pair of the PDN connections of foundation, each mark to including the TWAG currently connected be the terminal any bar The allocated identification information of connection and/or the new TWAG of foundation are the established newly assigned identification information of connection.

Based on above-mentioned the second situation, if the terminal has had been established at least one PDN connections, the new TWAG to After the TWAG currently connected returns to the handover resource allocation reply, the method further includes：

The new TWAG initiates the renewal process of the contextual information of the terminal to PGW.

Based on above-mentioned the second situation, the method further includes：

The TWAG currently connected is after receiving the switch acknowledgment message that the new TWAG is sent, according to the end The type for holding the connection that can be established at the new TWAG executes the resource release process of the terminal；

Wherein, the switch acknowledgment message be new TWAG determine PGW complete the terminal of itself storage up and down After the update of literary information, or sent to the TWAG currently connected after receiving the upstream data that the terminal is sent 's.

In force, the resource release process that the TWAG currently connected executes the terminal specifically includes：

If A, the terminal can only establish NSWO connections at the new TWAG, the TWAG currently connected execute with Lower resource discharges process：

If at least one PDN connections have had been established in the terminal, the TWAG currently connected initiates the terminal The release process of established all PDN connections, and it is the terminal to discharge the contextual information of the terminal and local The resource of all connection distribution；

If the terminal does not set up PDN connections, the TWAG currently connected discharges the context letter of the terminal Breath and the resource of the local all connections distribution for being the terminal.

If B, the terminal can only establish PDN connections at the new TWAG, the TWAG currently connected execute with Lower resource discharges process：

The TWAG currently connected discharges the contextual information of the terminal and local all companies for the terminal Connect the resource of distribution.

C, the terminal can establish NSWO connections at the new TWAG but also establish PDN connections, described currently to connect The TWAG connect executes following resource release process：

In the embodiment of the present invention, the MAC of SSID, the new AP that the switching request is broadcasted comprising the new AP Location, the new AP connections new TWAG MAC Address and the terminal support the credible WLAN based on S2a interfaces Access characteristic.

An embodiment of the present invention provides a kind of switching methods of end side, including：

Terminal is when determination needs to be linked into new AP, to the credible WLAN access gateway TWAG hairs currently connected Switching request, the switching request is sent to be used to initiate switching of the terminal between different AP to the TWAG currently connected Process；

After the switching for receiving the TWAG currently connected is replied, between the terminal disconnection and the AP currently connected Connection and be linked into the new AP；

Wherein, before being linked into the new AP, the new AP, the new AP connections new TWAG and It has been that the terminal establishes connection between PGW.

Processing mode as one preferred is receiving described cut if the switching does not carry mark pair in replying It gains after answering, the connection between the terminal disconnection and the AP currently connected is simultaneously linked into the new AP, specifically includes：

The terminal receives after the switching replys, and directly disconnects the connection between the AP that currently connects and is linked into The new AP；

Wherein, the switching reply is that the TWAG currently connected determines that this switching will not cause to carry for the terminal It changes for the TWAG of service, and after establishing data transmission tunnel between the TWAG currently connected and the new AP It is sent to the terminal.

It is being received if the switching carries at least one mark pair in replying as another preferred processing mode After being replied to the switching, the terminal disconnects the connection between the AP that currently connects and is linked into the new AP, specifically Including：

After the terminal receives the switching reply, all marks pair carried in being replied according to the switching, update The terminal with each mark to the identification information of corresponding connection；And

Complete with each mark to the update of the identification information of corresponding connection after, the terminal disconnect with currently Connection between the AP of connection is simultaneously linked into the new AP；

Wherein, each mark it is established to a corresponding terminal and with the terminal in the new TWAG The identical connection of type for the connection that can be established down, and each mark is to being described including the TWAG currently connected The allocated identification information of established connection and the new TWAG are the established newly assigned identification information of connection.

In force, it is preferred that if this switching can cause the TWAG for providing service for the terminal to change, institute It states after terminal sends switching request to the TWAG that currently connects, the terminal receives the switching of the TWAG currently connected Before reply, the method further includes：

It is workable at the new TWAG that the terminal receives the terminal that the TWAG currently connected is sent Credible WLAN access characteristics based on S2a interfaces；

According to the terminal, the workable credible WLAN based on S2a interfaces at the new TWAG is accessed the terminal Characteristic, judges whether itself continues to execute this switching；And

The terminal returns to instruction information according to judging result, to the TWAG currently connected, and the instruction information is used In showing whether the terminal continues to execute this switching.

In the embodiment of the present invention, the switching request includes the service set SSID, described new of the new AP broadcast The MAC Address of AP, the MAC Address of the corresponding new TWAG of the new AP and the terminal support based on S2a interfaces Credible WLAN access characteristics.

An embodiment of the present invention provides a kind of TWAG, including：

Receiving module, the switching request for receiving terminal transmission, the switching request are used for described in this TWAG initiations Handoff procedure of the terminal between different AP；

First processing module, for execute cut the terminal change process, to be on the new TWAG of new AP connections The terminal establishes connection；

Sending module is replied for sending switching to the terminal, and described switch back into is used to indicate the terminal disconnection again Connection between the AP currently connecting simultaneously is linked into the new AP.

In force, the first processing module is specifically used for：

According to the MAC Address of the MAC Address of itself and the new TWAG connected of the new AP in the switching request, judge Whether this switching can cause the TWAG for providing service for the terminal to change；And according to judging result, execute difference Processing procedure.

Based on the first situation, i.e. this switching will not cause the TWAG for providing service for terminal to change, then and first Processing module executes following processing procedure：

It is stored in the contextual information of the terminal, the tunnel for the data transmission tunnel established between this TWAG and new AP The identification information of road endpoint.

Based on the second situation, i.e. this switching can cause the TWAG for providing service for the terminal to change, then：

The sending module is additionally operable to：Handover resource allocation request, the switchable resource point are sent to the new TWAG With request for asking the new TWAG for the terminal distribution resource；

The receiving module is additionally operable to：It receives the handover resource allocation that the new TWAG is returned to reply, the switching money It is to be sent to the TWAG currently connected after the new TWAG completes the resource allocation process of the terminal that source distribution, which is replied, 's.

Based on above-mentioned the second situation, in force, if carrying the terminal in institute in handover resource allocation request The workable credible WLAN access characteristics based on S2a interfaces under new TWAG are stated, then the first processing module is according to following Step obtains the terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG：

By the interaction with the new TWAG, the credible WLAN based on S2a interfaces that the new TWAG is supported is obtained Access characteristic；The new TWAG credible WLAN access characteristics based on S2a interfaces supported and the terminal are supported Credible WLAN access characteristics based on S2a interfaces are sent to aaa server, and receive the described of the aaa server return Terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG；

Alternatively,

By the interaction with the new TWAG, the credible WLAN based on S2a interfaces that the new TWAG is supported is obtained Access characteristic；And the label for the credible WLAN access characteristics based on S2a interfaces, the terminal supported according to the new TWAG The credible WLAN access characteristics based on S2a interfaces that about information and the terminal are supported determine the terminal described new The workable credible WLAN access characteristics based on S2a interfaces under TWAG.

In force, it is preferred that sending module is additionally operable to：The terminal is sent at the new TWAG to the terminal The workable credible WLAN access characteristics based on S2a interfaces, to obtain the finger whether terminal continues to execute this switching Show information；

Correspondingly, first processing module is additionally operable to：If the receiving module receive that the terminal returns for showing The terminal continues to execute the instruction information of this switching, then triggers the sending module and send switching money to the new TWAG Source distribution request；If the receiving module receive that the terminal returns for showing that the terminal does not execute this switching It indicates information, then terminates this handoff procedure, and continue as the terminal forwarding data.

Further, the first processing module is additionally operable to：

After receiving the switch acknowledgment message that the new TWAG is sent, according to the terminal at the new TWAG The type for the connection that can be established executes the resource release process of the terminal；

Specifically, the resource release process that the first processing module executes terminal specifically includes：

If the terminal can only establish NSWO connections at the new TWAG, and the terminal has had been established at least one PDN connections, then initiate the release process of established all PDN connections of the terminal, and discharges the context of the terminal Information and the resource of the local all connections distribution for being the terminal；

If the terminal can only establish NSWO connections at the new TWAG, and when the terminal does not set up PDN connections, Then discharge the contextual information of the terminal and the resource of the local all connections distribution for being the terminal；

If the terminal can only establish PDN connections at the new TWAG, alternatively, the terminal is in the new TWAG Under can establish NSWO connections but also establish PDN connections, then discharge the terminal contextual information and it is local be the end The resource of all connections distribution at end.

Based on above-mentioned the second situation, if this TWAG is the new TWAG, the TWAG further includes：

Second processing module, for according to the terminal at the new TWAG it is workable based on S2a interfaces can Believe WLAN access characteristics, determines the type for the connection that the terminal can be established at the new TWAG；And according to described The currently-established all connections of the type and the terminal of the connection that terminal can be established at the new TWAG, execute The resource allocation process of the terminal.

In force, it can be used at the new TWAG if not carrying the terminal in handover resource allocation request The credible WLAN access characteristics based on S2a interfaces, then described in the Second processing module is additionally operable to be obtained according to following steps Terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG：

The credible WLAN based on S2a interfaces that the terminal is supported is obtained from handover resource allocation request accesses spy Property；By credible WLAN access characteristics based on S2a interfaces that itself is supported and the terminal support based on S2a interfaces can Letter WLAN access characteristics are sent to aaa server, and receive the terminal that the aaa server returns described new The workable credible WLAN access characteristics based on S2a interfaces under TWAG；

Alternatively,

The credible WLAN based on S2a interfaces that the terminal is supported is obtained from handover resource allocation request accesses spy The signing information of property and the terminal；According to the credible WLAN access characteristics based on S2a interfaces of itself support, the terminal Signing information and the terminal support the credible WLAN access characteristics based on S2a interfaces, determine the terminal described The workable credible WLAN access characteristics based on S2a interfaces under new TWAG.

Based on above-mentioned the second situation, the Second processing module specifically executes following resource allocation process：

If the terminal can only establish NSWO connections at the new TWAG, and NSWO companies have had been established in the terminal It connects, is then established NSWO connections allocation identification information；Wherein, the handover resource allocation carries established in replying NSWO connections it is corresponding mark pair, it is described mark to including the TWAG currently connected be the established NSWO connections The identification information of distribution is that the established NSWO connects newly assigned identification information with the new TWAG；

If the terminal can only establish PDN connections at the new TWAG, and the terminal has had been established at least one PDN connections are then every established PDN connections allocation identification information；Wherein, it is carried during the handover resource allocation is replied every The corresponding mark pair of the established PDN connections of item, each mark is to being one established including the TWAG currently connected The allocated identification information of PDN connections is that the established PDN of this connects newly assigned identification information with the new TWAG

If the terminal can establish NSWO connections at the new TWAG but also establish PDN connections, and the terminal NSWO connections and/or at least one PDN connections has had been established, then has been established NSWO connections and/or every PDN connections difference Allocation identification information；Wherein, the handover resource allocation carried in replying established NSWO connections it is corresponding identify pair and The corresponding mark pair of every established PDN connections, each mark is to being the terminal times including the TWAG currently connected One allocated identification information of established connection and/or the new TWAG are the established newly assigned mark letter of connection Breath.

Further, it is based on above-mentioned the second situation, if the terminal has had been established at least one PDN connections, described the Two processing modules are additionally operable to：

Request PGW updates the contextual information of the terminal stored in the PGW.

The embodiment of the present invention additionally provides a kind of TWAG, including transceiver and is connect at least with the transceiver One processor, wherein：

Transceiver is configured for：The switching request that terminal is sent is received, which is used to initiate to this TWAG Handoff procedure of the terminal between different AP；

Processor is configured for：Execute terminal handoff procedure, on the new TWAG of new AP connections for terminal Establish connection；And after completing the handoff procedure, triggering transceiver sends switching to terminal and replys, this switches back into multiplexing in finger Show the connection between terminal disconnection and the AP currently connected and is linked into new AP.

In force, processor is configured to be specifically used for：

According to the MAC Address of the MAC Address of itself and the new TWAG connected of the new AP in switching request, this is judged Whether switching can cause the TWAG for providing service for terminal to change；And according to judging result, execute different process Journey.

Specifically, processor is configured for judging whether this switching can cause to provide clothes for terminal according to following steps The TWAG of business changes：

If the MAC Address of this TWAG is identical as the MAC Address of new TWAG, it is determined that this switching will not cause for terminal The TWAG for providing service changes；

If the MAC Address of this TWAG is different from the MAC Address of new TWAG, it is determined that this switching can cause to carry for terminal It changes for the TWAG of service.

Based on the first situation, i.e. this switching will not cause the TWAG for providing service for terminal to change, then handle Device is configured for executing following processing procedure：

It is stored in the contextual information of terminal, the tunnel end for the data transmission tunnel established between this TWAG and new AP The information of point.

Based on above-mentioned the second situation, i.e. this switching can cause the TWAG for providing service for terminal to change, then：

Transceiver is also configured to be additionally operable to：Handover resource allocation request, the handover resource allocation are sent to new TWAG TWAG of the request for that please look for novelty is terminal distribution resource；And receive the handover resource allocation that new TWAG is returned and reply, it should It is to be sent to the TWAG's currently connected after new TWAG completes the resource allocation process of terminal that handover resource allocation, which is replied,.

Based on above-mentioned the second situation, in force, if carried terminal is at new TWAG in handover resource allocation request The workable credible WLAN access characteristics based on S2a interfaces, then processor be configured for according to following steps obtain terminal The workable credible WLAN access characteristics based on S2a interfaces at new TWAG：

By the interaction with new TWAG, the credible WLAN access characteristics based on S2a interfaces that new TWAG is supported are obtained； By the new TWAG credible WLAN access characteristics based on S2a interfaces supported and terminal support based on the credible of S2a interfaces WLAN access characteristics are sent to aaa server, and receive terminal that aaa server the returns workable base at new TWAG In the credible WLAN access characteristics of S2a interfaces；

Alternatively,

By the interaction with new TWAG, the credible WLAN access characteristics based on S2a interfaces that new TWAG is supported are obtained； And the signing information and terminal branch for the credible WLAN access characteristics based on S2a interfaces, terminal supported according to new TWAG The credible WLAN access characteristics based on S2a interfaces held, determine terminal at new TWAG it is workable based on S2a interfaces can Believe WLAN access characteristics.

In force, it is preferred that before sending handover resource allocation request, transceiver is additionally configured to be used for：

Terminal workable credible WLAN access characteristics based on S2a interfaces at new TWAG are sent to terminal, to obtain Take whether terminal continues to execute the instruction information of this switching.

Correspondingly, processor is additionally configured to：

If transceiver receive terminal return for show terminal continue to execute this switching instruction information, touch It sends out sending module and sends handover resource allocation request to new TWAG；

If transceiver receive terminal return for show terminal do not execute this switching instruction information, terminate This handoff procedure, and continue as terminal forwarding data.

Further, processor is additionally configured to：

It, can at new TWAG according to terminal after the switch acknowledgment message that transceiver receives that new TWAG is sent The type of the connection of foundation executes the resource release process of terminal；

Wherein, to be new TWAG determining that PGW completes the contextual information of the terminal of itself storage to switch acknowledgment message After update, or sent to the TWAG currently connected after the upstream data for receiving terminal transmission.

Specifically, processor is configured the resource for being specifically used for executing terminal release process：

If terminal can only establish NSWO connections at new TWAG, and at least one PDN connections have had been established in terminal, then send out The release process of established all PDN connections of terminal is played, and it is terminal to discharge the contextual information of terminal and local The resource of all connection distribution；

If terminal can only establish NSWO connections at new TWAG, and when terminal does not set up PDN connections, then terminal is discharged Contextual information and the resource of the local all connections distribution for being terminal；

If terminal can only establish PDN connections at new TWAG, alternatively, terminal can establish NSWO companies at new TWAG PDN connections are connect and can be established, then discharge the contextual information of terminal and the resource of the local all connections distribution for being terminal.

In force, if this TWAG is new TWAG, processor is additionally configured to：

According to terminal at new TWAG the workable credible WLAN access characteristics based on S2a interfaces, determine that terminal exists The type for the connection that can be established under new TWAG；And the type for the connection that can be established at new TWAG according to terminal with And all connections that terminal is currently-established, execute the resource allocation process of terminal.

Further, if this TWAG be new TWAG, and handover resource allocation request in non-carried terminal at new TWAG The workable credible WLAN access characteristics based on S2a interfaces, then processor be additionally configured to according to following steps obtain eventually End workable credible WLAN access characteristics based on S2a interfaces at new TWAG：

The credible WLAN access characteristics based on S2a interfaces that terminal is supported are obtained from handover resource allocation request；It will be certainly The credible WLAN accesses based on S2a interfaces for the credible WLAN access characteristics and terminal support based on S2a interfaces that body is supported Characteristic is sent to aaa server, and receives that terminal that aaa server returns is workable at new TWAG to be connect based on S2a The credible WLAN access characteristics of mouth；

Alternatively,

The credible WLAN access characteristics based on S2a interfaces and end that terminal is supported are obtained from handover resource allocation request The signing information at end；The signing information of the credible WLAN access characteristics based on S2a interfaces, terminal supported according to itself and end The credible WLAN access characteristics based on S2a interfaces supported are held, determines that terminal is workable at new TWAG and is based on S2a interfaces Credible WLAN access characteristics.

In force, if this TWAG is new TWAG, processor is configured specifically to execute following resource allocation process：

If terminal can only establish NSWO connections at new TWAG, and NSWO connections have had been established in terminal, then to have been established NSWO connection allocation identification information；Wherein, which carries the corresponding mark of established NSWO connections in replying Knowledge pair, each mark is the established allocated identification information of NSWO connections to the TWAG including currently connecting and new TWAG is The newly assigned identification information of established NSWO connections；

If terminal can only establish PDN connections at new TWAG, and at least one PDN connections have had been established in terminal, then for Every established PDN connections allocation identification information；Wherein, which carries every established PDN in replying Corresponding mark pair is connected, each mark is an allocated mark of established PDN connections to the TWAG including currently connecting It is that the established PDN of this connects newly assigned identification information to know information with new TWAG；

If terminal can establish NSWO connections at new TWAG but also establish PDN connections, and NSWO has had been established in terminal Connection and/or at least one PDN connections, then for established NSWO connections and/or every PDN connection, allocation identification is believed respectively Breath；Wherein, which carries the corresponding mark pair of established NSWO connections in replying and every established The corresponding mark pair of PDN connections, each mark are that the established connection of terminal any bar has divided to the TWAG including currently connecting The identification information and/or new TWAG matched are the established newly assigned identification information of connection.

In force, if this TWAG is new TWAG, and terminal can establish NSWO connections at new TWAG, then handle Device is additionally configured to：

In the resource allocation process for executing terminal, it is the local ip address of terminal distribution, and local ip address is carried In handover resource allocation reply, wherein the TWAG that terminal currently connects is replied when returning to switching reply to terminal in switching In also carry new TWAG be terminal distribution local ip address；

Alternatively,

It is the local ip address of terminal distribution after receiving the dynamic host configuration protocol DHCP request of terminal transmission, And local ip address is notified to terminal, wherein the DHCP request is that terminal is being linked into the rear to new TWAG hairs of new AP It send.

In force, if this TWAG is new TWAG, and at least one PDN connections have had been established in terminal, then processor is also It is configured for：

An embodiment of the present invention provides a kind of terminals, including：

Switch initiation module, for when determination needs to be linked into new access point AP, being sent to the TWAG currently connected Switching request, the switching request are used to initiate switching of this terminal between different AP to the TWAG currently connected Journey；

Switching executing module, for after the switching for receiving the TWAG currently connected is replied, disconnecting and currently connecting Connection between the AP connect is simultaneously linked into the new AP；

Wherein, it has been that this terminal is established before being linked into the new AP, on the new TWAG of the new AP connections Connection.

In force, the switching executing module is specifically used for：

If the switching does not carry mark pair in replying, after receiving the switching and replying, directly disconnect and current Connection between the AP of connection is simultaneously linked into the new AP；Wherein, the switching reply is that the TWAG currently connected is true This fixed switching will not cause the TWAG for providing service for the terminal to change, and the TWAG currently connected with it is described It establishes between new AP and is sent to the terminal after data transmission tunnel；

If the switching carries at least one mark pair in replying, after receiving the switching and replying, according to described All marks pair that switching carries in replying update the identification information with each mark to corresponding connection of this terminal； And complete with each mark to the update of the identification information of corresponding connection after, between disconnection and the AP currently connected Connection and be linked into the new AP；Wherein, each mark it is established to a corresponding terminal and with it is described The identical connection of type for the connection that terminal can be established at the new TWAG, and each mark is to including described work as The TWAG of preceding connection is the allocated identification information of the established connection and the new TWAG is the established connection Newly assigned identification information.

In force, it is preferred that the switching executing module is additionally operable to：

It is workable based on S2a interfaces at the new TWAG to receive this terminal that the TWAG currently connected is sent Credible WLAN access characteristics；According to this terminal, the workable credible WLAN based on S2a interfaces connects at the new TWAG Enter characteristic, judges whether itself continues to execute this switching；And it according to judging result, is returned to the TWAG currently connected Indicate information, the instruction information is for showing whether this terminal continues to execute this switching.

The embodiment of the present invention additionally provides a kind of terminal, including transceiver and is connect at least with the transceiver One processor, wherein：

Processor is configured for determining that triggering transceiver is connected to current when needing to be linked into new access point AP TWAG send switching request, which is used to the TWAG currently connected initiate switching of this terminal between different AP Process；And after transceiver receives the switching reply of the TWAG currently connected, between disconnection and the AP currently connected It connects and is linked into new AP；

Wherein, it has been that this terminal establishes connection before being linked into new AP, on the new TWAG of new AP connections.

In force, processor is configured to be specifically used for：

If the switching that transceiver receives does not carry mark pair in replying, directly between disconnection and the AP currently connected Connection and be linked into new AP；Wherein, switching reply is that the TWAG currently connected determines that this switching will not cause for end The TWAG that end provides service changes, and is established between the TWAG currently connected and new AP after data transmission tunnel to end What end was sent；

If the switching that transceiver receives carries at least one mark pair in replying, carried in being replied according to switching All marks pair update the identification information with each mark to corresponding connection of this terminal；And it completes and each mark After the update of the identification information of corresponding connection, disconnects the connection between the AP that currently connects and be linked into new AP；Its In, each mark is established and identical as the type for the connection that terminal can be established at new TWAG to a corresponding terminal Connection, and each mark is the allocated identification information of an established connection to the TWAG including currently connecting and new TWAG is the established newly assigned identification information of connection of this.

Preferably, transceiver is additionally configured to：This terminal of the TWAG transmissions currently connected is received in new TWAG The lower workable credible WLAN access characteristics based on S2a interfaces；

Correspondingly, processor is additionally configured to：It is workable based on S2a interfaces at new TWAG according to this terminal Credible WLAN access characteristics, judge whether itself continues to execute this switching；And according to judging result, to what is currently connected TWAG returns to instruction information, and the instruction information is for showing whether this terminal continues to execute this switching.

In force, NSWO connections can be established if this terminal is at new TWAG, it is preferred that processor is also configured to use In：

The switching received from transceiver obtains the local ip address that new TWAG is this terminal distribution in replying；Or Person,

After being linked into new AP, triggering transceiver sends DHCP request to new TWAG, to obtain new TWAG For the local ip address of this terminal distribution.

In the embodiment of the present invention, the TWAG currently connected executes the terminal after receiving the switching request of the terminal Then handoff procedure is switched back into terminal transmission again with being that the terminal establishes connection on the new TWAG of new AP connections It is multiple, to indicate the connection between terminal disconnection and the AP currently connected and be linked into new AP.Since terminal is being linked into newly AP before, be that the terminal establishes connection on the new TWAG of the new AP connections, thus it is guaranteed that the terminal traffic Continuity, improve the service experience of user.

Description of the drawings

Fig. 1 is the network architecture schematic diagram based on TWAN accesses in background technology；

Fig. 2 is the internal structure schematic diagram of TWAN in background technology；

Fig. 3 is the virtual point-to-point link model schematic based on VLAN ID in background technology；

Fig. 4 is the virtual point-to-point link model schematic based on layer 2TWAG MAC Address in background technology；

Fig. 5 is the switching method schematic diagram of network side provided in an embodiment of the present invention；

Fig. 6 is the switching method schematic diagram of end side provided in an embodiment of the present invention；

Fig. 7 is the schematic diagram of a scenario that terminal of the embodiment of the present invention switches between different AP；

Fig. 8 is the flow diagram of embodiment one provided by the invention；

Fig. 9 A are the first application scenarios schematic diagram of embodiment one provided by the invention；

Fig. 9 B are second of application scenarios schematic diagram of embodiment one provided by the invention；

Figure 10 is the flow diagram of embodiment three provided by the invention；

Figure 11 is the flow diagram of example IV provided by the invention；

Figure 12 is TWAG schematic diagrames provided in an embodiment of the present invention；

Figure 13 is terminal schematic diagram provided in an embodiment of the present invention.

Specific implementation mode

In the embodiment of the present invention, since terminal is before being linked into new AP, on the new TWAG of the new AP connections It has been that the terminal establishes connection, thus it is guaranteed that the continuity of the terminal traffic.

In the embodiment of the present invention, when UE is connected to credible WLAN accesses under the network architecture based on S2a, UE and network can It can support following five characteristics：

1、NSWO：If UE and network support the characteristic, UE that can establish NSWO connections simultaneously；

2, the PDN connections to acquiescence APN are only established：If UE and network support the characteristic, UE that can establish simultaneously It is connect with the acquiescence relevant PDN of APN；

3, the PDN connections (establishing a plurality of PDN connections) to non-default APN are established：It should if UE and network are supported simultaneously Characteristic, then UE can establish a plurality of PDN connections；

4, UE is accessed between credible WLAN in 3GPP and is switched；

5, when UE switches between 3GPP accesses and credible WLAN, IP address continuity is supported.

Above-mentioned characteristic is referred to as the credible WLAN access characteristics based on S2a interfaces.

The embodiment of the present invention is described in further detail with reference to the accompanying drawings of the specification.

It is shown in Figure 5, the switching method of network side provided in an embodiment of the present invention, including：

The TWAG that step 51, terminal currently connect receives the switching request of terminal transmission, which is used for working as Handoff procedure of the TWAG initiating terminals of preceding connection between different AP；

If specifically, signal strength of the terminal in the new AP for finding itself to receive is more and more stronger, and what is received works as The signal strength of the AP of preceding connection is more and more weaker, then the terminal desires access to new AP.Then, the terminal is to currently connecting TWAG sends switching request, to ask the TWAG currently connected to initiate handoff procedure of the terminal between different AP.

Step 52, the TWAG currently connected execute the handoff procedure of the terminal, on the new TWAG of new AP connections It establishes and connects for the terminal；

In this step, the TWAG currently connected is after the handoff procedure for completing the terminal, the new TWAG of new AP connections It is upper to establish connection for the terminal.

Step 53, the TWAG currently connected send switching after completing handoff procedure, to terminal and reply, this switches back into multiplexing The connection between the AP that currently connects is disconnected in instruction terminal and is linked into new AP.

In a kind of new handover mechanism provided in an embodiment of the present invention, the TWAG currently connected is receiving cutting for the terminal After changing request, the handoff procedure of the terminal is executed, to be that the terminal establishes connection on the new TWAG of new AP connections, then It sends switching to the terminal again to reply, to indicate the connection between terminal disconnection and the AP currently connected and be linked into new AP.It has been that the terminal establishes connection on the new TWAG of new AP connections since terminal is before being linked into new AP, because This, ensure that the continuity of the terminal traffic, improve the service experience of user.

In the embodiment of the present invention, switching request is including but not limited to following message：The SSID of new AP broadcast, new AP The credible WLAN accesses based on S2a interfaces that the MAC Address and terminal of the corresponding new TWAG of MAC Address, new AP is supported Characteristic.

Specifically, the terminal can obtain the service set of the new AP in road from the periodic broadcast message of new AP The letters such as the MAC Address of TWAG (i.e. new TWAG) of (Service Set Identification, SSID), new AP connections Breath.

In force, in step 52, the handoff procedure of the TWAG execution terminals currently connected specifically includes：

The new TWAG that the TWAG currently connected is connected according to the new AP carried in the MAC Address of itself and switching request MAC Address, judge whether this switching can cause the TWAG for providing service for terminal to change；And

Specifically, the TWAG currently connected in step 52 sentences according to the MAC Address of itself MAC Address and new TWAG Whether this disconnected switching can cause the TWAG for providing service for terminal to change, and specifically include following two situations：

If the MAC Address of the first situation, the TWAG currently connected are identical as the MAC Address of new TWAG, currently connect The TWAG connect determines that this switching will not cause the TWAG for providing service for terminal to change, i.e., this switching be terminal with It is switched between two different AP of the TWAG currently connected the connections；In the case of this kind, the TWAG that currently connects with it is new TWAG be the same TWAG.

If the MAC Address of the second situation, the TWAG currently connected are different from the MAC Address of new TWAG, currently connect The TWAG connect determines that this switching can cause the TWAG for providing service for terminal to change；In the case of this kind, currently connect TWAG is different TWAG from new TWAG.

Based on the first above-mentioned situation, i.e. this switching will not cause the TWAG for providing service for terminal to change, then The TWAG currently connected executes following handoff procedure：

The TWAG currently connected is stored in the contextual information of the terminal between the TWAG currently connected and new AP The information of the endpoint of a tunnel of the data transmission tunnel of foundation.

Further, following two preferred implementations are specifically included：

If data transmission tunnel has had been established between mode one, the TWAG currently connected and new AP, currently connect TWAG executes following handoff procedure：

The TWAG currently connected directly stores established data transmission in the contextual information for the terminal that itself is preserved The information of the endpoint of a tunnel in tunnel.

Further, the TWAG currently connected stores established data in the contextual information for the terminal that itself is stored After the information for transmitting the endpoint of a tunnel in tunnel, step 53 is executed, i.e., sending switching to the terminal replys.

Correspondingly, the terminal receives after the switching replys, directly disconnects the connection between the AP that currently connects and connect Enter to new AP.

Under which, terminal currently connects before the connection disconnected between the AP that currently connects and being linked into new AP Data transmission tunnel has had been established between the TWAG and new AP that connect, and the information of the endpoint of a tunnel of the data transmission tunnel has been deposited In the contextual information for having stored up the terminal, at this point, established on new TWAG (TWAG currently connected) with new AP it Between data transmission tunnel, ensure that the continuity of the terminal traffic.

If not setting up data transmission tunnel between mode two, the TWAG currently connected and new AP；Then, then it currently connects TWAG executes following handoff procedure：

What the TWAG that currently connects initiated the data transmission tunnel between new AP establishes process；And

After above-mentioned data transmission tunnel is successfully established, the TWAG currently connected believes in the context of the terminal itself stored The information of the endpoint of a tunnel of the data transmission tunnel of foundation is stored in breath.

Further, the TWAG currently connected stores newly-established data in the contextual information for the terminal that itself is stored After the information for transmitting the endpoint of a tunnel in tunnel, step 53 is executed, i.e., sending switching to the terminal replys.

Under which, terminal currently connects before the connection disconnected between the AP that currently connects and being linked into new AP Newly establish data transmission tunnel between the TWAG and new AP that connect, and by the endpoint of a tunnel of newly-established data transmission tunnel In information storage to the contextual information of the terminal, at this point, established on new TWAG (TWAG currently connected) with newly AP between data transmission tunnel, to ensure that the continuity of the terminal traffic.

Under above two mode, the letter of the endpoint of a tunnel of the data transmission tunnel between the TWAG and new AP that currently connect Breath is specifically as follows：Tunnel End Point Identifier (Tunnel Endpoint Identifier, TEID) or generic route encapsulation (Generic Routing Encapsulation, GRE) key (key).

Based on above-mentioned the second situation, i.e. this switching can cause the TWAG for providing service for terminal to change, then when The handoff procedure that the TWAG of preceding connection is executed, specifically includes：

The TWAG currently connected sends handover resource allocation request, the switchable resource point to the new corresponding new TWAG of AP TWAG with request for that please look for novelty executes the resource allocation process of terminal；And

The TWAG currently connected receives the handover resource allocation that new TWAG is returned and replys, wherein the handover resource allocation Reply is to be sent to the TWAG currently connected after new TWAG completes the resource allocation process of terminal.

In the embodiment of the present invention, handover resource allocation request includes but not limited at least one of following message information：

Terminal MAC address, the contextual information of the terminal of the TWAG currently connected storages, terminal support based on S2a The workable credible WLAN accesses based on S2a interfaces at new TWAG of the credible WLAN access characteristics and terminal of interface At least one of characteristic information；

Wherein, the contextual information of the terminal includes the relevant information and terminal of the currently-established all connections of terminal At least one of signing information information.

In force, above-mentioned the second situation, the handoff procedure that the TWAG currently connected in step 52 is executed, into one are based on Step includes following three kinds of preferred implementations method：

Method 1, this method specifically include following steps：

The TWAG currently connected is obtained by the interaction (such as to new TWAG transfer characteristics request message) with new TWAG The credible WLAN access characteristics based on S2a interfaces that new TWAG is supported；

The credible WLAN access characteristics and terminal branch based on S2a interfaces that the TWAG currently connected supports new TWAG The credible WLAN access characteristics (the access characteristic information is carried in switching request) based on S2a interfaces held are sent to AAA services Device；

The terminal of the TWAG reception aaa server returns currently connected is workable at new TWAG to be connect based on S2a The credible WLAN access characteristics of mouth；

The TWAG currently connected sends handover resource allocation request to new TWAG, is carried in handover resource allocation request Terminal MAC address, the contextual information of the terminal and terminal are workable based on the credible of S2a interfaces at new TWAG WLAN access characteristics；And

The TWAG currently connected receives the handover resource allocation that new TWAG is returned and replys.

Under this method, aaa server according to the signing information of the terminal, the preconfigured strategy of operator and is worked as first The information that the TWAG of preceding connection is provided determines that the terminal workable credible WLAN based on S2a interfaces at new TWAG connects Enter characteristic；Then, which is returned to the TWAG currently connected by aaa server.

Method 2, this method specifically include following steps：

The TWAG currently connected by the interaction with new TWAG, obtain that new TWAG supports based on S2a interfaces can Believe WLAN access characteristics；

Credible WLAN access characteristics based on S2a interfaces that the TWAG currently connected is supported according to new TWAG, terminal The credible WLAN access characteristics based on S2a interfaces that signing information and terminal are supported (carry the access characteristic in switching request Information), determine the terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG；

Based on the above method 1 and method 2, correspondingly, the resource allocation process that new TWAG executes terminal specifically includes：

New TWAG receives the handover resource allocation request that the TWAG currently connected is sent；

New TWAG workable credible WLAN access characteristics based on S2a interfaces at the new TWAG according to terminal, Determine the type (NSWO connections and/or PDN connections) for the connection that terminal can be established at the new TWAG；And

The type and terminal for the connection that new TWAG can be established according to terminal at the new TWAG are currently-established All connections (i.e. the terminal established all connections in the TWAG currently connected), execute the resource allocation mistake of the terminal Journey.

In the embodiment of the present invention, the type for the connection that terminal can be established at the new TWAG is different, and new TWAG is held The resource allocation process of row terminal is also different, specifically includes following three kinds of different resource allocation process：

One, terminal can only establish NSWO connections at new TWAG, and further, the new TWAG is according to the upper and lower of the terminal Literary information judges whether the terminal has had been established NSWO connections, and according to judging result difference, which executes different operation, Specially：

1) the new TWAG, which is determined, terminal has had been established NSWO connections (i.e. the terminal has been established in the TWAG currently connected NSWO connections)；And the new TWAG is established NSWO connections allocation identification information, so that terminal is used with new TWAG The NSWO connections of the identification information unique identification terminal；

Correspondingly, being carried in the handover resource allocation reply that the new TWAG is returned to the TWAG currently connected established The corresponding mark pair of NSWO connections, the mark are the allocated mark of established NSWO connections to the TWAG including currently connecting Information is that the established NSWO connects newly assigned identification information with new TWAG.

Further, the TWAG currently connected sends switching after receiving the handover resource allocation and replying, to terminal and replys, And the corresponding mark pair of the established NSWO connections of carried terminal in switching reply, so that terminal is before the switch, it will Update the corresponding identification information of the established NSWO connections of itself storage.

In such cases, terminal is before the connection disconnected between the AP that currently connects and being linked into new AP, new TWAG is what terminal established NSWO connections in the TWAG currently connected were assigned with new identification information, and currently connected Corresponding identify of the established NSWO connections is notified, to terminal, terminal to be made to update itself storage by TWAG to replying by switching The corresponding identification information of the established NSWO connections, therefore, after new AP is connected in terminal, which can be by this Established NSWO connections are communicated with new TWAG, to ensure that the continuity of the terminal traffic.

2) the new TWAG, which is determined, terminal does not set up NSWO connections (i.e. the terminal is not set up in the TWAG currently connected NSWO connections)；And the new TWAG is not connect with NSWO for terminal distribution and the relevant resource of PDN connections.

Correspondingly, the handover resource allocation that the new TWAG is returned to the TWAG currently connected does not carry any ginseng in replying Number.

Two, terminal can only establish PDN connections at new TWAG, and further, the new TWAG is according to the upper and lower of the terminal Literary information judges whether the terminal has had been established PDN connections, and according to judging result difference, which executes different operation, Specially：

1) the new TWAG, which is determined, terminal has had been established at least one PDN connections (i.e. the terminal is in the TWAG currently connected In at least one PDN connections have had been established)；And the new TWAG is every established PDN connections allocation identification information.

Correspondingly, the handover resource allocation that the new TWAG is returned to the TWAG that currently connects carried in replying every it is built The corresponding mark pair of vertical PDN connections, each mark are that an established PDN connection has divided to the TWAG including currently connecting The identification information matched is that the established PDN of this connects newly assigned identification information with new TWAG.

Further, the TWAG currently connected sends switching after receiving the handover resource allocation and replying, to terminal and replys, And the corresponding mark pair of the established PDN connections of carried terminal in switching reply, so that terminal is before the switch, it will more The corresponding identification information of the established PDN connections of itself new storage.

In such cases, terminal is before the connection disconnected between the AP that currently connects and being linked into new AP, new TWAG is that terminal established every PDN connections in the TWAG currently connected are assigned with new identification information, and currently connect Corresponding identify of the established PDN connections is notified, to terminal, terminal to be made to update itself by the TWAG connect to replying by switching The corresponding identification information of the established PDN connections of storage, therefore, after new AP is connected in terminal, which can lead to It crosses the established PDN connections to be communicated with new TWAG, to ensure that the continuity of the terminal traffic.

2) the new TWAG, which is determined, terminal does not set up PDN connections (i.e. the terminal does not set up PDN in the TWAG currently connected Connection)；And the new TWAG is not connect with NSWO for terminal distribution and the relevant resource of PDN connections.

Three, terminal can establish NSWO connections at new TWAG and establish PDN connections, further, the new TWAG Judge whether the terminal has had been established PDN connections or NSWO connections according to the contextual information of the terminal, not according to judging result Together, which executes different operation, specially：

1) the new TWAG determines that NSWO connections and/or at least one PDN connections has had been established in terminal；And this is new TWAG is established NSWO connections and/or every PDN connection allocation identification information respectively.

Correspondingly, being carried in the handover resource allocation reply that the new TWAG is returned to the TWAG currently connected established The corresponding mark pair of NSWO connections and/or the corresponding mark pair of every established PDN connections, each identify to including currently connecting The TWAG connect is established connection (NSWO connections or PDN connections) the allocated identification information of terminal any bar and new TWAG is The established newly assigned identification information of connection.

Further, the TWAG currently connected sends switching after receiving the handover resource allocation and replying, to terminal and replys, And the corresponding mark pair of the established every connection (NSWO connections and/or PDN connections) of carried terminal in switching reply, with Make terminal before the switch, corresponding identification information is connected by this established every that updates itself storage.

In such cases, terminal is before the connection disconnected between the AP that currently connects and being linked into new AP, new TWAG is what terminal established every connection in the TWAG currently connected was assigned with new identification information, and currently connected Corresponding identify of established every connection is notified, to terminal, terminal to be made to update itself storage by TWAG to replying by switching The corresponding identification information of established every connection, therefore, after new AP is connected in terminal, which can be by this Established connection is communicated with new TWAG, to ensure that the continuity of the terminal traffic.

2) the new TWAG determines that terminal does not set up NSWO connections and connects that (i.e. the terminal is in the TWAG currently connected with PDN In do not set up NSWO connections and connected with PDN)；And new TWAG is not that terminal distribution is connect with NSWO and PDN connections are relevant Resource.

It should be noted that every PDN connection of terminal includes positioned at the terminal and between the TWAG of the terminal service Point-to-point link and the tunnel (such as general packet wireless service tunnel protocol (GPRS between the TWAG and PGW Tunneling Protocol, GTP；General Packet Radio Service, GPRS) tunnel, proxy-mobile IP Tunnel (Proxy Mobile IP, PMIP)).

Therefore, in above-mentioned second and the third resource allocation process, new TWAG is the established PDN of every, the terminal Connection identification information of the distribution for the point-to-point link between the unique mark new TWAG and terminal respectively, and distribution are used The identification information in the tunnel in unique mark between the new TWAG and PGW.In the embodiment of the present invention, for every of the terminal Established PDN connections, the established PDN that new TWAG is generated connect corresponding mark to the TWAG including currently connecting It is that the established PDN of this connects for the allocated identification information of point-to-point link of the established PDN connections of this and new TWAG The newly assigned identification information of point-to-point link connect can update itself preservation so that terminal is receiving the mark to rear The corresponding mark of point-to-point link of the established PDN connections of this.

Based on the above method 1 and method 2, it is preferred that the TWAG currently connected sends handover resource allocation to new TWAG Before request, this method is further comprising the steps of：

It is workable based on the credible of S2a interfaces at new TWAG that the TWAG currently connected to terminal sends the terminal WLAN access characteristics, to obtain the instruction information whether terminal continues to execute this switching.

Further, if the TWAG currently connected receive terminal return for show terminal continue to execute this switching Indicate that information, the then TWAG currently connected execute to new TWAG and sends handover resource allocation request；

If the TWAG currently connected receive terminal return for show terminal do not execute this switching instruction information, The TWAG then currently connected terminates this handoff procedure, and continues as terminal forwarding data.

Correspondingly, terminal is workable based on the credible of S2a interfaces at new TWAG according to the terminal received WLAN access characteristics, judge whether these characteristics disclosure satisfy that the demand of itself, to decide whether to execute this switching, specifically 's：

If the terminal workable credible WLAN access characteristics based on S2a interfaces at new TWAG disclosure satisfy that the end The demand at end, then terminal, which decides to continue with, executes this switching, and is returned to the TWAG currently connected for showing that terminal continues to hold The instruction information of this switching of row；

If the terminal workable credible WLAN access characteristics based on S2a interfaces at new TWAG cannot meet the end The demand at end, then terminal decides not to perform this switching, and is returned to the TWAG currently connected for showing that terminal does not execute sheet The instruction information of secondary switching.

Method 3, this method specifically include following steps：

The TWAG currently connected sends handover resource allocation request to new TWAG, is carried in handover resource allocation request The credible WLAN access characteristics based on S2a interfaces that terminal MAC address, the contextual information of the terminal and terminal are supported；With And

Based on the above method 3, correspondingly, non-carried terminal in the handover resource allocation request received due to new TWAG The workable credible WLAN access characteristics based on S2a interfaces at new TWAG, therefore, new TWAG executes the resource of terminal Assigning process specifically includes：

The information that new TWAG is carried according to handover resource allocation request, obtains terminal workable base at new TWAG In the credible WLAN access characteristics of S2a interfaces；

The type and terminal for the connection that new TWAG can be established according to terminal at the new TWAG are currently-established All connections (i.e. the terminal TWAG in established all connections), execute the resource allocation process of terminal.

Specifically, the information that new TWAG is carried according to handover resource allocation request, obtaining terminal can at new TWAG The credible WLAN access characteristics based on S2a interfaces used, specifically include：

New TWAG from receive handover resource allocation request in obtain terminal support based on the credible of S2a interfaces WLAN access characteristics；The credible WLAN access characteristics based on S2a interfaces and the terminal that the new TWAG supports itself The credible WLAN access characteristics based on S2a interfaces supported are sent to aaa server, and receive the end that aaa server returns End workable credible WLAN access characteristics based on S2a interfaces at new TWAG；Alternatively,

The signing information of the credible WLAN access characteristics based on S2a interfaces, terminal that new TWAG is supported according to itself (can With from receive handover resource allocation request carry terminal contextual information in obtain) and terminal support based on The credible WLAN access characteristics (the access characteristic information is carried in switching request) of S2a interfaces, determine the terminal in new TWAG The lower workable credible WLAN access characteristics based on S2a interfaces.

In force, aaa server is preconfigured tactful and new according to the signing information of the terminal, operator first The information that provides of TWAG, determine the terminal workable credible WLAN access characteristics based on S2a interfaces at new TWAG； Then, which is returned to new TWAG by aaa server.

In force, the type and terminal for the connection that new TWAG can be established according to terminal at the new TWAG are worked as Preceding established all connections, execute the resource allocation process of terminal, referring specifically to described in the above method 1 and method 2 Three kinds of resource allocation process, details are not described herein again.

Under this method 3, new TWAG is after completing resource allocation process, to the switchable resource of the TWAG returns currently connected Distribution needs to carry the parameter information of the type for showing connection that terminal can be established at new TWAG in replying；Specifically For：

In the first resource allocation process, which needs to carry for showing terminal new in replying The parameter information of NSWO connections can only be established under TWAG；

In second of resource allocation process, which needs to carry for showing terminal new in replying The parameter information of PDN connections can only be established under TWAG；

In the third resource allocation process, which needs to carry for showing terminal new in replying NSWO connections can be established under TWAG but also establish the parameter information of PDN connections.

Under this method 3, it is preferred that the TWAG currently connected to terminal when returning to switching reply, in switching reply Carry the parameter information of the type for showing connection that terminal can be established at new TWAG.

In the embodiment of the present invention, new TWAG is in the handover resource allocation request for receiving the TWAG transmissions currently connected Afterwards, the contextual information of the terminal carried in being asked according to the handover resource allocation and the resource that itself is the terminal distribution, The contextual information of the terminal is established on the new TWAG.

In the embodiment of the present invention, this method further includes：

The TWAG currently connected is after receiving the switch acknowledgment message that new TWAG is sent, according to terminal in new TWAG The type for the connection that can be established down executes the resource release process of terminal；

Specifically, new TWAG is after the upstream data for receiving terminal transmission, it is known that the terminal has had access to newly AP, at this point, new TWAG can send switch acknowledgment message to the TWAG that currently connects, so that the TWAG currently connected is known This switching has been completed in the terminal；Alternatively, new TWAG is determining that PGW completes the contextual information of the terminal of itself storage After update, switch acknowledgment message is sent to the TWAG currently connected.Further, the TWAG currently connected is to receive the switching true It after recognizing message, determines that the terminal is integrated into new AP, and executes the resource release process of the terminal.

In force, the type for the connection that can be established at new TWAG according to terminal is different, the TWAG currently connected Different resource release processes is executed, including：

If A, terminal can only establish NSWO connections at new TWAG, the resource of the TWAG execution currently connected discharged Journey specifically includes：

If one, at least one PDN connections, the established institute of the TWAG initiating terminals currently connected has had been established in terminal There is the release process of PDN connections (the release process of the PDN connections of the terminal to be initiated to core net, so that core net is released to The resource of the PDN connections distribution of the terminal), and discharge the contextual information of terminal and local all connections (packet for terminal PDN connections are included to connect with NSWO) distribution resource；

Specifically, being directed to the established PDN connections of every, the terminal, the TWAG currently connected initiates PDN to core net and connects Disconnection process is connect, for details, reference can be made to 3GPP TS23.402 agreements.

Two, if terminal does not set up PDN connections, contextual information, the Yi Jiben of the TWAG release terminals currently connected Ground is the resource (including PDN connections are connected with NSWO) that all connections of terminal distribute.

If B, terminal can only establish PDN connections at new TWAG, the resource of the TWAG execution currently connected discharged Journey specifically includes：

The contextual information of the TWAG release terminals currently connected and the resource of the local all connections distribution for being terminal (including PDN connections are connected with NSWO).

If C, terminal can establish NSWO connections at new TWAG but also establish PDN connections, the TWAG currently connected The resource release process of execution specifically includes：

In the embodiment of the present invention, if terminal can establish NSWO connections at new TWAG, preferably：

New TWAG is replied when returning to handover resource allocation reply to the TWAG currently connected in the handover resource allocation In also carry new TWAG be terminal distribution local ip address (local IP address)；And

For the TWAG currently connected when returning to switching reply to terminal, it is eventually that new TWAG is also carried in switching reply Hold the local ip address of distribution.

Specifically, if terminal can establish NSWO connections at new TWAG, no matter whether the terminal is currently connecting NSWO connections are had been set up in TWAG, new TWAG is one local ip address of the terminal distribution.

As a kind of preferred implementation, new TWAG is terminal distribution local ip address in handoff procedure；Specially：

New TWAG can determine the end after receiving the handover resource allocation request that the TWAG currently connected is sent When end can establish NSWO connections at new TWAG, for one local ip address of the terminal distribution；Also, new TWAG is complete After resource allocation process, when being replied message to the TWAG returns handover resource allocation currently connected, pass through the switchable resource point With replying message the TWAG for being sent to local ip address and currently connecting.

Further, when which replies message to UE transmission switchings, which is sent to this Terminal.

As another preferred implementation, new TWAG is not terminal distribution local ip address in handoff procedure, After terminal is linked into new AP, for the terminal distribution local ip address；Specially：

New TWAG is receiving the DHCP request of terminal transmission (after wherein, terminal is linked into new AP, to new TWAG Send DHCP request) after, which is one local ip address of the terminal distribution；Then, new TWAG is returned to the terminal Dhcp reply is returned, and carries the local ip address for the terminal distribution.

In the embodiment of the present invention, if at least one PDN connections have had been established in terminal, (i.e. the terminal is in the TWAG currently connected In at least one PDN connections have had been established), and the terminal can establish PDN connections at new TWAG and (including be merely able to establish PDN connections, and NSWO connections can be established but also establish PDN connections), then new TWAG is cut to the TWAG returns currently connected It changes after resource allocation replys, alternatively, after new TWAG receives the upstream data of terminal, this method further includes：

The contextual information of the terminal stored in new TWAG updates PGW.

Specifically, every established PDN connection that new TWAG is the terminal is assigned with identification information, including point-to-point The identification information (be used for unique mark PDN connections between terminal and new TWAG) of link and Tunnel End Point Identifier is (i.e. TEID or GRE key).The new TWAG sends modification carrying request (Modify Bearer Request) message to PGW, with The contextual information of the terminal stored in the PGW is updated, which includes the IP address and the new TWAG of new TWAG Newly assigned Tunnel End Point Identifier.

Further, after PGW receives modification bearing request message, PGW updates itself storage using the parameter in message The PDN connections information, then return to modification carrying to new TWAG and reply (Modify Bearer Response) message, The message parameter includes charging identifier and mobile user comprehensive service digital net number (Mobile Subscriber ISDN Number, MSISDN；Integrated Services Digital Network, ISDN) etc. parameters.

It is shown in Figure 6, the switching method of end side provided in an embodiment of the present invention, including：

Step 61, terminal are determining that, to the TWAG transmission switching requests currently connected, this is cut when needing to be linked into new AP Request is changed for the handoff procedure to the TWAG initiating terminals currently connected between different AP.

If specifically, signal strength of the terminal in the new AP for finding itself to receive is more and more stronger, and what is received works as The signal strength of the AP of preceding connection is more and more weaker, then the terminal desires access to new AP, and the scene is shown in Figure 7.Then, The terminal sends switching request to the TWAG currently connected, to ask the TWAG currently connected to initiate the terminal between different AP Handoff procedure.

Step 62, after the switching for receiving the TWAG currently connected is replied, terminal disconnects between the AP that currently connects Connection and be linked into new AP, wherein be the terminal on the new TWAG of new AP connections before being linked into new AP Establish connection.

In a kind of new handover mechanism provided in an embodiment of the present invention, since terminal is before being linked into new AP, new AP connections new TWAG on be that the terminal establishes connection, thus it is guaranteed that the continuity of the terminal traffic, improves The service experience of user.

Processing mode as one preferred, if the switching that terminal receives does not carry mark pair in replying；Then step 62 Specially：

After terminal receives the switching reply that the TWAG currently connected is returned, directly between disconnection and the AP currently connected It connects and is linked into new AP；

Wherein, switching reply is that the TWAG currently connected determines that this switching will not cause to provide service for terminal TWAG changes, and establishes between the TWAG currently connected and new AP and sent to terminal after data transmission tunnel.

Under which, due to establishing data transmission tunnel between the TWAG currently connected and new AP, thus it is guaranteed that The continuity of the terminal traffic.

As another preferred processing mode, if the switching that terminal receives carries at least one mark pair in replying, Then step 62 is specially：

After terminal receives the switching reply that the TWAG currently connected is returned, according to all marks carried in switching reply Knowledge pair updates and each identifies the identification information to corresponding connection；And

Complete with each mark to the update of the identification information of corresponding connection after, terminal disconnection and the AP that currently connect Between connection and be linked into new AP；

Wherein, each mark is to corresponding terminal established and can be established at new TWAG with the terminal The identical connection of type of connection, and each mark is the established allocated mark of connection to the TWAG including currently connecting Information and new TWAG are the established newly assigned identification information of connection.

It should be noted that when terminal accesses EPC by TWAN, every PDN connection of terminal includes being located at the terminal Point-to-point link between the TWAG for the terminal service and tunnel (such as general packet between the TWAG and PGW Radio Service Tunneling Protocol (GPRS Tunneling Protocol, GTP；General Packet Radio Service, GPRS) tunnel, the tunnel proxy-mobile IP (Proxy Mobile IP, PMIP)).

Therefore, new TWAG be the established PDN connections of every, the terminal distribute respectively be used for unique mark this newly The identification information of point-to-point link between TWAG and terminal, and distribution is between the unique mark new TWAG and PGW Tunnel identification information.In the embodiment of the present invention, for every established PDN connection of the terminal, new TWAG is generated The established PDN connect corresponding mark to being arrived including the point that the TWAG that currently connects is the established PDN connections of this The point allocated identification information of link and the newly assigned mark letter of point-to-point link that new TWAG is that the established PDN of this is connected Breath can update the point-to-point chain of the established PDN connections of this of itself preservation so that terminal is receiving the mark to rear The corresponding mark in road.

Specifically, after receiving the switching that the TWAG currently connected is returned and replying, first, terminal is replied according to the switching The TWAG currently connected that the mark centering of middle carrying includes is the established allocated identification information of connection, is found corresponding Connection contextual information；Then, terminal is the established new distribution of connection using the new TWAG that the mark centering includes The update of identification information connection identification information；Finally, terminal disconnects the connection between the AP that currently connects and is linked into New AP.

Under which, due to establishing connection (NSWO connections and/or PDN connections) between terminal and new TWAG, at end After end is connected to new AP, which can be communicated by the established connection with new TWAG, thus it is guaranteed that should The continuity of terminal traffic.

It should be noted that this switching can cause the TWAG for providing service for the terminal to change, and switch back into Mark pair is not carried in again, then terminal directly disconnects and current after receiving the switching that the TWAG currently connected is returned and replying Connection between the AP of connection is simultaneously linked into new AP.

In force, it is preferred that after terminal sends switching request to the TWAG currently connected, terminal, which receives, currently to be connected Before the switching of the TWAG connect is replied, this method further includes：

Terminal receive the terminal that the TWAG that currently connects is sent at new TWAG it is workable based on S2a interfaces can Believe WLAN access characteristics；

Terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG according to the terminal, Judge whether itself continues to execute this switching；And

Terminal returns to instruction information according to judging result, to the TWAG currently connected, and the instruction information is for showing the end Whether end continues to execute this switching.

Specifically, terminal is workable based on the credible of S2a interfaces at new TWAG according to the terminal received WLAN access characteristics, judge whether these characteristics disclosure satisfy that the demand of itself, to decide whether to execute this switching, specifically For：

In force, if terminal workable credible WLAN access characteristics based on S2a interfaces at new TWAG indicate The terminal can establish NSWO connections at new TWAG, then：

Terminal obtains the local ip address that new TWAG is terminal distribution in being replied from switching, referring specifically to cutting for the sides TWAG The description in method is changed, details are not described herein again；Alternatively,

Terminal sends DHCP request after being linked into new AP, to new TWAG, to obtain new TWAG as terminal point The local ip address matched, referring specifically to the description in the switching method of the sides TWAG, details are not described herein again.

With reference to following four specific embodiment, to end side in the handoff procedure of the embodiment of the present invention and network side Interaction is described in detail.

The TWAG that embodiment one, the present embodiment describe currently to connect judges to provide the TWAG of service before and after moving for UE Whether changed process.Detailed process is shown in Figure 8, including：

Step 81, UE send switching request message to the TWAG currently connected；

Wherein, which includes：SSID, MAC Address, the new AP of new AP of new AP broadcast are wide The credible WLAN access characteristics based on S2a interfaces that the MAC Address and UE of the TWAG broadcast is supported.

Specifically, UE has found that the signal strength of received new AP is more and more stronger, and currently connecting of receiving The signal strength of AP is more and more weaker, at this point, UE desires access to new AP.Further, UE disappears from the periodic broadcast of new AP The relevant informations such as the MAC Address of TWAG of SSID and new AP connection of new AP are obtained in breath.Then, UE is connected to current TWAG send switching request message.

Step 82, the TWAG currently connected are after the switching request message for receiving UE transmissions, if judging to execute this Whether switching, the TWAG for providing service before and after switching for UE change.

Above-mentioned deterministic process specifically includes following two scenes：

TWAG is constant before and after scenario A, movement, referring to scene shown in Fig. 9 A, is retouched to above-mentioned deterministic process based on scenario A It states as follows：

UE sends switching request message to the TWAG that currently connects, which is the SSID, new that new AP is broadcasted The MAC Address of AP, new AP broadcast TWAG MAC Address (under this scene be MAC Address 1) and UE support based on S2a The credible WLAN access characteristics of interface；

After the TWAG currently connected receives the switching request message of UE, find the TWAG's carried in switching request message MAC Address is the MAC Address (MAC Address of the TWAG currently connected in the present embodiment is MAC Address 1) of oneself, therefore current The TWAG of connection knows that this switching is that UE is moved between 2 different AP that itself is connected.

TWAG changes before and after scenario B, movement, referring to scene shown in Fig. 9 B, is retouched to above-mentioned deterministic process based on scenario B It states as follows：

UE sends switching request message to the TWAG that currently connects, which is the SSID, new that new AP is broadcasted The MAC Address of AP, new AP broadcast TWAG MAC Address (under this scene be MAC Address 2) and UE support based on S2a The credible WLAN access characteristics of interface；

Correspondingly, after the TWAG currently connected receives the switching request message of UE, with finding the MAC for the TWAG that UE is provided Location (MAC Address 2) is not the MAC Address (MAC Address of the TWAG currently connected in the present embodiment is MAC Address 1) of oneself, because UE will be connected to new TWAG after this TWAG currently connected knows this switching.

Embodiment two, based on the scenario A in embodiment one, the present embodiment describe UE 2 to be connected with same TWAG not With the later handover processes moved between AP.Wherein, the data of different UE are transmitted between AP and TWAG by gre tunneling.This reality Apply example the specific implementation process is as follows：

The TWAG currently connected know this switching be UE 2 different AP being connected from the TWAG currently connected it Between when moving, judge oneself between the new AP whether according to the MAC Address of the new AP carried in switching request message Establish gre tunneling；

If so, the TWAG currently connected directly stores the endpoint of a tunnel of the gre tunneling in the contextual information of UE Information；

If it is not, then the TWAG currently connected establishes process to new AP initiation gre tunnelings, then believe in the context of UE The information of the endpoint of a tunnel of the gre tunneling is stored in breath.

Further, after which stores the information of gre tunneling in the contextual information of UE, to UE Switching is sent to reply message.

Correspondingly, UE is received after the switching replies message, UE disconnects the connection between the AP that currently connects, then It establishes and connects with new AP.In this way, UE can carry out the transmitting-receiving of data by new AP.

Embodiment three, based on the scenario B in embodiment one, the present embodiment describe UE from 2 AP of different TWAG connections Between the later handover processes that move.In the present embodiment, UE and new TWAG supports identical based on the credible of S2a interfaces WLAN access characteristics, these characteristics are NSWO (i.e. characteristic 1), more PDN connections (i.e. characteristic 3), switch (i.e. characteristic 4) and IP address Continuity (i.e. characteristic 5).

Assuming that：UE is established at the TWAG currently connected to be connected with NSWO connections and is connected with 2 PDN；S2a interfaces make Agreement is general packet wireless service tunnel protocol (GPRS Tunneling Protocol, GTP；General Packet Radio Service, GPRS)；The different connections of UE are distinguished using VLAN ID between UE and TWAG.It currently connects at this time The information for the established connection that TWAG is stored in the contextual information of UE is as follows：

1, NSWO connections：Local ip address, VLAN ID0.

2, PDN connections 1：

APN1, packet data network gateway (Packet Data Network Gateway, PGW) control plane IP address, PGW For the TEID1 of transmission control plane signaling distribution, the control plane IP address of the TWAG currently connected, the TWAG currently connected is transmission The TEID2 of plane signaling distribution is controlled, Evolved Packet System (Evolved Packet System, EPS) load identification is given tacit consent to (EPS carryings 1)；

The information of 1 relevant EPS carryings is connect with the PDN：

<EPS carries the IP address of 1, TFT1, PGW, and PGW is the TEID3, the IP of the TWAG currently connected of carrying distribution Address, the TWAG currently connected are the TEID4 of carrying distribution>；

<EPS carries the IP address of 2, TFT2, PGW, and PGW is the TEID5, the IP of the TWAG currently connected of carrying distribution Address, the TWAG currently connected are the TEID6 of carrying distribution>；

The mark of the link of the data of the PDN connections is used for transmission between the TWAG positioned at UE and currently connected：VLAN ID1。

3, PDN connections 2：

APN2, PGW control plane IP address, PGW are the TEID7 of transmission control plane signaling distribution, the TWAG's currently connected Control plane IP address, the TWAG currently connected are the TEID8 of transmission control plane signaling distribution, and (EPS is held default EPS bearing mark It carries 3)；

The information of 2 relevant EPS carryings is connect with the PDN：

<EPS carries the IP address of 3, TFT1, PGW, and PGW is the TEID9, the IP of the TWAG currently connected of carrying distribution Address, the TWAG currently connected are the TEID10 of carrying distribution>；

<EPS carries the IP address of 4, TFT2, PGW, and PGW is the TEID11, the IP of the TWAG currently connected of carrying distribution Address, the TWAG currently connected are the TEID12 of carrying distribution>.

The mark of the link of the data of the PDN connections is used for transmission between the TWAG positioned at UE and currently connected：VLAN ID2。

The handoff procedure of the present embodiment is shown in Figure 10, including：

Step 1, UE send switching request message to the TWAG currently connected, and the parameter in the message is that new AP is broadcasted SSID, the MAC Address (i.e. MAC Address 2) of TWAG (i.e. new TWAG) of new AP connections, the MAC Address of new AP, UE are supported Based on S2a interfaces credible WLAN access characteristics (i.e. NSWO, more PDN connections, switching and IP address continuity)；

Specifically, UE has found that the signal strength that it is received from new AP is stronger, UE desires access to new AP.UE is from new AP broadcast message in obtain new AP connections TWAG MAC Address (i.e. MAC Address 2), from the source MAC of broadcast message Location obtains the MAC Address of new AP.Then, UE sends switching request message to the TWAG currently connected.

TWAG changes after step 2, the TWAG currently connected determine switching, and to new TWAG transfer characteristic request messages, To obtain the credible WLAN access characteristics based on S2a interfaces that new TWAG is supported；

It is new due to what is provided in the message specifically, after the TWAG currently connected receives switching request message The MAC Address of TWAG is MAC Address 2, which is not the MAC Address of the TWAG currently connected, therefore currently connect TWAG knows that TWAG will change after switching if UE executes this switching.Further, the TWAG currently connected According to MAC Address 2, obtained newly by address resolution protocol (Address Resolution Protocol, ARP) process The IP address of TWAG, then to new TWAG transfer characteristic request messages.

After step 3, new TWAG receive property request message, returns to characteristic reply to the TWAG currently connected and disappear It ceases, the parameter in the message is credible WLAN access characteristics (i.e. NSWO, the more PDN companies based on S2a interfaces that new TWAG is supported It connects, switching and IP address continuity).

Step 4, in order to obtain the credible WLAN access characteristics based on S2a interfaces that UE can be used at new TWAG, The TWAG currently connected sends request message to AAA Server, the message parameter be SSID, UE that UE is provided support based on The credible WLAN access characteristics based on S2a interfaces that the credible WLAN access characteristics of S2a interfaces and new TWAG are supported.

In the concrete realization, which can be realized by extending existing Diameter message, can also be defined on Dedicated new message is realized between TWAG and AAA Server.

Step 5, AAA Server are according to the signing information of user, the strategy and UE and new TWAG of operator's configuration The credible WLAN access characteristics based on S2a interfaces supported respectively determine that UE is workable at new TWAG and are based on S2a interfaces Credible WLAN access characteristics, and replied message to the TWAG currently connected, the parameter in the message is NSWO, more PDN Connection, switching and IP address continuity.

It should be noted that if the TWAG currently connected preserves the signing information of UE, then the TWAG currently connected can be with The credible WLAN access characteristics based on S2a interfaces supported respectively according to the signing information of user, UE and new TWAG, determine UE The workable credible WLAN access characteristics based on S2a interfaces at new TWAG, without being handed over AAA Server Mutually.

After step 6, the TWAG currently connected receive the message that AAA Server are returned, sends switching confirmation to UE and ask Seek message；

Wherein, which is UE workable credible WLAN access characteristics based on S2a interfaces at new TWAG (i.e. NSWO, more PDN connections, switching and IP address continuity).

Step 7, UE send switching confirmation to the TWAG currently connected and reply message, which shows whether the UE holds This switching (determined for the UE in the present embodiment and execute this switching) of row.

Specifically, after UE receives switching confirmation request message, according to the parameter in the message, know from new The workable credible WLAN access characteristics based on S2a interfaces are respectively NSWO, more PDN connections, switching and IP address under TWAG Continuity.It is connected with PDN since NSWO connections have had been established in current UE, and new TWAG is able to that this two class is supported to connect It connects, therefore, new TWAG disclosure satisfy that the demand of UE, so UE decisions are linked into new AP.

Step 8, the TWAG currently connected receive UE switching confirmation reply message after, send switching to new TWAG Resource allocation request message；

Wherein, the parameter in the message be UE MAC Address, currently connect TWAG storage UE contextual information (including the signing information of the UE and relevant information of the established connections of the UE) and UE are workable at new TWAG Credible WLAN access characteristics based on S2a interfaces.

Step 9, new TWAG send handover resource allocation to the TWAG currently connected and reply message, the parameter in the message For local ip address that new TWAG is UE distribution, it connect with NSWO relevant identify pair<VLAN ID0, VLAN ID10>And The relevant mark pair of PDN connections 1<VLAN ID1, VLAN ID11>, connect with PDN 2 relevant marks pair<VLAN ID2, VLAN ID12>。

Specifically, after new TWAG receives handover resource allocation request message, according to the parameter in the message It can provide the characteristics such as NSWO, more PDN connections, switching and IP address continuity to UE；The new TWAG has been established according to UE Link information, it is known that UE has had been established NSWO connections and has been connected with 2 PDN；New TWAG is the NSWO connections of UE, PDN connections 1 And PDN connections 2 distribute the identification information that every connection is identified between the new TWAG and UE, i.e. VLAN ID10, VLAN respectively ID11 and VLAN ID12, since NSWO connections have had been established before UE, so new TWAG is also for one local IP of UE distribution Location；The new TWAG sends handover resource allocation to the TWAG currently connected and replies message.

Step 10, the TWAG currently connected receive the TWAG that after handover resource allocation replies message, currently connects to UE sends switching and replies message, and the parameter in the message is that handover resource allocation replies message the mark of middle appearance to (i.e.<VLAN ID0, VLAN ID10>,<VLAN ID1,VLAN ID11>With<VLAN ID2, VLAN ID12>) and new TWAG be UE point The local ip address matched.

Correspondingly, UE is received after the switching replies message, UE searched according to VLAN ID0 connect with NSWO it is relevant Contextual information, then using the link identification information in the VLAN ID10 update contextual informations of mark centering；UE according to VLAN ID1 lookups connect 1 relevant context with PDN, then update contextual information using the VLAN ID11 of mark centering In link identification information；UE connect 2 relevant contexts with PDN according to VLAN ID2 lookups, then using mark centering Link identification information in VLAN ID12 update contexts；Connection between UE disconnections and the AP currently connected, and be connected to new AP, later UE new mark can be used to pass through new AP transmission datas.

Step 11, new TWAG are according to the information of the PDN connections in UE contextual informations, every PDN connection based on UE Modification bearing request message is sent to PDN GW.

For example, for PDN connections 1, it is assumed that new TWAG is that EPS carryings 1 distribution TEID13, new TWAG are that EPS carries 2 TEID14 is distributed, then the world that the parameter carried in the modification bearing request message that new TWAG is sent to PDN GW is UE is mobile User identifier (International Mobile Subscriber Identifier, IMSI), the IP address of new TWAG, <EPS carryings 1, TEID13>,<EPS carryings 2, TEID14>.

Step 12, PDN GW are updated in the contextual information of the UE of itself storage and are somebody's turn to do according to modification bearing request message Every relevant information of PDN connections of UE, and send modification carrying to new TWAG and reply message.

Still by taking PDN connections 1 as an example, after PDN GW receive modification bearing request message, according to what is carried in the message< EPS carryings 1, TEID13>, it is updated for the information of the endpoint of a tunnel of 1 storage of EPS carryings, according in the message using TEID13 It carries<EPS carryings 2, TEID14>, it is updated for the information of the endpoint of a tunnel of 2 storage of EPS carryings using TEID14.Then, PDN GW return to modification carrying to new TWAG and reply message, and the parameter which carries is charging identifier and MSISDN.

Step 13, after new TWAG receives the upstream data of UE transmissions, new TWAG is to the TWAG currently connected Send switch acknowledgment message.

Correspondingly, after the TWAG currently connected receives the message, be released from as the UE resources distributed and itself The contextual information of the UE of storage.

Example IV, the present embodiment describe to connect based on S2a when what new TWAG was provided to UE on the basis of embodiment three When the credible WLAN access characteristics of mouth cannot meet the requirement of UE, UE decides not to perform the process of switching.

In the present embodiment, the credible WLAN access characteristics based on S2a interfaces that UE is supported include NSWO, more PDN connections, cut It changes and IP address continuity；The credible WLAN access characteristics based on S2a interfaces that new TWAG is supported include that NSWO, list PDN connect It connects (i.e. above-mentioned characteristic 2).

The process of the present embodiment is shown in Figure 11, including：

Step 1~step 4 is the same as step 1~step 4 in embodiment three；

Step 5, AAA Server determine the credible WLAN based on S2a interfaces of UE workable supports at new TWAG Access characteristic is NSWO, list PDN connections.

It is NSWO and list PDN companies that step 6, the TWAG currently connected send the parameter in switching confirmation request message to UE It connects.

Step 7, UE send switching confirmation to the TWAG currently connected and reply message, and the parameter in the message shows not cut It changes.

Specifically, UE understands that new TWAG can only provide NSWO and list PDN connects after receiving switching confirmation request message It connects, after this illustrates UE access to new AP, a plurality of PDN connections currently-established UE cannot all reuse, and cannot meet The demand of user, therefore UE decisions are not linked into new AP；Then, UE sends switching confirmation and replys and disappears to the TWAG currently connected It ceases, the parameter in the message shows not switch.

Correspondingly, after the TWAG currently connected receives the message, the TWAG currently connected no longer executes subsequent operation (step 8~step 13) i.e. in embodiment three, and continue as UE transmission datas.

Further, UE continues search for the signal strength for the AP that it can be received, when UE has found that the signal strength of some AP is excellent When the signal strength for the AP being currently accessed, UE initiates the handoff procedure of the embodiment of the present invention again.

Above method process flow can realize that the software program can be stored in a storage medium with software program, when When the software program of storage is called, above method step is executed.

Based on same inventive concept, a kind of TWAG is additionally provided in the embodiment of the present invention, is solved the problems, such as due to the TWAG Principle is similar to above-mentioned method shown in fig. 5, therefore the implementation of the TWAG may refer to the implementation of method, and it is no longer superfluous to repeat place It states.

It is shown in Figure 12, TWAG provided in an embodiment of the present invention, including：

Receiving module 121, the switching request for receiving terminal transmission, the switching request are used for this TWAG initiating terminals Handoff procedure between different AP；

First processing module 122, the handoff procedure for executing terminal, to be somebody's turn to do on the new TWAG of new AP connections Terminal establishes connection；

Sending module 123 is replied for sending switching to terminal, this switches back into multiplexing and disconnects in instruction terminal and currently connect Connection between the AP connect is simultaneously linked into new AP.

Further, first processing module 122 is specifically used for：

Specifically, first processing module 122 judges whether this switching can cause to provide clothes for terminal according to following steps The TWAG of business changes：

Based on the first situation, i.e. this switching will not cause the TWAG for providing service for terminal to change, then and first Processing module 122 executes following processing procedure：

In the contextual information of terminal, the tunnel end for the data transmission tunnel established between this TWAG and new AP is stored The identification information of point.

Specially：If data transmission tunnel has had been established between this TWAG and new AP, directly in the context of terminal The information of the endpoint of a tunnel of established data transmission tunnel is stored in information；

If not setting up data transmission tunnel between this TWAG and new AP, the data transmission tunnel between new AP is initiated The foundation in road；And after data transmission tunnel is successfully established, the data transmission of foundation is stored in the contextual information of terminal The information of the endpoint of a tunnel in tunnel.

Based on above-mentioned the second situation, i.e. first processing module 122 determines that this switching can cause to provide service for terminal TWAG change, then：

Sending module 123 is additionally operable to：Handover resource allocation request is sent to new TWAG, handover resource allocation request is used In the TWAG that please be look for novelty be terminal distribution resource；

Receiving module 121 is additionally operable to：It receives the handover resource allocation that new TWAG is returned to reply, which returns It is sent to the TWAG currently connected after the resource allocation process for being again new TWAG completion terminals.

Based on above-mentioned the second situation, in force, if carried terminal is at new TWAG in handover resource allocation request The workable credible WLAN access characteristics based on S2a interfaces, then first processing module 122 according to following steps obtain terminal exist The workable credible WLAN access characteristics based on S2a interfaces under new TWAG：

Alternatively,

In force, it is preferred that sending module 123 is additionally operable to before sending handover resource allocation request：

Further, first processing module 122 is additionally operable to：

If receiving module 121 receive terminal return for show terminal continue to execute this switching instruction information, It then triggers sending module and sends handover resource allocation request to new TWAG；

If receiving module 121 receive terminal return for show terminal do not execute this switching instruction information, Terminate this handoff procedure, and continues as terminal forwarding data.

Further, first processing module 122 is additionally operable to：

After receiving the switch acknowledgment message that new TWAG is sent, the company that can be established at new TWAG according to terminal The type connect executes the resource release process of terminal；

Specifically, the resource release process that first processing module 122 executes terminal specifically includes：

In force, it is based on above-mentioned the second situation, if this TWAG is new TWAG, which further includes：

Second processing module 124, for according to terminal at new TWAG the workable credible WLAN based on S2a interfaces Access characteristic determines the type for the connection that terminal can be established at new TWAG；And according to terminal at new TWAG energy The currently-established all connections of the type and terminal of the connection enough established, execute the resource allocation process of terminal.

Preferably, if non-carried terminal is workable at new TWAG in handover resource allocation request is based on S2a interfaces Credible WLAN access characteristics, then Second processing module 124 be additionally operable to according to following steps obtain terminal can at new TWAG The credible WLAN access characteristics based on S2a interfaces used：

Alternatively,

Further, Second processing module 124 specifically executes following resource allocation process：

In force, NSWO connections can be established if terminal is at new TWAG, Second processing module 124 is additionally operable to：

In the resource allocation process for executing terminal, it is the local ip address of terminal distribution, and local ip address is carried In handover resource allocation reply, wherein the TWAG that terminal currently connects is replied when returning to switching reply to terminal in switching In also carry new TWAG be terminal distribution local ip address；Alternatively,

In force, if at least one PDN connections have had been established in terminal, Second processing module 124 is additionally operable to：

Based on same inventive concept, a kind of terminal is additionally provided in the embodiment of the present invention, is solved the problems, such as due to the terminal Principle is similar to above-mentioned method shown in fig. 6, therefore the implementation of the terminal may refer to the implementation of method, and it is no longer superfluous to repeat place It states.

It is shown in Figure 13, terminal provided in an embodiment of the present invention, including：

Switch initiation module 131, for when determination needs to be linked into new access point AP, being sent out to the TWAG currently connected Switching request is sent, which is used to initiate handoff procedure of this terminal between different AP to the TWAG currently connected；

Switching executing module 132, for after the switching for receiving the TWAG currently connected is replied, disconnecting and currently connecting AP between connection and be linked into new AP；

Wherein, it has been that this terminal establishes connection on the new TWAG of the new AP connections before being linked into new AP.

In force, switching executing module 132 is specifically used for：

If not carrying mark pair in switching reply, after receiving switching and replying, directly disconnection and the AP currently connecting Between connection and be linked into new AP；Wherein, switching reply is that the TWAG currently connected determines that this switching will not cause The TWAG that service is provided for terminal changes, and after establishing data transmission tunnel between the TWAG currently connected and new AP It is sent to terminal；

If switching carries at least one mark pair in replying, after receiving switching and replying, taken in being replied according to switching All marks pair of band update the identification information with each mark to corresponding connection of this terminal；And in completion and each After mark is to the update of the identification information of corresponding connection, disconnects the connection between the AP that currently connects and be linked into new AP；Wherein, each mark is established to a corresponding terminal and the class connecting can be established at new TWAG with terminal The identical connection of type, and each mark is an established allocated identification information of connection to the TWAG including currently connecting It is the established newly assigned identification information of connection of this with new TWAG.

Preferably, switching executing module 132 is additionally operable to：

It is workable based on the credible of S2a interfaces at new TWAG to receive this terminal that the TWAG currently connected is sent WLAN access characteristics；The workable credible WLAN access characteristics based on S2a interfaces, judgement at new TWAG according to this terminal Whether itself continues to execute this switching；And according to judging result, instruction information, the instruction are returned to the TWAG currently connected Information is for showing whether this terminal continues to execute this switching.

In force, NSWO connections can be established if this terminal is at new TWAG, it is preferred that switching executing module 132 It is additionally operable to：

The local ip address that new TWAG is this terminal distribution is obtained in being replied from switching；

Alternatively, after being linked into new AP, DHCP request is sent to new TWAG, to obtain new TWAG as this terminal The local ip address of distribution.

With reference to particular hardware structure, structure, the processing mode of TWAG provided in an embodiment of the present invention are illustrated.

In the 5 embodiment of figure 5, TWAG includes transceiver and at least one processing for being connect with the transceiver Device, wherein：

In force, processor is configured to be specifically used for：

Specially：If data transmission tunnel has had been established between this TWAG and new AP, directly in the context of terminal The information of the endpoint of a tunnel of established data transmission tunnel is stored in information；If not setting up data between this TWAG and new AP Tunnel is transmitted, then establishes process to new AP initiation data transmission tunnels；And after data transmission tunnel is successfully established, The information of the endpoint of a tunnel of the data transmission tunnel of foundation is stored in the contextual information of terminal.

Alternatively,

Correspondingly, processor is additionally configured to：

Further, processor is additionally configured to：

In force, if this TWAG is new TWAG, processor is additionally configured to：

Alternatively,

Request PGW updates the contextual information of the terminal of PGW storages.

With reference to particular hardware structure, structure, the processing mode of terminal provided in an embodiment of the present invention are illustrated.

In the embodiment in fig 6, terminal includes transceiver and at least one processing for being connect with the transceiver Device, wherein：

In force, processor is configured to be specifically used for：

It should be understood by those skilled in the art that, the embodiment of the present invention can be provided as method, system or computer program Product.Therefore, complete hardware embodiment, complete software embodiment or reality combining software and hardware aspects can be used in the present invention Apply the form of example.Moreover, the present invention can be used in one or more wherein include computer usable program code computer The computer program production implemented in usable storage medium (including but not limited to magnetic disk storage, CD-ROM, optical memory etc.) The form of product.

The present invention be with reference to according to the method for the embodiment of the present invention, the flow of equipment (system) and computer program product Figure and/or block diagram describe.It should be understood that can be realized by computer program instructions every first-class in flowchart and/or the block diagram The combination of flow and/or box in journey and/or box and flowchart and/or the block diagram.These computer programs can be provided Instruct the processor of all-purpose computer, special purpose computer, Embedded Processor or other programmable data processing devices to produce A raw machine so that the instruction executed by computer or the processor of other programmable data processing devices is generated for real The device for the function of being specified in present one flow of flow chart or one box of multiple flows and/or block diagram or multiple boxes.

These computer program instructions, which may also be stored in, can guide computer or other programmable data processing devices with spy Determine in the computer-readable memory that mode works so that instruction generation stored in the computer readable memory includes referring to Enable the manufacture of device, the command device realize in one flow of flow chart or multiple flows and/or one box of block diagram or The function of being specified in multiple boxes.

These computer program instructions also can be loaded onto a computer or other programmable data processing device so that count Series of operation steps are executed on calculation machine or other programmable devices to generate computer implemented processing, in computer or The instruction executed on other programmable devices is provided for realizing in one flow of flow chart or multiple flows and/or block diagram one The step of function of being specified in a box or multiple boxes.

Although preferred embodiments of the present invention have been described, it is created once a person skilled in the art knows basic Property concept, then additional changes and modifications may be made to these embodiments.So it includes excellent that the following claims are intended to be interpreted as It selects embodiment and falls into all change and modification of the scope of the invention.

Obviously, various changes and modifications can be made to the invention without departing from essence of the invention by those skilled in the art God and range.In this way, if these modifications and changes of the present invention belongs to the range of the claims in the present invention and its equivalent technologies Within, then the present invention is also intended to include these modifications and variations.

Claims

1. a kind of switching method, which is characterized in that this method includes：

The credible WLAN access gateway TWAG that terminal currently connects receives the switching request that the terminal is sent, described to cut Request is changed for initiating handoff procedure of the terminal between different AP to the TWAG currently connected；

The TWAG currently connected executes the handoff procedure of the terminal, to be described on the new TWAG of new AP connections Terminal establishes connection；

The TWAG currently connected sends switching to the terminal and replys, and described switch back into is used to indicate the terminal disconnection again Connection between the AP currently connecting simultaneously is linked into the new AP.

2. the method as described in claim 1, which is characterized in that the TWAG currently connected executes handoff procedure, specific to wrap It includes：

The TWAG currently connected in the MAC address of itself and the switching request according to described in carrying The MAC Address of new TWAG, judges whether this switching can cause the TWAG for providing service for the terminal to change；

3. method as claimed in claim 2, which is characterized in that if this switching will not cause to provide service for the terminal TWAG changes, and the TWAG currently connected executes following processing procedure, specifically includes：

The TWAG currently connected in the contextual information of the terminal, store the TWAG currently connected with it is described new AP between the information of the endpoint of a tunnel of data transmission tunnel established.

4. method as claimed in claim 2, which is characterized in that if this switching can cause to provide service for the terminal TWAG changes, and the TWAG currently connected executes following processing procedure, specifically includes：

The TWAG currently connected sends handover resource allocation request, the handover resource allocation request to the new TWAG It is the terminal distribution resource for asking the new TWAG；

The TWAG currently connected receives the handover resource allocation that the new TWAG is returned and replys, the handover resource allocation Reply is to be sent to the TWAG currently connected after the new TWAG completes the resource allocation process of the terminal.

5. method as claimed in claim 4, which is characterized in that handover resource allocation request includes：

The contextual information for the terminal that the terminal MAC address, the TWAG currently connected are stored, the terminal are supported Credible WLAN access characteristics based on S2a interfaces and the terminal is workable at the new TWAG is connect based on S2a At least one of the credible WLAN access characteristics of mouth information；

Wherein, the contextual information of the terminal includes the relevant informations of the currently-established all connections of the terminal and described At least one of signing information of terminal information.

6. method as claimed in claim 4, which is characterized in that exist if carrying the terminal in handover resource allocation request The workable credible WLAN access characteristics based on S2a interfaces under the new TWAG, then the TWAG currently connected according to Following steps obtain the terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG：

The TWAG currently connected by the interaction with the new TWAG, obtain that the new TWAG supports based on S2a The credible WLAN access characteristics of interface；The TWAG currently connected by the new TWAG support based on S2a interfaces can The credible WLAN access characteristics based on S2a interfaces that letter WLAN access characteristics and the terminal are supported are sent to certification, authorize With charging aaa server, and the terminal that the aaa server the returns workable base at the new TWAG is received In the credible WLAN access characteristics of S2a interfaces；

Alternatively,

The TWAG currently connected by the interaction with the new TWAG, obtain that the new TWAG supports based on S2a The credible WLAN access characteristics of interface；The TWAG currently connected according to the new TWAG support based on S2a interfaces The credible WLAN based on S2a interfaces that credible WLAN access characteristics, the signing information of the terminal and the terminal are supported connects Enter characteristic, determines the terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG.

7. method as claimed in claim 6, which is characterized in that the TWAG currently connected is cut to the new TWAG transmissions It changes before resource allocation request, the method further includes：

The TWAG currently connected is connect workable for sending the terminal at the new TWAG to the terminal based on S2a The credible WLAN access characteristics of mouth, to obtain the instruction the information whether terminal continues to execute this switching.

8. the method for claim 7, which is characterized in that

If the TWAG currently connected receive that the terminal returns for showing that the terminal continues to execute this switching Instruction information, then the TWAG currently connected send handover resource allocation request to the new TWAG；

If the TWAG currently connected receive that the terminal returns for showing that the terminal does not execute this switching Indicate information, then the TWAG currently connected terminates this handoff procedure, and continues as the terminal forwarding data.

9. method as claimed in claim 4, which is characterized in that the new TWAG executes following resource allocation process：

According to the terminal, the workable credible WLAN based on S2a interfaces at the new TWAG is accessed the new TWAG Characteristic determines the type for the connection that the terminal can be established at the new TWAG；

The type and the terminal for the connection that the new TWAG can be established according to the terminal at the new TWAG Currently-established all connections, execute the resource allocation process of the terminal.

10. method as claimed in claim 9, which is characterized in that if not carrying the end in handover resource allocation request End workable credible WLAN access characteristics based on S2a interfaces at the new TWAG, then the new TWAG according to Lower step obtains the terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG：

The new TWAG obtain that the terminal supports from handover resource allocation request based on the credible of S2a interfaces WLAN access characteristics；The credible WLAN access characteristics based on S2a interfaces and the end that the new TWAG supports itself The credible WLAN access characteristics based on S2a interfaces that end is supported are sent to aaa server, and receive the aaa server and return The terminal returned workable credible WLAN access characteristics based on S2a interfaces at the new TWAG；

Alternatively,

The new TWAG obtain that the terminal supports from handover resource allocation request based on the credible of S2a interfaces The signing information of WLAN access characteristics and the terminal；The new TWAG supported according to itself based on S2a interfaces can Believe the credible WLAN accesses based on S2a interfaces that WLAN access characteristics, the signing information of the terminal and the terminal are supported Characteristic determines the terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG.

11. method as claimed in claim 9, which is characterized in that the terminal can only establish NSWO at the new TWAG Connection, the new TWAG execute following resource allocation process：

Wherein, the handover resource allocation carries the corresponding mark pair of established NSWO connections in replying, and the mark is to packet It is that connect allocated identification information and the new TWAG be institute to the established NSWO to include the TWAG currently connected State the newly assigned identification information of established NSWO connections.

12. method as claimed in claim 9, which is characterized in that the terminal can only establish PDN companies at the new TWAG It connects, the new TWAG executes following resource allocation process：

Wherein, the handover resource allocation carries the corresponding mark pair of every established PDN connections in replying, and each identifies pair It is that connect allocated identification information and the new TWAG be this to an established PDN including the TWAG currently connected The newly assigned identification information of the established PDN connections of item.

13. method as claimed in claim 9, which is characterized in that the terminal can establish NSWO at the new TWAG Connection can establish PDN connections again, and the new TWAG executes following resource allocation process：

Wherein, the handover resource allocation carries the corresponding mark pair of established NSWO connections in replying and every has been established The corresponding mark pair of PDN connections, each mark is to being that the terminal any bar has been established including the TWAG currently connected The allocated identification information of connection and/or the new TWAG be the newly assigned identification information of established connection.

14. method as claimed in claim 4, which is characterized in that if at least one PDN connections have had been established in the terminal, After the new TWAG returns to the handover resource allocation reply to the TWAG currently connected, the method further includes：

The new TWAG requests packet data network gateway PGW updates the contextual information of the terminal stored in the PGW.

15. method as claimed in claim 4, which is characterized in that the method further includes：

The TWAG currently connected exists after receiving the switch acknowledgment message that the new TWAG is sent according to the terminal The type for the connection that can be established under the new TWAG executes the resource release process of the terminal；

Wherein, to be new TWAG determining that PGW completes the context letter of the terminal of itself storage to the switch acknowledgment message After the update of breath, or sent to the TWAG currently connected after receiving the upstream data that the terminal is sent.

16. method as claimed in claim 15, which is characterized in that if the terminal can only be established at the new TWAG NSWO connections, the TWAG currently connected execute following resource release process：

If at least one PDN connections have had been established in the terminal, the TWAG currently connected initiates the built of the terminal The release process of vertical all PDN connections, and discharge the contextual information of the terminal and local owning for the terminal Connect the resource of distribution；

If the terminal does not set up PDN connections, the TWAG currently connected discharge the terminal contextual information, with And the resource of the local all connections distribution for being the terminal.

17. method as claimed in claim 15, which is characterized in that if the terminal can only be established at the new TWAG PDN connections, alternatively, the terminal can establish NSWO connections at the new TWAG but also establish PDN connections, it is described current The TWAG of connection executes following resource and discharges process：

The TWAG currently connected discharges contextual information and the local all connections for the terminal point of the terminal The resource matched.

18. such as claim 1~17 any one of them method, which is characterized in that the switching request includes the new AP The SSID of broadcast, the MAC Address of the new AP, the new AP connections new TWAG MAC Address and the terminal The credible WLAN access characteristics based on S2a interfaces supported.

19. a kind of switching method, which is characterized in that this method includes：

Terminal is when determination needs to be linked into new access point AP, to the credible WLAN access gateway TWAG currently connected Switching request is sent, the switching request is used to initiate the terminal cutting between different AP to the TWAG currently connected Change process；

After the switching for receiving the TWAG currently connected is replied, the company between the terminal disconnection and the AP currently connected It connects and is linked into the new AP；

Wherein, it has been that the terminal is established on the new TWAG of the new AP connections before being linked into the new AP Connection.

20. method as claimed in claim 19, which is characterized in that if the switching does not carry mark pair in replying, connecing It receives after the switching replys, the terminal disconnects the connection between the AP that currently connects and is linked into the new AP, has Body includes：

The terminal receives after the switching replys, and directly disconnects the connection between the AP that currently connects and is linked into described New AP；

Wherein, the switching reply is that the TWAG currently connected determines that this switching will not cause to provide clothes for the terminal The TWAG of business changes, and is established between the TWAG currently connected and the new AP after data transmission tunnel to institute State terminal transmission.

21. method as claimed in claim 19, which is characterized in that if the switching carries at least one mark pair in replying, Then after receiving the switching and replying, the terminal disconnects the connection between the AP that currently connects and is linked into described new AP is specifically included：

The terminal receives after the switching replys, all marks pair carried in being replied according to the switching, described in update Terminal with each mark to the identification information of corresponding connection；And

Complete with each mark to the update of the identification information of corresponding connection after, the terminal disconnection and currently connect AP between connection and be linked into the new AP；

Wherein, each mark it is established to a corresponding terminal and with the terminal at the new TWAG energy The identical connection of type for the connection enough established, and each mark is to being described built including the TWAG currently connected The vertical allocated identification information of connection and the new TWAG are the established newly assigned identification information of connection.

22. method as claimed in claim 19, which is characterized in that if this switching can cause to provide service for the terminal TWAG changes, then after the terminal sends switching request to the TWAG currently connected, the terminal receives described work as Before the switching of the TWAG of preceding connection is replied, the method further includes：

The terminal receives that the terminal that the TWAG that currently connects is sent is workable at the new TWAG to be based on The credible WLAN access characteristics of S2a interfaces；

According to the terminal, the workable credible WLAN based on S2a interfaces at the new TWAG accesses spy to the terminal Property, judge whether itself continues to execute this switching；And

The terminal returns to instruction information according to judging result, to the TWAG currently connected, and the instruction information is used for table Whether the bright terminal continues to execute this switching.

23. such as claim 19~22 any one of them method, which is characterized in that the switching request includes the new AP The service set SSID of broadcast, the MAC Address of the new AP, the corresponding new TWAG of the new AP MAC Address, with And the credible WLAN access characteristics based on S2a interfaces that the terminal is supported.

24. a kind of credible WLAN access gateway TWAG, which is characterized in that the TWAG includes：

Receiving module, the switching request for receiving terminal transmission, the switching request are used to initiate the terminal to this TWAG Handoff procedure between different AP；

First processing module, for execute cut the terminal change process, to be described on the new TWAG of new AP connections Terminal establishes connection；

Sending module is replied for sending switching to the terminal, and described switch back into is used to indicate the terminal disconnection and works as again Connection between the AP of preceding connection is simultaneously linked into the new AP.

25. TWAG as claimed in claim 24, which is characterized in that the first processing module is specifically used for：

According to the MAC Address of the MAC Address of itself and the new TWAG connected of the new AP in the switching request, this is judged Whether switching can cause the TWAG for providing service for the terminal to change；And according to judging result, execute different places Reason process.

26. TWAG as claimed in claim 25, which is characterized in that if this switching will not cause to provide service for the terminal TWAG change, the first processing module executes following processing procedure：

In the contextual information of the terminal, the tunnel for the data transmission tunnel established between this TWAG and the new AP is stored The identification information of road endpoint.

27. TWAG as claimed in claim 25, which is characterized in that if the first processing module determines that this switching can cause The TWAG that service is provided for the terminal changes, then：

The sending module is additionally operable to：Handover resource allocation request is sent to the new TWAG, the handover resource allocation is asked It is the terminal distribution resource to ask for asking the new TWAG；

The receiving module is additionally operable to：It receives the handover resource allocation that the new TWAG is returned to reply, the switchable resource point It is to be sent to the TWAG's currently connected after the new TWAG completes the resource allocation process of the terminal with replying.

28. TWAG as claimed in claim 27, which is characterized in that if carrying the terminal in handover resource allocation request The workable credible WLAN access characteristics based on S2a interfaces at the new TWAG, then the first processing module according to Following steps obtain the terminal workable credible WLAN access characteristics based on S2a interfaces at the new TWAG：

By the interaction with the new TWAG, the credible WLAN accesses based on S2a interfaces that the new TWAG is supported are obtained Characteristic；By the new TWAG credible WLAN access characteristics based on S2a interfaces supported and the terminal support based on The credible WLAN access characteristics of S2a interfaces are sent to aaa server, and receive the terminal that the aaa server returns The workable credible WLAN access characteristics based on S2a interfaces at the new TWAG；

Alternatively,

By the interaction with the new TWAG, the credible WLAN accesses based on S2a interfaces that the new TWAG is supported are obtained Characteristic；And the signing for the credible WLAN access characteristics based on S2a interfaces, the terminal supported according to the new TWAG is believed The credible WLAN access characteristics based on S2a interfaces that breath and the terminal are supported, determine the terminal in the new TWAG The lower workable credible WLAN access characteristics based on S2a interfaces.

29. TWAG as claimed in claim 28, which is characterized in that

The sending module is additionally operable to：It is workable based on S2a at the new TWAG that the terminal is sent to the terminal The credible WLAN access characteristics of interface, to obtain the instruction the information whether terminal continues to execute this switching；

The first processing module is additionally operable to：If the receiving module receive that the terminal returns for showing the terminal The instruction information for continuing to execute this switching then triggers the sending module and is asked to the new TWAG transmissions handover resource allocation It asks；If the receiving module receives believing for showing that the terminal does not execute the instruction that this switches for the terminal return Breath, then terminate this handoff procedure, and continues as the terminal forwarding data.

30. TWAG as claimed in claim 27, which is characterized in that the first processing module is additionally operable to：

It, can at the new TWAG according to the terminal after receiving the switch acknowledgment message that the new TWAG is sent The type of the connection of foundation executes the resource release process of the terminal；

31. TWAG as claimed in claim 30, which is characterized in that the first processing module is specifically used for：

If the terminal can only establish NSWO connections at the new TWAG, and at least one PDN has had been established in the terminal Connection, then initiate the release process of established all PDN connections of the terminal, and discharges the context letter of the terminal Breath and the resource of the local all connections distribution for being the terminal；

If the terminal can only establish NSWO connections at the new TWAG, and when the terminal does not set up PDN connections, then release Put the contextual information of the terminal and the resource of the local all connections distribution for being the terminal；

If the terminal can only establish PDN connections at the new TWAG, alternatively, the terminal at the new TWAG both NSWO connections can be established and PDN connections can be established, then it is the terminal to discharge the contextual information of the terminal and local The resource of all connection distribution.

32. TWAG as claimed in claim 27, which is characterized in that if this TWAG is the new TWAG, the TWAG is also Including：

Second processing module, for workable based on the credible of S2a interfaces at the new TWAG according to the terminal WLAN access characteristics determine the type for the connection that the terminal can be established at the new TWAG；And according to the end The type for the connection that can be established at the new TWAG and all connections that the terminal is currently-established are held, institute is executed State the resource allocation process of terminal.

33. TWAG as claimed in claim 32, which is characterized in that if not carrying the end in handover resource allocation request End workable credible WLAN access characteristics based on S2a interfaces at the new TWAG, then the Second processing module is also It is accessed for obtaining the terminal workable credible WLAN based on S2a interfaces at the new TWAG according to following steps Characteristic：

The credible WLAN access characteristics based on S2a interfaces that the terminal is supported are obtained from handover resource allocation request； The credible WLAN access characteristics based on S2a interfaces and the terminal that itself is supported support based on the credible of S2a interfaces WLAN access characteristics are sent to aaa server, and receive the terminal of the aaa server return in the new TWAG The lower workable credible WLAN access characteristics based on S2a interfaces；

Alternatively,

Obtained from handover resource allocation request the credible WLAN access characteristics based on S2a interfaces that the terminal is supported with And the signing information of the terminal；The label of the credible WLAN access characteristics based on S2a interfaces, the terminal supported according to itself The credible WLAN access characteristics based on S2a interfaces that about information and the terminal are supported determine the terminal described new The workable credible WLAN access characteristics based on S2a interfaces under TWAG.

34. TWAG as claimed in claim 32, which is characterized in that the Second processing module specifically executes following resource allocation Process：

If the terminal can only establish NSWO connections at the new TWAG, and NSWO connections have had been established in the terminal, then For established NSWO connections allocation identification information；Wherein, the handover resource allocation carries established NSWO and connects in replying Corresponding mark pair is connect, the mark is to being that the established NSWO connections are allocated including the TWAG currently connected Identification information is that the established NSWO connects newly assigned identification information with the new TWAG；

If the terminal can only establish PDN connections at the new TWAG, and at least one PDN companies have had been established in the terminal It connects, is then every established PDN connections allocation identification information；Wherein, the handover resource allocation has carried every in replying The corresponding mark pair of PDN connections of foundation, each mark is to being that an established PDN connects including the TWAG currently connected It is that the established PDN of this connects newly assigned identification information that allocated identification information, which is connect, with the new TWAG

If the terminal can establish NSWO connections at the new TWAG but also establish PDN connections, and the terminal is built NSWO connections and/or at least one PDN connections have been stood, then has been distributed respectively for established NSWO connections and/or every PDN connection Identification information；Wherein, the handover resource allocation carries the corresponding mark pair of established NSWO connections and every in replying The corresponding mark pair of established PDN connections, each mark is to being the terminal any bar including the TWAG currently connected The allocated identification information of established connection and/or the new TWAG are the established newly assigned mark letter of connection Breath.

35. TWAG as claimed in claim 32, which is characterized in that if at least one PDN connections have had been established in the terminal, The Second processing module is additionally operable to：

36. a kind of terminal, which is characterized in that the terminal includes：

Switch initiation module, for when determination needs to be linked into new access point AP, switching to be sent to the TWAG currently connected Request, the switching request are used to initiate handoff procedure of this terminal between different AP to the TWAG currently connected；

Switching executing module, for after the switching for receiving the TWAG currently connected is replied, disconnecting and currently connecting Connection between AP is simultaneously linked into the new AP；

Wherein, it has been that this terminal establishes company on the new TWAG of the new AP connections before being linked into the new AP It connects.

37. terminal as claimed in claim 36, which is characterized in that the switching executing module is specifically used for：

If the switching does not carry mark pair in replying, after receiving the switching and replying, directly disconnects and currently connect AP between connection and be linked into the new AP；Wherein, it is that the TWAG currently connected determines this that the switching, which is replied, Secondary switching will not cause the TWAG for providing service for the terminal to change, and the TWAG currently connected with it is described new It establishes between AP and is sent to the terminal after data transmission tunnel；

If the switching carries at least one mark pair in replying, after receiving the switching and replying, according to the switching All marks pair carried in reply update the identification information with each mark to corresponding connection of this terminal；And Complete with each mark to the update of the identification information of corresponding connection after, the company between disconnection and the AP currently connected It connects and is linked into the new AP；Wherein, each mark it is established to a corresponding terminal and with the terminal The identical connection of type for the connection that can be established at the new TWAG, and each mark is to including described currently connecting The TWAG connect is the allocated identification information of the established connection and the new TWAG is that the established connection is new The identification information of distribution.

38. terminal as claimed in claim 36, which is characterized in that the switching executing module is additionally operable to：

Receive this terminal that the TWAG that currently connects is sent at the new TWAG it is workable based on S2a interfaces can Believe WLAN access characteristics；According to this terminal, the workable credible WLAN based on S2a interfaces accesses spy at the new TWAG Property, judge whether itself continues to execute this switching；And according to judging result, instruction is returned to the TWAG currently connected Information, the instruction information is for showing whether this terminal continues to execute this switching.