CN103517255A

CN103517255A - Service distributing method, mobility management entity and terminal

Info

Publication number: CN103517255A
Application number: CN201210198872.4A
Authority: CN
Inventors: 梁爽; 朱春晖
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2012-06-15
Filing date: 2012-06-15
Publication date: 2014-01-15

Abstract

The invention discloses a service distributing method, a mobility management entity and a terminal. The service distributing method comprises the following steps: in the circuit switched fallback (CSFB) process, the mobility management entity (MME) is used to determine whether bearing of the terminal is allowed to be distributed to a wireless local area network (WLAN); and the MME is used to indicate the bearing allowed to be distributed to the WLAN for the terminal. According to the invention, by accessing some PS services through the WLAN, when a CS service is performed, the hang-up of the PS services can be avoided, and the service layer demands of the PS services can be satisfied, so the advantage of good user service experience can be realized.

Description

Service distribution method, mobility management entity and terminal

Technical Field

The present invention relates to the field of mobile communications, and in particular, to a service offloading method, a mobility management entity, and a terminal.

Background

In order to maintain the competitiveness of the third Generation mobile communication System in the communication field, provide a mobile communication service with faster rate, lower delay and more personalization for users, and at the same time, reduce the operation cost of operators, the 3GPP (3rd Generation Partnership Project) standard working group is working on the research of the Evolved Packet System (EPS for short).

The system can provide better transmission rate, so that the realization of VoIP (voice over IP) service becomes practical, and therefore, the EUTRAN (Evolved UTRAN) access in the system does not separately provide voice access. Therefore, if it is desired to implement voice communication, in addition to VoIP service, it is also possible to select to fall back to the UTRAN or GERAN (GSM EDGE radio access network, where GSM is an abbreviation of Global System for mobile communications, i.e. Global System for mobile communications, EDGE is an abbreviation of Enhanced Data Rate for GSM Evolution, i.e. Enhanced Data Rate GSM Evolution) System with the same coverage for voice access. The architecture diagram of the system is shown in fig. 1, and includes the following network elements:

a Mobile Station (or Mobile terminal, MS for short)/user equipment (UE for short) 101. A terminal having the capability of accessing both wireless networks is called a dual mode terminal. The MS/UE described herein is a dual mode terminal capable of accessing both a GSM network and an EPS network. The MS/UE uses UE or terminal representative collectively in the subsequent description herein.

E-UTRAN 102: the radio access network of the EPS network can provide higher uplink and downlink rates, lower transmission delay and more reliable wireless transmission. The network element included in the E-UTRAN is an eNodeB (Evolved NodeB) that provides radio resources for access of the terminal.

A Mobility Management Entity (MME) 103 is a control plane Entity, a server for temporarily storing user data, and is responsible for managing and storing UE context (such as UE/user identity, Mobility Management status, user security parameters, etc.), allocating a temporary identity to a user, and authenticating the user when the UE camps in the tracking area or the network. The MME is primarily responsible for user access from the E-UTRAN.

GERAN/UTRAN 104: radio access network of a conventional GSM/UMTS network.

GSM/UMTS networks are divided into Circuit Switching (CS) and Packet Switching (PS) domains.

A Serving GPRS Support Node (SGSN) 105 is a control network element of the PS domain of the GSM/UMTS network, and is mainly used to record the location information of the UE and complete sending and receiving of mobile packet data between the UE and a GPRS Gateway Support Node (GGSN). The SGSN is mainly responsible for the work of access control, mobility management and the like when the UE is accessed from the PS domain of the GSM/UMTS network.

A Mobile Switching Center (MSC)/Visitor Location Register (VLR) 106. The MSC/VLR may also be a new functional entity MSC Server after 3GPP R4(Release 4) phase, and is collectively referred to as MSC/VLR herein. The MSC/VLR is a core network element of the CS domain of the GSM/UMTS network and is responsible for user access, mobility and control of voice and short message services of the circuit domain.

S-GW (Serving Gateway)/P-GW (PDN Gateway) 107: the service gateway is a gateway from a core network to a wireless system and is responsible for user plane bearing from a terminal to the core network, data caching in a terminal idle mode, a function of initiating a service request at a network side, and functions of legal interception, packet data routing and forwarding; the packet data network gateway is an Evolved Packet System (EPS) and a gateway of an external network of the system, and is responsible for functions of IP address allocation, a charging function, packet filtering, policy application, and the like of a terminal.

A WLAN (Wireless Local Area network) can provide Wireless access services with different rates according to different air interface technologies, gradually replaces a traditional wired Local Area network, and can provide a lower access cost for a user because an access frequency band is free, thereby saving a certain operation cost for an operator.

When the terminal is in EUTRAN network, VLR can inform MME of the arrival of voice session through SGs interface, MME triggers UE to fall back to GERAN/UTRAN to access CS service. But considering the access network capabilities of 2G/3G may lead to the following problems:

for example, the dual-receiving and dual-sending of the CS service and the PS service are not supported, which may cause the PS service to be suspended when the CS service is performed, thereby causing the PS service to be interrupted and the service experience to be very poor;

for another example, although the 2G/3G network supports dual-transceiving for CS and PS services, due to the limited access rate of the 2G/3G air interface, although the PS service can be switched to the 2G/3G, the service layer requirement cannot be met, the service may be interrupted, and the service experience is also poor.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a service offloading method, a mobility management entity and a terminal, which can ensure that a CS service and a PS service are performed simultaneously and meet the service layer requirements of the PS service.

In order to solve the above technical problem, a service offloading method of the present invention includes:

in a voice service fallback (CSFB) process, a Mobility Management Entity (MME) judges whether the load of a terminal is allowed to be shunted to a Wireless Local Area Network (WLAN);

the MME indicates to the terminal that bearers allowed to be offloaded to WLAN.

Further, the MME indicating to the terminal bearers allowed to be offloaded to WLAN, including:

the MME releases the bearer allowed to be shunted to the WLAN, sends a bearer release request to the terminal, and carries release indication information and an identifier of the bearer to be released in the bearer release request, wherein the identifier of the bearer to be released is the identifier of the bearer allowed to be shunted to the WLAN, and indicates the terminal to transfer the relevant service of the bearer allowed to be shunted to the WLAN on the WLAN connection.

Further, still include:

the MME initiates modification of terminal context after indicating the terminal to allow the bearer to be shunted to the WLAN, the CSFB indication information is contained in the terminal context, the terminal is triggered to switch the bearer which is not allowed to be shunted to the WLAN to a global system for mobile communication enhanced radio access network (GERAN)/global system for mobile communication terrestrial radio access network (UTRAN), or the terminal is triggered to reselect to the GERAN/UTRAN, and the bearer which is not allowed to be shunted to the WLAN is established in the GERAN/UTRAN.

Further, still include:

and after releasing the bearer which is allowed to be shunted to the WLAN, the MME continuously reserves the core network resource corresponding to the bearer which is allowed to be shunted to the WLAN.

Further, the step of the MME judging whether the bearer of the terminal is allowed to be offloaded to the WLAN according to the obtained offloading policy, and obtaining the offloading policy includes:

the MME sends a session establishment request to a packet data network gateway (P-GW) through a serving gateway (S-GW) after receiving a Packet Data Network (PDN) connection establishment request sent by a terminal, and receives the offloading policy after the offloading policy is generated by the P-GW or a Policy and Charging Rules Function (PCRF).

Further, the MME judging whether the bearer of the terminal is allowed to be offloaded to the WLAN according to the obtained offloading policy, and obtaining the offloading policy includes:

the MME receives a offloading policy after the PCRF updates the offloading policy in an IP connection access network (IPCAN) session modification process; or

And the MME receives the shunting strategy after the PGW updates the shunting strategy.

Further, in a dedicated bearer establishing process, a bearer modifying process, a terminal requested resource allocation process, or a terminal requested resource modifying process, the PCRF or the PGW updates the offloading policy.

Further, still include:

and after receiving the shunting strategy, the MME stores the shunting strategy in a terminal context.

Further, still include:

the MME receives a service request message of a terminal requesting a voice service before judging whether the load of the terminal is allowed to be shunted to the WLAN, judges whether WLAN shunting is allowed to be executed according to the indication information of whether WLAN coverage exists currently carried in the service request message, and judges whether the load of the terminal is allowed to be shunted to the WLAN if the indication information indicates that WLAN coverage exists currently.

Further, a service offloading method includes:

and the terminal transmits the related service of the bearer allowed to be shunted to the WLAN on the WLAN connection according to the indication of the bearer allowed to be shunted to the WLAN, which is sent by the MME.

Further, the indication of the bearer allowed to be offloaded to the WLAN sent by the MME is release indication information included in the bearer release request and an identifier of the bearer to be released, the identifier of the bearer to be released is the identifier of the bearer allowed to be offloaded to the WLAN, and the terminal performs the related service of transferring the bearer allowed to be offloaded to the WLAN over the WLAN connection according to the release indication information and the identifier of the bearer to be released.

Further, still include:

and after receiving the indication of the bearer which is allowed to be shunted to the WLAN and sent by the MME, the terminal switches the bearer which is not allowed to be shunted to the WLAN to GERAN/UTRAN or reselects to GERAN/UTRAN, and establishes the bearer which is not allowed to be shunted to the WLAN in GERAN/UTRAN.

Further, still include:

the terminal sends a request message to an MME before receiving an indication of bearer which is sent by the MME and allowed to be shunted to the WLAN, wherein the request message carries indication information whether WLAN coverage exists currently.

Further, a mobility management entity includes: a judging unit and an indicating unit, wherein:

the judging unit is configured to judge whether a bearer of the terminal is allowed to be shunted to a Wireless Local Area Network (WLAN) in a voice service fallback (CSFB) process;

the indication unit is configured to indicate, to the terminal, bearers allowed to be offloaded to the WLAN.

Further, the indicating unit is specifically configured to release the bearer allowed to be offloaded to the WLAN, and send a bearer release request to the terminal, where the bearer release request carries release indication information and an identifier of a bearer to be released, and the identifier of the bearer to be released is the identifier of the bearer allowed to be offloaded to the WLAN, and indicates the terminal to transfer, over the WLAN connection, a service related to the bearer allowed to be offloaded to the WLAN.

Further, a terminal context unit is included, wherein:

the terminal context unit is configured to initiate a terminal context modification after the indication unit indicates to the terminal that the bearer is allowed to be offloaded to the WLAN, include CSFB indication information in the terminal context, trigger the terminal to switch the bearer that is not allowed to be offloaded to the WLAN to a global system for mobile communications enhanced radio access network (GERAN)/global system for mobile communications terrestrial radio access network (UTRAN), or trigger the terminal to reselect to the GERAN/UTRAN, and establish the bearer that is not allowed to be offloaded to the WLAN in the GERAN/UTRAN.

Further, the system also comprises a policy acquisition unit, wherein:

the policy acquisition unit is used for sending a session creation request to a packet data network gateway (P-GW) through a service gateway (S-GW) after receiving a Packet Data Network (PDN) connection establishment request sent by a terminal, and receiving the offloading policy after the offloading policy is generated by the P-GW or a Policy and Charging Rules Function (PCRF); or,

after a PCRF updates a offloading policy in an IP connection access network (IPCAN) session modification process, receiving the offloading policy; or,

and after the PGW updates the shunting strategy, receiving the shunting strategy.

Further, a terminal, comprising: receiving element and bearing maintenance unit, wherein:

the receiving unit is configured to receive an indication that bearers are allowed to be offloaded to the WLAN, where the indication is sent by the MME;

and the bearer maintenance unit is configured to transfer, according to the indication of the bearer allowed to be shunted to the WLAN, the relevant service of the bearer allowed to be shunted to the WLAN over the WLAN connection.

Further, the indication sent by the MME for the bearer allowed to be offloaded to the WLAN is release indication information included in a bearer release request and an identifier of a bearer to be released, where the identifier of the bearer to be released is the identifier of the bearer allowed to be offloaded to the WLAN;

the bearer maintenance unit is specifically configured to execute the relevant service of transferring the bearer allowed to be shunted to the WLAN over the WLAN connection according to the release indication information and the identifier of the bearer to be released.

Further, the bearer maintenance unit is further configured to handover a bearer that is not allowed to be offloaded to the WLAN to GERAN/UTRAN or reselect to GERAN/UTRAN according to a trigger, and establish the bearer that is not allowed to be offloaded to the WLAN in GERAN/UTRAN.

In summary, the present invention accesses some PS services through WLAN, so that when performing CS services, the PS services can be prevented from being suspended, and the service layer requirements of the PS services can be met, so that the service experience of the user is good.

Drawings

Fig. 1 is a schematic structural diagram of an evolved packet domain system in the prior art;

fig. 2 is a flowchart of a service offloading method according to this embodiment;

fig. 3 is a flowchart of a method for acquiring a offloading policy according to this embodiment;

fig. 4 is a flowchart of another method for acquiring a offloading policy according to this embodiment;

fig. 5 is an architecture diagram of a mobility management entity of the present embodiment;

fig. 6 is an architecture diagram of the terminal of the present embodiment.

Detailed Description

Considering that most 3GPP terminals can support the WLAN access module, and the WLAN access module and the conventional access module can work together, in this embodiment, it is considered that by dropping the CS domain service to GERAN/UTRAN in a CSFB (voice service Fallback) scenario, the PS service not suitable for 2G/3G access is accessed through WLAN, and the PS service suitable for 2G/3G access is still accessed from 2G/3G.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the following detailed description of the present embodiments is provided with reference to the accompanying drawings.

Fig. 2 is a process of implementing PS service partial offloading to WLAN by the service offloading method of this embodiment, including:

step 201-202: VLR receives the call of the terminal as the called user, and sends the paging message to MME through SGs interface;

step 203-204: the MME judges whether the UE is in a connected state, if so, the MME sends a CS service notification message to the terminal through the base station; if the UE is in an idle state, the MME pages the UE through the base station;

the paging message is described as an example in fig. 2, but the present embodiment is also applicable to the case where the UE is in a connected state.

For the process that the terminal actively initiates the CS call, the steps 201-204 do not need to be executed, and the subsequent steps are directly executed from the step 205.

Step 205: UE judges whether WLAN coverage exists at present;

the UE judges whether WLAN coverage exists currently according to a strategy acquired from an ANDSF (access network discovery and selection function); or the WLAN access module may be started to detect whether there is WLAN coverage currently; or if the terminal supports the WLAN access module and the EUTRAN access module to work simultaneously, the UE judges whether WLAN coverage exists according to whether WLAN connection exists currently.

It is assumed that the UE determines that there is WLAN coverage, and the UE determines that there is no WLAN coverage is the prior art, which is not described herein again.

Step 206: UE sends a service request message to MME through a base station, wherein the service request message carries indication information whether WLAN coverage exists currently;

step 207: when the indication information indicates that the current WLAN coverage exists, the MME judges that WLAN offload can be executed, and judges whether the bearer of the terminal is allowed to be offloaded to the WLAN or not according to an offload strategy configured locally or acquired in advance, namely judges that the bearer allowed to be offloaded to the WLAN and the bearer not allowed to be offloaded to the WLAN (to be switched to GERAN/UTRAN bearer);

step 208-209: the MME releases the bearer which is allowed to be shunted to the WLAN, and initiates a bearer release request to the terminal, wherein the bearer release request comprises the identifier of the bearer to be released and release indication information, and the identifier of the bearer to be released is the identifier of the bearer which is allowed to be shunted to the WLAN;

the release indication information and the identifier of the bearer to be released may be included in only a bearer release request of an NAS (non-access stratum) sent by the MME to the UE, or may be included in a bearer release request sent by the MME to the base station, and sent to the terminal through a radio bearer release request sent by the base station.

The release indication information indicates that traffic associated with the bearer to be released by the terminal can be delivered over the WLAN connection.

Step 210: the UE can execute the connection establishment process of the WLAN according to the release indication information, and if the UE already establishes the WLAN connection, the related service of the bearer to be released can be transferred on the WLAN connection;

step 211 to step 212: the UE returns a bearer release response message to the MME through the base station;

step 213: the MME continues to reserve the core network resources corresponding to the bearer allowed to be shunted to the WLAN at the moment;

step 214-215: MME initiates a UE context modification process, a base station initiates a switching process to indicate UE to switch to GERAN/UTRAN according to CSFB indication information contained in the UE, or releases connection to indicate UE to reselect to GERAN/UTRAN, and a bearer which is not allowed to be shunted to WLAN is established in GERAN/UTRAN;

which process is initiated by the base station may be determined according to different configurations, which is not described herein in detail for the prior art.

Step 216: and the UE executes CS service fallback according to the triggering of switching to the GERAN/UTRAN or the triggering of reselecting to the GERAN/UTRAN, and switches or reselects the bearer which is not allowed to be shunted to the WLAN to the GERAN or UTRAN.

In this embodiment, instead of transferring the traffic related to the bearer allowed to be offloaded to the WLAN on the WLAN connection according to the release indication information in step 210, the UE may establish the WLAN connection and transfer the traffic related to the bearer allowed to be offloaded to the WLAN on the WLAN connection when performing the CS traffic fallback and the handover or reselection of the bearer not allowed to be offloaded to the WLAN in step 216.

The terminal performs CS service fallback and switches or reselects a bearer that is not allowed to be offloaded to WLAN to GERAN or UTRAN, which is the prior art and is not described herein. If there is already a WLAN connection, the UE will subsequently allow the traffic associated with the bearer offloaded to the WLAN to be delivered over the WLAN connection.

Fig. 3 is a process of implementing an MME to acquire a offloading policy in the service offloading method of the embodiment, including:

the procedure takes a PDN connection establishment request as an example, and the embodiment is also applicable to an attach procedure because a PDN connection procedure also occurs during attach.

Step 301: UE initiates a PDN connection establishment request to MME through a base station;

step 302: the MME sends a session creation request to the PGW through the SGW;

step 303: if the network side deploys PCRF, the PGW sends an IPCAN session establishment request to the PCRF, and the PCRF generates QoS and charging strategies for the PDN connection of the UE and simultaneously generates a shunting strategy; if the network side does not deploy PCRF, the related strategy is generated by PGW;

in this embodiment, under the condition that the PCRF is deployed on the network side, the offload policy may also be locally generated by the PGW according to the generated QoS and the charging policy.

Step 304: the PGW returns a session creating response to the MME through the SGW, wherein the session creating response comprises a shunting strategy;

step 305: the MME stores the shunting strategy in the context of the UE;

step 306: and executing a subsequent PDN connection establishment process, wherein the process is consistent with the prior art and is not described in detail.

Fig. 4 is a process of implementing, by the service offloading method of the present embodiment, an MME to acquire or update an offloading policy, where the process includes:

step 400: the PGW initiates an IPCAN session modification process to the PCRF in the resource modification or resource allocation process initiated by the UE; or the PCRF is triggered by the service layer, and the PCRF initiates an IPCAN session modification process;

step 401: the PCRF may update the QoS, the charging policy and the shunting policy in the IPCAN session modification process;

if the network side does not deploy PCRF, the updating of the relevant strategy is completed by the PGW; or under the condition that the PCRF is deployed on the network side, the offloading policy may also be locally updated by the PGW according to the QoS and charging policy update.

Step 402: the PGW sends a dedicated bearer establishment and/or bearer modification request to the MME through the SGW, wherein the dedicated bearer establishment and/or bearer modification request comprises a shunting strategy;

the PGW may trigger a bearer modification and/or a dedicated bearer establishment procedure according to the offloading policy, and if there are different offloading policies for different IP data flows, different bearers need to be generated, so that the dedicated bearer establishment and/or the bearer modification procedure may be triggered.

Step 403: the MME stores the shunting strategy in the context of the UE;

step 404: and executing subsequent dedicated bearer establishment and/or bearer modification processes, which are consistent with the prior art and are not described in detail.

Furthermore, in addition to sending the offloading policy to the MME through the dedicated bearer establishment and/or bearer modification request in the process of resource modification or resource allocation initiated by the UE, the network side may also initiate a dedicated bearer establishment and bearer modification request process, and update the offloading policy by the PCRF or the PGW in the dedicated bearer establishment and bearer modification process, and send the updated offloading policy to the MME.

Since the bearers in EPS are the smallest processing granularity, if the policy is different for splitting different data flows, the PGW preferably ensures that these data flows are not aggregated on one bearer, thereby avoiding more complex operations.

As shown in fig. 5, the present embodiment further provides a mobility management entity, including: the device comprises a judging unit, an indicating unit, a terminal context unit and a strategy acquiring unit, wherein:

a judging unit, configured to judge whether a bearer of the terminal is allowed to be shunted to the WLAN in a CSFB procedure;

an indicating unit, configured to indicate to a terminal a bearer allowed to be offloaded to a WLAN, including: releasing the bearer allowed to be shunted to the WLAN, and sending a bearer release request to the terminal, wherein the bearer release request carries release indication information and an identifier of the bearer to be released, the identifier of the bearer to be released is the identifier of the bearer allowed to be shunted to the WLAN, and the terminal is instructed to transfer the relevant service of the bearer allowed to be shunted to the WLAN on the WLAN connection.

And the terminal context unit is used for initiating the modification of the terminal context after the indication unit indicates the bearer which is allowed to be shunted to the WLAN to the terminal, the CSFB indication information is contained in the terminal context, the terminal is triggered to switch the bearer which is not allowed to be shunted to the WLAN to GERAN/UTRAN, or the terminal is triggered to reselect to GERAN/UTRAN, and the bearer which is not allowed to be shunted to the WLAN is established in the GERAN/UTRAN.

The system comprises a policy acquisition unit, a service gateway and a policy management and control unit, wherein the policy acquisition unit is used for sending a session creation request to a P-GW through an S-GW after receiving a PDN connection establishment request sent by a terminal, and receiving a shunting policy after the P-GW or a PCRF generates the shunting policy; or,

after the PCRF updates the shunting strategy in the IPCAN session modification process, receiving the shunting strategy; or after the PGW updates the offloading policy, the offloading policy is received.

As shown in fig. 6, the present embodiment also provides a terminal, including: receiving element and bearing maintenance unit, wherein:

a receiving unit, configured to receive an indication that bearers are allowed to be offloaded to the WLAN, where the indication is sent by an MME;

and the bearer maintenance unit is used for transferring the relevant service of the bearer allowed to be shunted to the WLAN on the WLAN connection according to the indication of the bearer allowed to be shunted to the WLAN.

The indication sent by the MME for allowing the bearer to be shunted to the WLAN is release indication information contained in the bearer release request and an identifier of the bearer to be released, and the identifier of the bearer to be released is the identifier of the bearer to be shunted to the WLAN;

and a bearer maintenance unit, configured to perform, according to the release indication information and the identifier of the bearer to be released, delivery of a service related to the bearer allowed to be offloaded to the WLAN over the WLAN connection.

And the bearer maintenance unit is also used for switching the bearer which is not allowed to be shunted to the WLAN to GERAN/UTRAN or reselecting to GERAN/UTRAN according to the trigger, and establishing the bearer which is not allowed to be shunted to the WLAN in GERAN/UTRAN.

It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and alternatively, they may be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, or they may be separately fabricated into various integrated circuit modules, or multiple modules or steps thereof may be fabricated into a single integrated circuit module. Thus, the present invention is not limited to any specific combination of hardware and software.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A service offloading method, comprising:

the MME indicates to the terminal that bearers allowed to be offloaded to WLAN.

2. The method of claim 1, wherein the MME indicates to the terminal that bearers allowed to be offloaded to WLAN are allowed, comprising:

3. The method of claim 1, further comprising:

4. The method of claim 2, further comprising:

5. The method of claim 1, wherein the MME determining whether the bearer of the terminal is allowed to be offloaded to the WLAN according to the obtained offloading policy, and obtaining the offloading policy comprises:

6. The method of claim 1, wherein the MME judges whether the bearer of the terminal is allowed to be offloaded to the WLAN according to the obtained offloading policy, and obtaining the offloading policy comprises:

7. The method of claim 6, wherein the PCRF or PGW updates the offloading policy in a dedicated bearer establishment procedure, a bearer modification procedure, a terminal requested resource allocation procedure, or a terminal requested resource modification procedure.

8. The method of claim 5 or 6, further comprising:

9. The method of claim 1, further comprising:

10. A service offloading method, comprising:

11. The method of claim 10, wherein the indication sent by the MME for the bearer allowed to be offloaded to the WLAN is release indication information included in a bearer release request and an identifier of a bearer to be released, wherein the identifier of the bearer to be released is the identifier of the bearer allowed to be offloaded to the WLAN, and wherein the terminal performs the related service of transferring the bearer allowed to be offloaded to the WLAN over the WLAN connection according to the release indication information and the identifier of the bearer to be released.

12. The method of claim 10, further comprising:

13. The method of claim 10, further comprising:

14. A mobility management entity, comprising: a judging unit and an indicating unit, wherein:

15. The mobility management entity according to claim 14, characterized by:

the indication unit is specifically configured to release the bearer allowed to be offloaded to the WLAN, and send a bearer release request to the terminal, where the bearer release request carries release indication information and an identifier of a bearer to be released, where the identifier of the bearer to be released is the identifier of the bearer allowed to be offloaded to the WLAN, and indicates the terminal to transfer, over the WLAN connection, a service related to the bearer allowed to be offloaded to the WLAN.

16. The mobility management entity according to claim 14, further comprising a terminal context unit, wherein:

17. The mobility management entity according to claim 14, further comprising a policy acquisition unit, wherein:

18. A terminal, comprising: receiving element and bearing maintenance unit, wherein:

19. The terminal of claim 18, wherein:

the indication sent by the MME for allowing the bearer to be shunted to the WLAN is release indication information contained in a bearer release request and an identifier of a bearer to be released, wherein the identifier of the bearer to be released is the identifier of the bearer allowing the shunting to the WLAN;

20. The terminal of claim 18, wherein:

and the bearer maintenance unit is further used for switching the bearer which is not allowed to be shunted to the WLAN to GERAN/UTRAN or reselecting to GERAN/UTRAN according to the trigger, and establishing the bearer which is not allowed to be shunted to the WLAN in GERAN/UTRAN.