WO2014005444A1

WO2014005444A1 - Access method, system, mme, and ue for wireless local area network shunting

Info

Publication number: WO2014005444A1
Application number: PCT/CN2013/073759
Authority: WO
Inventors: 梁爽; 朱春晖
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-05-14
Filing date: 2013-04-03
Publication date: 2014-01-09
Also published as: CN103428822A

Abstract

An access method, system, mobility management entity (MME), and user equipment (UE) for wireless local area network (WLAN) shunting, the method comprising the following steps: under the scenario of voice service circuit switching fallback (CSFB), an MME receives via a substation a service request message from a UE, the service request message carrying information indicating that the UE is covered by a WLAN (S202); the MME determines according to the indication information to allow packet switching (PS) services access from the WLAN (S204). The present invention solves the problem in the prior art that under the scenario of CSFB, user cannot be provided with high quality PS services because the PS service flow is not clearly determined by the terminal and the network. The present invention ensures simultaneous access by the circuit switching (CS) domain and the PS domain services, and enhances the user experience of PS services.

Description

The present invention relates to the field of mobile communications, and in particular to an access method for offloading to a wireless local area network (Wireless Local Area Network, WLAN for short). And the system, the Mobility Management Entity (MME) and the User Equipment (UE). BACKGROUND OF THE INVENTION In order to maintain the competitiveness of the third generation mobile communication system in the communication field, the mobile communication service with faster speed, lower delay and more personalized is provided for the user, and at the same time, the operating cost of the operator is reduced, and the third generation cooperation The 3rd Generation Partnership Project (3GPP) Standards Working Group is working on the Evolved Packet System (EPS). The system can provide a better transmission rate, and the application of the Voice over IP (VoIP) service becomes a reality. Therefore, the evolved Universal Mobile Telecommunications System (UMTS) in the system is a reality. The Evolved UMTS Terrestrial Radio Access Network (EUTRAN) access does not provide voice access separately. Therefore, if you want to implement voice communication, in addition to VoIP services, you can choose to fall back to the same coverage UTRAN and Global System for Mobile communications (GSM) Enhanced Data Rate for GSM (Enhanced Data Rate for GSM) Evolution, referred to as EDGE) GSM EDGE radio access network (GERAN) system for voice access. 1 is a schematic structural diagram of an evolved packet domain system according to the related art. As shown in FIG. 1, the system includes the following network elements: a mobile station (or mobile terminal, Mobile Station, abbreviated as MS)/user equipment (User

Equipment, referred to as UE) 101, a terminal with the ability to access two wireless networks is called a dual-mode terminal; an E-UTRAN 102 with an evolved EPS network can provide a higher uplink and downlink rate, Low transmission delay and more reliable wireless transmission, wherein the network element included in the E-UTRAN is an evolved Node B (evolved Node B, referred to as eNode B or e B;), providing radio resources for terminal access; A Mobility Management Entity (MME) 103 is a control plane entity that temporarily stores user data and is responsible for managing and storing UE contexts (eg, UE/user identity, mobility management state, user security parameters). And so on, assigning a temporary identifier to the user, and when the UE is stationed in the tracking area or the network, is responsible for authenticating the user, and the MME is mainly responsible for accessing the user from the E-UTRAN; The radio access network (GERAN/UTRAN) 104 of the traditional GSM/UMTS network, the GSM/UMTS network is divided into a Circuit Switching (CS) domain and a Packet Switching (PS) domain;

The GPRS Service Support Node (SGSN) 105 is a control network element of the PS domain of the GSM/UMTS network. The main function is to record the location information of the UE, and the UE and the GPRS Gateway Support Node (Gateway GPRS Supporting Node, The SGSN is responsible for the transmission and reception of mobile packet data between GGSNs. The SGSN is mainly responsible for access control and mobility management when the UE accesses the PS domain from the GSM/UMTS network. The Mobile Switching Center (Mobile Switching Center, referred to as The MSC)/Visitor Location Register (VLR) 106 is the 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 in the circuit domain, where The MSC/VLR may also be a new functional entity MSC Server after the 3GPP R4 (Release 4) phase (hereinafter unified with the MSC/VLR representative); a Serving Gateway (S-GW for short) / a packet data network gateway ( PDN Gateway, referred to as P-GW) 107, where the service gateway is the gateway of the core network to the wireless system, and is responsible for the user plane bearer of the terminal to the core network, and the terminal is empty. Data caching in idle mode, network side originating service request function, lawful eavesdropping and packet data routing and forwarding function; packet data network gateway is an evolved packet domain system (EPS) and gateway of the system external network, responsible for terminal IP Address allocation, billing function, packet filtering, policy application, etc.; and Wireless Local Area Networks (WLAN) 108, which can provide different rates of wireless access services according to different air interface technologies, are gradually It replaces the traditional wired local area network, and because the access frequency band is free, it can provide users with lower access fees and save operators a certain operating cost. When the terminal resides in the EUTRAN network, the VLR can notify the MME that the voice session is reached through the SGs interface, and the MME triggers the UE to fall back to the GERAN/UTRAN to access the CS service. However, most of the current GERAN/UTRAN networks do not support dual-issue and dual-issue of CS services and PS services. That is to say, when the CS service is performed, the PS service is suspended, which causes the interruption of the PS service and the service experience is very bad. In the related art, in the case of the CS Fallback (CSFB) scenario, the terminal and the network side determine the flow direction of the PS service correctly according to the principle, which may result in the inability to provide the optimal PS for the user. Business experience. SUMMARY OF THE INVENTION The embodiments of the present invention provide an access scheme for offloading to a WLAN, so as to at least solve the above-mentioned related art, because the flow direction of the terminal and the network side decision PS service in the CSFB scenario is unclear, the user cannot provide high quality. PS business experience issues. In order to achieve the above object, according to an aspect of an embodiment of the present invention, an access method for offloading to a WLAN is provided. The access method for offloading to the WLAN according to the embodiment of the present invention includes the following steps: In the scenario of the CSFB, the MME receives the service request message from the UE by using the base station, where the service request message carries the information that the UE currently has WLAN coverage. The indication information of the MME is determined to access the packet switched PS service from the WLAN according to the indication information. Preferably, the MME determines, according to the indication information, that the PS service is accessed from the WLAN, the MME determines, according to the indication information and the predetermined condition, that the base station does not notify the base station to initiate the PS domain handover, where the predetermined condition includes at least one of the following: The indication of switching the PS service to the WLAN, the RFSP for the indication obtained before the subscription, the local policy configuration, whether the GERAN/UTRAN network to be dropped back supports the circuit-switched CS service and the PS service simultaneously, the WLAN connection of the UE Ability to enter. Preferably, the determining, by the MME, that the base station does not notify the base station to initiate the PS domain handover according to the foregoing indication information and the foregoing predetermined condition comprises: sending, by the MME, a UE context modification message or a UE context release message to the base station, to notify the base station not to perform the PS domain handover. Preferably, after the MME sends the UE context modification message or the UE context release message to the base station, the method further includes: the base station receiving the UE context modification message or the UE context release message from the MME, and sending a connection release request message to the UE, where The message includes an indication identifier for notifying access to the PS service from the WLAN: a UE context modification message, a UE context release message, and a connection release request message. Preferably, after the base station sends a connection release request message to the UE, the method further includes: receiving, by the UE, a connection release request message from the base station, and determining, according to the indication identifier carried in the connection release request message, establishing a data connection by using the WLAN to access the PS service. And sending a CS service to the GERAN/UTRAN network, where the CS service includes a CS domain call procedure; or, the UE receives a connection release request message from the base station, and determines, according to the connection release request message, that the GERAN/UTRAN indication is not included, Then, the WLAN is used to establish a data connection to access the PS service, and the GE service is initiated by the GERAN/UTRAN network. The CS service includes a CS domain call process. Preferably, the MME determines, according to the indication information, that the PS service is accessed from the WLAN, includes: the MME determines whether to access part of the PS service from the WLAN and reserves another part of the PS service in the 3GPP access system; if yes, the MME returns the service to the UE. The request accepts the message, and the UE determines, according to the received service request accept message, the bearer accessed by the WLAN and/or the bearer that is reserved in the 3GPP access system, where the service request accept message carries the PS indicating the access through the WLAN. Information of the service and/or information of the PS service retained in the 3GPP access system. Preferably, the MME determines, according to the indication information, that the PS service is accessed from the WLAN, includes: the MME determines whether to access part of the PS service from the WLAN and reserves another part of the PS service in the 3GPP access system; if yes, the MME passes the base station to the UE Sending a bearer release request message, where the bearer release request message carries an EPS status list, and the UE determines, according to the received bearer release request message from the base station, the bearer accessed through the WLAN and/or the bearer retained in the 3GPP access system, The EPS status list includes information indicating the PS service accessed through the WLAN and/or information indicating the PS service retained in the 3GPP access system. Preferably, before the MME receives the service request message from the UE, the method further includes: the UE performing WLAN coverage detection in one of the following situations: a policy of the ANDSF download, a priority of the WLAN indicated in the previously received RFSP index, The terminal supports the WLAN module and the EUTRAN access module to work simultaneously; the UE determines that there is currently WLAN coverage according to one of the following: The policy of the ANDSF, the activated WLAN module detects the WLAN signal, and the WLAN data connection has been established. Preferably, before the UE determines whether there is currently WLAN coverage, the method further includes: the MME acquiring the subscription data from the home subscriber server HSS, where the subscription data includes one of the following: indicating whether to allow the PS service to be connected from the WLAN in the CSFB process. Incoming information; an RFSP index that defines the subscription of the WLAN to the 3GPP access priority. In order to achieve the above object, according to still another aspect of an embodiment of the present invention, an MME is provided. The MME according to the embodiment of the present invention includes: a receiving module, configured to receive, by the base station, a service request message from the UE in a scenario of the CSFB, where the service request message carries indication information indicating that the UE currently has WLAN coverage; The determining module is configured to determine to access the packet switched PS service from the WLAN according to the indication information. In order to achieve the above object, according to still another aspect of an embodiment of the present invention, a UE is provided. The UE according to the embodiment of the present invention includes: a sending module, configured to send a service request message to the base station in a scenario of the CSFB, where the service request message carries indication information indicating that the UE currently has WLAN coverage, and the MME according to the indication The information determines that the packet switched PS service is accessed from the WLAN. In order to achieve the above object, according to another aspect of an embodiment of the present invention, an access system for offloading to a WLAN is provided. An access system for offloading to a WLAN according to an embodiment of the present invention includes the foregoing UE, a base station, and the foregoing MME, where the MME further includes: a notification module, configured to send a UE context modification message or a UE context release message to the base station to notify the base station The base station includes: a transceiver module configured to receive a UE context modification message or a UE context release message from the MME, and send a connection release request message to the UE, where the following messages are included for notifying the permission from the WLAN The indication identifier of the access PS service: a UE context modification message, a UE uplink and downlink release message, and a connection release request message; and the UE includes: a PS service access module, configured to receive a connection release request message from the base station, and according to the connection release request message The indication flag carried in the presence or absence of the access GERAN/UTRAN indication determines that the PS service is accessed by using the WLAN to establish a data connection; and the CS service initiation module is configured to initiate a CS service to the GERAN/UTRAN network, where the CS service includes the CS domain. The process of calling. Preferably, the determining module of the MME includes: a determining unit, configured to determine whether to access part of the PS service from the WLAN and to reserve another part of the PS service in the 3GPP access system; and the processing unit, configured to determine that the result is If yes, the service request accept message is returned to the UE, where the service request accept message carries information indicating the PS service accessed through the WLAN and/or information of the PS service retained in the 3GPP access system; or If the judgment result of the judgment unit is YES, the base station sends a bearer release request message to the UE, where the bearer release request message carries an EPS status list, which is used to indicate information and/or reservation of the PS service accessed through the WLAN. The information of the PS service in the 3GPP access system; the UE includes: a decision module, configured to determine, according to the received service request accept message or the bearer release request message from the base station, the bearer accessed through the WLAN and/or retained in the 3GPP a bearer into the system, where the service request accept message or the EPS status list includes an indication to access through the WLAN PS service information and / or PS service indication information retained in the 3GPP access system. According to the embodiment of the present invention, the method for accessing the PS service through the WLAN in the CSFB scenario is adopted, and the related technology cannot solve the problem that the flow of the terminal and the network side to determine the PS service in the CSFB scenario is unclear. The quality of the PS service experience ensures that the CS domain and the PS domain service can be continuously accessed simultaneously, improving the user experience of the PS service. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawing: 1 is a schematic structural diagram of an evolved packet domain system according to the related art; FIG. 2 is a flowchart of an access method for offloading to a WLAN according to an embodiment of the present invention; FIG. 3 is a structural block diagram of an MME according to an embodiment of the present invention; 4 is a structural block diagram of a UE according to an embodiment of the present invention; FIG. 5 is a structural block diagram of an access system for offloading to a WLAN according to an embodiment of the present invention; FIG. 6 is an access system for offloading to a WLAN according to an embodiment of the present invention; FIG. 7 is a schematic flowchart of the first manner of implementing the PS service routing from the WLAN according to the first embodiment of the present invention; FIG. 8 is a flowchart of the second method for implementing the PS service routing from the WLAN according to the second embodiment of the present invention; FIG. 9 is a schematic flowchart of a third method for implementing a PS service route from a WLAN according to Embodiment 3 of the present invention; FIG. 10 is a schematic flowchart of a method for implementing a PS service part route from a WLAN according to Embodiment 4 of the present invention; 11 is a schematic flowchart of a second method for implementing a PS service part to be routed from a WLAN according to Embodiment 5 of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. Based on most 3GPP terminals, the WLAN access module can be supported, and the WLAN module and the traditional access module can work together. Therefore, it is considered that the CS domain service is dropped back to the GERAN/UTRAN in the CSFB scenario. The PS service is accessed through the WLAN to ensure that the services of the CS and PS domains can be continuous. According to the embodiment of the present invention, an access method for offloading to a WLAN is provided, and the method can ensure that the UE enjoys a superior PS service experience in a specific scenario. FIG. 2 is a flowchart of an access method for offloading to a WLAN according to an embodiment of the present invention. As shown in FIG. 2, the method includes the following steps: In the scenario of the CSFB, the mobility management entity (MME) receives the service request message from the UE by using the base station, where the service request message carries indication information indicating that the UE currently has WLAN coverage; Step 204, MME It is determined according to the indication information that the packet switched (PS) service is accessed from the WLAN. Through the above steps, the method of accessing the PS service through the WLAN in the CSFB scenario is used to solve the problem that the related technologies cannot provide high quality for the user due to unclear flow of the decision-making PS service in the CSFB scenario. The problem of the PS service experience ensures that the CS domain and the PS domain service can be continuously accessed at the same time, improving the user experience of the PS service. It should be noted that the UE or the terminal in the embodiment of the present invention represents a dual mode terminal capable of accessing the GSM network and the EPS network. Preferably, in step 204, the MME may determine, according to the indication information and the predetermined condition, that the base station does not notify the base station to initiate the PS domain handover, where the predetermined condition includes at least one of the following: an indication of the previously subscribed acquisition that allows the terminal to switch the PS service to the WLAN, Whether the previously acquired RAT/Frequency Selection Priority (RFSP) index, local policy configuration, GERAN/UTRAN network to be dropped back to support the circuit-switched CS service and PS The service simultaneously transmits and receives, and the WLAN access capability of the UE. The method is simple and practical, and has high operability. Preferably, the determining, by the MME, that the base station does not notify the base station to initiate the PS domain handover according to the foregoing indication information and the foregoing predetermined condition may include: the MME sending a UE context modification message or a UE context release message (for example, an S1 release procedure) to the base station, to notify the base station not to perform the PS Domain switching. Further, the base station may receive a UE context modification message or an S1 release message from the MME, and send a connection release request message to the UE, where the following messages include an indication identifier for notifying that the PS service is allowed to be accessed from the WLAN: UE context Modify message, S1 release message, connection release request message. Further, after the base station sends the connection release request message to the UE, the UE receives the connection release request message from the base station, and determines to use the WLAN to establish a data connection to access the PS service according to the indication identifier carried in the connection release request message, and accesses the GE service/ The UTRAN network initiates a CS service, where the CS service includes a CS domain call procedure; or the UE receives the connection release request message from the base station, and determines that the GERAN/UTRAN indication is not included according to the connection release request message, and uses the WLAN to establish data. The connection connects the PS service and initiates the CS service to the GERAN/UTRAN network, where the CS service includes the CS domain call process. The method can instruct the UE to establish a data connection through the WLAN to access the PS service, and simultaneously drop the CS service to the GERAN/UTRAN network for implementation, thereby realizing the double-receiving and dual-issue of the PS service and the CS service, thereby improving the processing capability of the system. Preferably, in step 204, the MME may determine whether to access part of the PS service from the WLAN and reserve another part of the PS service in the 3GPP access system; if yes, the MME may adopt the following two modes: The UE returns a service request accept message, and the UE determines, according to the received service request accept message, a bearer that is accessed through the WLAN and/or a bearer that is reserved in the 3GPP access system, where the service request accept message is carried in the Information about the incoming PS service and/or information of the PS service retained in the 3GPP access system. Manner 2: The MME sends a bearer release request message to the UE by using the base station, where the bearer release request message carries an EPS status list, and the UE determines, according to the received bearer release request message from the base station, the bearer accessed through the WLAN and/or remains. The bearer in the 3GPP access system, wherein the EPS status list includes information indicating the PS service accessed through the WLAN and/or information indicating the PS service retained in the 3GPP access system. Preferably, before step 202, first, the UE may perform WLAN coverage detection in one of the following situations: Access Network Discovery and Selection Function (ANDSF) downloaded policy, previously received RFSP The priority of the WLAN indicated in the index, the terminal supporting the WLAN module and the EUTRAN access module work simultaneously; secondly, the UE may determine that there is currently WLAN coverage according to one of the following: the policy of the ANDSF, the WLAN module that has been activated detects the WLAN signal, A WLAN data connection has been established. In addition, before the UE determines whether there is currently WLAN coverage, the MME may obtain subscription data from a Home Subscriber Server (HSS), where the subscription data includes one of the following: indicating whether to allow the PS to be used in the CSFB process. Information that the service accesses from the WLAN; an RFSP index that defines the subscription of the WLAN to the access priority of the 3GPP. The method may enable the UE to determine whether it currently has WLAN coverage, so as to notify the MME that the PS service can be accessed through the WLAN, which is a prerequisite for the PS service to access through the WLAN. Corresponding to the foregoing method, an embodiment of the present invention further provides an MME. FIG. 3 is a structural block diagram of an MME according to an embodiment of the present invention. As shown in FIG. 3, the MME 30 includes: a receiving module 32, configured to receive a service request message from a UE by using a base station in a scenario of a CSFB, where The request message carries indication information indicating that the UE currently has WLAN coverage; and the determining module 34 is coupled to the receiving module 32, and is configured to determine to access the packet switched PS service from the WLAN according to the indication information. Through the foregoing MME 30, the determining module 34 accesses the PS service through the WLAN in the CSFB scenario, and solves the problem that the related technology cannot provide high quality for the user due to unclear flow of the decision-making PS service in the CSFB scenario. The problem of the PS service experience ensures that the CS domain and the PS domain service can be continuously accessed at the same time, improving the user experience of the PS service. According to an embodiment of the present invention, a UE is further provided. FIG. 4 is a structural block diagram of a UE according to an embodiment of the present invention. As shown in FIG. 4, the UE 40 includes: a sending module 42 that can be coupled to the receiving module 32 of the MME 30, and configured to send to the base station in a scenario of CSFB. The service request message, where the service request message carries indication information indicating that the UE 40 currently has WLAN coverage, and the MME 30 determines to access the PS service from the WLAN according to the indication information. According to an embodiment of the invention, an access system for offloading to a WLAN is also provided. FIG. 5 is a structural block diagram of an access system for offloading to a WLAN according to an embodiment of the present invention. The system includes a UE 40, a base station 52, and the foregoing MME 30, where the MME 30 further includes: a notification module 36, coupled to the determining module 34, It is configured to send a UE context modification message or a UE context release message to the base station 52 to notify the base station 52 not to perform PS domain handover. The base station 52 includes: a transceiver module 522 coupled to the notification module 36, configured to receive UE context modification from the MME 30. The message or the UE context release message is sent to the UE 40, and the following message includes an indication identifier for notifying the access to the PS service from the WLAN: the UE context modification message, the S1 release message, and the connection release request. And the UE 40 includes: a PS service access module 402, coupled to the transceiver module 522, configured to receive the connection release request message from the base station 52, and according to the indication carried in the connection release request message or without accessing the GERAN/ UTRAN indicates to determine to establish a data connection using WLAN to access PS service; and CS service initiation module 404, coupled To the transceiver module 522, set to GERAN / UTRAN CS network initiated service, wherein, the process including the CS service in the CS call. FIG. 6 is a block diagram of a preferred structure of an access system for offloading to a WLAN according to an embodiment of the present invention. As shown in FIG. 6, the determining module 34 of the MME 30 includes: a determining unit 342, configured to determine whether to connect part of the PS service from the WLAN. And the other part of the PS service is reserved in the 3GPP access system; the processing unit 344 is coupled to the determining unit 342, and is configured to return a service request accept message to the UE 40 if the determining unit 342 determines that the result is yes, where The service request accept message carries information indicating the PS service accessed through the WLAN and/or information of the PS service reserved in the 3GPP access system; or, in the case where the determination unit 342 determines that the result is YES, the base station passes The UE sends a bearer release request message to the UE 40, where the bearer release request message carries an EPS status list, which is used to indicate information of the PS service accessed through the WLAN and/or information of the PS service retained in the 3GPP access system; The UE 40 includes: a decision module 406, configured to determine to pass the WLAN according to the received service request accept message or the bearer release request message from the base station 52. Incoming bearers and/or bearers reserved in the 3GPP access system, wherein the service request accept message or the EPS status list includes information indicating PS services accessed through the WLAN and/or indications are reserved in the 3GPP access system. PS business information. The implementation process of the above embodiment will be described in detail below in conjunction with the preferred embodiments and the accompanying drawings. Embodiment 1 FIG. 7 is a schematic flowchart of a method for implementing all the PS services from the WLAN according to the first embodiment of the present invention. As shown in FIG. 7, the process includes the following steps: Step 700: In this process, the UE is attached to the EUTRAN through the EUTRAN. In the network, an SGs interface is established between the MME and the VLR. It should be noted that, in the process, the MME obtains the subscription data from the Home Subscriber Server (HSS), and the HSS indicates in the subscription data whether to allow the PS service to be connected from the WLAN in the CSFB process. In. Optionally, in the process, the UE may also report its WLAN access capability to the MME by using an attach request, or a Tracking Area Update (TAU) request. Step 701: The VLR receives a mobile terminal (Mobile Terminal, referred to as MT) as a called call, and sends a paging message to the MME through the SGs interface. Step 702 to step 704, the MME determines whether the UE is in a connected state. If the UE is in the connected state, the MME sends a CS service notification message to the terminal through the base station; if the UE is in the idle state, the MME paging (Paging) the UE through the base station. It should be noted that the UE described in this embodiment is in an idle state. For the process of the terminal actively initiating a CS call, step 701 704 is not required, and the subsequent steps are directly started from step 705. Step 705: The UE determines whether there is currently WLAN coverage. The UE determines whether there is currently WLAN coverage according to the policy downloaded from the ANDSF, or can start the WLAN module to detect whether there is currently WLAN coverage; or if the terminal supports the WLAN module and the EUTRAN access module to work simultaneously, the UE according to whether there is currently a WLAN connection Determine if there is WLAN coverage. It is assumed as follows that the result of the UE judgment is that there is WLAN coverage. Step 706: The UE sends a service request message to the MME through the base station, where the indication that the current WLAN coverage is present is carried. Step 707: The MME is configured according to at least one of the following conditions: an indication of current WLAN coverage, an indication of previous subscription acquisition, a local policy configuration, whether the GERAN/UTRAN network to be dropped back supports simultaneous CS/PS service transmission, and WLAN access of the terminal ability. It is judged whether the PS service is accessed from the WLAN in the process; if yes, the MME does not notify the base station to initiate the handover. Assume that the result of the MME judgment is YES as follows. Step 708: The MME initiates a UE context modification process, and notifies the eNB that the PS domain handover is not performed. If the message is received, the eNB needs to return a response to the MME. Alternatively, the MME initiates an S1 release process. In order to release the context of the UE, optionally, a new indication may be included to allow access to the PS service from the WLAN. Step 709: The base station initiates a connection release process of the air interface. Optionally, if an indication that the PS service is allowed to access from the WLAN is received in step 708, the indication is also included in the message. Step 710: After receiving the release request, the UE initiates the PS service to access from the WLAN. If the UE receives the indication, the foregoing operation is performed according to the indication; or, if the UE does not include special information (for example, accessing the GERAN/UTRAN indication), and the UE is confirmed to be the CSFB process, the foregoing operation is performed. Step 711: The UE initiates a CS service fallback and a WLAN data connection establishment. If there is already a WLAN data connection, the UE subsequently transmits all PS services on the connection. Step 712, the MME may initiate the detachment of the EPS and the release of the SGs connection after a period of time. The processes of steps 711 to 712 are similar to the prior art, and are not described herein. Embodiment 2 FIG. 8 is a schematic flowchart of a second method for implementing all the PS services from the WLAN according to the second embodiment of the present invention. As shown in FIG. 8, the process includes the following steps: Step 800: In this process, the UE passes The EUTRAN is attached to the network and an SGs interface is established between the MME and the VLR. It should be noted that, in the process, when the MME obtains the subscription data from the HSS, the HSS extends the support for the WLAN in the contracted RFSP index in the subscription data, that is, the WLAN and the 3GPP are delivered in the RFSP index. The priority index of the defined Radio Access Technology (RAT). Optionally, in the process, the UE may also report its WLAN access capability to the MME by using an attach request or a TAU request.

The MME generates the used RFSP index according to the local policy, the capability information of the UE, and the signed RFSP index. Optionally, the MME may send the used RFSP index to the base station, where the WLAN access priority order is used, and send the base station to the UE when the UE enters the idle state. If the impact of the extension of the RFSP index on the base station is avoided, the MME may send the used RFSP index without the WLAN access priority order to the base station. Step 801: The VLR receives the call as the called party, and sends a paging message to the MME through the SGs interface. Step 802 to step 804, the MME determines whether the UE is in the connected state. If the UE is in the connected state, the MME sends a CS service notification message to the terminal through the base station; if the UE is in the idle state, the MME pages the UE through the base station. It should be noted that the UE described in this embodiment is in an idle state. For the process of the terminal actively initiating a CS call, step 801 804 is not required, and the subsequent steps are directly started from step 805. In step 805, the UE determines whether there is currently WLAN coverage. The UE determines whether there is currently WLAN coverage according to the policy downloaded from the ANDSF; or may enable the WLAN module to detect whether there is currently WLAN coverage; or whether the terminal has included the priority of the WLAN according to the previously received RFSP index, and the priority thereof. The WLAN access module is activated, and the UE determines whether there is WLAN coverage at this time. Alternatively, if the terminal supports the WLAN module and the EUTRAN access module to work simultaneously, the UE determines whether there is WLAN coverage according to whether there is a WLAN connection currently. It is assumed as follows that the result of the UE judgment is that there is WLAN coverage. Step 806: The UE sends a service request message to the MME through the base station, where the indication that the current WLAN coverage is present is carried. Step 807: The MME is configured according to at least one of the following conditions: an indication of current WLAN coverage, an RFSP index obtained by previous subscription, a local policy configuration, whether the GERAN/UTRAN network to be dropped back supports CS/PS service simultaneous transmission and reception, and the terminal WLAN access capability. It is judged whether the PS service is accessed from the WLAN in the process. If yes, the MME does not notify the base station to initiate the handover. Assume that the result of the MME judgment is YES as follows. Step 808: The MME initiates a UE context modification process, and notifies the eNB that the PS domain handover is not performed. If the message is received, the eNB needs to return a response to the MME. Alternatively, the MME initiates an S1 release process. In order to release the context of the UE, an optional indication may be included to allow access to the PS service from the WLAN. Step 809: The base station initiates a connection release process of the air interface. Optionally, if an indication that the PS service is allowed to access from the WLAN is received in step 808, the indication is also included in the message. Step 810: After receiving the release request, the UE initiates the PS service to access from the WLAN. If the UE receives the indication, the foregoing operation is performed according to the indication; or, if the UE does not include the special information according to the release request, and the UE is confirmed to be the CSFB process, the foregoing operation is performed. In step 811, the UE initiates a CS service fallback and a WLAN data connection establishment. If there is already a WLAN data connection, the UE subsequently transmits all PS services on the connection. In step 812, the MME may initiate detachment of the EPS and release of the SGs connection after a period of time. The processes of steps 811 to 812 are similar to the prior art, and are not described herein. Embodiment 3 FIG. 9 is a schematic flowchart of a third method for implementing all routes of a PS service from a WLAN according to Embodiment 3 of the present invention. As shown in FIG. 9, the process includes the following steps: Steps 900 to 902, and FIG. 7 Steps 700 to 702 or steps 800 to 802 of FIG. 8 are similar, and are not described again. Step 903: The MME determines that the UE is in the connected state, and according to at least one of the following conditions: an indication of subscription acquisition (for example, Embodiment 1) or an RFSP index (for example, Embodiment 2), a local policy configuration, and a GERAN/UTRAN network to be dropped back to. Whether to support CS/PS service simultaneous transmission and reception, terminal WLAN access capability. It is judged whether the PS service is accessed from the WLAN in the process, and if so, the MME indicates the terminal in the CS service notification. Step 904, in addition to the steps described in step 705 in FIG. 7 and step 805 in FIG. 8, it is also possible to determine whether to perform WLAN signal detection according to the indication information in step 903. Step 905 to step 911, and step 706 to step 712 in FIG. 7 or step 806 to step in FIG.

Similar to 812, I will not repeat them. Embodiment 4 FIG. 10 is a schematic flowchart of a method for implementing a route for a PS service part to be routed from a WLAN according to Embodiment 4 of the present invention. As shown in FIG. 10, the process includes the following steps: Before step 1006, in FIG. 7, 8, and 9. Steps X00 to X06 (X stands for 7, 8, 9) are applicable to this embodiment. Step 1007: In addition to performing the judgments in FIG. 7, 8, and 9, the MME further determines whether only part of the PS is carried to the WLAN access, and the rest remains in the 3GPP access system. Step 1008: The MME returns a service request accept message to the terminal, where it indicates which bearers are reserved in the 3GPP access and which are accessed through the WLAN. In the implementation process, the MME can give such an indication to all bearers respectively, or indicate which needs to remain in the 3GPP access, then the remaining bearers are accessed through the WLAN, and vice versa. This indication can be represented by an EPS status list. Step 1009: The terminal determines, according to the network indication (can be a status list), which bearers are reserved in the 3GPP access and which are accessed through the WLAN. Step 1010: The MME initiates a bearer release procedure to the base station, and the base station simultaneously releases the bearer of the air interface. After the release is complete, the UE returns a bearer release response to the base station, and the base station returns a bearer release response to the MME. Step 1011: The MME sends a UE context modification procedure to the base station, and triggers a PS handover (Handover, referred to as HO) or a release process of the CSFB. The process is the same as the prior art, and is not described herein. Step 1012: The UE initiates a CS service fallback and a WLAN data connection establishment. If there is already a data connection of the WLAN, the UE will subsequently transmit the PS traffic that is not reserved in the 3GPP on the connection. Step 1013: The MME may initiate release of the bearer that is not reserved in the 3GPP after a period of time. The processes in steps 1012 to 1013 are similar to the prior art, and are not described herein. Embodiment 5 FIG. 11 is a schematic flowchart of a method for implementing a route of a PS service part from a WLAN according to Embodiment 5 of the present invention. As shown in FIG. 11, the process includes the following steps: Before step 1106, in FIG. 7, 8, and 9. Steps X00 to X06 (X stands for 7, 8, 9) are applicable to this embodiment. Step 1107: In addition to performing the judgments in FIG. 7, 8, and 9, the MME further determines whether only part of the PS is carried to the WLAN access, and the rest remains in the 3GPP access system. Step 1108 to step 1109, the MME sends a bearer release procedure to the base station, where it indicates which bearers are reserved in the 3GPP access and which are accessed through the WLAN. The base station sends a bearer release request to the terminal, which also indicates which bearers remain in the 3GPP access and which are accessed through the WLAN. In the implementation process, the foregoing indication manner may respectively give such indication to all bearers, or indicate which needs to remain in the 3GPP access, then the remaining bearers are accessed through the WLAN, and vice versa. Step 1110: The terminal determines, according to the network indication, which bearers are reserved in the 3GPP access and which are accessed through the WLAN. Step 1111: The UE initiates a CS service fallback and a WLAN data connection establishment. If there is already a data connection of the WLAN, the UE will subsequently transmit the PS traffic that is not reserved in the 3GPP on the connection. Step 1112: The MME may initiate release of the bearer that is not reserved in the 3GPP after a period of time. The processes in steps 1111 to 1112 are similar to the prior art, and are not described herein. In summary, the embodiment of the present invention adopts a method of accessing a PS service through a WLAN in a CSFB scenario, and solves the problem in the related art that the flow of the decision-making PS service on the terminal and the network side is unclear in the CSFB scenario. The problem of providing a high-quality PS service experience ensures that the CS domain and the PS domain service can be continuously accessed at the same time, improving the user experience of the PS service. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device so that they may be stored in the storage device by the computing device, or they may be separately fabricated into individual integrated circuit modules, or Multiple modules or steps are made into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

1. An access method for offloading to a WLAN of a wireless local area network, including:

In a scenario where the voice service falls back to the CSFB, the mobility management entity MME receives the service request message from the user equipment UE through the base station, where the service request message carries indication information indicating that the UE currently has WLAN coverage;

The MME determines to access the packet switched PS service from the WLAN according to the indication information.

2. The method according to claim 1, wherein the determining, by the MME, that the PS service is accessed from the WLAN according to the indication information comprises:

Determining, by the MME, that the base station does not notify the base station to initiate a PS domain handover according to the indication information and the predetermined condition, where the predetermined condition includes at least one of the following: an indication of a previously subscribed terminal that allows the terminal to switch the PS service to the WLAN, before The wireless access technology/frequency selection priority RFSP for the indication obtained by the subscription, the local policy configuration, whether the GERAN/UTRAN network to be dropped back supports the circuit switched CS service and the PS service simultaneously transmitting and receiving, the WLAN of the UE Access capability.

The method according to claim 2, wherein the determining, by the MME, that the eNB does not notify the base station to initiate the PS domain handover according to the indication information and the predetermined condition comprises:

And the MME sends a UE context modification message or a UE context release message to the base station to notify the base station not to perform the PS domain handover.

The method according to claim 3, wherein, after the MME sends the UE context modification message or the UE context release message to the base station, the method further includes:

Receiving, by the base station, the UE context modification message or the UE context release message from the MME, and sending the connection release request message to the UE, where the following messages are included to notify that the permission is allowed to be received from the WLAN. The indication identifier of the incoming PS service: the UE context modification message, the UE context release message, and the connection release request message.

The method of claim 4, after the sending, by the base station, the connection release request message to the UE, the method further includes:

The UE receives the connection release request message from the base station, and determines to use the WLAN to establish a data connection to connect the PS service according to the indication identifier carried in the connection release request message. Initiating a CS service to the GERAN/UTRAN network, where the CS service includes a CS domain call process; or

Receiving, by the UE, the connection release request message from the base station, and determining, according to the connection release request message, that the access to the GERAN/UTRAN indication is not included, the WLAN establishes a data connection to access the PS service, and accesses the GERAN/ The UTRAN network initiates a CS service, where the CS service includes a CS domain call procedure.

The method according to claim 1, wherein the determining, by the MME, that the PS service is accessed from the WLAN according to the indication information comprises:

The MME determines whether part of the PS service is accessed from the WLAN and another part of the PS service is retained in the 3rd Generation Partnership Project 3GPP access system;

If yes, the MME returns a service request accept message to the UE, and the UE determines, according to the received service request accept message, a bearer accessed through the WLAN and/or a bearer retained in the 3GPP access system, where And the service request accept message carries information indicating PS services accessed through the WLAN and/or information of PS services reserved in the 3GPP access system.

The MME determines whether part of the PS service is accessed from the WLAN and another part of the PS service is retained in the 3GPP access system;

If yes, the MME sends a bearer release request message to the UE by using the base station, where the bearer release request message carries an evolved packet system EPS state list, and the UE receives the received base station from the base station. The bearer release request message determines a bearer accessed by the WLAN and/or a bearer reserved in the 3GPP access system, where the EPS status list includes information indicating that the PS service accessed through the WLAN and/or the indication remains in the Information about PS services within the 3GPP access system.

The method according to any one of claims 1 to 7, wherein, before the MME receives the service request message from the UE by using the base station, the method further includes:

The UE performs WLAN coverage detection in one of the following situations:

Accessing the network discovery and selection function ANDSF downloading policy, the priority of the WLAN indicated in the previously received RFSP index, and the terminal supporting the WLAN module and the EUTRAN access module to work simultaneously; The UE determines that there is currently WLAN coverage according to one of the following:

The ANDSF policy, the activated WLAN module detects that there is a WLAN signal, and a WLAN data connection has been established.

The method according to claim 8, wherein the UE further determines whether the WLAN coverage is currently included, and the method further includes:

The MME obtains subscription data from the home subscriber server HSS, where the subscription data includes one of the following:

Information indicating whether to allow PS services to be accessed from the WLAN during the CSFB procedure; an RFSP index defining the subscription of the WLAN to the 3GPP access priority.

10. A mobility management entity MME, comprising:

The receiving module is configured to receive, by the base station, a service request message from the user equipment UE, where the service request message carries an indication for indicating that the UE currently has a WLAN coverage of the wireless local area network. Information;

A determining module is arranged to determine to connect the packet switched PS traffic from the WLAN based on the indication information.

11. A user equipment UE, comprising:

The sending module is configured to send a service request message to the base station in a scenario where the voice service falls back to the CSFB, where the service request message carries indication information used to indicate that the UE currently has a WLAN coverage of the wireless local area network, to improve mobility The management entity MME determines to access the packet switched PS service from the WLAN according to the indication information.

An access system for offloading to a WLAN, comprising a base station, a user equipment UE as claimed in claim 11, and a mobility management entity MME according to claim 10, wherein

The MME further includes: a notification module, configured to send a UE context modification message or a UE context release message to the base station, to notify the base station not to perform the PS domain handover;

The base station includes: a transceiver module, configured to receive the UE context modification message or the UE context release message from the MME, and send the connection release request message to the UE, where the following messages are included An indication identifier for notifying access to the PS service from the WLAN: the UE context modification message, the UE up and down release message, the connection release request message; The UE includes: a PS service access module, configured to receive the connection release request message from the base station, and according to the indication identifier carried in the connection release request message or without an access GERAN/UTRAN indication Determining to establish a data connection using a WLAN to access the PS service; and the circuit-switched CS service initiation module is configured to initiate a CS service to the GERAN/UTRAN network, where the CS service includes a CS domain call procedure.

13. The access system according to claim 12, wherein

The determining module of the MME includes: a determining unit, configured to determine whether to access part of the PS service from the WLAN and to reserve another part of the PS service in the 3rd Generation Partnership Project 3GPP access system; and processing unit, setting If the result of the determination by the determining unit is YES, the service request accept message is returned to the UE, where the service request accept message carries information and/or reserved for indicating the PS service accessed through the WLAN. The information of the PS service in the 3GPP access system; or, in the case that the judgment unit determines that the result is yes, the base station sends a bearer release request message to the UE, where the bearer release request message is Carrying an EPS status list for indicating information of a PS service accessed through the WLAN and/or information of a PS service retained in the 3GPP access system;

The UE includes: a decision module, configured to determine, according to the received service request accept message or the bearer release request message from the base station, a bearer accessed through a WLAN and/or retained in a 3GPP access system The bearer, where the service request accept message or the EPS status list includes information indicating a PS service accessed through the WLAN and/or information indicating a PS service retained in the 3GPP access system.