CN108464038B

CN108464038B - Circuit domain fallback method, base station, mobile management entity and terminal

Info

Publication number: CN108464038B
Application number: CN201780005485.5A
Authority: CN
Inventors: 何岳; 金辉; 杨皓睿; 欧阳国威
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-11-25
Filing date: 2017-06-08
Publication date: 2020-03-10
Anticipated expiration: 2037-06-08
Also published as: CN108464038A; WO2018095015A1

Abstract

The embodiment of the invention provides a circuit switched fallback method, a base station, a mobile management entity and a terminal. The method comprises the following steps: the base station receives a first message sent by a mobile management entity, wherein the first message is used for indicating that a first terminal of the base station needs circuit switched fallback. The base station determines a connection technology between the first terminal and the second terminal, and the base station sends a second message to the first terminal according to the connection technology, wherein the second message is used for indicating a circuit switched fallback mode of the first terminal. In the embodiment of the invention, when the base station determines that the first terminal and the second terminal are connected by adopting the non-3GPP technology through the indirect access technology indication information, the base station does not release the RRC connection between the base station and the first terminal, so that the first terminal can carry out the CS service and simultaneously carry out the PS service through the connection between the base station and the second terminal. And when the base station determines that the first terminal and the second terminal are connected by adopting the 3GPP technology, the base station enables the second terminal to reserve RRC context information, so that the PS service can be rapidly carried out after the CS service is finished.

Description

Circuit domain fallback method, base station, mobile management entity and terminal

The present application claims priority of the chinese patent application entitled "a method of circuit domain fallback" filed by the chinese intellectual property office patent office at 25/11/2016 under the reference number 201611064469.7, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method, a base station, a mobility management entity, and a terminal for circuit switched fallback.

Background

Wearable Devices (WD) are becoming more and more popular because they have the advantages of being intelligent, convenient to carry, attractive, fashionable and the like. Currently, the industry has introduced a watch that can be installed with a Subscriber Identity Module (SIM) card, which can be directly connected to the network and perform voice call services without the need for a connection to a handset. WD is a future trend to connect directly to the network and support voice call services. However, since WD is limited in size and has a small battery capacity, direct communication with the base station network results in fast battery consumption and short standby time. In addition, WD is usually special in shape and difficult in antenna design, and at present, only a single antenna can be realized, and under the condition of transmitting the same data volume, more time is needed and a lot of network resources are consumed compared with a multi-antenna device. Thus, WD is typically connected to the network through terminals to save power, increase the number of network connections and improve transmission efficiency. The terminal includes a device such as a mobile phone that can perform Packet Switch (PS) service.

Currently, the category of Voice call includes Voice over long term evolution (VoLTE) and Circuit Switched (CS) Voice services based on the long term evolution system. WD typically supports only CS voice traffic or supports both VoLTE voice traffic and CS voice traffic. When the WD and the network where the WD is located both support the VoLTE voice service, the WD may perform the VoLTE voice service through a relay link with the terminal after being connected to the terminal. However, when the network in which the WD and/or WD is located does not support VoLTE voice service, there is no solution in the prior art to the problem of using the WD already connected to the terminal for CS voice service in such a situation.

Disclosure of Invention

The embodiment of the invention provides a circuit switched fallback method, a base station, a mobile management entity and a terminal, and aims to solve the problem that a first terminal connected to a second terminal cannot perform voice call.

In a first aspect, an embodiment of the present invention provides a circuit switched fallback method. The method comprises the following steps: the base station receives a first message sent by a mobile management entity, wherein the first message is used for indicating that a first terminal of the base station needs circuit switched fallback. The base station determines a connection technology between the first terminal and the second terminal, and the base station sends a second message to the first terminal according to the connection technology, wherein the second message is used for indicating a circuit switched fallback mode of the first terminal.

In the method for circuit switched fallback provided by the embodiment of the present invention, after the base station receives a message indicating that the first terminal needs circuit switched fallback from the mobile management entity, the base station determines a connection technology between the first terminal rod and the second terminal, and sends a second message to the first terminal according to the connection technology to indicate a circuit switched fallback mode of the first terminal. The problem of among the prior art be connected to the first terminal of second terminal and can't carry out voice call is solved.

In one possible embodiment, the base station determines a connection technology between the first terminal and the second terminal, and includes: the base station determines a connection technology between the first terminal and the second terminal according to the context information of the first terminal; or the base station receives first indication information sent by the mobile management entity, and the base station determines a connection technology between the first terminal and the second terminal according to the first indication information; or the base station receives second indication information sent by the first terminal, and the base station determines the connection technology between the first terminal and the second terminal according to the second indication information. By adopting the embodiment, the base station can determine the connection technology between the first terminal and the second terminal, and further determine the content of the second message for indicating the circuit switched fallback mode of the first terminal.

In a possible implementation manner, a base station sends a second message to a first terminal according to a connection technology, where the second message is used to indicate a way for a circuit switched fallback of the first terminal, including: if the connection technology is non-third generation partnership project non-3GPP technology, the second message indicates that the first terminal reserves the radio resource control RRC connection with the base station when the circuit domain falls back; or, if the connection technology is 3GPP technology, the second message indicates that the first terminal suspends the RRC connection with the base station when the circuit switched fallback. By adopting the embodiment, when the base station determines that the first terminal and the second terminal are connected by adopting the non-3GPP technology through the indirect access technology indication information, the base station will not release the RRC connection between the base station and the first terminal, but send an RRC connection reconfiguration message to the first terminal, so that the first terminal can perform a PS service through the connection with the second terminal while dropping back to the circuit domain to perform the CS service according to the information of the 2G or 3G cell included in the message. And when the base station determines that the first terminal and the second terminal are connected by adopting the 3GPP technology through the indirect access technology indication information, the base station sends an RRC connection suspension message to the first terminal, so that the first terminal can fall back to the circuit domain according to the information of the 2G or 3G cell contained in the message to perform CS service. Meanwhile, the second terminal reserves RRC context information according to the RRC connection suspension message, so that the RRC connection between the second terminal and the base station can be recovered directly through a recovery (resume) message, and the time delay of user plane establishment is shortened. Therefore, the first terminal can quickly return to the previous communication network, such as the LTE network, for the PS service after the CS service is ended.

In one possible embodiment, if the connection technology is non-3GPP technology, the method further comprises: the base station does not release the RRC connection of the second terminal if the inactivity timer of the second terminal expires. By the embodiment, when the base station determines that the second terminal does not receive and send data, the second terminal cannot enter the idle state without starting the inactivity timer, so that the first terminal can be quickly accessed to the second terminal to perform PS (packet switched) service after the CS voice service is finished, and time and signaling consumption of the terminal entering the connection state from the idle state are saved.

In a second aspect, an embodiment of the present invention provides a method for circuit domain fallback. The method comprises the following steps: the mobile management entity receives a first message sent by a first terminal, wherein the first message is used for indicating that the first terminal needs circuit domain fallback. And the mobile management entity sends a second message to the base station, wherein the second message is used for indicating that the first terminal of the base station needs circuit switched fallback.

In one possible embodiment, the first message includes a connection technology between the first terminal and the second terminal.

In one possible embodiment, the second message includes a connection technology between the first terminal and the second terminal.

In a third aspect, an embodiment of the present invention provides a method for circuit domain fallback. The method comprises the following steps: the first terminal sends a first message to the mobile management entity, wherein the first message is used for indicating that the first terminal needs circuit domain fallback. And the first terminal receives a second message sent by the base station, wherein the second message is used for indicating the circuit switched fallback mode of the first terminal, and the first terminal performs circuit switched fallback according to the second message.

In a possible implementation manner, the performing, by the first terminal, a circuit domain fallback according to the second message includes: the first terminal reserves the Radio Resource Control (RRC) connection with the base station when the circuit switched fallback; or, the first terminal suspends the RRC connection with the base station when the circuit switched fallback.

In a fourth aspect, an embodiment of the present invention provides a base station, where the base station may implement a function executed by the base station in the application program authorization method in the first aspect, and the function may be implemented by hardware or may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

In one possible design, the base station includes a receiving module, a transmitting module, and a processing module. The receiving module is used for receiving a first message sent by the mobile management entity, wherein the first message is used for indicating that the first terminal of the base station needs circuit switched fallback. The processing module is used for determining a connection technology between the first terminal and the second terminal. The sending module is used for sending a second message to the first terminal according to the connection technology, wherein the second message is used for indicating the circuit switched fallback mode of the first terminal.

In one possible design, the processing module is further to: determining a connection technology between the first terminal and the second terminal according to the context information of the first terminal; or after the receiving module receives the first indication information sent by the mobility management entity, determining a connection technology between the first terminal and the second terminal according to the first indication information; or after the receiving module receives the second indication information sent by the first terminal, determining the connection technology between the first terminal and the second terminal according to the second indication information.

In one possible design, the sending module is further configured to: after the processing module determines that the connection technology is non-third generation partnership project (non-3 GPP) technology, sending a second message to the first terminal according to the connection technology, wherein the second message indicates that the first terminal reserves Radio Resource Control (RRC) connection with the base station when the circuit domain falls back; or after the processing module determines that the connection technology is the 3GPP technology, sending a second message to the first terminal according to the connection technology, where the second message indicates that the first terminal suspends the RRC connection with the base station when the circuit switched fallback is performed.

In one possible design, the processing module is further configured to not release the RRC connection of the second terminal if the inactivity timer of the second terminal expires after determining that the connection technology is non-3GPP technology.

In a fifth aspect, an embodiment of the present invention provides a mobility management entity, where the mobility management entity may implement a function executed by the mobility management entity in the application authorization method of the first aspect, and the function may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

In one possible design, the mobility management entity includes a receiving module and a sending module. The receiving module is used for receiving a first message sent by the first terminal, and the first message is used for indicating that the first terminal needs circuit domain fallback. And the sending module is used for sending a second message to the base station, wherein the second message is used for indicating that the first terminal of the base station needs circuit switched fallback.

In one possible design, the first message includes a connection technology between the first terminal and the second terminal.

In one possible design, the second message includes a connection technology between the first terminal and the second terminal.

In a sixth aspect, an embodiment of the present invention provides a terminal, where the terminal may implement a function executed by the terminal in the application program authorization method in the first aspect, and the function may be implemented by hardware or may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

In one possible design, the terminal includes a receiving module, a transmitting module, and a processing module. The sending module is used for sending a first message to the mobile management entity, wherein the first message is used for indicating that the first terminal needs circuit domain fallback. The receiving module is used for receiving a second message sent by the base station, wherein the second message is used for indicating the fallback mode of the first terminal circuit domain. The processing module is used for performing circuit switched fallback according to the second message.

In one possible design, the processing module is further to: reserving Radio Resource Control (RRC) connection between the base station and the circuit switched fallback; or, suspending the RRC connection with the base station when the circuit switched fallback.

In a seventh aspect, an embodiment of the present invention provides a base station, where the base station may implement a function executed by the base station in the application program authorization method in the first aspect, and the function may be implemented by hardware or may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

In one possible design, the base station includes a processor, a memory, and a communication interface. The memory is for storing program instructions. The processor is configured to perform the following operations according to program instructions stored in the memory: the method comprises the steps that a communication interface is indicated to receive a first message sent by a mobile management entity, wherein the first message is used for indicating that a first terminal of a base station needs circuit switched fallback; and determining a connection technology between the first terminal and the second terminal, and indicating the communication interface to send a second message to the first terminal according to the connection technology, wherein the second message is used for indicating a circuit switched fallback mode of the first terminal.

In one possible design, the processor is further configured to perform the following operations according to the program instructions stored in the memory: determining a connection technology between the first terminal and the second terminal according to the context information of the first terminal; or, the indication communication interface receives first indication information sent by the mobility management entity, and determines a connection technology between the first terminal and the second terminal according to the first indication information; or, the indication communication interface receives second indication information sent by the first terminal, and determines the connection technology between the first terminal and the second terminal according to the second indication information.

In one possible design, the processor is further configured to perform the following operations according to the program instructions stored in the memory: determining that the connection technology is a non-third generation partnership project (non-3 GPP) technology, and indicating a communication interface to send a second message to the first terminal according to the connection technology, wherein the second message indicates that the first terminal reserves Radio Resource Control (RRC) connection with the base station when the circuit domain falls back; or, determining that the connection technology is the 3GPP technology, and instructing the communication interface to send a second message to the first terminal according to the connection technology, where the second message instructs the first terminal to suspend the RRC connection with the base station when the circuit switched fallback.

In one possible design, the processor is further configured to perform the following operations according to the program instructions stored in the memory: determining the connection technology to be non-3GPP technology, and if the inactivity timer of the second terminal is overtime, not releasing the RRC connection of the second terminal.

In an eighth aspect, an embodiment of the present invention provides a mobility management entity, where the mobility management entity may implement a function executed by the mobility management entity in the application authorization method of the first aspect, and the function may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

In one possible design, the mobility management entity includes a processor, a memory, and a communication interface. The memory is for storing program instructions. The processor is configured to perform the following operations according to program instructions stored in the memory: the method comprises the steps that a communication interface is indicated to receive a first message sent by a first terminal, and the first message is used for indicating that the first terminal needs circuit domain fallback; and indicating the communication interface to receive a second message sent to the base station, wherein the second message is used for indicating that the first terminal of the base station needs circuit switched fallback.

In a ninth aspect, an embodiment of the present invention provides a terminal, where the terminal may implement the function executed by the terminal in the application program authorization method in the first aspect, and the function may be implemented by hardware or may be implemented by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions.

In one possible design, the terminal includes a processor, a memory, and a communication interface. The memory is for storing program instructions. The processor is configured to perform the following operations according to program instructions stored in the memory: indicating a communication interface to send a first message to a mobile management entity, wherein the first message is used for indicating that a first terminal needs circuit domain fallback; the communication interface is indicated to receive a second message sent by the base station, and the second message is used for indicating the circuit switched fallback mode of the first terminal; and performing circuit switched fallback according to the second message.

In one possible design, the processor is further configured to perform the following operations according to the program instructions stored in the memory: reserving Radio Resource Control (RRC) connection between the base station and the circuit switched fallback; or, suspending the RRC connection with the base station when the circuit switched fallback.

Compared with the prior art, in the method for circuit switched fallback provided by the embodiment of the present invention, the first terminal sends the CSFB indication information and the indirect access technology indication information to the base station through the mobility management entity; or after the first terminal sends the CSFB instruction information to the base station through the mobility management entity, the base station sends an indirect access technology query request message to the first terminal, and receives the indirect access technology instruction information from the first terminal. And the base station determines the connection technology between the first terminal and the second terminal according to the indirect access technology indication information. When the base station determines that the first terminal and the second terminal are connected by adopting the non-3GPP technology through the indirect access technology indication information, the base station does not release the RRC connection between the base station and the first terminal, but sends an RRC connection reconfiguration message to the first terminal, so that the first terminal can perform the PS service through the connection with the second terminal while falling back to the circuit domain to perform the CS service according to the information of the 2G or 3G cell contained in the message. And when the base station determines that the first terminal and the second terminal are connected by adopting the 3GPP technology through the indirect access technology indication information, the base station sends an RRC connection suspension message to the first terminal, so that the first terminal can fall back to the circuit domain according to the information of the 2G or 3G cell contained in the message to perform CS service. Meanwhile, the second terminal reserves RRC context information according to the RRC connection suspension message, so that the RRC connection between the second terminal and the base station can be recovered directly through a recovery (resume) message, and the time delay of user plane establishment is shortened. Therefore, the first terminal can quickly return to the previous communication network, such as the LTE network, for the PS service after the CS service is ended.

Drawings

Fig. 1 is a diagram of an environment for using a wearable device according to an embodiment of the present invention;

fig. 2 is a communication schematic diagram of a circuit switched fallback method according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a wearable device simultaneously performing a CS voice service and a PS service according to an embodiment of the present invention;

fig. 4 is a communication diagram of another circuit switched fallback method according to an embodiment of the present invention;

fig. 5 is a communication diagram of another circuit domain fallback method according to an embodiment of the present invention;

fig. 6 is a communication diagram of another circuit switched fallback method according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a base station according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a mobility management entity according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a terminal according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of another base station according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of another mobility management entity according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of another terminal according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention.

It should be noted that the first terminal in the embodiment of the present invention may be a wearable device, such as any one of multiple devices including a smart watch, a smart bracelet, and smart glasses, and the first terminal may send a wireless signal to the base station through its own radio frequency circuit and antenna, and may also perform data communication with the second terminal through a wireless communication manner such as bluetooth. The second terminal may be a device such as a mobile phone that can perform PS service.

Fig. 1 is a usage environment diagram of a wearable device according to an embodiment of the present invention. The embodiment of the present invention may be applied to the scenario shown in fig. 1, and the embodiment of the present invention relates to a first terminal, where the first terminal may be a wearable device 10, and the wearable device 10 may wirelessly communicate with a network side base station 11 and a core network device 13, or wirelessly communicate with a terminal 12. For example, the wearable device 10 may send a wireless signal to the base station 11 through the wireless communication link 14 through its own radio frequency circuit and antenna, and request the base station 11 to perform a wireless network service to process a specific service requirement of the wearable device 10; for another example, the wearable device 10 may match with the terminal 12 through its own bluetooth, and perform data communication with the mobile phone through the bluetooth communication link 15 after the matching is successful, or certainly perform data communication with the mobile phone through other wireless communication methods, such as a radio frequency identification technology, a short-range wireless communication technology, and the like.

In the embodiment of the present invention, the base station 11 is an evolved Node B (eNB) in a Long Term evolution (Long Term evolution, LTE) system or a Radio Access Network (RAN) of 5G.

In the embodiment of the present invention, the core network device 13 may be a Mobility Management Entity (MME), a service GateWay (S-GW), a Public Data GateWay (P-GW), or a Serving GateWay Node (Cellular Internet of gateways-Serving GateWay Node, C-SGN).

In the method for circuit switched fallback provided by the embodiment of the present invention, a first terminal sends CSFB indication information and indirect access technology indication information to a base station through a mobility management entity; or after the first terminal sends the CSFB instruction information to the base station through the mobility management entity, the base station sends an indirect access technology query request message to the first terminal, and receives the indirect access technology instruction information from the first terminal. And the base station determines the connection technology between the first terminal and the second terminal according to the indirect access technology indication information. When the base station determines that the first terminal and the second terminal are connected by adopting the non-3GPP technology through the indirect access technology indication information, the base station does not release the RRC connection between the base station and the first terminal, but sends an RRC connection reconfiguration message to the first terminal, so that the first terminal can perform the PS service through the connection with the second terminal while falling back to the circuit domain to perform the CS service according to the information of the 2G or 3G cell contained in the message. And when the base station determines that the first terminal and the second terminal are connected by adopting the 3GPP technology through the indirect access technology indication information, the base station sends an RRC connection suspension message to the first terminal, so that the first terminal can fall back to the circuit domain according to the information of the 2G or 3G cell contained in the message to perform CS service. Meanwhile, the second terminal reserves RRC context information according to the RRC connection suspension message, so that the RRC connection between the second terminal and the base station can be recovered directly through a recovery (resume) message, and the time delay of user plane establishment is shortened. Therefore, the first terminal can quickly return to the previous communication network, such as the LTE network, for the PS service after the CS service is ended.

Fig. 2 is a communication schematic diagram of a circuit switched fallback method according to an embodiment of the present invention. As shown in fig. 2, this embodiment may include:

step 201, the first terminal sends an Extended Service Request (ESR) message to the mobility management entity, where the ESR message carries Circuit Switched Fallback (CSFB) Indication information and Indirect Access technology Indication (Indirect Access technology Indication) information.

It should be noted that the ESR message is used to request an extended service. The CSFB indication message is used to indicate that the first terminal is ready to initiate a circuit switched fallback service, where the circuit switched fallback service includes a CSFB calling service, a CSFB called service, and the like. The indirect access technology indication message is used for indicating a connection technology between the first terminal and the second terminal, the connection technology is a non-third Generation Partnership Project (3 GPP) technology or a 3GPP technology, and the first terminal establishes a communication connection with the base station through the second terminal.

Illustratively, the non-3GPP technologies include Bluetooth (BT) technology, Wireless-Fidelity (Wi-Fi) technology, and other Wireless communication technologies.

Illustratively, 3GPP technologies include Device-to-Device (D2D) technologies and like communication technologies.

For example, in step 201, the first terminal may send the ESR message to the mobility management entity by: the first terminal sends an ESR message to the second terminal, which sends the ESR message to the mobility management entity.

In step 202, the base station receives a terminal context modification Request (UE context modification Request) message from the mobility management entity, where the terminal context modification Request message carries the CSFB indication information and the indirect access technology indication information.

It should be noted that the terminal context modification request message is used to request the base station to modify the context of the first terminal. The context of the first terminal includes Radio Resource Control (RRC) connection information or an access bearer between the serving gateway and the base station.

Illustratively, after step 202, the method may further include: the base station sends a terminal context Modification request (UE context Modification Response) message to the mobility management entity, where the message is used to inform the mobility management entity: the base station has received the terminal context modification request information and will continue processing according to the request information.

Optionally, in step 203, the base station receives a measurement report of a cell of a second Generation mobile phone communication technology (2-Generation wireless telephone technology, 2G) or a cell of a third Generation mobile communication technology (3rd-Generation, 3G) from the first terminal, and determines the target cell according to the measurement report. The target cell is a cell to which the first terminal needs to access in the circuit switched fallback process.

The first terminal is generally in a Single Radio frequency (SR) mode, i.e., can receive only a Radio signal of one carrier frequency at one time point, and thus cannot simultaneously camp on a 4rd-Generation mobile communication technology (4G) cell and a 2G cell, or a 4G cell and a 3G cell. In the 2G communication technology and the 3G communication technology, a core network is divided into a CS domain and a Packet Switch (PS) domain, and a first terminal may perform a voice service in the CS domain through a circuit signal and perform a data service in the PS domain through an Internet Protocol (IP) Packet. In the 4G communication technology, the CS domain is cancelled, and the first terminal cannot perform a voice service by entering the CS domain when accessing the 4G cell.

In step 204, the base station determines that the indirect access technology indication information indicates that the connection technology between the first terminal and the second terminal is a non-3GPP technology, and sends an RRC connection reconfiguration message to the first terminal.

The RRC connection reconfiguration message is used to reconfigure the radio resource control connection of the first terminal. And the RRC reconfiguration message sent by the base station to the first terminal carries the access information of the target cell. For example, the access information of the target cell may come from the access information of the target cell determined by the base station according to the measurement report received from the first terminal in step 203. For another example, the base station does not receive the measurement report of the 2G or 3G cell from the first terminal, i.e. step 203 is not performed, and the base station has stored the access information of the target cell.

Illustratively, in step 204, the base station may further determine, through the context information of the first terminal, that the connection technology between the first terminal and the second terminal is a non-3GPP technology, and send an RRC connection reconfiguration message to the first terminal.

For example, in step 204, the sending, by the base station, the RRC connection reconfiguration message to the first terminal may be: and the base station sends the RRC connection reconfiguration message to the second terminal, and the second terminal sends the RRC connection reconfiguration message to the first terminal.

Illustratively, after step 204, the method may further include: the base station receives an RRC connection reconfiguration complete message from the first terminal. Or, the second terminal receives the RRC connection reconfiguration complete message from the first terminal, and the base station receives the RRC connection reconfiguration complete message from the second terminal. Wherein, the RRC connection reconfiguration complete message is used to inform the base station: the first terminal has completed the RRC connection reconfiguration.

Illustratively, after step 204, the method may further include: and the first terminal accesses the target cell according to the access information of the target cell carried in the RRC reconfiguration message.

It should be noted that, in step 204, after the base station determines that the connection technology between the first terminal and the second terminal is the non-3GPP technology, it will not release its RRC connection with the first terminal. Accordingly, the first terminal can perform the PS service on the communication system using the communication link connected with the second terminal while performing the CS voice service through the link directly connected with the base station. For example, as shown in fig. 3, the first terminal establishes a connection with the base station through a 3GPP radio frequency based on a 2G/3G protocol stack and performs a CS voice service. Meanwhile, based on a Packet Data Convergence Protocol (PDCP), a Radio Link Control (RLC), a Media Access Control (MAC) and Physical Layer (PHY), and a bluetooth Protocol stack, PS services are performed on a communication system through bluetooth Radio frequency. The communication system may be a Long Term Evolution (LTE) communication system or other communication systems.

In the method for circuit switched fallback provided by the embodiment of the present invention, a first terminal sends CSFB indication information and indirect access technology indication information to a base station through a mobile management entity, and when the base station determines that the first terminal and a second terminal are connected by using a non-3GPP technology through the indirect access technology indication information, the base station does not release the RRC connection between the first terminal and the first terminal, but sends an RRC connection reconfiguration message to the first terminal, so that the first terminal can fall back to a circuit switched domain according to information of a 2G or 3G cell included in the message to perform a CS service, and can also perform a PS service through the connection with the second terminal.

Fig. 4 is a communication diagram of another circuit switched fallback method according to an embodiment of the present invention. As shown in fig. 4, this embodiment may include:

step 401, the first terminal sends an ESR message to the mobility management entity, where the ESR message carries circuit switched fallback CSFB indication information.

It should be noted that the ESR message is used to request an extended service. The CSFB indication message is used to indicate that the first terminal is ready to initiate a circuit switched fallback service, where the circuit switched fallback service includes a CSFB calling service, a CSFB called service, and the like.

In step 402, the base station receives a terminal context modification request message from the mobility management entity, where the terminal context modification request message includes CSFB indication information.

It should be noted that the terminal context modification request message is used to request the base station to modify the context of the first terminal. Wherein the context of the first terminal includes RRC connection information or an access bearer between the serving gateway and the base station.

Illustratively, after step 402, the method may further include: the base station sends a context modification request response message of the first terminal to the mobile management entity, wherein the message is used for informing the mobile management entity to: the base station has received the context modification request information of the first terminal and will continue processing according to the request information.

Optionally, in step 403, the base station receives a measurement report of the 2G or 3G cell from the first terminal, and determines the target cell according to the measurement report. The target cell is a cell to which the first terminal needs to access in the circuit switched fallback process.

For a detailed description of step 403, reference may be made to the description of step 203 in the foregoing embodiment, which is not described herein again.

In step 404, the base station sends an Indirect Access technology query request (index Access TechInquiry) message to the first terminal.

It should be noted that the indirect access technology query request message is used to request to query a connection technology between the first terminal and the second terminal, where the connection technology is a non-3GPP technology or a 3GPP technology, and the first terminal establishes a communication connection with the base station through the second terminal. For the description of 3GPP technology or 3GPP technology, please refer to the above, which is not described herein.

Illustratively, before step 404, the method may further include: the base station determines that the first terminal is establishing a communication connection with the base station through the second terminal. For example, in step 402, after receiving the terminal context request message from the mobility management entity, the base station queries information stored in the base station about a first terminal that sent the terminal context request message to the mobility management entity, and determines that the first terminal is establishing a communication connection with the base station through a second terminal. For another example, in step 402, after receiving the terminal context modification request message from the mobility management entity, the base station queries the information about the second terminal that has sent the terminal context modification request message to the mobility management entity, and determines that the first terminal is hung under the second terminal.

In step 405, the base station receives an Indirect access technology query request Response (Indirect access technology Response) message from the first terminal, where the Indirect access technology query request Response message carries Indirect access technology indication information.

It should be noted that the indirect access technology query request response message is used to inform the base station: the first terminal has received the indirect access technology query request message and completed the indirect access technology query. The indirect access technology indication message is used for indicating a connection technology between the first terminal and the second terminal.

In step 406, the base station determines that the indirect access technology indication information indicates that the connection technology between the first terminal and the second terminal is a non-3GPP technology, and sends an RRC connection reconfiguration message to the first terminal.

For a detailed description of step 406, reference may be made to the description of step 204 in the foregoing embodiment, which is not described herein again.

In the method for circuit switched fallback provided by the embodiment of the present invention, after a first terminal sends CSFB indication information to a base station through a mobility management entity, the base station sends an indirect access technology query request message to the first terminal, and receives the indirect access technology indication information from the first terminal. When the base station determines that the first terminal and the second terminal are connected by adopting the non-3GPP technology through the indirect access technology indication information, the base station does not release the RRC connection between the base station and the first terminal, but sends an RRC connection reconfiguration message to the first terminal, so that the first terminal can perform the PS service through the connection with the second terminal while falling back to the circuit domain to perform the CS service according to the information of the 2G or 3G cell contained in the message.

Fig. 5 is a communication diagram of another circuit domain fallback method according to an embodiment of the present invention. As shown in fig. 5, this embodiment may include:

step 501, a first terminal sends an extended service request ESR message to a mobility management entity, where the ESR message carries CSFB indication information and indirect access technology indication information.

In step 502, the base station receives a terminal context modification request message from the mobility management entity, where the terminal context modification request message includes CSFB indication information and indirect access technology indication information.

Optionally, in step 503, the base station receives a measurement report of the 2G or 3G cell from the first terminal, and determines the target cell according to the measurement report. The target cell is a cell to which the first terminal needs to access in the circuit switched fallback process.

It should be noted that, for specific descriptions of step 501, step 502, and step 503, reference is made to the description of step 201, step 202, and step 203 in the foregoing embodiment, and details are not described here.

In step 504, the base station determines that the indirect access technology indication information indicates that the connection technology between the first terminal and the second terminal is the 3GPP technology, and sends an RRC connection Suspend message to the first terminal.

It should be noted that the RRC connection suspend message is used to request the first terminal to reserve the context of the RRC connection. The RRC connection suspension message sent by the base station to the first terminal carries the access information of the target cell. For example, the access information of the target cell may come from the access information of the target cell determined by the base station according to the measurement report received from the first terminal in step 503. For another example, the base station does not receive the measurement report of the 2G or 3G cell from the first terminal, i.e. step 503 is not performed, but the base station already stores the access information of the target cell.

Illustratively, step 504 may also be that the base station determines, through the context information of the first terminal, that the connection technology between the first terminal and the second terminal is a 3GPP technology, and sends an RRC connection suspend message to the first terminal.

For example, in step 504, the base station sends an RRC connection suspend message to the first terminal, which may be: and the base station sends the RRC connection suspension message to the second terminal, and the second terminal sends the RRC connection suspension message to the first terminal.

Illustratively, after step 504, the method may further include: the base station sends a terminal context modification request response message and an RRC connection suspension completion message to the mobility management entity. The terminal context modification request response message is used for informing the mobility management entity to: the base station has received the terminal context modification request information and will continue processing according to the request information. The RRC connection suspend complete message is used to inform the mobility management entity: the base station has completed the RRC connection suspension, i.e. the RRC connection context is preserved at the base station and the first terminal device.

The suspend (suspend) state means: the base station side and the first terminal side retain context information of the RRC connection, respectively, but cannot use the RRC connection. When the first terminal is in a suspended state, the RRC connection with the base station can be directly recovered through a recovery (resume) message, so as to shorten the time delay of the user plane establishment, and thus the first terminal can quickly return to the previous communication network, such as an LTE network, after the CS voice is ended.

Illustratively, after step 504, the method may further include: the inactivity timer of the second terminal expires and the base station does not release the RRC connection of said second terminal. In general, after determining that the second terminal does not perform data receiving and transmitting services, the base station starts an inactive timer in order to save channel resources and power consumption of the terminal, and when the inactive timer records that the time when the second terminal does not perform data receiving and transmitting services reaches a predetermined time limit, the base station releases the second terminal to enter an idle state. When the second terminal enters the connected state from the idle state, the RRC connection needs to be re-established through related signaling of the RRC connection. In the embodiment of the invention, when the base station determines that the second terminal does not receive and send data, the base station does not start the inactive timer, and the second terminal cannot enter the idle state, so that the first terminal can be quickly accessed to the second terminal to perform PS (packet switched) service after the CS voice service is finished, and the time and signaling consumption of the terminal entering the connection state from the idle state are saved.

In step 505, the mme sends a Release Access Bearer Request (Release Access Bearer Request) message to the Serving GateWay (SGW).

It should be noted that the release access bearer request message is used to request the serving gateway to release the access bearer between the serving gateway and the base station.

Illustratively, after step 505, the method may further include: the mobility management entity receives a Release Access Bearer request Response (Release Access Bearer Response) message from the SGW, where the message is used to inform the mobility management entity to: the SGW has released the access bearer with the base station.

In the method for circuit switched fallback provided by the embodiment of the present invention, a first terminal sends CSFB indication information and indirect access technology indication information to a base station through a mobile management entity, and when the base station determines that the first terminal and a second terminal are connected by using a 3GPP technology through the indirect access technology indication information, the base station sends an RRC connection suspend message to the first terminal, so that the first terminal can fall back to a circuit switched fallback according to information of a 2G or 3G cell included in the message to perform a CS service. Meanwhile, the second terminal reserves RRC context information according to the RRC connection suspension message, so that the RRC connection between the second terminal and the base station can be recovered directly through a recovery (resume) message, and the time delay of user plane establishment is shortened. Therefore, the first terminal can quickly return to the previous communication network, such as the LTE network, for the PS service after the CS service is ended.

Fig. 6 is a communication diagram of another circuit domain fallback method according to an embodiment of the present invention. As shown in fig. 6, this embodiment may include:

step 601, the first terminal sends an ESR message to the mobility management entity, where the ESR message carries the CSFB instruction information.

In step 602, the base station receives a terminal context modification request message from the mobility management entity, where the terminal context modification request message includes CSFB indication information.

Optionally, in step 603, the base station receives information of at least one cell accessible in the circuit switched fallback process from the first terminal, and the base station determines a cell to be accessed according to the information of the at least one cell accessible.

In step 604, the base station sends an indirect access technology query request message to the first terminal.

Step 605, the base station receives an indirect access technology query request response message from the first terminal, where the indirect access technology query request response message carries indirect access technology indication information.

It should be noted that for a detailed description of the steps 601-605, refer to the description of the steps 401-405 in the foregoing embodiment, which is not repeated herein.

Step 606, the base station determines that the indirect access technology indication information indicates that the connection technology between the first terminal and the second terminal is the 3GPP technology, and sends an RRC connection suspend message to the first terminal.

In step 607, the mobility management entity sends a release access bearer request message to the SGW.

It should be noted that, for concrete introduction of steps 606 and 607, refer to the description of steps 504 and 505 in the above embodiments, which are not described herein again.

In the method for circuit switched fallback provided by the embodiment of the present invention, after a first terminal sends CSFB indication information to a base station through a mobility management entity, the base station sends an indirect access technology query request message to the first terminal, and receives the indirect access technology indication information from the first terminal. When the base station determines that the first terminal and the second terminal are connected by adopting the 3GPP technology through the indirect access technology indication information, the base station sends an RRC connection suspension message to the first terminal, so that the first terminal can fall back to a circuit domain according to the information of the 2G or 3G cell contained in the message to perform CS service. Meanwhile, the second terminal reserves RRC context information according to the RRC connection suspension message, so that the RRC connection between the second terminal and the base station can be recovered directly through a recovery (resume) message, and the time delay of user plane establishment is shortened. Therefore, the first terminal can quickly return to the previous communication network, such as the LTE network, for the PS service after the CS service is ended.

The method for circuit switched fallback according to the embodiment of the present invention is described in detail above with reference to fig. 1 to 6, and the base station, the mobility management entity, and the terminal according to the embodiment of the present invention are described in detail below with reference to fig. 7.

Fig. 7 is a schematic structural diagram of a base station according to an embodiment of the present invention. The base station 700 may include a transmitting module 701, a receiving module 702, and a processing module 703.

Those skilled in the art will appreciate that fig. 7 merely illustrates a simplified design of the structure of a base station. The base station structure shown in fig. 7 does not constitute a limitation of the base station, which may comprise more or less components than those shown in fig. 7, for example, the base station may further comprise a storage module for storing instructions corresponding to a communication algorithm, and further, in order to save a chip area, the receiving module 702 and the transmitting module 701 may be integrated together to form a transceiver.

As shown in fig. 7, the receiving module 702 is configured to receive a first message sent by a mobility management entity, where the first message is used to indicate that the first terminal of the base station needs circuit domain fallback. The processing module 703 is configured to determine a connection technology between the first terminal and the second terminal. The sending module 701 is configured to send a second message to the first terminal according to the connection technology, where the second message is used to indicate a fallback mode of the circuit domain of the first terminal.

Illustratively, the processing module 703 is further configured to: determining a connection technology between the first terminal and the second terminal according to the context information of the first terminal; or, after the receiving module 702 receives the first indication information sent by the mobility management entity, determining a connection technology between the first terminal and the second terminal according to the first indication information; alternatively, after the receiving module 702 receives the second indication information sent by the first terminal, the connection technology between the first terminal and the second terminal is determined according to the second indication information.

Illustratively, the sending module 701 is further configured to: after the processing module 703 determines that the connection technology is non-3GPP technology, sending a second message to the first terminal according to the connection technology, where the second message indicates that the first terminal reserves radio resource control RRC connection with the base station when the circuit switched fallback; or, after the processing module 703 determines that the connection technology is the 3GPP technology, sending a second message to the first terminal according to the connection technology, where the second message indicates that the first terminal suspends the RRC connection with the base station when the circuit switched fallback.

Illustratively, the processing module 703 is further configured to not release the RRC connection of the second terminal if the inactivity timer of the second terminal expires after determining that the connection technology is non-3GPP technology.

The base station provided by the embodiment of the invention determines the connection technology between the first terminal and the second terminal according to the indirect access technology indication information received from the first terminal or the mobile management entity. When the base station determines that the connection technology is the non-3GPP technology, the base station does not release the RRC connection with the first terminal, but sends an RRC connection reconfiguration message to the first terminal, so that the first terminal can perform a CS service by falling back to a circuit domain according to the information of the 2G or 3G cell contained in the message, and simultaneously can perform a PS service by connecting with the second terminal. When the base station determines that the connection technology is the 3GPP technology, the base station sends an RRC connection suspension message to the first terminal, so that the first terminal can fall back to a circuit domain according to the information of the 2G or 3G cell contained in the message to perform CS service. Meanwhile, the second terminal reserves RRC context information according to the RRC connection suspension message, so that the RRC connection between the second terminal and the base station can be recovered directly through a recovery (resume) message, and the time delay of user plane establishment is shortened. Therefore, the first terminal can quickly return to the previous communication network, such as the LTE network, for the PS service after the CS service is ended.

Fig. 8 is a schematic structural diagram of a mobility management entity according to an embodiment of the present invention. The mobility management entity 800 may include a sending module 801 and a receiving module 802.

It will be appreciated by those skilled in the art that fig. 8 merely illustrates a simplified design of the structure of the mobility management entity. The mobility management entity structure shown in fig. 8 does not constitute a limitation of the mobility management entity, which may comprise more or less components than those shown in fig. 8, for example, the mobility management entity may further comprise a storage module for storing instructions corresponding to the communication algorithm. Also for example, a processing module 803 may be included for processing operations in accordance with instructions in the memory module. In addition, in order to save chip area, the receiving module 802 and the transmitting module 801 may be integrated together to form a transceiver.

As shown in fig. 8, the receiving module 802 is configured to receive a first message sent by a first terminal, where the first message is used to indicate that the first terminal needs a circuit domain fallback. The sending module 801 is configured to send a second message to the base station, where the second message is used to indicate that the first terminal of the base station needs circuit domain fallback.

Illustratively, the first message includes a connection technology between the first terminal and the second terminal.

Illustratively, the second message includes a connection technology between the first terminal and the second terminal.

The mobility management entity provided in the embodiment of the present invention receives the CSFB indication information and the indirect access technology indication information from the first terminal, and sends the CSFB indication information and the indirect access technology indication information to the base station. And the base station can judge the connection technology between the first terminal and the second terminal according to the indirect access technology indication information. When the base station determines that the connection technology is the non-3GPP technology, the base station does not release the RRC connection with the first terminal, but sends an RRC connection reconfiguration message to the first terminal, so that the first terminal can perform a CS service by falling back to a circuit domain according to the information of the 2G or 3G cell contained in the message, and simultaneously can perform a PS service by connecting with the second terminal. When the base station determines that the connection technology is the 3GPP technology, the base station sends an RRC connection suspension message to the first terminal, so that the first terminal can fall back to a circuit domain according to the information of the 2G or 3G cell contained in the message to perform CS service. Meanwhile, the second terminal reserves RRC context information according to the RRC connection suspension message, so that the RRC connection between the second terminal and the base station can be recovered directly through a recovery (resume) message, and the time delay of user plane establishment is shortened. Therefore, the first terminal can quickly return to the previous communication network, such as the LTE network, for the PS service after the CS service is ended.

Fig. 9 is a schematic structural diagram of a terminal according to an embodiment of the present invention. The terminal 900 can include a transmitting module 901, a receiving module 902, and a processing module 903.

It will be appreciated by those skilled in the art that fig. 9 merely shows a simplified design of the structure of the terminal. The terminal structure shown in fig. 9 does not constitute a limitation of the terminal, and the terminal may include more or less components than those shown in fig. 9, for example, the terminal may further include a storage module for storing instructions corresponding to a communication algorithm, and in addition, in order to save a chip area, the receiving module 902 and the transmitting module 901 may be integrated together to form a transceiver.

As shown in fig. 9, the sending module 901 is configured to send a first message to the mobility management entity, where the first message is used to indicate that the first terminal needs a circuit domain fallback. The receiving module 902 is configured to receive a second message sent by the base station, where the second message is used to indicate a fallback mode of the first terminal circuit domain. The processing module 903 is configured to perform circuit switched fallback according to the second message.

Illustratively, the processing module 903 is further configured to reserve a radio resource control RRC connection with the base station when the circuit switched fallback; or, suspending the RRC connection with the base station when the circuit switched fallback.

The terminal provided by the embodiment of the invention can ensure that the base station can determine the connection technology between the terminal and the second terminal according to the indication information by sending the indirect access technology indication information to the base station. When the base station determines that the connection technology is the non-3GPP technology, the base station does not release the RRC connection between the base station and the terminal, but sends an RRC connection reconfiguration message to the terminal, so that the terminal can perform a CS service by falling back to a circuit domain according to the information of the 2G or 3G cell contained in the message, and simultaneously can perform a PS service by connecting with a second terminal. When the base station determines that the connection technology is the 3GPP technology, the base station sends an RRC connection suspension message to the terminal, so that the terminal can fall back to a circuit domain to perform CS service according to the information of the 2G or 3G cell contained in the message. Meanwhile, the second terminal reserves RRC context information according to the RRC connection suspension message, so that the RRC connection between the second terminal and the base station can be recovered directly through a recovery (resume) message, and the time delay of user plane establishment is shortened. Therefore, the terminal can quickly return to the previous communication network, such as an LTE network, for PS service after the CS service is ended.

Fig. 10 is a schematic structural diagram of another base station according to an embodiment of the present invention. As shown in fig. 10, the base station 1000 includes: memory 1001, processor 1002, and communications interface 1003. A memory 1001 may be used to store program codes and data for the base stations. The Processor 1002 may be a Central Processing Unit (CPU), a general purpose Processor, a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, transistor logic, hardware components, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. The processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, DSPs, and microprocessors, among others. The communication interface is a generic term and may include one or more interfaces. Those skilled in the art will appreciate that the base station architecture shown in fig. 10 is not meant to be limiting and may include more or fewer components than shown, or some components may be combined, or a different arrangement of components. The base station may also include a bus 1004, for example. The communication interface 1003, the processor 1002, and the memory 1001 may be connected to each other by a bus 1004; the bus 1004 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus 1004 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 10, but this is not intended to represent only one bus or type of bus.

As shown in fig. 10, a memory 1001 for storing program instructions. A processor 1002 for performing the following operations according to program instructions stored in memory 1001: indicating a communication interface 1003 to receive a first message sent by a mobility management entity, where the first message is used to indicate that a first terminal of a base station needs circuit switched fallback; determining a connection technology between the first terminal and the second terminal, and instructing the communication interface 1003 to send a second message to the first terminal according to the connection technology, where the second message is used to instruct the first terminal to drop the circuit switched domain.

Illustratively, the processor 1002 is further configured to perform the following operations in accordance with program instructions stored in the memory 1001: determining a connection technology between the first terminal and the second terminal according to the context information of the first terminal; or, the instruction communication interface 1003 receives first instruction information sent by the mobility management entity, and determines a connection technology between the first terminal and the second terminal according to the first instruction information; alternatively, the instruction communication interface 1003 receives second instruction information sent by the first terminal, and determines a connection technology between the first terminal and the second terminal according to the second instruction information.

Illustratively, the processor 1002 is further configured to perform the following operations in accordance with program instructions stored in the memory 1001: determining that the connection technology is non-3GPP technology, and instructing the communication interface 1003 to send a second message to the first terminal according to the connection technology, wherein the second message instructs the first terminal to reserve the radio resource control RRC connection with the base station when the circuit domain falls back; or, determining that the connection technology is the 3GPP technology, and instructing the communication interface 1003 to send a second message to the first terminal according to the connection technology, where the second message instructs the first terminal to suspend the RRC connection with the base station when the circuit switched fallback.

Illustratively, the processor 1002 is further configured to perform the following operations according to program instructions stored in the memory 1001: determining the connection technology to be non-3GPP technology, and if the inactivity timer of the second terminal is overtime, not releasing the RRC connection of the second terminal.

Fig. 11 is a schematic structural diagram of another mobility management entity according to an embodiment of the present invention. As shown in fig. 11, the mobility management entity 1100 includes: memory 1101, processor 1102, and communication interface 1103. The memory 1101 may be used for storing program codes and data of the mobility management entity. The Processor 1102 may be a Central Processing Unit (CPU), a general purpose Processor, a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other Programmable logic device, transistor logic, hardware components, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. The processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, DSPs, and microprocessors, among others. The communication interface is a generic term and may include one or more interfaces. Those skilled in the art will appreciate that the mobility management entity configuration shown in fig. 11 does not constitute a limitation of the mobility management entity and may include more or fewer components than shown, or some components in combination, or a different arrangement of components. The mobility management entity may also include a bus 1104, for example. The communication interface 1103, the processor 1102, and the memory 1101 may be connected to each other by a bus 1104; the bus 1104 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus 1104 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 11, but this is not intended to represent only one bus or type of bus.

As shown in fig. 11, a memory 1101 for storing program instructions. A processor 1102 for performing the following operations in accordance with program instructions stored in memory 1101: indicating a communication interface 1103 to receive a first message sent by a first terminal, where the first message is used to indicate that the first terminal needs circuit domain fallback; and instruct the communication interface 1103 to receive a second message sent to the base station, where the second message is used to instruct the base station that the first terminal needs circuit switched fallback.

Fig. 12 is a schematic structural diagram of another terminal according to an embodiment of the present invention. As shown in fig. 12, the terminal 1200 includes: radio Frequency (RF) circuit 1210, memory 1220, input unit 1230, display unit 1240, processor 1250, Wireless Local Area Network (WLAN) module 1260, power supply 1270, and bluetooth module 1280. Those skilled in the art will appreciate that the terminal configuration shown in fig. 12 is not intended to be limiting and may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.

The RF circuit 1210 may be used to transceive information, for example, to connect mobile broadband. In general, RF circuit 1210 includes, but is not limited to, an antenna, at least one Amplifier, a transceiver, a coupler, a Low Noise Amplifier (LNA), a duplexer, and the like. In addition, RF circuit 1210 may also forward mobile bandwidth traffic to WLAN module 1260 for forwarding to other terminals through WLAN module 1260. The wireless communication may adopt any communication standard or protocol, including but not limited to Global System for Mobile communication (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), email, Short Messaging Service (SMS), and the like.

The memory 1220 may be used for storing program instructions, and the processor 1250 may cause the terminal to execute the circuit domain fallback method as described above in fig. 2, 4, 5 or 6 by executing the program instructions stored in the memory 1220. The memory 1220 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, application programs required for implementing the above-described circuit domain fallback method, and the like. The storage data area may store list information of the terminal, data generated when the terminal performs the above-described circuit domain fallback method, and the like. Further, the memory 1220 may include a volatile memory (volatile memory), such as a random-access memory (RAM); the memory 1220 may also include a non-volatile memory (non-volatile memory), such as a read-only memory (ROM), a flash memory (flash memory), a Hard Disk Drive (HDD), or a solid-state drive (SSD). The memory 1220 may also include a combination of the above types of memories.

The input unit 1230 may be configured to receive numeric or character information input by a user, including an instruction to turn on a WLAN hotspot, an instruction to select a terminal sharing the WLAN hotspot, and the like. Specifically, the input unit 1230 may include a touch panel 1231 and other input devices 1232. The touch panel 1231, also referred to as a touch screen, can collect touch operations of a user (e.g., operations of the user on or near the touch panel 1231 using any suitable object or accessory such as a finger, a stylus, etc.) thereon or nearby, and drive the corresponding connection device according to a preset program. Alternatively, the touch panel 1231 may include two portions, a touch detection device and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts the touch information into touch point coordinates, and sends the touch point coordinates to the processor 1250, and can receive and execute commands sent from the processor 1250. In addition, the input unit 1230 may implement the touch panel 1231 in various types, such as a resistive type, a capacitive type, an infrared ray, and a surface acoustic wave. The input unit 1230 may include other input devices 1232 in addition to the touch panel 1231. In particular, other input devices 1232 may include, but are not limited to, one or more of a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, a joystick, and the like.

The display unit 1240 may be used to display information input by a user or information provided to the user and various menus of the terminal. The display unit 1240 may include a display screen 1241, and optionally, the display screen 1241 may be configured in the form of a Liquid Crystal Display (LCD), an Organic Light-Emitting Diode (OLED), or the like. Further, touch panel 1231 can overlay display 1241, and when touch panel 1231 detects a touch operation thereon or nearby, the touch panel can transmit the touch operation to processor 1250 to determine the type of the touch event, and then processor 1250 can provide a corresponding visual output on display 1241 according to the type of the touch event. Although in fig. 12, the touch panel 1231 and the display 1241 are implemented as two separate components to implement the input and output functions of the terminal, in some embodiments, the touch panel 1231 and the display 1241 may be integrated to implement the input and output functions of the terminal.

The processor 1250 is a control center of the terminal, connects various parts of the entire terminal using various interfaces and lines, and performs the circuit domain fallback method as shown in fig. 2, 4, 5 or 6 by running or executing software programs and/or modules stored in the memory 1220 and calling data stored in the memory 1220. Alternatively, processor 1250 may include one or more processing units. Preferably, the processor 1250 may integrate an application processor, which mainly handles operating systems, user interfaces, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into processor 1250.

WLAN module 1260 may be used to assist a user in emailing, browsing web pages, accessing streaming media, etc., which provides wireless broadband WLAN internet access for the user. The WLAN belongs to a short-distance wireless transmission technology, and the terminal can access a WLAN hotspot through the WLAN module 1260, and can also open the WLAN hotspot through the WLAN module 1260, so as to forward the mobile bandwidth service to other terminals. The WLAN module 1260 may also perform Wi-Fi broadcasting and scanning to enable wireless communication with other surrounding terminals.

The terminal also includes a power supply 1270 (e.g., a battery) that provides power to the various components and optionally may be logically connected to the processor 1250 via a power management system that may be used to manage charging, discharging, and power consumption.

The Bluetooth module 1270 may be a Bluetooth Low Energy (BLE) device, a legacy Bluetooth device, or a dual-mode Bluetooth device supporting legacy Bluetooth and BLE. The bluetooth module 1270 establishes BLE or classic bluetooth connection with bluetooth modules of other terminals, and the bluetooth module 1270 can also perform BR or BLE broadcasting and scanning to realize wireless communication with other surrounding terminals.

Although not shown, the terminal may further include a camera, a speaker, and the like, which will not be described herein.

Illustratively, RF circuit 1210, bluetooth module 1280, and WLAN module 1260 may be collectively referred to as a communication interface.

Illustratively, the terminal includes a processor 1250, a memory 1220, and a communication interface. The memory 1220 is used to store program instructions. The processor 1250 is operative to perform the following operations in accordance with program instructions stored in the memory 1220: and indicating the communication interface to send a first message to the mobile management entity, wherein the first message is used for indicating that the first terminal needs circuit domain fallback. The communication interface is indicated to receive a second message sent by the base station, and the second message is used for indicating the circuit switched fallback mode of the first terminal; and performing circuit switched fallback according to the second message.

Illustratively, the processor 1250 is further configured to perform the following operations according to program instructions stored in the memory 1220: reserving Radio Resource Control (RRC) connection between the base station and the circuit switched fallback; or, suspending the RRC connection with the base station when the circuit switched fallback.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied in hardware, a software module executed by a processor, or a combination of the two. A software module may reside in Random Access Memory (RAM), memory, Read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A method of circuit switched fallback, the method comprising:

a base station receives a first message sent by a mobile management entity, wherein the first message is used for indicating that a first terminal of the base station needs circuit switched fallback;

and the base station determines a connection technology between the first terminal and a second terminal, and the base station sends a second message to the first terminal according to the connection technology, wherein the second message is used for indicating a circuit switched fallback mode of the first terminal.

2. The method of claim 1, wherein the base station determines a connection technology between the first terminal and the second terminal, and comprises:

the base station determines a connection technology between the first terminal and the second terminal according to the context information of the first terminal; or

The base station receives first indication information sent by the mobile management entity, and the base station determines a connection technology between the first terminal and the second terminal according to the first indication information; or

And the base station receives second indication information sent by the first terminal, and the base station determines a connection technology between the first terminal and the second terminal according to the second indication information.

3. The method of claim 1, wherein the base station sends a second message to the first terminal according to the connection technology, and wherein the second message is used to indicate a circuit switched fallback manner for the first terminal, and the method comprises:

if the connection technology is non-third generation partnership project (non-3 GPP) technology, the second message indicates that the first terminal reserves Radio Resource Control (RRC) connection with the base station when the circuit switched domain falls back; or

And if the connection technology is the third generation partnership project 3GPP technology, the second message indicates that the first terminal suspends the Radio Resource Control (RRC) connection with the base station when the circuit switched fallback.

4. The method of claim 3, wherein if the connection technology is non-3GPP technology, the method further comprises:

the base station does not release the RRC connection of the second terminal if the inactivity timer of the second terminal expires.

5. A method of circuit switched fallback, the method comprising:

a mobile management entity receives a first message sent by a first terminal, wherein the first message is used for indicating that the first terminal needs circuit switched fallback; the first message comprises a connection technology between the first terminal and a second terminal;

the mobile management entity sends a second message to a base station, wherein the second message is used for indicating that the first terminal of the base station needs circuit switched fallback; the second message includes a connection technology between the first terminal and a second terminal.

6. A method of circuit switched fallback, the method comprising:

a first terminal sends a first message to a mobile management entity, wherein the first message is used for indicating that the first terminal needs circuit domain fallback; the first message comprises a connection technology between the first terminal and a second terminal;

the first terminal receives a second message sent by the base station, the second message is used for indicating the circuit switched fallback mode of the first terminal, and the first terminal performs circuit switched fallback according to the second message.

7. The method of claim 6, wherein the first terminal performs circuit domain fallback according to the second message, comprising:

the first terminal reserves the Radio Resource Control (RRC) connection with the base station when the circuit switched fallback;

or, the first terminal suspends the RRC connection with the base station when the circuit switched fallback.

8. A base station, characterized in that the base station comprises:

a receiving module, configured to receive a first message sent by a mobility management entity, where the first message is used to indicate that a first terminal of a base station needs circuit switched fallback;

the processing module is used for determining the connection technology between the first terminal and the second terminal;

and the sending module is used for sending a second message to the first terminal according to the connection technology, wherein the second message is used for indicating the circuit switched fallback mode of the first terminal.

9. The base station of claim 8, wherein the processing module is further configured to:

determining a connection technology between the first terminal and the second terminal according to the context information of the first terminal; or

After the receiving module receives first indication information sent by the mobility management entity, determining a connection technology between the first terminal and the second terminal according to the first indication information; or

After the receiving module receives second indication information sent by the first terminal, determining a connection technology between the first terminal and the second terminal according to the second indication information.

10. The base station of claim 8, wherein the sending module is further configured to:

after the processing module determines that the connection technology is non-third generation partnership project (non-3 GPP) technology, sending a second message to the first terminal according to the connection technology, wherein the second message indicates that the first terminal reserves Radio Resource Control (RRC) connection with the base station when the first terminal falls back to a circuit domain; or

After the processing module determines that the connection technology is a third generation partnership project (3 GPP) technology, sending a second message to the first terminal according to the connection technology, wherein the second message indicates that the first terminal suspends the RRC connection with the base station when the circuit switched fallback occurs.

11. The base station of claim 10, wherein the processing module is further configured to not release the Radio Resource Control (RRC) connection of the second terminal if the inactivity timer of the second terminal expires after the determination that the connection technology is non-3GPP technology.

12. A mobility management entity, characterized in that the mobility management entity comprises:

the receiving module is used for receiving a first message sent by a first terminal, wherein the first message is used for indicating that the first terminal needs circuit domain fallback; the first message comprises a connection technology between the first terminal and a second terminal;

a sending module, configured to send a second message to a base station, where the second message is used to indicate that the first terminal of the base station needs circuit switched fallback; the second message includes a connection technology between the first terminal and a second terminal.

13. A terminal, characterized in that the terminal comprises:

a sending module, configured to send a first message to a mobility management entity, where the first message is used to indicate that a first terminal needs a circuit switched fallback; the first message comprises a connection technology between the first terminal and a second terminal;

a receiving module, configured to receive a second message sent by a base station, where the second message is used to indicate a fallback mode of the first terminal circuit domain;

and the processing module is used for performing circuit switched fallback according to the second message.

14. The terminal of claim 13, wherein the processing module is further configured to:

reserving Radio Resource Control (RRC) connection with the base station when the circuit switched fallback; or

Suspending the RRC connection with the base station upon a circuit switched fallback.

15. A base station, characterized in that the base station comprises: a processor, a memory, and a communication interface;

the memory to store program instructions;

the processor is configured to perform the following operations according to program instructions stored in the memory:

indicating the communication interface to receive a first message sent by a mobile management entity, wherein the first message is used for indicating that a first terminal of the base station needs circuit switched fallback; and determining a connection technology between the first terminal and a second terminal, and indicating the communication interface to send a second message to the first terminal according to the connection technology, wherein the second message is used for indicating a circuit switched fallback mode of the first terminal.

16. The base station of claim 15, wherein the processor is further configured to perform the following operations according to program instructions stored in the memory:

The communication interface is instructed to receive first indication information sent by the mobile management entity, and the connection technology between the first terminal and the second terminal is determined according to the first indication information; or

And indicating the communication interface to receive second indication information sent by the first terminal, and determining a connection technology between the first terminal and the second terminal according to the second indication information.

17. The base station of claim 15, wherein the processor is further configured to perform the following operations according to program instructions stored in the memory:

determining that the connection technology is a non-third generation partnership project (non-3 GPP) technology, and instructing the communication interface to send a second message to the first terminal according to the connection technology, wherein the second message instructs the first terminal to reserve Radio Resource Control (RRC) connection with the base station when a circuit switched domain falls back; or

Determining that the connection technology is a third generation partnership project (3 GPP) technology, and instructing the communication interface to send a second message to the first terminal according to the connection technology, wherein the second message instructs the first terminal to suspend RRC connection with the base station when a circuit switched domain falls back.

18. The base station of claim 17, wherein the processor is further configured to perform the following operations according to program instructions stored in the memory:

determining that the connection technology is non-3GPP technology, and if the inactivity timer of the second terminal is overtime, not releasing the RRC connection of the second terminal.

19. A mobility management entity, characterized in that the mobility management entity comprises: a processor, a memory, and a communication interface;

the memory to store program instructions;

the communication interface is instructed to receive a first message sent by a first terminal, and the first message is used for indicating that the first terminal needs circuit domain fallback; the first message comprises a connection technology between the first terminal and a second terminal; and instructing the communication interface to receive a second message sent to a base station, wherein the second message is used for instructing the base station that the first terminal needs circuit switched fallback; the second message includes a connection technology between the first terminal and a second terminal.

20. A terminal, characterized in that the terminal comprises: a processor, a memory, and a communication interface;

the memory to store program instructions;

the communication interface is instructed to send a first message to a mobile management entity, and the first message is used for indicating that a first terminal needs circuit domain fallback; the communication interface is instructed to receive a second message sent by the base station, and the second message is used for instructing the first terminal circuit switched fallback mode; and performing circuit switched fallback according to the second message;

the first message includes a connection technology between the first terminal and a second terminal.

21. The terminal of claim 20, wherein the processor is further configured to perform the following operations according to program instructions stored in the memory: