WO2016106562A1

WO2016106562A1 - Circuit switched fallback method, device and system

Info

Publication number: WO2016106562A1
Application number: PCT/CN2014/095589
Authority: WO
Inventors: 吴晓波; 崇卫微; 席国宝
Original assignee: 华为技术有限公司
Priority date: 2014-12-30
Filing date: 2014-12-30
Publication date: 2016-07-07
Also published as: CN107005895A

Abstract

Disclosed is a circuit switched fallback method. Before a user equipment accesses a CS domain of a 2G or 3G network, an MME can learn about the congestion situation of the CS domain of the 2G or 3G network, and terminate a circuit switched fallback when determining that the CS domain of the 2G or 3G network does not have available resources. In this way, the user equipment is prevented from accessing the 2G or 3G network in case of congestion of the CS domain of the 2G or 3G network, so that unnecessary signaling flows between an LTE network and the 2G or 3G network are reduced, signaling impact of the LTE network on the 2G or 3G network is avoided, network load is alleviated, and user experience is improved.

Description

Method, device and system for circuit domain fallback

Technical field

The present invention relates to the field of communications technologies, and in particular, to a method, device, and system for circuit domain fallback.

Background technique

Second Generation (Second Generation, 2G) or Third Generation (3G) networks such as Global System of Mobile Communication (GSM) or Wideband Code Division Multiple Access (WCDMA) Basic coverage has been basically achieved.

With the development of Long Term Evolution (LTE) network technologies, these LTE networks have covered some urban areas and traffic hotspots, so that in current communication networks, LTE networks coexist with 2G or 3G networks. As the LTE network is in the construction phase, some LTE networks may only support data services and do not support voice services. When a user equipment (User Equipment, UE) in the LTE network initiates voice services, the UE needs to first fall back to have circuit switching. The 2G or 3G network in the (Circuit Switched, CS) domain performs voice services on the 2G or 3G network with the CS domain. The above technology of switching from the CS domain of the LTE network to the CS domain of the 2G or 3G network is called circuit domain fallback. (Circuit Switched Fallback, CSFB) technology, or circuit-switched domain fallback technology; while some LTE networks may support voice services, the UE may use Voice over LTE (VoLTE) services, however, due to LTE networks The full coverage is not achieved. If the UE that is using VoLTE is in the border area of the LTE network and the 2G or 3G network or is about to enter the area that covers only the 2G or 3G network, it is usually necessary to switch the VoLTE to the CS domain of the 2G or 3G network. To avoid voice interruptions.

In the prior art, after the user equipment performs the redirection-based CSFB from the LTE network, it returns to the 2G or 3G network to initiate a voice call. If the 2G or 3G network is congested, the voice service cannot be established, causing the call to fail, and the UE returns to the LTE. The internet. The UE may initiate the CSFB to fall back to the 2G or 3G network again or automatically reselect the 2G or 3G network to initiate the voice service. If the 2G or 3G network is still congested, the call will fail again and return to the LTE network, thus generating a ping-pong effect. This not only causes unnecessary signaling processes in the LTE network and the 2G or 3G network, but also increases the load on the network and affects the services of the user equipment, resulting in poor user experience. For example, in the above process, the user may not be able to perform voice. Call, still can't get online.

Summary of the invention

For the above problems in the prior art, the embodiment of the present invention provides a method for circuit domain fallback, which can terminate the circuit domain fallback in the case of 2G or 3G network congestion in the process of implementing CSFB, and avoid unnecessary signaling flow. Reduce the load on the network and improve the user experience.

In a first aspect, an embodiment of the present invention provides a method for circuit domain fallback, including:

The mobility management entity MME receives a request message sent by the user equipment of the long term evolution LTE network, where the request message is used to request the circuit domain to fall back;

During the circuit switched CS domain handover preparation process of the LTE network to the second generation 2G or the third generation 3G network, the MME determines that the CS domain of the 2G or 3G network has no available resources;

Sending, by the MME, a request rejection message to the user equipment, where the request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, where the request rejection message is used to indicate that the user equipment receives the The request rejection message begins, and the circuit domain cannot be requested to fall back until the time corresponding to the value of the timer arrives.

With reference to the first aspect, in a first possible implementation manner, in a circuit-switched CS domain handover preparation process of the LTE network to a second-generation 2G or third-generation 3G network, the MME determines the 2G or 3G The QoS of the CS domain of the network includes: the MME sends a handover request message to the mobile switching center MSC, where the handover request message is used to request the MSC to switch the user equipment from the LTE network to the 2G or 3G. Circuit-switched CS domain of the network to perform circuit domain fallback; the MME receives a handover response message returned by the MSC according to the handover request message, where the handover response message includes a CS domain indicating that the 2G or 3G network does not The indication information of the available resources; the MME determines, according to the handover response message, that the CS domain of the 2G or 3G network has no available resources.

With reference to the first aspect, or the first possible implementation manner of the first aspect, in a second possible implementation manner, before the MME determines that the CS domain of the 2G or 3G network has no available resources, the method is The MME further includes: sending, by the MME, a notification message to the eNodeB eNodeB according to the service request message, where the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to a CS domain of a 2G or 3G network. The MME receives the handover request message returned by the eNodeB according to the notification message, and the handover request message is used to trigger the CS domain handover process of the LTE network to the 2G or 3G network.

With the second possible implementation of the first aspect, in a third possible implementation, after the MME determines that the CS domain of the 2G or 3G network has no available resources, the method further includes:

And sending, by the MME, a handover request response message to the eNodeB, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback.

In a second aspect, an embodiment of the present invention provides a method for circuit domain fallback, the method comprising:

The evolved base station eNodeB located in the Long Term Evolution (LTE) network receives the notification message sent by the mobility management entity MME, and the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to the second generation 2G or third generation 3G network. Circuit-switched CS domain for circuit domain fallback;

Sending, by the eNodeB, a handover request message to the MME, to trigger a CS domain handover process of the LTE network to the 2G or 3G network;

Receiving, by the eNodeB, a handover request response message, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback; the handover request response message is The MME sends in the case that it is determined that the circuit switched CS domain of the 2G or 3G network has no available resources;

The eNodeB terminates the circuit domain fallback according to the termination indication.

In a third aspect, an embodiment of the present invention provides a method for circuit domain fallback, where the method includes:

The user equipment of the LTE-based LTE network sends a request message to the mobility management entity MME, where the request message is used to request the circuit domain to fall back;

Receiving, by the user equipment, a request rejection message returned by the MME, where the request rejection message is sent by the MME when determining that the circuit switched CS domain of the second generation 2G or third generation 3G network has no available resources, The request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, the request rejection message is used to indicate that the user equipment starts from receiving the request rejection message, and corresponds to a value of the timer. The time of the circuit cannot be requested to fall back before the time is reached;

The user equipment does not request the circuit domain to fall back from the receipt of the request rejection message until the time corresponding to the value of the timer arrives.

In a fourth aspect, an embodiment of the present invention provides a method for circuit domain fallback, where the method includes: a mobility management entity MME receives a paging message sent by a mobile switching center MSC, where the paging message is used to request the MME Initiating a circuit domain fallback for user equipment located in the Long Term Evolution (LTE) network;

Prepared for circuit switched CS domain switching from the LTE network to the second generation 2G or third generation 3G network The MME determines that the CS domain of the 2G or 3G network has no available resources;

The MME does not send a circuit domain fallback paging message to the user equipment, to prevent the user equipment from selecting a 2G or 3G network for voice service after receiving the circuit domain fallback paging message.

With reference to the fourth aspect, in a first possible implementation manner, in a circuit-switched CS domain handover preparation process of the LTE network to a second-generation 2G or third-generation 3G network, the MME determines the 2G or 3G No resources available for the CS domain of the network include:

Sending, by the MME, a handover request message to the mobile switching center MSC, where the handover request message is used to request the MSC to switch the user equipment from the LTE network to a circuit switched CS domain of the 2G or 3G network to perform a circuit. The MME receives the handover response message returned by the MSC according to the handover request message, where the handover response message includes indication information indicating that the CS domain of the 2G or 3G network has no available resources; the MME According to the handover response message, it is determined that the CS domain of the 2G or 3G network has no available resources.

With reference to the fourth aspect, or the first possible implementation manner of the fourth aspect, in a second possible implementation manner, before the MME determines that the CS domain of the 2G or 3G network has no available resources, the method is Also includes:

Sending, by the MME, a notification message to the eNodeB eNodeB according to the service request message, where the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to a CS domain of a 2G or 3G network to perform a circuit. The MME receives the handover request message returned by the eNodeB according to the notification message, and the handover request message is used to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network.

With reference to the second possible implementation manner of the fourth aspect, in a third possible implementation manner, after the MME determines that the CS domain of the 2G or 3G network has no available resources, the method further includes: The MME sends a handover request response message to the eNodeB, where the handover request response message carries a termination indication, and the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback.

With the second or third possible implementation of the fourth aspect, in a fourth possible implementation, before the MME sends the notification message to the eNodeB, the method further includes: The MME sends a packet domain paging message to the user equipment in an idle state; the MME receives a service request message sent by the user equipment.

In a fifth aspect, an embodiment of the present invention provides a mobility management entity, including:

a receiving unit, configured to receive a request message sent by a user equipment that is located in a long term evolution LTE network, where the request message is used to request a circuit domain to fall back;

a determining unit, configured to determine that the CS domain of the 2G or 3G network has no available resources during the circuit switched CS domain handover preparation process of the LTE network to the second generation 2G or the third generation 3G network;

a sending unit, configured to send a request rejection message to the user equipment, where the request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, where the request rejection message is used to indicate that the user equipment receives the The request rejection message begins, and the circuit domain cannot be requested to fall back until the time corresponding to the value of the timer arrives.

With reference to the fifth aspect, in a first possible implementation, the sending unit is further configured to send a handover request message to the mobile switching center MSC, where the handover request message is used to request the MSC to take the user equipment from the The LTE network switches to a circuit switched CS domain of the 2G or 3G network to perform circuit domain fallback;

The receiving unit is further configured to receive a handover response message that is returned by the MSC according to the handover request message, where the handover response message includes indication information indicating that the CS domain of the 2G or 3G network has no available resources;

The determining unit is specifically configured to determine, according to the handover response message, that the CS domain of the 2G or 3G network has no available resources.

With reference to the fifth aspect, or the first possible implementation manner of the fifth aspect, in a second possible implementation, the sending unit is further configured to determine, in the determining unit, a CS domain of the 2G or 3G network Before the available resources, the notification message is sent to the evolved base station eNodeB, where the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to the CS domain of the 2G or 3G network for circuit domain fallback;

The receiving unit is further configured to receive a handover request message that is returned by the eNodeB according to the notification message, where the handover request message is used to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network.

With the second possible implementation of the fifth aspect, in a third possible implementation, the sending unit is further configured to: after the determining unit determines that the CS domain of the 2G or 3G network has no available resources, Sending a handover request response message to the eNodeB, where the handover request response message carries a termination indication, the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback.

In a sixth aspect, an embodiment of the present invention provides an evolved base station, including:

a receiving unit, configured to receive a notification message sent by the mobility management entity MME, where the notification message is used to indicate that the evolved base station moves the user equipment from the long term evolution LTE network to the circuit switching of the second generation 2G or third generation 3G network. CS domain to perform circuit domain fallback;

a sending unit, configured to send a handover request message to the MME, to trigger a CS domain handover process of the LTE network to the 2G or 3G network;

The receiving unit is further configured to receive a handover request response message sent by the MME, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback; the handover request response The message is that the MME sends if it is determined that the circuit switched CS domain of the 2G or 3G network has no available resources;

And a terminating unit, configured to terminate the circuit domain fallback according to the termination indication.

The seventh aspect of the present invention provides a user equipment, including:

a sending unit, configured to send a request message to the mobility management entity MME, where the request message is used to request that the circuit domain fall back;

a receiving unit, configured to receive a request rejection message returned by the MME, where the request rejection message is sent by the MME in determining that the circuit switched CS domain of the second generation 2G or third generation 3G network has no available resources, The request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, the request rejection message is used to indicate that the user equipment starts from receiving the request rejection message, to a value of the timer. The circuit domain cannot be requested to fall back before the corresponding duration arrives;

The processing unit is configured to start from the receipt of the request rejection message, and does not request the circuit domain to fall back until the time corresponding to the value of the timer arrives.

In an eighth aspect, an embodiment of the present invention provides a mobility management entity, including:

a receiving unit, configured to receive a paging message sent by the mobile switching center MSC, where the paging message is used to request the mobility management entity to initiate a circuit domain fallback for a user equipment located in a long term evolution LTE network;

a processing unit, configured to: after the determining unit determines that the CS domain of the 2G or 3G network has no available resources, send a circuit domain fallback paging message to the user equipment, to prevent the user equipment from receiving the After the circuit domain falls back to the paging message, the 2G or 3G network is selected for voice service.

With reference to the eighth aspect, in a first possible implementation manner, the mobility management entity further includes: a first sending unit, configured to send a handover request message to the mobile switching center MSC, where the handover request message is used to request the MSC to switch the user equipment from the LTE network to the 2G or Circuit-switched CS domain of 3G network to perform circuit domain fallback;

With reference to the eighth aspect, or the first possible implementation manner of the eighth aspect, in the second possible implementation manner, the mobility management entity further includes:

a second sending unit, configured to send, to the evolved base station eNodeB, a notification message, before the determining unit determines that the CS domain of the 2G or 3G network has no available resources, where the notification message is used to instruct the eNodeB to use the user equipment Moving from the LTE network to a CS domain of a 2G or 3G network for circuit domain fallback;

With the second possible implementation of the eighth aspect, in a third possible implementation, the second sending unit is further configured to determine, in the determining unit, that the CS domain of the 2G or 3G network has no available resources. Then, a handover request response message is sent to the eNodeB, where the handover request response message carries a termination indication, and the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback.

With reference to the second or third possible implementation manner of the eighth aspect, in a fourth possible implementation, the second sending unit is further configured to: before being sent to the eNodeB The user equipment in the idle state sends a packet domain paging message; the receiving unit is further configured to receive a service request message sent by the user equipment.

A ninth aspect, an embodiment of the present invention provides a mobility management entity, including a bus, and a processor, a memory, a transmitter, and a receiver connected to the bus;

The memory is for storing computer execution instructions, the computer execution instructions being configured to be executed by the processor;

The receiver is configured to receive a request message sent by a user equipment located in a long term evolution LTE network, where The request message is used to request that the circuit domain fall back;

The processor is configured to determine that the CS domain of the 2G or 3G network has no available resources during the circuit switched CS domain handover preparation process of the LTE network to the second generation 2G or the third generation 3G network;

The sender is configured to send a request rejection message to the user equipment, where the request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, where the request rejection message is used to indicate that the user equipment is Upon receiving the request rejection message, the circuit domain cannot be requested to fall back until the time corresponding to the value of the timer arrives.

Optionally, the specific implementation of the transmitter in the embodiment of the present invention may refer to the sending unit in any one of the possible implementation manners in the fifth aspect or the fifth aspect. The specific implementation of the receiver in the embodiment of the present invention may be referred to. The receiving unit according to any one of the possible implementations of the fifth aspect or the fifth aspect, the specific implementation of the processor in the embodiment of the present invention may refer to the fifth aspect or the fifth aspect, any one of the possible implementation manners. Determine the unit.

According to a tenth aspect, an embodiment of the present invention provides an evolved base station, including a bus, and a processor, a memory, a transmitter, and a receiver connected to the bus;

The receiver is configured to receive a notification message sent by the mobility management entity MME, where the notification message is used to indicate that the evolved base station moves the user equipment from the long term evolution LTE network to the circuit switching of the second generation 2G or third generation 3G network. CS domain to perform circuit domain fallback;

The transmitter is configured to send a handover request message to the MME to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network;

The receiver is further configured to receive a handover request response message sent by the MME, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback; the handover request response The message is that the MME sends if it is determined that the circuit switched CS domain of the 2G or 3G network has no available resources;

The processor is configured to terminate the circuit domain fallback according to the termination indication.

In an eleventh aspect, an embodiment of the present invention provides a user equipment, including a bus, and a processor, a memory, a transmitter, and a receiver connected to the bus;

The sender is configured to send a request message to the mobility management entity MME, where the request message is used to request that the circuit domain fall back;

The receiver is configured to receive a request rejection message returned by the MME, where the request rejection message is sent by the MME if it is determined that the circuit switched CS domain of the second generation 2G or third generation 3G network has no available resources. The request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, the request rejection message is used to indicate that the user equipment starts from receiving the request rejection message, to the timer The circuit domain cannot be requested to fall back before the time corresponding to the value arrives;

The processor is configured to not request the circuit domain to fall back before receiving the request rejection message until the time corresponding to the value of the timer arrives.

According to a twelfth aspect, an embodiment of the present invention provides a mobility management entity, including a bus, and a processor, a memory, a transmitter, and a receiver connected to the bus;

The receiver is configured to receive a paging message sent by the mobile switching center MSC, where the paging message is used to request the mobility management entity to initiate a circuit domain fallback of a user equipment located in a long term evolution LTE network;

The processor is configured to determine, during the circuit-switched CS domain handover preparation process of the LTE network to the second-generation 2G or the third-generation 3G network, that the CS domain of the 2G or 3G network has no available resources, where the determining unit is After determining that the CS domain of the 2G or 3G network has no available resources, sending a circuit domain fallback paging message to the user equipment, to prevent the user equipment from selecting 2G after receiving the circuit domain fallback paging message or The 3G network performs voice services.

Optionally, the specific implementation of the transmitter in the embodiment of the present invention may refer to the first sending unit and the second sending unit according to any one of the possible implementations of the eighth aspect or the eighth aspect, where For a specific implementation of the receiver, reference may be made to the receiving unit according to any of the possible implementations of the eighth aspect or the eighth aspect. The specific implementation of the processor in the embodiment of the present invention may refer to any one of the eighth aspect or the eighth aspect. Possible implementations are the determining unit and the processing unit.

A thirteenth aspect, the embodiment of the present invention provides a system for circuit domain fallback, comprising the mobility management entity according to any of the possible implementations of the fifth aspect or the fifth aspect, and the sixth aspect or the An evolved base station as described in any of the possible implementations of the six aspects.

In conjunction with the thirteenth aspect, in a first possible implementation, the system further includes a seventh aspect Or the user equipment of any one of the possible implementation manners of the seventh aspect.

A fourteenth aspect, the embodiment of the present invention provides a system for circuit domain fallback, comprising the mobility management entity according to any of the possible implementations of the fifth aspect or the fifth aspect, and the seventh aspect or the The user equipment described in any of the possible implementations of the seven aspects.

In conjunction with the fourteenth aspect, in a first possible implementation, the system further includes the evolved base station according to any one of the possible implementations of the sixth aspect or the sixth aspect.

A fifteenth aspect, the embodiment of the present invention provides a system for circuit domain fallback, comprising the mobility management entity according to any of the possible implementations of the eighth aspect or the eighth aspect, and the sixth aspect or the An evolved base station as described in any of the possible implementations of the six aspects.

In the embodiment of the present invention, the mobility management entity may learn the CS domain congestion of the 2G or 3G network before the user equipment accesses the CS domain of the 2G or 3G network, and determine the 2G or 3G network. When the CS domain has no available resources, the termination circuit domain is dropped, and the user equipment is prevented from accessing the 2G or 3G network when the CS domain of the 2G or 3G network is congested, thereby reducing unnecessary LTE networks and 2G. Or the signaling process of the 3G network avoids the signaling impact on the LTE network and the 2G or 3G network, reduces the load on the network, and improves the user experience.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention. Other drawings can also be obtained from those skilled in the art based on these drawings without paying any creative effort.

1 is a flowchart of a method for circuit domain fallback according to an embodiment of the present invention;

2 is a flowchart of still another method for circuit domain fallback according to an embodiment of the present invention;

FIG. 3 is a flowchart of still another method for circuit domain fallback according to an embodiment of the present invention;

4 is a flowchart of still another method for circuit domain fallback according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a mobility management entity according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an evolved base station according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of a user equipment according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of still another mobility management entity according to an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of an apparatus for circuit domain fallback according to an embodiment of the present invention.

detailed description

The embodiment of the invention provides a circuit domain fallback method. In the process of implementing the circuit domain fallback, the LTE network can know the congestion of the CS domain network of the 2G or 3G network in advance, terminate the circuit domain fallback call flow, and avoid unnecessary LTE. The signaling flow of the network and the 2G or 3G network avoids the signaling impact on the LTE network and the 2G or 3G network, reduces the load on the network, and improves the user experience. The embodiments of the present invention also provide corresponding devices and systems. The details are described below separately.

As shown in FIG. 1 , an embodiment of the present invention provides a method for circuit domain fallback. In this method, a User Equipment (UE) located in an LTE network as a calling party requests a CSFB from a Mobile Management Entity (MME) of the LTE network. The method is as follows.

S101: The MME receives a request message sent by a user equipment located in an LTE network, where the request message is used to request CSFB.

S102: During the CS domain handover preparation process of the LTE network to the 2G or 3G network, the MME determines that the CS domain of the 2G or 3G network has no available resources.

During the CSFB process, the user equipment needs to be handed over from the LTE network to the CS domain of the 2G or 3G network, so that the MME can be in the circuit of the LTE network to the second generation 2G or the third generation 3G network. Before the CS domain handover preparation process, that is, before the user equipment accesses the CS domain of the 2G or 3G network, it is determined whether the CS domain of the 2G or 3G network has available resources, and if no resources are available, the 2G is indicated. Or the CS domain of the 3G network may be congested.

S103: The MME sends a request rejection message to the user equipment, where the request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, where the request rejection message is used to indicate that the user equipment receives the The request rejection message begins, and the CSFB cannot be requested until the time corresponding to the value of the timer arrives.

The MME sends a request rejection message to the user equipment, rejecting the current CSFB, thereby terminating the CSFB. Further, since the user equipment may reselect to the 2G or 3G network to initiate the voice flow after waiting for a period of time, the request rejection message may include a cause value indicating that the CS domain is unavailable and a value of the timer, so that the user equipment From the receipt of the request rejection message, the CSFB is not requested until the time corresponding to the value of the timer arrives.

In the embodiment of the present invention, the MME may access the CS of the 2G or 3G network in the user equipment. Before the domain, the CS domain congestion condition of the 2G or 3G network is known, and the CS domain of the 2G or 3G network is determined to have available resources. When it is determined that the CS domain of the 2G or 3G network has no available resources, The user equipment sends a request rejection message, thereby rejecting this CSFB. And the request rejection message further includes a cause value indicating that the CS domain is unavailable and a value of the timer, so that the user equipment starts from receiving the request rejection message, and before the time corresponding to the value of the timer arrives The CSFB cannot be requested, so that the user equipment is prevented from accessing the 2G or 3G network when the CS domain of the 2G or 3G network is congested, and the CS domain of the user equipment in the 2G or 3G network is also avoided. In the case of congestion, CSFB is again requested to fall back to the 2G or 3G network, which reduces the signaling impact on the LTE network and the 2G/3G network and improves the user experience.

As shown in FIG. 2, an embodiment of the present invention provides a method of CSFB. In this method, the Mobile Services Switching Centre (MSC) may request the MME to initiate CSFB (ie, initiate a CSFB call), and the user equipment located in the LTE network may serve as a called party. The method is as follows.

S201: The MME receives a paging message sent by the MSC, where the paging message is used to request the MME to initiate a CSFB to the user equipment.

S202: During the CS domain handover preparation process of the LTE network to the 2G or 3G network, the MME determines that the CS domain of the 2G or 3G network has no available resources.

When CSFB is performed, the user equipment needs to be handed over from the LTE network to a CS domain of a 2G or 3G network, so that the MME can perform circuit switching on the LTE network to a second generation 2G or third generation 3G network. During the CS domain handover preparation process, that is, before the user equipment accesses the CS domain of the 2G or 3G network, it is determined whether the CS domain of the 2G or 3G network has available resources, and if no resources are available, the 2G or The CS domain of the 3G network may be congested.

S203: The MME does not send a CSFB paging message to the user equipment, so as to prevent the user equipment from selecting a 2G or 3G network to perform voice service after receiving the CSFB paging message.

After determining that the CS domain of the 2G or 3G network has no available resources, the MME does not send a CSFB paging message to the user equipment, so that the user equipment does not receive the CSFB paging request, which not only avoids the user equipment being If the CS domain of the 2G or 3G network is congested, the 2G or 3G network is connected to the voice service, and the user equipment is prevented from selecting 2G again if the CS domain of the 2G or 3G network is congested. The 3G network performs voice services, which reduces the signaling impact on the LTE network and the 2G/3G network and improves the user experience.

Optionally, before S102 or S202, the MME may indicate that an evolved base station (eNodeB) of the LTE network moves the user equipment from the LTE network to a CS domain of a 2G or 3G network to perform CSFB. After the eNodeB triggers the CS domain handover of the LTE network to the 2G or 3G network, it is determined whether the CS domain of the 2G or 3G network has available resources, and the method further includes: the MME according to the request message Sending a notification message to the evolved base station eNodeB, the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to a CS domain of a 2G or 3G network for CSFB; the MME receives the eNodeB according to the eNodeB The handover request message returned by the notification message, where the handover request message is used to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network.

Further, after the MME determines that the circuit switched CS domain of the 2G or 3G network has no available resources, the MME may send a handover request response message to the eNodeB, where the handover request response message carries a termination indication, and the termination The indication is for instructing the eNodeb to terminate the CSFB.

This is because for some eNodeBs, after transmitting the handover request message to the MME, even if no response message returned by the MME is received, CSFB may continue to be performed to switch the user equipment from the LTE network to the 2G or 3G network. CS domain. Therefore, the MME may further send a handover request response message including the termination indication to the eNodeB, so that the eNodeB terminates the CSFB according to the termination indication, that is, does not use the user equipment from the LTE network. Switching to the CS domain of the 2G or 3G network, thereby avoiding the ping-pong effect generated by the user equipment after accessing the 2G or 3G network in the case that the CS domain of the 2G or 3G network is congested, The signaling impact of LTE networks and 2G/3G networks improves the user experience.

In order to more clearly describe the embodiments of the present invention, a specific embodiment of the method of CSFB according to the present invention is provided below with reference to FIGS. 3 and 4. The specific implementations of FIGS. 1 and 2 can be referred to the following embodiments.

Referring to FIG. 3, an embodiment of the present invention provides a method for circuit domain call.

S301: The UE sends a request message to the MME, where the request message is used to request CSFB.

The request message may be an extended service request.

Optionally, the MME may determine whether the LTE network and the 2G or 3G network support switching the UE from the LTE network to the CS domain of the 2G or 3G network for the CSFB. The MME may also not judge, but by default, the communication network supports switching the UE from the LTE network to the CS domain of the 2G or 3G network for the CSFB, or only to some of the communication networks. Judging, wherein the communication network The network is the LTE network or the 2G or 3G network.

S302: The MME sends a notification message to the eNodeB according to the extended service request, where the notification message is used to instruct the eNodeB to move the UE from an LTE network to a CS domain of a 2G or 3G network to perform CSFB. That is, the notification message is used to instruct the eNodeB to move the UE from the LTE network to the 2G or 3G network in order to perform the CSFB.

When the MME determines that the LTE network and the 2G or 3G network support to switch the UE from the LTE network to the CS domain of the 2G or 3G network for the CSFB, the MME may notify the eNodeB of the LTE network and the 2G or 3G by sending a notification message. Whether the network supports handover of the UE from the LTE network to a CS domain of a 2G or 3G network for the CSFB to enable the eNodeB to initiate handover of the UE from the LTE network to a CS domain of a 2G or 3G network Claim.

S303: The eNodeB sends a handover request message to the MME.

The handover request message is used to indicate that the UE is switched from the LTE network to the CS domain of the 2G or 3G network, that is, the CS domain handover process that can be used to trigger the LTE network to the 2G or 3G network. The handover request message. The handover request message may be a CS domain handover request message from the LTE network to the 2G or 3G network, such as an LTE to 2G or 3G SRVCC HO Required message, or from the LTE network to the 2G Or PS domain and CS domain handover request messages of the 3G network (for example: LTE to 2G or 3G SRVCC and PS HO Required messages).

S304: The MME sends a first handover request message to an MSC in the 2G or 3G network, where the first handover request message is used to request the MSC to switch the UE from the LTE network to the 2G or Circuit switched CS domain of 3G networks.

S305: The MSC sends a second handover request message to the base station, where the second handover request message is used to request the base station to allocate a CS domain resource to the CS domain of the 2G or 3G network.

The base station in the embodiment of the present invention includes a base station controller (BSC) or a radio network controller (RNC).

S306: The base station sends a second handover request response message to the MSC, where the second handover request response message carries indication information indicating that the CS domain of the 2G or 3G network has no available resources.

If the CS domain of the 2G or 3G network cannot allocate the CS domain radio resource, for example, the target cell has no radio resource, the base station may carry the second handover request response message for indicating the 2G or 3G network. The CS domain has no indication of available resources to notify the MSC, the 2G or 3G The CS domain of the network cannot allocate CS domain resources.

S307: The MSC sends a first handover response message to the MME, where the first handover response message includes indication information indicating that the CS domain of the 2G or 3G network has no available resources.

After receiving the second handover request response message, the MSC may send a first handover response message to the MME in response to the first handover request message, because the first handover response message includes For indicating that the CS domain of the 2G or 3G network has no available resources, the first handover response message may also include indication information indicating that the CS domain of the 2G or 3G network has no available resources.

In addition, if the MSC has no resources, the first handover response message sent by the MSC to the MME may also include indication information for indicating that the CS domain of the 2G or 3G network has no available resources.

S308: The MME sends a handover request response message to the eNodeB, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the CSFB.

The MME may terminate the CSFB by transmitting a termination indication to the eNodeB upon receiving a first handover response message including indication information for indicating that the CS domain of the 2G or 3G network has no available resources. To prevent the eNodeB from continuing to execute this CSFB process.

Further, the handover request response message may further include indication information for indicating that the 2G or 3G network has no available resources.

S309: The eNodeB terminates the CSFB.

Specifically, after receiving the handover request response message, the eNodeB does not transfer the UE from the LTE network to the 2G or 3G network, thereby terminating the CSFB, thereby preventing the user equipment from being in the When the CS domain of the 2G or 3G network is congested, access to the 2G or 3G network reduces the signaling impact on the LTE network and the 2G/3G network, and improves the user experience.

S310: The MME sends a request rejection message to the UE, where the request rejection message includes a cause value and a timer value, the cause value is a CS domain unavailable, and the request rejection message is used to indicate the user equipment. From the receipt of the request rejection message, CSFB cannot be requested until the time corresponding to the value of the timer arrives.

For example, the request rejection message may be a Service Reject message, and the reason value included in the service rejection message is CS service temporarily unavailable, and the value of the timer included in the service rejection message is timed. The value of T3442.

After receiving the service rejection message, the UE starts a timer T3442, where the timeout period of the timer T3442 is the value of T3442 included in the service rejection message, and the UE does not wait before the timer T3442 times out. Try to initiate a CSFB service. The user equipment is not only allowed to access the 2G or 3G network when the CS domain of the 2G or 3G network is congested, but also the user equipment is prevented from being congested in the CS domain of the 2G or 3G network. Requesting CSFB to fall back to the 2G or 2G network again, reducing the signaling impact on the LTE network and the 2G/3G network, and improving the user experience.

In the above embodiment, the user equipment is used as the calling party. When the user equipment is called, the circuit domain switching method described in FIG. 4 may be referred to. For the specific implementation of the S403-S409 in the embodiment of the present invention, reference may be made to S303-S309, and details are not described herein again.

S401: The MSC sends a paging message to the MME to request to initiate a CSFB call procedure to the user equipment.

The paging message may specifically be a CS paging request.

S402: The MME sends a notification message to the eNodeB eNodeB according to the paging message, where the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to a CS domain of a 2G or 3G network. Perform CSFB.

Optionally, if the MME finds that the user equipment is in an idle state, the MME may send a packet domain paging message to the user equipment in an idle state, thereby changing the user equipment from an idle state to a connected state. After receiving the packet domain paging message, the user equipment may send a service request message to the MME.

S403: The eNodeB sends a handover request message to the MME.

S404: The MME sends a first handover request message to an MSC in the 2G or 3G network, where the first handover request message is used to request the MSC to switch the UE from the LTE network to the 2G or Circuit switched CS domain of 3G networks.

S405: The MSC sends a second handover request message to the base station, where the second handover request message is used to request the base station to allocate a CS domain resource to the CS domain of the 2G or 3G network.

S406: The base station sends a second handover request response message to the MSC, where the second handover request response message carries indication information indicating that the CS domain of the 2G or 3G network has no available resources.

S407: The MSC sends a first handover response message to the MME, where the first handover response message includes indication information indicating that the CS domain of the 2G or 3G network has no available resources.

S408: The MME sends a handover request response message to the eNodeB to terminate the CSFB.

Specifically, the handover request response message carries a termination indication, and the termination indication is used to instruct the eNodeb to terminate the CSFB.

S409: The eNodeB terminates the CSFB.

Specifically, after receiving the handover request response message, the eNodeB does not transfer the UE from the LTE network to the 2G or 3G network, thereby terminating the CSFB.

S410: The MME does not send a CSFB paging message to the user equipment.

It should be noted that, in the prior art, after receiving the paging message, the MME sends a CSFN paging message to the user equipment. Different from the prior art, in the embodiment of the present invention, after receiving the paging message sent by the user equipment, if the MME determines that the CS domain of the 2G or 3G network has no available resources, the MME does not The user equipment sends a CSFB paging message to prevent the user equipment from automatically selecting a 2G or 3G network for voice service after receiving the CSFB paging message, thereby avoiding selecting a 2G or 3G network for voice service. After the voice service fails due to congestion of the 2G or 3G network, the LTE network is returned to the LTE network, which reduces the signaling impact on the LTE network and the 2G/3G network and improves the user experience.

Corresponding to the method embodiment shown in FIG. 1 or FIG. 3, the embodiment of the present invention provides a mobility management entity 50, as shown in FIG. 5, comprising: a receiving unit 501, a determining unit 502, and a sending unit 503;

The receiving unit 501 is configured to receive a request message sent by a user equipment located in an LTE network, where the request message is used to request a CSFB;

The determining unit 502 is configured to determine that the CS domain of the 2G or 3G network has no available resources during the CS domain handover preparation process of the LTE network to the 2G or 3G network.

The sending unit 503 is configured to send a request rejection message to the user equipment, where the request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, where the request rejection message is used to indicate the user equipment From the receipt of the request rejection message, CSFB cannot be requested until the time corresponding to the value of the timer arrives.

In the CS domain handover preparation process of the LTE network to the 2G or 3G network, it is determined that the CS domain of the 2G or 3G network has no available resources. In a specific implementation, the sending unit 503 may perform the mobile switching. The central MSC sends a handover request message, the handover request message is used to request the The MSC switches the user equipment from the LTE network to a circuit switched CS domain of the 2G or 3G network to perform CSFB; the receiving unit 501 receives a handover response message returned by the MSC according to the handover request message, The handover response message includes indication information indicating that the CS domain of the 2G or 3G network has no available resources; then the determining unit 502 may determine, according to the handover response message, that the CS domain of the 2G or 3G network is unavailable. Resources.

Optionally, the sending unit 503 is further configured to: before the determining unit 502 determines that the CS domain of the 2G or 3G network has no available resources, send a notification message to the evolved base station eNodeB, where the notification message is used to indicate the The eNodeB moves the user equipment from the LTE network to a CS domain of a 2G or 3G network to perform CSFB; the receiving unit 501 is further configured to receive a handover request message returned by the eNodeB according to the notification message, where the handover is performed. The request message is used to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network. Therefore, after receiving the handover request message, the MME may determine whether the CS domain of the 2G or 3G network has available resources.

In addition, after the determining unit 502 determines that the CS domain of the 2G or 3G network has no available resources, the sending unit 503 may further send a handover request response message to the eNodeB, where the handover request response message carries a termination indication. The termination indication is used to instruct the eNodeb to terminate the CSFB.

The specific implementation manners of the mobility management network element and the interaction with other network elements provided by the embodiments of the present invention may be referred to the method embodiments in FIG. 1 or FIG. 3, and details are not described herein again.

In the embodiment of the present invention, the determining unit 502 may know the congestion of the CS domain of the 2G or 3G network and determine the 2G or 3G network before the user equipment accesses the CS domain of the 2G or 3G network. If the CS domain has available resources, the sending unit 503 may send a request rejection message to the user equipment when the determining unit 502 determines that the CS domain of the 2G or 3G network has no available resources, thereby rejecting the CSFB. . And the request rejection message further includes a cause value indicating that the CS domain is unavailable and a value of the timer, so that the user equipment starts from receiving the request rejection message, and before the time corresponding to the value of the timer arrives The CSFB cannot be requested, so that the user equipment is prevented from accessing the 2G or 3G network when the CS domain of the 2G or 3G network is congested, and the CS domain of the user equipment in the 2G or 3G network is also avoided. In the case of congestion, CSFB is again requested to fall back to the 2G or 3G network, which reduces the signaling impact on the LTE network and the 2G/3G network and improves the user experience.

Corresponding to the method embodiment of any one of FIG. 1 to FIG. 4, the embodiment of the present invention provides an evolved base station, as shown in FIG. 6, comprising: a receiving unit 601, a sending unit 602, and a terminating unit 603;

The receiving unit 601 is configured to receive a notification message sent by the MME, where the notification message is used to instruct the evolved base station to move the user equipment from the long term evolution LTE network to the circuit switched CS domain of the second generation 2G or third generation 3G network. For CSFB;

The sending unit 602 is configured to send a handover request message to the MME, to trigger a CS domain handover process of the LTE network to the 2G or 3G network;

The receiving unit 601 is further configured to receive a handover request response message sent by the MME, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the CSFB; the handover request response message The MME is sent if it is determined that the circuit switched CS domain of the 2G or 3G network has no available resources;

The terminating unit 603 is configured to terminate the CSFB according to the termination indication. For the specific implementation of the evolved base station and the interaction with other network elements, the method embodiments of any one of the embodiments of the present invention are not described herein.

In the embodiment of the present invention, after determining that the CS domain of the 2G or 3G network has no available resources, the MME may send a handover request response message including the termination indication to the eNodeB, so that the eNodeB can be used according to the Terminating the termination of the CSFB, that is, not switching the user equipment from the LTE network to the CS domain of the 2G or 3G network, thereby preventing the user equipment from being congested in the CS domain of the 2G or 3G network. The ping-pong effect generated after accessing the 2G or 3G network reduces the signaling impact on the LTE network and the 2G/3G network, and improves the user experience.

Corresponding to the method embodiment shown in FIG. 1 or FIG. 3, the embodiment of the present invention provides a user equipment 70, as shown in FIG. 7, comprising: a sending unit 701, a receiving unit 702, and a processing unit 703;

The sending unit 701 is configured to send a request message to the MME, where the request message is used to request CSFB;

The receiving unit 702 is configured to receive a request rejection message returned by the MME, where the request rejection message is sent by the MME when determining that the CS domain of the 2G or 3G network has no available resources, the request rejection message Included with a value indicating a reason value and a timer that is unavailable for the CS domain, the request rejection message is used to indicate that the user equipment 70 starts from receiving the request rejection message, to the The CSFB cannot be requested until the time corresponding to the value of the timer arrives;

The processing unit 703 is configured to start from the receipt of the request rejection message, and not request CSFB until the time corresponding to the value of the timer arrives. Therefore, the user equipment 70 is prevented from requesting the CSFB to fall back to the 2G or 3G network again when the CS domain of the 2G or 3G network is congested, which reduces the signaling impact on the LTE network and the 2G/3G network, and improves the user. Experience.

The specific implementation of the user equipment 70 and the interaction with other network elements provided by the embodiments of the present invention may be referred to the method embodiments in FIG. 1 or FIG. 3, and details are not described herein again.

Corresponding to the method embodiment described in FIG. 2 or FIG. 4, the embodiment of the present invention provides a mobility management entity 80, as shown in FIG. 8, including a receiving unit 801, a determining unit 802, and a processing unit 803:

The receiving unit 801 is configured to send, by the MSC, a paging message, where the paging message is used to request the mobility management entity to initiate a CSFB to a user equipment located in an LTE network.

The determining unit 802 is configured to determine that the CS domain of the 2G or 3G network has no available resources during the CS domain handover preparation process of the LTE network to the 2G or 3G network.

The processing unit 803 is configured to: after the determining unit 802 determines that the CS domain of the 2G or 3G network has no available resources, does not send a CSFB paging message to the user equipment, to prevent the user equipment from receiving The CSFB paging message is followed by a 2G or 3G network for voice service.

In the process of the CS domain handover preparation process of the LTE network to the 2G or 3G network, how to determine that the CS domain of the 2G or 3G network has no available resources, specifically: the mobility management entity further includes the first a sending unit, configured to send a handover request message to the mobile switching center MSC, where the handover request message is used to request the MSC to switch the user equipment from the LTE network to a circuit switched CS domain of the 2G or 3G network. The receiving unit 801 is further configured to receive a handover response message that is returned by the MSC according to the handover request message, where the handover response message includes, to indicate that the CS domain of the 2G or 3G network has no available resources. The determining unit 802 is specifically configured to determine, according to the handover response message, that the CS domain of the 2G or 3G network has no available resources.

Optionally, the mobility management entity further includes: a second sending unit 805, configured to send a notification message to the evolved base station eNodeB before the determining unit 802 determines that the CS domain of the 2G or 3G network has no available resources, The notification message is used to instruct the eNodeB to use the user equipment from The LTE network moves to the CS domain of the 2G or 3G network to perform CSFB; the receiving unit 801 is further configured to receive a handover request message that is returned by the eNodeB according to the notification message, where the handover request message is used to trigger the The CS domain handover procedure of the LTE network to the 2G or 3G network, so that the MME may determine whether the CS domain of the 2G or 3G network has available resources after receiving the handover request message.

Optionally, the second sending unit 805 is further configured to: after the determining unit 802 determines that the CS domain of the 2G or 3G network has no available resources, send a handover request response message to the eNodeB, where the handover request response The message carries a termination indication, the termination indication being used to instruct the eNodeb to terminate the CSFB.

Optionally, if the user equipment is in an idle state, the second sending unit 805 may further send a packet domain paging message to the user equipment in an idle state before sending the notification message to the eNodeB. The receiving unit 801 can also receive a service request message sent by the user equipment.

The specific implementation manners of the mobility management network element and the interaction with other network elements provided by the embodiments of the present invention may be referred to the method embodiments in FIG. 2 or FIG. 4, and details are not described herein again.

In the embodiment of the present invention, after the determining unit 802 determines that the CS domain of the 2G or 3G network has no available resources, the processing unit 803 does not send a CSFB paging message to the user equipment, so that the user equipment does not receive The access to the CSFB paging request not only prevents the user equipment from accessing the 2G or 3G network for voice service when the CS domain of the 2G or 3G network is congested, but also avoids the user equipment being in the 2G When the CS domain of the 3G network is congested, the 2G or 3G network is selected again for voice services, which reduces the signaling impact on the LTE network and the 2G/3G network, and improves the user experience.

A person skilled in the art can understand that, in the foregoing embodiments of FIG. 5 to FIG. 8 , a unit for transmitting a message, such as a sending unit 503, a sending unit 602, a sending unit 701, a first sending unit 804, or a second sending unit 805, It can be implemented by a transmitter or by a transceiver; a unit for receiving a message, such as a receiving unit 501, a receiving unit 601, a receiving 702 or a receiving unit 801, can be implemented by a receiver or by using a transceiver. In physical implementation, the transmitter or receiver or transceiver can be implemented by one physical entity or multiple physical entities. The transmitter, receiver, and transceiver can be implemented by one physical entity or multiple physical entities. Entity implementation, the present invention does not limit this. Other units, such as determining unit 502, terminating unit 603, processing unit 703, determining Unit 802 or processing unit 803 can be implemented using one or more processors. The above transmitter, receiver, transceiver and processor can be connected by a bus.

The embodiment of the present invention further provides an apparatus for circuit domain fallback, and the apparatus may include:

Processor 901, memory 902, bus 904, receiver 905, and transmitter 906. The processor 901, the memory 902, the receiver 905, and the transmitter 906 are connected by a bus 904 and complete communication with each other.

Processor 901 may be a single core or multi-core central processing unit, or a particular integrated circuit, or one or more integrated circuits configured to implement embodiments of the present invention.

The memory 902 may be a high speed RAM memory or a non-volatile memory such as at least one disk memory.

The memory 902 is used to store computer execution instructions 903. Specifically, the computer execution instructions 903 may include program code.

When the device is running, the processor 901 runs the computer execution instruction 903, and can execute the method flow of the circuit domain fallback described in the method embodiment corresponding to any one of FIG. 1 to FIG. When the method flow of the circuit domain fallback described in the method embodiment corresponding to FIG. 1 or FIG. 3 is performed, the device may be a mobility management entity, an evolved base station, or a user equipment. When the method flow of the circuit domain fallback described in the method embodiment corresponding to FIG. 2 or FIG. 4 is performed, the device may be a mobility management entity or an evolved base station.

The embodiment of the present invention provides a computer readable medium, including a computer executing instruction, when the processor of the computer executes the computer execution instruction, the computer performs the method embodiment corresponding to any one of FIG. 1 to FIG. The method flow of the circuit domain fallback.

The embodiment of the present invention further provides a system for circuit domain fallback, including a mobility management entity 50 and an evolved base station 60; optionally, a user equipment 70; a mobility management entity 50, an evolved base station 60, and a user For the operations performed by the device 70 and the interaction between the devices 70, reference may be made to the description of the method embodiment corresponding to FIG. 1 or FIG. 3, and the description of the device embodiment corresponding to FIG. 5 to FIG. 7 is omitted, and details are not described herein again.

The embodiment of the present invention further provides a system for circuit domain fallback, including a mobility management entity 50 and a user equipment 70; optionally, an evolved base station 60; a mobility management entity 50, an evolved base station 60, and a user For the actions performed by the device 70 and the interaction between the devices 70, refer to the description of the method embodiment corresponding to FIG. 1 or FIG. 3, or refer to the description of the device embodiment corresponding to FIG. 5 to FIG. I won't go into details here.

The embodiment of the present invention further provides a system for circuit domain fallback, including a mobility management entity 80 and an evolved base station 60; optionally, a user equipment; a mobility management entity 80, an evolved base station 60, and a user equipment For the actions of the respective operations and the interaction between them, refer to the description of the method embodiment corresponding to FIG. 2 or FIG. 4, and the description of the device embodiment corresponding to FIG. 6 or FIG. 8 is omitted, and details are not described herein again.

The LTE network mentioned in the present invention includes an LTE A network, and may subsequently have an LTE version.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention contributes in essence or to the prior art, or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium. A number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like. .

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, for clarity of hardware and software. Interchangeability, the composition and steps of the various examples have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

It will be apparent to those skilled in the art that, for the convenience and brevity of the description, the specific working processes of the systems, devices, and units described above may be referred to the corresponding embodiments in the foregoing method embodiments. Cheng, will not repeat them here.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, or an electrical, mechanical or other form of connection.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the embodiments of the present invention.

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any equivalent person can be easily conceived within the technical scope of the present invention by any person skilled in the art. Modifications or substitutions are intended to be included within the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

A method for circuit domain fallback, characterized in that it comprises:

The mobility management entity MME receives a request message sent by the user equipment of the long term evolution LTE network, where the request message is used to request the circuit domain to fall back;

During the circuit switched CS domain handover preparation process of the LTE network to the second generation 2G or the third generation 3G network, the MME determines that the CS domain of the 2G or 3G network has no available resources;

Sending, by the MME, a request rejection message to the user equipment, where the request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, where the request rejection message is used to indicate that the user equipment receives the The request rejection message begins, and the circuit domain cannot be requested to fall back until the time corresponding to the value of the timer arrives.
The method according to claim 1, wherein in the circuit-switched CS domain handover preparation process of the LTE network to the second-generation 2G or third-generation 3G network, the MME determines the 2G or 3G network No resources available in the CS domain include:

Sending, by the MME, a handover request message to the mobile switching center MSC, where the handover request message is used to request the MSC to switch the user equipment from the LTE network to a circuit switched CS domain of the 2G or 3G network to perform a circuit. Domain fall

Receiving, by the MME, a handover response message returned by the MSC according to the handover request message, where the handover response message includes indication information indicating that the CS domain of the 2G or 3G network has no available resources;

The MME determines, according to the handover response message, that there is no available resource in the CS domain of the 2G or 3G network.
The method according to claim 1 or 2, wherein before the MME determines that the CS domain of the 2G or 3G network has no available resources, the method further includes:

Sending, by the MME, a notification message to the eNodeB eNodeB according to the service request message, where the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to a CS domain of a 2G or 3G network to perform a circuit. Domain fall

The MME receives a handover request message returned by the eNodeB according to the notification message, where the handover request message is used to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network.
The method according to claim 3, wherein after the MME determines that the CS domain of the 2G or 3G network has no available resources, the method further includes:

And sending, by the MME, a handover request response message to the eNodeB, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback.
A method for circuit domain fallback, characterized in that the method comprises:

The evolved base station eNodeB located in the Long Term Evolution (LTE) network receives the notification message sent by the mobility management entity MME, and the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to the second generation 2G or third generation 3G network. Circuit-switched CS domain for circuit domain fallback;

Sending, by the eNodeB, a handover request message to the MME, to trigger a CS domain handover process of the LTE network to the 2G or 3G network;

Receiving, by the eNodeB, a handover request response message, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback; the handover request response message is The MME sends in the case that it is determined that the circuit switched CS domain of the 2G or 3G network has no available resources;

The eNodeB terminates the circuit domain fallback according to the termination indication.
A method for circuit domain fallback, characterized in that the method comprises:

The user equipment of the LTE-based LTE network sends a request message to the mobility management entity MME, where the request message is used to request the circuit domain to fall back;

Receiving, by the user equipment, a request rejection message returned by the MME, where the request rejection message is sent by the MME when determining that the circuit switched CS domain of the second generation 2G or third generation 3G network has no available resources, The request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, the request rejection message is used to indicate that the user equipment starts from receiving the request rejection message, and corresponds to a value of the timer. The time of the circuit cannot be requested to fall back before the time is reached;

The user equipment does not request the circuit domain to fall back from the receipt of the request rejection message until the time corresponding to the value of the timer arrives.
A method for circuit domain fallback, characterized in that it comprises:

The mobility management entity MME receives the paging message sent by the mobile switching center MSC, and the paging message is used to request the MME to initiate a circuit domain fallback for the user equipment located in the long term evolution LTE network;

During the circuit switched CS domain handover preparation process of the LTE network to the second generation 2G or the third generation 3G network, the MME determines that the CS domain of the 2G or 3G network has no available resources;

The MME does not send a circuit domain fallback paging message to the user equipment to avoid the user After receiving the circuit domain fallback paging message, the device selects a 2G or 3G network for voice service.
The method according to claim 7, wherein in the circuit switched CS domain handover preparation process of the LTE network to the second generation 2G or the third generation 3G network, the MME determines the 2G or 3G network No resources available in the CS domain include:

Sending, by the MME, a handover request message to the mobile switching center MSC, where the handover request message is used to request the MSC to switch the user equipment from the LTE network to a circuit switched CS domain of the 2G or 3G network to perform a circuit. Domain fall

Receiving, by the MME, a handover response message returned by the MSC according to the handover request message, where the handover response message includes indication information indicating that the CS domain of the 2G or 3G network has no available resources;

The MME determines, according to the handover response message, that there is no available resource in the CS domain of the 2G or 3G network.
The method according to claim 7 or 8, wherein before the MME determines that the CS domain of the 2G or 3G network has no available resources, the method further includes:

Sending, by the MME, a notification message to the eNodeB eNodeB according to the service request message, where the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to a CS domain of a 2G or 3G network to perform a circuit. Domain fall

The MME receives a handover request message returned by the eNodeB according to the notification message, where the handover request message is used to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network.
The method according to claim 9, wherein after the MME determines that the CS domain of the 2G or 3G network has no available resources, the method further includes:

And sending, by the MME, a handover request response message to the eNodeB, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback.
The method according to claim 9 or 10, wherein before the MME sends the notification message to the eNodeB, the method further includes:

Sending, by the MME, a packet domain paging message to the user equipment in an idle state;

The MME receives a service request message sent by the user equipment.
A mobility management entity, comprising:

a receiving unit, configured to receive a request message sent by a user equipment located in a long term evolution LTE network, where The request message is used to request that the circuit domain fall back;

a determining unit, configured to determine that the CS domain of the 2G or 3G network has no available resources during the circuit switched CS domain handover preparation process of the LTE network to the second generation 2G or the third generation 3G network;

a sending unit, configured to send a request rejection message to the user equipment, where the request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, where the request rejection message is used to indicate that the user equipment receives the The request rejection message begins, and the circuit domain cannot be requested to fall back until the time corresponding to the value of the timer arrives.
The mobility management entity according to claim 12, wherein the sending unit is further configured to send a handover request message to the mobile switching center MSC, where the handover request message is used to request the MSC to Switching the LTE network to a circuit switched CS domain of the 2G or 3G network for circuit domain fallback;

The receiving unit is further configured to receive a handover response message that is returned by the MSC according to the handover request message, where the handover response message includes indication information indicating that the CS domain of the 2G or 3G network has no available resources;

The determining unit is specifically configured to determine, according to the handover response message, that the CS domain of the 2G or 3G network has no available resources.
The mobility management entity according to claim 12 or 13, wherein the sending unit is further configured to send, to the evolved base station eNodeB, before the determining unit determines that the CS domain of the 2G or 3G network has no available resources. a notification message, the notification message is used to instruct the eNodeB to move the user equipment from the LTE network to a CS domain of a 2G or 3G network to perform circuit domain fallback;

The receiving unit is further configured to receive a handover request message that is returned by the eNodeB according to the notification message, where the handover request message is used to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network.
The mobility management entity according to claim 14, wherein the sending unit is further configured to send a handover request to the eNodeB after the determining unit determines that the CS domain of the 2G or 3G network has no available resources. In response to the message, the handover request response message carries a termination indication, the termination indication being used to instruct the eNodeb to terminate the circuit domain fallback.
An evolved base station, comprising:

a receiving unit, configured to receive a notification message sent by the mobility management entity MME, where the notification message is used to instruct the evolved base station to move the user equipment from the long term evolution LTE network to the second generation 2G or Circuit-switched CS domain of the third-generation 3G network for circuit domain fallback;

a sending unit, configured to send a handover request message to the MME, to trigger a CS domain handover process of the LTE network to the 2G or 3G network;

The receiving unit is further configured to receive a handover request response message sent by the MME, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback; the handover request response The message is that the MME sends if it is determined that the circuit switched CS domain of the 2G or 3G network has no available resources;

And a terminating unit, configured to terminate the circuit domain fallback according to the termination indication.
A user equipment, comprising:

a sending unit, configured to send a request message to the mobility management entity MME, where the request message is used to request that the circuit domain fall back;

a receiving unit, configured to receive a request rejection message returned by the MME, where the request rejection message is sent by the MME in determining that the circuit switched CS domain of the second generation 2G or third generation 3G network has no available resources, The request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, the request rejection message is used to indicate that the user equipment starts from receiving the request rejection message, to a value of the timer. The circuit domain cannot be requested to fall back before the corresponding duration arrives;

The processing unit is configured to start from the receipt of the request rejection message, and does not request the circuit domain to fall back until the time corresponding to the value of the timer arrives.
A mobility management entity, comprising:

a receiving unit, configured to receive a paging message sent by the mobile switching center MSC, where the paging message is used to request the mobility management entity to initiate a circuit domain fallback for a user equipment located in a long term evolution LTE network;

a determining unit, configured to determine that the CS domain of the 2G or 3G network has no available resources during the circuit switched CS domain handover preparation process of the LTE network to the second generation 2G or the third generation 3G network;

a processing unit, configured to: after the determining unit determines that the CS domain of the 2G or 3G network has no available resources, send a circuit domain fallback paging message to the user equipment, to prevent the user equipment from receiving the After the circuit domain falls back to the paging message, the 2G or 3G network is selected for voice service.
The mobility management entity according to claim 18, further comprising: a first sending unit;

The first sending unit is configured to send a handover request message to the mobile switching center MSC, where the And the request message is used to request the MSC to switch the user equipment from the LTE network to a circuit switched CS domain of the 2G or 3G network to perform circuit domain fallback;

The receiving unit is further configured to receive a handover response message that is returned by the MSC according to the handover request message, where the handover response message includes indication information indicating that the CS domain of the 2G or 3G network has no available resources;

The determining unit is specifically configured to determine, according to the handover response message, that the CS domain of the 2G or 3G network has no available resources.
The mobility management entity according to claim 18 or 19, further comprising:

a second sending unit, configured to send, to the evolved base station eNodeB, a notification message, before the determining unit determines that the CS domain of the 2G or 3G network has no available resources, where the notification message is used to instruct the eNodeB to use the user equipment Moving from the LTE network to a CS domain of a 2G or 3G network for circuit domain fallback;

The receiving unit is further configured to receive a handover request message that is returned by the eNodeB according to the notification message, where the handover request message is used to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network.
The mobility management entity according to claim 20, wherein the second sending unit is further configured to send, after the determining unit determines that the CS domain of the 2G or 3G network has no available resources, send the signal to the eNodeB. And a handover request response message, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback.
The method according to claim 20 or 21, wherein the second sending unit is further configured to send a packet domain page to the user equipment in an idle state before sending the notification message to the eNodeB. Message

The receiving unit is further configured to receive a service request message sent by the user equipment.
A mobility management entity, including a bus, and a processor, a memory, a transmitter, and a receiver connected to the bus;

The memory is for storing computer execution instructions, the computer execution instructions being configured to be executed by the processor;

The receiver is configured to receive a request message sent by a user equipment that is located in a Long Term Evolution (LTE) network, where the request message is used to request a circuit domain to fall back;

The processor is used for circuit switching between the LTE network to a second generation 2G or third generation 3G network During the CS domain handover preparation process, it is determined that the CS domain of the 2G or 3G network has no available resources;

The sender is configured to send a request rejection message to the user equipment, where the request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, where the request rejection message is used to indicate that the user equipment is Upon receiving the request rejection message, the circuit domain cannot be requested to fall back until the time corresponding to the value of the timer arrives.
An evolved base station, comprising: a bus, and a processor, a memory, a transmitter, and a receiver connected to the bus;

The memory is for storing computer execution instructions, the computer execution instructions being configured to be executed by the processor;

The receiver is configured to receive a notification message sent by the mobility management entity MME, where the notification message is used to indicate that the evolved base station moves the user equipment from the long term evolution LTE network to the circuit switching of the second generation 2G or third generation 3G network. CS domain to perform circuit domain fallback;

The transmitter is configured to send a handover request message to the MME to trigger a CS domain handover procedure of the LTE network to the 2G or 3G network;

The receiver is further configured to receive a handover request response message sent by the MME, where the handover request response message carries a termination indication, where the termination indication is used to instruct the eNodeb to terminate the circuit domain fallback; the handover request response The message is that the MME sends if it is determined that the circuit switched CS domain of the 2G or 3G network has no available resources;

The processor is configured to terminate the circuit domain fallback according to the termination indication.
A user equipment, comprising: a bus, and a processor, a memory, a transmitter, and a receiver connected to the bus;

The memory is for storing computer execution instructions, the computer execution instructions being configured to be executed by the processor;

The sender is configured to send a request message to the mobility management entity MME, where the request message is used to request that the circuit domain fall back;

The receiver is configured to receive a request rejection message returned by the MME, where the request rejection message is sent by the MME if it is determined that the circuit switched CS domain of the second generation 2G or third generation 3G network has no available resources. The request rejection message includes a cause value indicating that the CS domain is unavailable, and a value of a timer, the request rejection message is used to indicate that the user equipment starts from receiving the request rejection message, to the timer The circuit domain cannot be requested to fall back before the time corresponding to the value arrives;

The processor is configured to not request the circuit domain to fall back before receiving the request rejection message until the time corresponding to the value of the timer arrives.
Embodiments of the present invention provide a mobility management entity, including a bus, and a processor, a memory, a transmitter, and a receiver connected to the bus;

The memory is for storing computer execution instructions, the computer execution instructions being configured to be executed by the processor;

The receiver is configured to receive a paging message sent by the mobile switching center MSC, where the paging message is used to request the mobility management entity to initiate a circuit domain fallback of a user equipment located in a long term evolution LTE network;

The processor is configured to determine, during the circuit-switched CS domain handover preparation process of the LTE network to the second-generation 2G or the third-generation 3G network, that the CS domain of the 2G or 3G network has no available resources, where the determining unit is After determining that the CS domain of the 2G or 3G network has no available resources, sending a circuit domain fallback paging message to the user equipment, to prevent the user equipment from selecting 2G after receiving the circuit domain fallback paging message or The 3G network performs voice services.