WO2016086386A1 - Procédé de repli sur un réseau et équipement utilisateur associé - Google Patents

Procédé de repli sur un réseau et équipement utilisateur associé Download PDF

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Publication number
WO2016086386A1
WO2016086386A1 PCT/CN2014/093020 CN2014093020W WO2016086386A1 WO 2016086386 A1 WO2016086386 A1 WO 2016086386A1 CN 2014093020 W CN2014093020 W CN 2014093020W WO 2016086386 A1 WO2016086386 A1 WO 2016086386A1
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Prior art keywords
network
message
service
msc
lai
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PCT/CN2014/093020
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English (en)
Chinese (zh)
Inventor
段小嫣
金辉
王雷
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华为技术有限公司
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Priority to PCT/CN2014/093020 priority Critical patent/WO2016086386A1/fr
Priority to CN201480072607.9A priority patent/CN105917685B/zh
Publication of WO2016086386A1 publication Critical patent/WO2016086386A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/16—Communication-related supplementary services, e.g. call-transfer or call-hold

Definitions

  • the present invention relates to the field of communications, and in particular, to a network fallback method and related user equipment.
  • LTE Long Term Evolution
  • the LTE network is a Packet Switched (PS) network. It does not support Circuit Switched (CS) services such as voice calls. At this stage, voice calls are still an indispensable important communication service. For this reason, in the prior art, the 2G/3G network in the CS network is used to overlap the service area with the LTE network, and the LTE network is used to provide the PS network service for the user equipment (User Equipment, UE for short), and the UE receives the CS. When the paging message of the network needs to perform the service of the voice call service or other CS network, it is redirected to the 2G/3G network by the CS Fallback (CSFB) to perform the service, and returns to the LTE after the service ends.
  • CS CS Fallback
  • the CSFB process has a high failure rate and cannot meet the communication requirements.
  • the embodiment of the invention provides a network fallback method and related user equipment, which can reduce the failure rate of the CSFB process and meet the communication requirements.
  • a first aspect of the embodiments of the present invention provides a network fallback method, including:
  • the user equipment UE receives the first message in the Long Term Evolution (LTE) network, where the first message is used to instruct the UE to perform a service of the circuit switched CS network;
  • LTE Long Term Evolution
  • the UE After receiving the first message, the UE falls back to the CS network; where the UE determines the location area LA change information before falling back to the CS network, and the LA change information is used to indicate the pre- Whether the LAI of the UE has changed during the time period;
  • the UE sends a location update to the mobile switching center MSC accessed by the UE after falling back to the CS network.
  • the location update request includes indication information of a service of the CS network;
  • the UE receives a service setup message corresponding to the location update request, and completes a process of establishing a service of the CS network with the MSC.
  • the preset time period is a preset duration of time before the UE receives the first message.
  • the segment, or the preset time period is a time period between a time when the UE receives the first message and a time when the UE falls back to the CS network.
  • the determining LA change information Indicates whether the LAI of the UE has changed before falling back to the CS network, including:
  • the UE performs the tracking area update TAU process, determining LA change information, where the LA change information is specifically used to indicate that the UE starts and terminates at the start of the TAU process before falling back to the CS network. Whether the LAI has changed;
  • the UE performs the LTE intra-network handover HO procedure, determining the LA change information, where the LA change information is specifically used to indicate that the UE starts the HO process in the LTE network before falling back to the CS network. Whether the LAI at the time of the change and the time of the change has occurred.
  • the LA change information includes a first location area identifier LAI and a second LAI, where the first LAI is used to identify the LA of the UE at the start of the TAU process.
  • the second LAI is used to identify the LA of the UE when the TAU process is terminated;
  • the LA change information includes a first LAI and a second LAI, where the first LAI is used to identify that the UE is initiating the HO process in the LTE network.
  • the second LAI is used to identify an LA of the UE when the HO process is terminated in the LTE network.
  • the LA change information includes a first value or a second The value, the determining LA change information includes:
  • the LA of the UE does not change within the preset time period, determine that the value of the LA change information is the second value.
  • the foregoing LA change information indicates that the preset time period is The LA of the UE is changed, and after the UE falls back to the CS network, sending the location update request to the MSC accessed by the UE includes:
  • the UE sends a location update request to the MSC accessed by the UE.
  • the location update Requesting for the MSC, to initiate a CSFB roaming forward procedure to the MSC that sent the first message, and/or for the MSC to initiate CSFB roaming to the visited location register VLR corresponding to the MSC that sent the first message A trial process to send a service setup message to the UE.
  • a second aspect of the embodiments of the present invention provides a network fallback method, including:
  • the UE determines whether the circuit domain fallback CSFB is currently being executed;
  • the UE determines that the CSFB is currently being executed, the UE performs the TAU or LTE intra-network HO procedure after the CSFB process ends.
  • the determining, by the UE, whether the circuit domain is currently being executed to fall back to the CSFB further includes:
  • the HO process in the TAU or LTE network is performed:
  • the UE falls back to the CS network, and returns to the LTE network to perform a TAU or LTE intra-HO procedure after the service execution of the CS network is completed;
  • the UE performs a TAU or LTE intra-network HO procedure.
  • the determining, by the UE, whether the current domain is currently performing the CSFA fallback includes:
  • the HO process in the TAU or LTE network is performed:
  • the UE falls back to the CS network, and returns to the LTE network to perform a TAU or LTE intra-HO procedure after the service execution of the CS network is completed;
  • the UE performs a TAU or LTE intra-network HO procedure.
  • a third aspect of the embodiments of the present invention provides a network fallback method, including:
  • the fourth message is sent to the accessed MSC, where the fourth message is used to request the MSC to perform the service of the CS network.
  • the UE determines that the UE does not complete the execution process of the service of the CS network before receiving the fifth message, sending a location update request to the MSC, where the location update request includes the service of the CS network Instructions;
  • the UE receives the service setup message corresponding to the location update request, or sends a service setup message corresponding to the location update request to the MSC, and completes the establishment process of the CS network service with the MSC.
  • the preset area identifier is saved in the UE, and the preset area identifier is used to identify the preset area.
  • the UE Before the UE determines whether the UE completes the execution process of the service of the CS network before receiving the fifth message, the UE further includes:
  • the step of triggering the UE to determine whether the UE completes the execution process of the service of the CS network before receiving the fifth message If the UE determines that the current location of the UE belongs to the preset area, the step of triggering the UE to determine whether the UE completes the execution process of the service of the CS network before receiving the fifth message .
  • the feature of the preset area is:
  • the location area identifier LAI of the UE may change
  • the location area identifier LAI of the UE may change
  • the location area identifier LAI of the UE changes.
  • the UE determines whether the UE completes the CS network before receiving the fifth message. Before the execution of the business, it also includes:
  • the UE determines that the UE performs a TAU or intra-LTE intra-HO procedure before falling back from the LTE network to the CS network, triggering the UE to determine whether the UE completes the CS before receiving the fifth message.
  • the location update Requesting for the MSC to initiate a CSFB roaming forward procedure, and/or for the MSC to initiate a CSFB roaming retry procedure to the visited location register VLR corresponding to the MSC transmitting the first message to send to the UE
  • the service establishes a message or receives a service setup message sent by the UE.
  • a fourth aspect of the embodiments of the present invention provides a UE, including:
  • a first receiving module configured to receive, in a long term evolution LTE network, a first message, where the first message is used to instruct the UE to perform a service of a circuit switched CS network;
  • a fallback execution module configured to fall back to the CS network after receiving the first message
  • the LA information module is configured to determine location area LA change information before the fallback to the CS network, where the LA change information is used to indicate whether the LA of the UE has changed within a preset time period;
  • an update requesting module configured to: when the LA change information indicates that the LA of the UE changes in the preset time period, after moving back to the CS network, the mobile switching center MSC accessing the UE Sending a location update request, where the location update request includes indication information of a service of the CS network;
  • a service establishing module configured to receive a service establishment message corresponding to the location update request, and complete a process of establishing a service of the CS network with the MSC.
  • the preset time period is a preset duration of time before the UE receives the first message.
  • the segment, or the preset time period is a time period between a time when the UE receives the first message and a time when the UE falls back to the CS network.
  • the second implementation manner of the fourth aspect of the embodiment of the present invention is characterized in that:
  • the LA change information is specifically used to indicate whether the LAI of the UE changes at the start and end of the TAU process before falling back to the CS network;
  • the UE performs the LTE intra-network handover HO procedure, determining the LA change information, where the LA change information is specifically used to indicate that the UE starts the HO process in the LTE network before falling back to the CS network. Whether the LAI at the time of the change and the time of the change has occurred.
  • the third implementation manner of the fourth aspect of the embodiment of the present invention is characterized by:
  • the LA change information includes a first location area identifier LAI and a second LAI, where the first LAI is used to identify the LA of the UE at the start of the TAU process.
  • the second LAI is used to identify the LA of the UE when the TAU process is terminated;
  • the LA change information includes a first LAI and a second LAI, where the first LAI is used to identify the LA of the UE when the HO process is terminated in the LTE network.
  • the second LAI is used to identify the LA of the UE at the latest moment before falling back to the CS network.
  • the LA change information includes: a first value or a second Value
  • the LA determination module is specifically used to:
  • the LA of the UE does not change within the preset time period, determine that the value of the LA change information is the second value.
  • the update request module includes:
  • An LA determining unit configured to determine, after the UE falls back to the CS network, a third LAI, where the third LAI is used to indicate an LA of the UE in the CS network;
  • an update requesting unit configured to send a location update request to the MSC accessed by the UE when the second LAI is the same as the third LAI, and the second LAI is different from the first LAI.
  • the location update Requesting, for the MSC, to initiate a CSFB roaming forward procedure to the MSC that sent the first message, and/or for the MSC to initiate CSFB roaming to the visited location register VLR corresponding to the MSC that sent the first message A trial process to send a service setup message to the UE.
  • a fifth aspect of the embodiments of the present invention provides a UE, including:
  • a state judging module configured to determine, when the UE satisfies a condition of performing a tracking area update TAU or an intra-HO handover HO in an LTE network, whether the UE is currently performing a circuit domain fallback CSFB;
  • the task deferring module is configured to: when the state judging module determines that the UE is currently performing CSFB, after the CSFB process ends, perform a TAU or LTE intra-network HO process.
  • the UE further includes:
  • a second receiving module configured to receive a second message in the LTE network, where the second message is used to instruct the UE to perform a service of the CS network;
  • the fallback request module is configured to send a third message to the mobility management entity MME before the state determining module determines whether the circuit domain fallback CSFB is currently being executed, where the third message is used to indicate that the UE requests to fall back to the CS network. Performing services of the CS network;
  • the task postponement module includes:
  • a network fallback unit configured to fall back to the CS network when the MME accepts the third message
  • a task execution unit configured to perform a TAU or LTE intra-network HO process when the network fallback unit returns to the LTE network after the service execution of the CS network is completed; or when the MME does not accept the third In the case of a message, the HO process in the TAU or LTE network is performed.
  • the UE further includes:
  • a second receiving module configured to receive a second message in the LTE network, where the second message is used to instruct the UE to perform a service of the CS network;
  • the task postponement module includes:
  • a fallback requesting unit configured to send a third message to the mobility management entity MME, where the third message is used to indicate that the UE requests to fall back to the CS network to perform the service of the CS network;
  • a network fallback unit configured to fall back to the CS network when the MME accepts the third message
  • a task execution unit configured to perform a TAU or LTE intra-network HO process when the network fallback unit returns to the LTE network after the service execution of the CS network is completed; or when the MME does not accept the third In the case of a message, the HO process in the TAU or LTE network is performed.
  • a sixth aspect of the embodiments of the present invention provides a UE, including:
  • a service requesting module configured to send a fourth message to the accessed MSC after the UE falls back from the LTE network to the CS network, where the fourth message is used to request the MSC to perform the service of the CS network;
  • a third receiving module configured to receive a fifth message sent by the MSC, where the fifth message is used to: if the MSC does not accept the fourth message, instruct the UE to release a connection with the MSC; Or, if the MSC accepts the fourth message, and completes the process of performing the service of the CS network with the UE, instructing the UE to release the connection with the MSC;
  • a service judging module configured to determine whether the UE completes the execution process of the service of the CS network before receiving the fifth message
  • a request updating module configured to: when the service determining module determines that the UE does not complete the execution process of the service of the CS network before receiving the fifth message, send a location update request to the MSC, where the location update is performed Requesting indication information including services of the CS network;
  • Establishing a service module configured to receive a service establishment message corresponding to the location update request, or send a service setup message corresponding to the location update request to the MSC, and complete a service establishment process of the CS network with the MSC.
  • the preset area identifier is saved in the UE, and the preset area identifier is used to identify the preset area.
  • the UE further includes:
  • An area determining module configured to determine whether a current location of the UE belongs to the preset area
  • the area determining module determines that the current location of the UE belongs to the preset area, triggering the service determining module to determine whether the UE completes the The steps of the execution process of the CS network's business.
  • the preset area is characterized by:
  • the location area identifier LAI of the UE may change
  • the location area identifier LAI of the UE may change
  • the location area identifier LAI of the UE changes.
  • the UE further includes:
  • Determining a service module configured to determine whether the HO process in the TAU or LTE network is performed before the UE falls back from the LTE network to the CS network;
  • the service determining service module determines that the UE performs a TAU or an intra-HO process in the LTE network before the LTE network falls back to the CS network, the service determining module is triggered to determine whether the UE completes before receiving the fifth message. The steps of the execution process of the service of the CS network.
  • the location update Requesting for the MSC to initiate a CSFB roaming forward procedure, and/or for the MSC to initiate a CSFB roaming retry procedure to the visited location register VLR corresponding to the MSC transmitting the first message to send to the UE
  • the service establishes a message or receives a service setup message sent by the UE.
  • a seventh aspect of the embodiments of the present invention provides a UE including an input device, an output device, a processor, and a memory.
  • the processor is configured to perform the following steps by calling an operation instruction stored in the memory:
  • the UE After receiving the first message, fall back to the CS network; wherein, before the UE falls back to the CS network, determine the location area LA change information, where the LA change information is used to indicate Whether the LAI of the UE has changed within a preset time period;
  • the LA change information indicates that the LA of the UE changes in the preset time period, after the UE falls back to the CS network, sending a location update request to the mobile switching center MSC accessed by the UE, where
  • the location update request includes indication information of the service of the CS network;
  • the preset time period is a preset duration of time before the UE receives the first message.
  • the segment, or the preset time period is a time period between a time when the UE receives the first message and a time when the UE falls back to the CS network.
  • the processor is further configured to execute by calling an operation instruction stored in the memory. The following steps:
  • the UE performs the tracking area update TAU process, determining LA change information, where the LA change information is specifically used to indicate that the UE starts and terminates at the start of the TAU process before falling back to the CS network. Whether the LAI has changed;
  • the UE performs the LTE intra-network handover HO procedure, determining the LA change information, where the LA change information is specifically used to indicate that the UE starts the HO process in the LTE network before falling back to the CS network. Whether the LAI at the time of the change and the time of the change has occurred.
  • the LA change information includes a first location area identifier LAI and a second LAI, where the first LAI is used to identify the LA of the UE at the start of the TAU process.
  • the second LAI is used to identify the LA of the UE when the TAU process is terminated;
  • the LA change information includes a first LAI and a second LAI, where the first LAI is used to identify that the UE is initiating the HO process in the LTE network.
  • the second LAI is used to identify the HO process of the UE in the LTE network LA at the time of termination.
  • the LA change information includes a first value or a second The value is also used to perform the following steps by calling an operation instruction stored in the memory:
  • the LA of the UE does not change within the preset time period, determine that the value of the LA change information is the second value.
  • the processor is further configured to perform the following steps by calling an operation instruction stored in the memory:
  • determining a third LAI After falling back to the CS network, determining a third LAI, where the third LAI is used to indicate an LA of the UE in the CS network;
  • a location update request is sent to the MSC accessed by the UE.
  • the location update Requesting, for the MSC, to initiate a CSFB roaming forward procedure to the MSC that sent the first message, and/or for the MSC to initiate CSFB roaming to the visited location register VLR corresponding to the MSC that sent the first message A trial process to send a service setup message to the UE.
  • An eighth aspect of the embodiments of the present invention provides a UE including an input device, an output device, a processor, and a memory.
  • the processor is configured to perform the following steps by calling an operation instruction stored in the memory:
  • the HO process in the TAU or LTE network is performed after the CSFB process ends.
  • the processor is further configured to perform the following steps by calling an operation instruction stored in the memory:
  • the MME accepts the third message, it falls back to the CS network, and returns to the LTE network to perform a TAU or LTE intra-network HO process after the service execution of the CS network is completed;
  • the processor is further configured to perform the following steps by calling an operation instruction stored in the memory:
  • the MME accepts the third message, it falls back to the CS network, and returns to the LTE network to perform a TAU or LTE intra-network HO process after the service execution of the CS network is completed;
  • a ninth aspect of the embodiments of the present invention provides a UE including an input device, an output device, a processor, and a memory.
  • the processor is configured to perform the following steps by calling an operation instruction stored in the memory:
  • the fourth message is sent to the accessed MSC, where the fourth message is used to request the MSC to perform the service of the CS network.
  • the fifth message is used to: if the MSC does not accept the fourth message, instruct the UE to release a connection with the MSC; or, if the MSC accepts Determining, by the UE, that the UE completes the connection with the MSC by performing the process of performing the service of the CS network with the UE;
  • the preset area identifier is saved in the UE, and the preset area identifier is used to identify the preset area.
  • the processor is also used to perform the following steps by calling an operation instruction stored in the memory:
  • the feature of the preset area is:
  • the location area identifier LAI of the UE may change
  • the location area identifier LAI of the UE may change
  • the location area identifier LAI of the UE changes.
  • the processor is further configured to perform the following steps by calling an operation instruction stored in the memory:
  • the UE If it is determined that the UE performs the TAU or the intra-HO process in the LTE network before the LTE network falls back to the CS network, it is triggered to determine whether the UE completes the execution process of the service of the CS network before receiving the fifth message. A step of.
  • the location update Requesting for the MSC to initiate a CSFB roaming forward procedure, and/or for the MSC to initiate a CSFB roaming retry procedure to the visited location register VLR corresponding to the MSC that sent the first message to The UE sends a service setup message or receives a service setup message sent by the UE.
  • An embodiment of the present invention provides a network fallback method, including: a UE receiving a first message in an LTE network; and after receiving the first message, falling back to the CS network; and before falling back to the CS network, Determining the LA change information; after falling back to the CS network, sending a location update request to the MSC accessed by the UE according to the LA change information, so that the MSC completes the establishment process of the service of the CS network.
  • the process of the HO in the TAU or the LTE network often causes the change of the location area to which the UE belongs. If the location area of the UE changes, the MSC that sends the paging message in the CS network and the MSC that the UE accesses.
  • the LA change information is determined, where the LA change information is used to indicate whether the LA of the UE changes before falling back to the CS network; after the UE falls back to the CS network, according to the The LA change information sends a location update request to the MSC, so that the MSC completes the establishment process of the service of the CS network.
  • the UE is enabled to estimate the change of the MSC according to the change of the LA, and instructs the MSC to complete the establishment process of the service of the CS network according to the change of the LA, so that even if the MSC that sends the first message is different from the MSC accessed by the UE, the UE It is also possible to complete the establishment process of the CS network service with the accessed MSC, reduce the failure rate of the CSFB process, and meet the communication requirements.
  • FIG. 1 is a schematic diagram of an application scenario of a CSFB according to an embodiment of the present invention
  • FIG. 2 is a flowchart of an embodiment of a network fallback method according to an embodiment of the present invention
  • FIG. 3 is a flowchart of another embodiment of a network fallback method according to an embodiment of the present invention.
  • FIG. 4 is a flowchart of another embodiment of a network fallback method according to an embodiment of the present invention.
  • FIG. 5 is a flowchart of another embodiment of a network fallback method according to an embodiment of the present invention.
  • FIG. 6 is a flowchart of another embodiment of a network fallback method according to an embodiment of the present invention.
  • FIG. 7 is a flowchart of another embodiment of a network fallback method according to an embodiment of the present invention.
  • FIG. 8 is a flowchart of an embodiment of a UE according to an embodiment of the present invention.
  • FIG. 9 is a flowchart of another embodiment of a UE according to an embodiment of the present invention.
  • FIG. 10 is a flowchart of another embodiment of a UE according to an embodiment of the present invention.
  • FIG. 11 is a flowchart of another embodiment of a UE according to an embodiment of the present invention.
  • FIG. 12 is a flowchart of another embodiment of a UE according to an embodiment of the present invention.
  • FIG. 13 is a flowchart of another embodiment of a UE according to an embodiment of the present invention.
  • FIG. 14 is a flowchart of another embodiment of a UE according to an embodiment of the present invention.
  • the embodiment of the invention provides a network fallback method, which can reduce the failure rate of the CSFB process and meet the communication requirements.
  • the present invention also proposes related user equipment, which will be separately described below.
  • the CSFB is a service process that enables the UE to fall back from the LTE network to the CS network.
  • the process mainly includes the following four steps:
  • Step 1 The UE receives a paging message from the MSC of the CS network in the LTE network.
  • Step 2 The UE requests the MME of the CS network to fall back to the CS network.
  • Step 3 If the MME receives the request of the UE, the UE falls back from the LTE network to the paging message in the CS network response step 1.
  • Step 4 The UE returns to the LTE network after the response ends.
  • the UE After the UE falls back from the LTE network to the CS network in step 3, the UE accesses the MSC and attempts to complete service establishment with the MSC to perform the service of the CS network, that is, respond to the paging message in step 1.
  • the UE performs CSFB fallback from the LTE network to the CS network if the accessed MSC is different from the MSC that sends the paging message to the UE in step 1, the MSC accessed by the UE cannot identify the UE to the paging.
  • the UE cannot complete the service establishment with the accessed MSC, and the UE cannot perform the service of the CS network normally, and the CSFB process fails.
  • cells 1 and 2 belong to the Tracking Area (TA) 1; Cell 3 and Cell 4 belong to TA 2; and Cell 5, Cell 6, and Cell 7 belong to TA 3.
  • TA Tracking Area
  • Cell 1 and Cell 2 belong to a Location Area (LA) 1; Cell 3 and Cell 4 belong to LA 2; and Cell 5 and Cell 6 belong to LA 3.
  • LA Location Area
  • MSC1 is responsible for the services of Cell 1
  • Cell 2, Cell 3, and Cell 4 and MSC2 is responsible for the services of Cell 5 and Cell 6.
  • the UE located in Cell 4 receives a paging message from MSC1 on the LTE network and performs CSFB. However, during the fallback process, the UE moves from Cell 4 to Cell 5 and performs a TAU operation such that the TA to which it belongs changes from TA 2 to TA 3. After the UE falls back to the 2G/3G network, it is connected to MSC2 because it is in Cell 5. However, the MSC2 is not the MSC1 that sends the paging message to the UE. Therefore, the UE cannot recognize the response of the UE to the paging message, the UE cannot complete the service establishment with the MSC2, and the CSFB process fails.
  • FIG. 2 mainly includes:
  • the UE receives the first message in the LTE network.
  • the LTE network is used to provide the UE with the service of the PS network, and when the UE needs to perform the service of the CS network, the UE receives the first message in the LTE network, where the first message is used to instruct the UE to perform the circuit switched CS network. Business.
  • the UE After receiving the first message in the LTE network, the UE performs a CSFB process to fall back to the CS network to perform the service of the CS network.
  • the UE determines LA change information.
  • the UE determines LA change information, which is used to indicate whether the LA of the UE has changed within a preset time period.
  • LA change information is various, and will be described in detail in the following embodiments, which are not limited herein.
  • the LA of the UE may change if the UE performs the TAU process, or the HO process in the LTE network, or other processes.
  • the reason for causing the LA of the UE to change is not limited.
  • the step 202 may also be before step 201, which is not limited herein.
  • the UE falls back to the CS network.
  • the UE After receiving the first message and determining the LA change information, the UE falls back to the CS network. It can be understood that since step 203 is performed after step 202, the LA change information actually indicates whether the LA of the UE has changed before falling back to the CS network.
  • the UE After the UE falls back to the CS network, it accesses the MSC in the CS network. If the MSC can complete the establishment process of the CS network with the UE, the UE can perform the service of the CS network.
  • step 204 is performed.
  • the UE sends a location update request to the MSC accessed by the UE.
  • the UE sends a location update request (Location Updating Request) to the accessed MSC after dropping back to the CS network and accessing the MSC, where the location update is performed.
  • the request includes the indication information of the service of the CS network, and the MSC can complete the location update of the UE and complete the establishment process of the service of the CS network with the UE according to the location update request.
  • the UE receives a service establishment message corresponding to the location update request, and completes a process of establishing a service of the CS network with the MSC.
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then sends a service setup message (Setup) corresponding to the location update request to the UE, and the UE completes the service establishment process of the CS network according to the service setup message and the MSC. .
  • the embodiment provides a network fallback method, including: the UE receives the first message in the LTE network; after receiving the first message, it falls back to the CS network; and, before falling back to the CS network, determining The LA change information; if the LA change information indicates that the LA of the UE has changed within the preset time period, after falling back to the CS network, sending a location update request to the MSC accessed by the UE, and completing the location with the MSC The establishment process of the CS network service.
  • the process of the HO in the TAU or the LTE network is an important reason that the MSC that sends the first message in the CS network is different from the MSC that the UE accesses, and the processes such as the HO in the TAU or the LTE network are often caused at the same time.
  • the LA change information is used to indicate whether the LA of the UE changes during the preset time period before falling back to the CS network; the UE is falling back to the CS.
  • the location update request is sent to the MSC according to the LA change information, so that the MSC completes the establishment process of the service of the CS network.
  • the UE is enabled to estimate the change of the MSC according to the change of the LA, and instructs the MSC to complete the establishment process of the service of the CS network according to the change of the LA, so that even if the MSC that sends the first message is different from the MSC accessed by the UE, the UE It is also possible to complete the establishment process of the CS network service with the accessed MSC, reduce the failure rate of the CSFB process, and satisfy the communication. Claim.
  • FIG. 2 provides a basic flow of the network fallback method provided by the present invention.
  • the following embodiment provides a more detailed network fallback method.
  • the method mainly includes:
  • the UE receives the first message in the LTE network.
  • the LTE network is used to provide the UE with the service of the CS network, and when the UE needs to perform the service of the CS network, the UE receives the first message in the LTE network, where the first message is used to instruct the UE to perform the service of the CS network. .
  • the MSC of the CS network sends a paging request (Paging Request), and the paging request is sent to the UE in the form of a first message after being processed by the Mobility Management Entity (MME).
  • Paging Request a paging request
  • MME Mobility Management Entity
  • the UE is in an idle state, that is, there is no wireless connection between the UE and the LTE network, the first message is in the form of a Paging message; if the UE is in a connected state, that is, there is a wireless connection between the UE and the LTE network, the The first message is in the form of a CS Service Notification.
  • the UE After receiving the first message in the LTE network, the UE performs a CSFB process to fall back to the CS network to perform the service of the CS network.
  • the UE determines LA change information.
  • the UE determines LA change information, which is used to indicate whether the LA of the UE has changed within a preset time period.
  • the LA of the UE may change. Specifically, if the UE performs the TAU process, the UE determines LA change information, where the LA change information is specifically used to indicate whether the LA changes at the start and end of the TAU process before the UE falls back to the CS network; or If the UE performs the intra-LTE intra-HO procedure, the UE determines the LA change information, where the LA change information is specifically used to indicate whether the LA of the UE starts and terminates during the HO process in the LTE network before falling back to the CS network. Change.
  • the LA of the UE may also change due to other reasons, and is not limited herein.
  • the LAI is stored in the UE, and the LAI is used to identify the LA in which the UE is located. There are many ways for the UE to obtain the LAI. Generally, when the UE performs the location area update, the tracking area update, or other operations, the network side sends the LA of the UE to the UE in the form of the LAI, which is not limited herein.
  • the LA change information includes a first LAI and a second LAI, where the first LAI is used to identify the LA of the UE at the start time of the preset time period, that is, the LAI saved by the UE at the start time of the preset time period.
  • the second LAI is used to identify the LA of the UE at the time of termination of the preset time period. Specifically, if the UE performs the TAU procedure, the first LAI is used to identify the LA of the UE at the start of the TAU process, that is, the LAI saved by the UE at the start time of the TAU process, and the second LAI is used to identify the UE in the TAU process.
  • the first LAI is used to identify the LA of the UE in the LTE network at the start of the HO process, that is, the LAI saved by the UE at the start time of the HO process, and the second The LAI is used to identify the LA of the UE when the HO procedure is terminated.
  • the first LAI is different from the second LAI, it indicates that the UE has changed at the start of the TAU or HO process and the LA at the time of termination.
  • the step 302 may also be before step 301, which is not limited herein. If the step 302 is before the step 301, the preset time period is a time period of the preset time length before the UE receives the first message; if the step 302 is after the step 301, the preset time period is that the UE receives the first message. The time period between the moment and the moment of falling back to the CS network.
  • the MME may wait for the UE to complete the execution of the TAU or other process, and then send the message to the UE.
  • the UE may receive the first message from the LTE network within the preset time after performing step 302, and then perform steps 303 to 305.
  • the UE falls back to the CS network.
  • the UE After receiving the first message and determining the LA change information, the UE falls back to the CS network.
  • the UE After the UE falls back to the CS network, it accesses the MSC in the CS network. If the MSC can complete the establishment process of the CS network with the UE, the UE can perform the service of the CS network.
  • the UE determines a third LAI
  • the third LAI is determined, where the third LAI is used to indicate the LA of the UE in the CS network.
  • the third LAI can also be considered as the LAI of the cell in which the UE resides in the CS network, because the UE camps in the CS network for a short period of time.
  • the UE may obtain the third LAI from the broadcast message of the cell of the CS network, and may obtain the third LAI from other channels, which is not limited herein.
  • the UE indicates that the LA changes in the LTE network before falling back to the CS network, indicating that the first message is sent to the UE.
  • the MSC is likely to be different from the MSC accessed by the UE. The operation of step 305 is triggered at this time.
  • the operation of step 305 may also be triggered. That is, if the third LAI is different from the first LAI, the operation of step 305 is triggered.
  • the UE does not change in the LTE network before the UE falls back to the CS network, and the MSC that sends the first message to the UE is likely to be the same as the MSC accessed by the UE.
  • the MSC that sends the first message to the UE is the same as the MSC that the UE accesses
  • the MSC that the UE accesses can identify the response of the UE to the first message, and the UE can directly perform the service of the CS network.
  • the UE sends a location update request to the MSC accessed by the UE.
  • the UE After falling back to the CS network and accessing the MSC, the UE sends a location update request to the accessed MSC according to the LA change information, where the location update request includes indication information of the service of the CS network, and the MSC can update according to the location.
  • VLR Visitor Location Register
  • the CSFB roaming retry process is initiated to send a service setup message to the UE, and complete the establishment process of the CS network service with the UE.
  • the UE receives the service establishment message corresponding to the location update request, and completes the establishment process of the service of the CS network with the MSC.
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then sends a service setup message corresponding to the location update request to the UE, and the UE completes the establishment process of the CS network service according to the service setup message and the MSC.
  • This embodiment provides a more detailed network fallback method based on the embodiment shown in FIG. 2, wherein the UE determines LA change information, and the LA change information includes a first LAI and a second LAI, and the first LAI
  • the LA is used to identify the UE at the start time of the preset time period
  • the second LAI is used to identify the LA of the UE at the preset time period termination time.
  • the UE determines the third LAI. Pass Comparing the first LAI, the second LAI, and the third LAI to determine whether the LA of the UE changes in the LTE network.
  • the MSC that sends the first message is different from the MSC accessed by the UE, and the UE sends the location to the MSC. And updating the request, so that the MSC completes the location update of the UE and the establishment process of the service of the CS network according to the second message.
  • the UE is enabled to estimate the change of the MSC according to the change of the LA, and instructs the MSC to complete the establishment process of the service of the CS network according to the change of the LA, so that even if the MSC that sends the first message is different from the MSC accessed by the UE, the UE It is also possible to complete the establishment process of the CS network service with the accessed MSC, reduce the failure rate of the CSFB process, and meet the communication requirements.
  • the LA change information may also be in other forms.
  • the LA change information may include two values: a first value or a second value. If the LA of the UE changes during the preset time period, the value of the LA change information is determined to be the first value; if the LA of the UE does not change within the preset time period, the LA change information is determined. The value is the second value. If the value of the LA change information is the first value, the UE sends a location update request carrying the knowledge information of the service of the CS network to the MSC accessed by the UE after falling back to the CS network.
  • the LA change information may also be in other forms, which is not limited herein.
  • the UE in the idle state receives the first message, and the first message is in the form of a Paging message, and is used to indicate that the UE performs the called service in response to the calling party of the CS network.
  • the UE detects that the UE satisfies the condition for performing the TAU after receiving the first message, and thus performs TAU.
  • the UE records that the LA at the start of the TAU procedure is the first LAI, and the LA at the end of the recording TAU procedure is the second LAI.
  • the UE falls back to the CS network according to the first message.
  • the UE determines that the identity of the LA after falling back to the CS network is the third LAI, and determines that the third LAI is the same as the second LAI, and the first LAI is different from the third LAI.
  • the UE sends a Location Updating Request carrying the indication information of the calling service to the accessed MSC, and instructs the MSC to complete the location update of the UE and the establishment process of the called service.
  • the UE receives the Setup message corresponding to the Location Updating Request, and completes the establishment process of the called service with the MSC.
  • the embodiment of the present invention further provides another network fallback method, which can also reduce the failure rate of the CSFB process and meet the communication requirements.
  • the basic process includes:
  • the UE determines whether the CSFB is currently being executed.
  • the UE determines whether CSFB is currently being executed.
  • There are many conditions for performing the TAU or the HO in the LTE network including: the tracking area of the UE is changed, and the changed tracking area is not in the tracking area list saved by the UE, which is not limited in this embodiment.
  • the CSFB process includes the four steps described previously in the application scenario shown in FIG. Wherein, the UE determines whether CSFB is currently being executed, and as long as the UE is currently performing any of the four steps, it determines that CSFB is currently being executed.
  • step 402 If the UE determines that CSFB is currently being executed, then the operation of step 402 is triggered.
  • the HO process in the TAU or LTE network is performed after the CSFB process ends.
  • the CSFB process ends, which refers to the four steps described before the UE completes the application scenario shown in Figure 1, and returns to the LTE network smoothly.
  • the UE requests the MME of the CS network to fall back to the CS network, and the MME may not accept the request of the UE, and the CSFB fails, and the UE remains in the LTE network, and the CSFB process may be considered as ending.
  • the embodiment is not limited.
  • the UE determines whether the CSFB is currently being executed; if the UE determines that the CSFB is currently being executed, the TAU or the TAU is performed after the CSFB process ends. HO process within the LTE network. Through such a method, it is ensured that the UE does not perform the TAU or the intra HO process in the LTE network when performing CSFB.
  • the method in this embodiment can reduce the probability that the MSC changes when the UE performs CSFB.
  • the probability that the UE cannot complete the service establishment with the accessed MSC in the CSFB process is reduced, and the success rate of the CSFB is improved, and the communication requirement can be met.
  • the UE receives the second message in the LTE network.
  • the LTE network is used to provide the UE with the service of the PS network, and when the UE needs to perform the service of the CS network, the UE receives the second message in the LTE network, where the second message is used to instruct the UE to perform the service of the CS network.
  • the MSC of the CS network sends a Paging Request, and the paging request is sent to the UE in the form of a second message after being processed by the MME. If the UE is in an idle state, the second message is in the form of a Paging message; if the UE is in a connected state, the second message is in the form of a CS Service Notification.
  • the UE After receiving the second message in the LTE network, the UE performs step 502 to perform the CSFB process, and then falls back to the CS network to perform the service of the CS network.
  • the UE sends a third message to the MME.
  • the UE sends a third message to the MME, where the third message is used to indicate that the UE requests to fall back to the CS network to perform the service of the CS network.
  • the third message may be in the form of an extended service request, and the extended service request carries an indication that the UE accepts the service of the CS network.
  • the UE determines that the CSFB is currently being executed.
  • the UE determines whether CSFB is currently being executed.
  • There are many conditions for performing the TAU or the HO in the LTE network including: the tracking area of the UE is changed, and the changed tracking area is not in the tracking area list saved by the UE, which is not limited in this embodiment.
  • the UE since the UE receives the second message in step 501, the UE is currently executing CSFB.
  • the UE determines that CSFB is currently being executed, and after the end of the CSFB process, performs a HO procedure within the TAU or LTE network. Specifically, if the MME accepts the third message, step 504 is performed; if the MME does not accept the third message, step 505 is performed.
  • the UE falls back to the CS network, and returns to the LTE network to perform the HO process in the TAU or LTE network after the service execution of the CS network is completed.
  • the UE successfully falls back to the CS network, and the UE is back. After falling into the CS network and completing the execution of the CS network service, that is, after the CSFB process ends, the LTE network is returned to perform the TAU or LTE intra-HO procedure.
  • the UE performs a HO process in a TAU or LTE network.
  • the MME does not accept the third message, the UE does not successfully fall back to the CS network, and the CSFB process ends.
  • the UE still stays in the LTE network at this time, and the UE directly performs the HO process in the TAU or LTE network.
  • the UE after receiving the second message, the UE sends a third message to the MME. If the MME accepts the third message, the CSFB is successful, and the UE returns to the LTE network after performing the execution of the service of the CS network and then performs the TAU or LTE intra-HO procedure; if the MME does not accept the third message, the CSFB is used. If the UE is unsuccessful, the UE still stays in the LTE network, and the UE directly performs the HO process in the TAU or LTE network. Through such a method, it is ensured that the UE does not perform the TAU or the intra HO process in the LTE network when performing CSFB.
  • the method in this embodiment can reduce the probability that the MSC changes when the UE performs CSFB.
  • the probability that the UE cannot complete the service establishment with the accessed MSC in the CSFB process is reduced, and the success rate of the CSFB is improved, and the communication requirement can be met.
  • the step 502 may be performed after the step 503 is performed because the UE may meet the condition of performing the TAU or the HO in the LTE network immediately after receiving the second message.
  • step 505 since the UE has not dropped back to the CS network, the HO process in the TAU or LTE network can be directly executed. However, since the UE determines whether the CSFB is currently being executed, and the MME determines whether to accept the fourth message or the like, it takes a certain time, and thus the steps 505 and 503 have a certain delay in time. Even if the UE satisfies the condition for performing HO in the TAU or LTE network in step 503, it is likely that the condition for performing the HO in the TAU or LTE network is no longer satisfied in step 505. Therefore, in step 505, the UE may determine whether the condition for performing the TAU or the HO in the LTE network is met, and if yes, perform the TAU or LTE intra-network HO procedure.
  • the UE in the idle state receives the second message, and the second message is Paging.
  • the form of the message is used to indicate that the UE performs the called service in response to the calling of the CS network.
  • the UE After receiving the second message, the UE sends a third message to the MME, where the third message is in the form of an Extended Service Request, and carries an indication that the UE accepts the service of the CS network.
  • the third message is in the form of an Extended Service Request, and carries an indication that the UE accepts the service of the CS network.
  • the UE determines that the TAU condition is currently met and determines that CSFB is currently being executed. The UE then does not perform the TAU procedure temporarily.
  • the MME accepts the third message, and the UE then falls back to the CS network, and the execution of the service of the CS network is completed.
  • the UE returns to the LTE network to perform TAU.
  • the embodiment of the present invention further provides another network fallback method, which can also reduce the failure rate of the CSFB process and meet the communication requirements.
  • the basic process includes:
  • the UE performs CSFB, and after the LTE network falls back to the CS network, sends a fourth message to the accessed MSC, where the fourth message is used to request the MSC to perform the service of the CS network.
  • the MSC that the UE accesses in the CS network may be the same as the MSC that sends the CS network service to the UE.
  • the MSC accessed by the UE can accept the fourth message sent by the UE;
  • the incoming MSC may not be the MSC that sends the CS network service to the UE.
  • the MSC accessed by the UE cannot accept the fourth message of the UE.
  • the UE receives a fifth message sent by the MSC.
  • the UE receives a fifth message sent by the MSC, where the fifth message is used to release the connection between the MSC and the UE.
  • the UE receiving the fifth message may have many scenarios, including:
  • the MSC does not accept the fourth message, the MSC cannot complete the establishment process of the service of the CS network, and the MSC sends a fifth message to the UE, instructing the UE to release the connection with the MSC, and the UE receives the fifth message;
  • the MSC accepts the fourth message, establishes the service of the CS network, and completes the process of performing the service of the CS network with the UE, the MSC sends a fifth message to the UE, instructing the UE to release the connection with the MSC, and the UE receives the fifth. Message.
  • the fifth message sent by the UE to the MSC may also be other scenarios, which is not limited in this embodiment.
  • the UE determines whether the UE completes the execution process of the service of the CS network before receiving the fifth message.
  • the UE receives the fifth message sent by the MSC, but the UE cannot directly learn the scenario in which the MSC sends the fifth message after the fifth message. Then, the UE determines whether the UE completes the execution process of the service of the CS network before receiving the fifth message.
  • step 604 is performed.
  • the UE sends a location update request to the MSC.
  • the UE determines that the UE does not complete the process of performing the service of the CS network before receiving the fifth message, it indicates that the MSC cannot complete the establishment process of the service of the CS network, and then the UE sends a location update request to the MSC, where the location update request includes the The indication information of the service of the CS network enables the MSC to complete the location update of the UE and complete the establishment process of the service of the CS network with the UE according to the location update request.
  • the UE receives the service establishment message corresponding to the location update request, or sends a service establishment message corresponding to the location update request to the MSC, and completes the establishment process of the service of the CS network with the MSC.
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then sends a service setup message (Setup) corresponding to the location update request to the UE, and the UE completes the service establishment process of the CS network according to the service setup message and the MSC. .
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then the UE sends a service setup message corresponding to the location update request to the MSC, and the MSC completes the service establishment process of the CS network according to the service setup message and the UE.
  • the UE after the UE falls back from the LTE network to the CS network, the UE sends a fourth message to the accessed MSC; the UE receives the fifth message sent by the MSC, where the fifth message is used to release the connection between the MSC and the UE; Whether the MSC can not complete the establishment process of the service of the CS network before receiving the fifth message; if not, the MSC cannot complete the establishment process of the service of the CS network, and the UE sends a location update request to the MSC, so that the MSC can update according to the location.
  • the request completes the location update of the UE and the establishment process of the service of the CS network.
  • the UE can send the location update request to the MSC, so that the MSC
  • the process of establishing the location of the UE and the establishment of the service of the CS network is completed, thereby reducing the probability that the UE cannot complete the service establishment with the accessed MSC during the CSFB process, improving the success rate of the CSFB, and meeting the communication requirements. begging.
  • the UE performs CSFB, and after the LTE network falls back to the CS network, sends a fourth message to the accessed MSC, where the fourth message is used to request the MSC to perform the service of the CS network.
  • the fourth message may be in the form of a Paging Response, or may be in other forms, which is not limited in this embodiment.
  • the MSC that the UE accesses in the CS network may be the same as the MSC that sends the CS network service to the UE.
  • the MSC accessed by the UE can accept the fourth message sent by the UE;
  • the incoming MSC may not be the MSC that sends the CS network service to the UE.
  • the MSC accessed by the UE cannot accept the fourth message of the UE.
  • the UE receives a fifth message sent by the MSC.
  • the UE receives a fifth message sent by the MSC, where the fifth message is used to release the connection between the MSC and the UE.
  • the fifth message may be in the form of a Channel Release message or an RRC Connection Release message. If the CS network is a 3G network, the fifth message may be in the form of an RRC Connection Release message.
  • the UE receiving the fifth message may have many scenarios, including:
  • the MSC does not accept the fourth message, the MSC cannot complete the establishment process of the service of the CS network, and the MSC sends a fifth message to the UE, instructing the UE to release the connection with the MSC, and the UE receives the fifth message;
  • the MSC accepts the fourth message, establishes the service of the CS network, and completes the process of performing the service of the CS network with the UE, the MSC sends a fifth message to the UE, instructing the UE to release the connection with the MSC, and the UE receives the fifth. Message.
  • the fifth message sent by the UE to the MSC may also be other scenarios, which is not limited in this embodiment.
  • the UE determines whether the current location of the UE belongs to the preset area.
  • the preset area identifier is saved in the UE, and the preset area identifier is used to identify the preset area.
  • the UE determines whether the current location of the UE belongs to the preset area.
  • the preset area may be manually specified, or may be determined by the UE by default, or the UE may be configured according to the network.
  • the indication information of the preset area that is sent by the network is determined, which is not limited in this embodiment.
  • the preset area identifier may be in the form of a cell identifier (Cell ID), an LAI, or the like, and may be in other forms, which is not limited herein.
  • the preset area may be used to indicate a range of locations in which the UE is prone to LA change when performing the CSFB process.
  • the LA of the default UE changes.
  • the preset area may have a feature that if the UE performs a TAU procedure in the preset area, the location area identifier LAI of the UE may change; and/or, if the UE performs in the preset area In the HO procedure, the location area identifier LAI of the UE may change; and/or, if the UE falls back from the LTE network to the CS network in the preset area, the location area identifier LAI of the UE changes.
  • the location areas described in the previous paragraph generally exist at the boundaries of different LAs.
  • the UE performs TAU, and the TA is changed from TA 2 to TA 3, and the LA in which the LA is located is also LA 3 changed from LA 2 . Since the UE at the boundary portion of the Cell 4 close to the Cell 5 is likely to enter the Cell 5, the boundary portion of the Cell 4 close to the Cell 5 can be regarded as a preset area.
  • step 704 If the UE determines that the current location of the UE belongs to the preset area, triggering the operation of step 704;
  • step 707 If the UE determines that the current location of the UE does not belong to the preset area, triggering the operation of step 707;
  • the UE determines whether the UE completes the execution process of the service of the CS network before receiving the fifth message.
  • the UE determines that the current location of the UE belongs to the preset area, it is considered that the LA of the UE changes when the UE performs the CSFB process.
  • the TAU, the HO or other processes in the LTE network are the important reasons for the change of the LA of the UE, and the processes such as the TAU and the HO in the LTE network are likely to cause the MSC accessed by the UE to be inconsistent with the MSC that delivers the CS network service to the UE. Therefore, if the LA of the UE changes, it indicates that the MSC accessed by the UE is likely to not accept the fourth message, and the establishment process of the service of the CS network cannot be completed. Since the UE cannot directly learn from the fifth message whether the MSC completes the establishment process of the service of the CS network, the UE determines in this step whether the UE completes the execution process of the service of the CS network before receiving the fifth message.
  • step 705 is performed;
  • step 707 may be performed.
  • the UE sends a location update request to the MSC.
  • the UE determines that the UE does not complete the process of performing the service of the CS network before receiving the fifth message, it indicates that the MSC cannot complete the establishment process of the service of the CS network, and then the UE sends a location update request to the MSC, and the location update request is used for
  • the MSC that the UE accesses sends the CSFB roaming forwarding process to the MSC that sends the CS network service, and/or the MSC initiates the CSFB roaming retry process to the VLR corresponding to the MSC that sends the first message, to the UE.
  • the UE receives the service establishment message corresponding to the location update request, and completes the establishment process of the service of the CS network with the MSC.
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then sends a service setup message corresponding to the location update request to the UE, and the UE completes the establishment process of the CS network service according to the service setup message and the MSC.
  • the UE returns to the LTE network.
  • the MSC is likely to have established the service of the CS network and completes the execution process of the service of the CS network with the UE, so the UE returns to the LTE network.
  • the UE determines whether the current location of the UE belongs to the preset area. If so, an operation of judging whether or not the execution process of the service of the CS network is completed is performed. If not, the UE directly returns to the LTE network.
  • the method provided in this embodiment may determine whether to perform an operation of determining whether the service of the CS network is completed or a location update request to the MSC by determining whether the current location belongs to the preset area by the UE. In the process of reducing the CSFB, the UE can not complete the service establishment with the accessed MSC, improve the success rate of the CSFB, and simplify the process, reduce the burden on the UE and the MSC, and meet the communication requirements.
  • the UE cannot directly learn from the fifth message whether the MSC completes the process of establishing the service of the modified CS network.
  • the MSC accepts the fourth message in step 702
  • the service of the CS network is established, and the UE performs the process of performing the service of the CS network
  • the fifth message may include redirection information for indicating the UE. Return to the LTE network.
  • the received fifth message includes the redirection information
  • the LTE network is returned according to the redirection information; if the redirection information is not included in the received fifth message, the operation of step 703 is triggered, or Step 703 is skipped and the operation of step 704 is performed.
  • step 703 the operation of the UE determining whether the current location of the UE belongs to the preset area may also be replaced by other determining operations, and double judgment may also be implemented.
  • step 703 may be replaced by: the UE determines whether the TAU or the intra-LTE intra-HO procedure is performed before the UE falls back from the LTE network to the CS network; if the UE determines that the UE falls back from the LTE network to the CS network, the TAU or the LTE intra-network HO is performed.
  • step 704 The process triggers the operation of step 704; if the UE determines that the UE does not perform the TAU or LTE intra-network HO procedure before dropping back from the LTE network to the CS network, the operation of step 706 is triggered. More preferably, step 703 can also combine several judgment conditions to implement multiple judgments, which is not limited in this embodiment.
  • the UE Preferably, if the MSC does not complete the establishment process of the service of the CS network within the preset time after the UE sends the location update request to the MSC in step 705, the UE returns to the LTE network.
  • step 706 the UE receives the service establishment message corresponding to the location update request, and completes the establishment process of the service of the CS network with the MSC.
  • step 706 may also be that the UE sends a service establishment message corresponding to the location update request to the MSC, and completes the CS with the MSC.
  • the establishment process of the network business is not limited here.
  • the UE performs the CSFB, and after the LTE network falls back to the CS network, sends a fourth message to the accessed MSC, where the fourth message is in the form of a Paging Response.
  • the UE receives the fifth message sent by the MSC, where the fifth message is in the form of an RRC Connection Release message.
  • the preset area identifier is saved in the UE, and the preset area identifier is used to identify the preset area. Due to UE The saved preset area identifier includes the cell ID of the current cell of the UE, so the UE determines that the current location belongs to the preset area.
  • the UE determines that the execution process of the service of the CS network is not completed before receiving the fifth message, so the Location Updating Request is sent to the MSC, and the location disclosure request includes the indication information of the service of the CS network.
  • the UE receives the Setup message corresponding to the location update request, and completes the establishment process of the service of the CS network with the MSC.
  • the embodiment of the present invention further provides a related UE, where the network fallback method is implemented.
  • the basic structure is shown in Figure 8, including:
  • the first receiving module 801 is configured to receive the first message in the LTE network.
  • the LTE network is configured to provide the UE with the service of the PS network, and when the UE needs to perform the service of the CS network, the first receiving module 801 of the UE receives the first message in the LTE network, where the first message is used to indicate the The UE performs the services of the circuit switched CS network.
  • the UE After the first receiving module 801 receives the first message in the LTE network, the UE performs a CSFB process to fall back to the CS network to perform the service of the CS network.
  • the LA information module 802 is configured to determine LA change information before falling back to the CS network.
  • the LA information module 802 determines LA change information, which is used to indicate whether the LA of the UE has changed within a preset time period.
  • the form of the LA change information is various, and will be described in detail in the following embodiments, which are not limited herein.
  • the LA of the UE may change if the UE performs the TAU process, or the HO process in the LTE network, or other processes.
  • the reason for causing the LA of the UE to change is not limited.
  • the order in which the first receiving module 801 and the LA information module 802 perform their corresponding steps is not limited.
  • the fallback execution module 803 is configured to: after the first receiving module 801 receives the first message and the LA information module 802 determines the LA change information, it falls back to the CS network;
  • the LA change information actually indicates whether the LA of the UE has changed before falling back to the CS network.
  • the UE After the UE falls back to the CS network, it accesses the MSC in the CS network. If the MSC can complete the establishment process of the CS network with the UE, the UE can perform the service of the CS network.
  • the update requesting module 804 is configured to: when the LA change information indicates that the LA of the UE changes within a preset time period, send a location update request to the accessed MSC after falling back to the CS network;
  • the update request module 804 sends a location update request to the accessed MSC according to the LA change information, where the location update request includes an indication of the service of the CS network.
  • the MSC can complete the location update of the UE and complete the establishment process of the service of the CS network with the UE according to the location update request.
  • the service establishing module 805 is configured to receive a service setup message corresponding to the location update request, and complete a service establishment process of the CS network with the MSC.
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then sends a service setup message (Setup) corresponding to the location update request to the UE, and the service establishment module 805 completes the service of the CS network according to the service setup message and the MSC.
  • the establishment process After receiving the location update request, the MSC completes the location update of the UE, and then sends a service setup message (Setup) corresponding to the location update request to the UE, and the service establishment module 805 completes the service of the CS network according to the service setup message and the MSC. The establishment process.
  • Setup Service setup message
  • the embodiment provides a UE, including: the first receiving module 801 receives the first message in the LTE network; after receiving the first message, the fallback execution module 803 falls back to the CS network; and, the LA information module 802 Before the fallback to the CS network, the LA change information is determined; if the LA change information indicates that the LA of the UE has changed within the preset time period, the update request module 804 is connected to the UE after falling back to the CS network.
  • the incoming MSC sends a location update request, and the service establishing module 805 and the MSC complete the process of establishing the service of the CS network.
  • the process of the HO in the TAU or the LTE network is an important reason that the MSC that sends the first message in the CS network is different from the MSC that the UE accesses, and the processes such as the HO in the TAU or the LTE network are often caused at the same time.
  • the LA change information is used to indicate whether the LA of the UE changes during the preset time period before falling back to the CS network; the UE is falling back to the CS.
  • the location update request is sent to the MSC according to the LA change information, so that the MSC completes the establishment process of the service of the CS network.
  • the UE is enabled to estimate the change of the MSC according to the change of the LA, and instructs the MSC to complete the establishment process of the service of the CS network according to the change of the LA, so that even if the MSC that sends the first message is different from the MSC accessed by the UE, the UE It is also possible to complete the CS with the accessed MSC.
  • the establishment process of the network business reduces the failure rate of the CSFB process and can meet the communication requirements.
  • FIG. 8 shows the basic structure of the UE provided by the present invention.
  • the following embodiment will provide a more detailed UE.
  • the method mainly includes:
  • the first receiving module 901 is configured to receive the first message in the LTE network.
  • the LTE network is configured to provide the UE with the service of the PS network, and when the UE needs to perform the service of the CS network, the first receiving module 901 of the UE receives the first message in the LTE network, where the first message is used to indicate the The UE performs the services of the circuit switched CS network.
  • the MSC of the CS network sends a paging request (Paging Request), and the paging request is sent to the UE in the form of a first message after being processed by the Mobility Management Entity (MME).
  • Paging Request a paging request
  • MME Mobility Management Entity
  • the UE is in an idle state, that is, there is no wireless connection between the UE and the LTE network, the first message is in the form of a Paging message; if the UE is in a connected state, that is, there is a wireless connection between the UE and the LTE network, the The first message is in the form of a CS Service Notification.
  • the UE After the first receiving module 901 receives the first message in the LTE network, the UE performs a CSFB process to fall back to the CS network to perform the service of the CS network.
  • the LA information module 902 is configured to determine LA change information before falling back to the CS network.
  • the LA information module 902 determines LA change information, which is used to indicate whether the LA of the UE has changed within a preset time period.
  • the LA of the UE may change. Specifically, if the UE performs the TAU process, the UE determines LA change information, where the LA change information is specifically used to indicate whether the LA changes at the start and end of the TAU process before the UE falls back to the CS network; or If the UE performs the intra-LTE intra-HO procedure, the UE determines the LA change information, where the LA change information is specifically used to indicate whether the LA of the UE starts and terminates during the HO process in the LTE network before falling back to the CS network. Change.
  • the LA of the UE may also change due to other reasons, and is not limited herein.
  • the LAI is stored in the UE, and the LAI is used to identify the LA in which the UE is located. There are many ways for the UE to obtain the LAI. Generally, when the UE performs the location area update, the tracking area update, or other operations, the network side sends the LA of the UE to the UE in the form of the LAI, which is not limited herein.
  • the LA change information includes a first LAI and a second LAI, where the first LAI is used to identify the LA of the UE at the start time of the preset time period, that is, the LAI saved by the UE at the start time of the preset time period.
  • the second LAI is used to identify the LA of the UE at the time of termination of the preset time period. Specifically, if the UE performs the TAU procedure, the first LAI is used to identify the LA of the UE at the start of the TAU process, that is, the LAI saved by the UE at the start time of the TAU process, and the second LAI is used to identify the UE in the TAU process.
  • the first LAI is used to identify the LA of the UE in the LTE network at the start of the HO process, that is, the LAI saved by the UE at the start time of the HO process, and the second The LAI is used to identify the LA of the UE when the HO procedure is terminated.
  • the first LAI is different from the second LAI, it indicates that the UE has changed at the start of the TAU or HO process and the LA at the time of termination.
  • the steps performed by the LA information module 902 may also be located before the step performed by the first receiving module 901, which is not limited herein. If the step performed by the LA information module 902 is located before the step performed by the first receiving module 901, the preset time period is a time period of the preset duration before the first receiving module 901 receives the first message; if the LA information module 902 performs The step is located after the step performed by the first receiving module 901, and the preset time period is a time period between the time when the first receiving module 901 receives the first message and the time when the UE reaches the CS network.
  • the MME when the MME is to send the first message to the UE, if the UE is performing the TAU or other process, the MME may wait for the UE to complete the execution of the TAU or other process, and then send the message to the UE.
  • the UE may receive the first message from the LTE network within the preset time, and then trigger the execution step of the subsequent module.
  • the fallback execution module 903 is configured to: after the first receiving module 901 receives the first message and the LA information module 902 determines the LA change information, it falls back to the CS network;
  • the UE After the UE falls back to the CS network, it accesses the MSC in the CS network. If the MSC can complete the establishment process of the CS network with the UE, the UE can perform the service of the CS network.
  • the update request module 904 is configured to send a location update request to the accessed MSC according to the LA change information after falling back to the CS network. After the UE drops back to the CS network and accesses the MSC, the update request module 904 sends a location update request to the accessed MSC according to the LA change information, where the location update request includes indication information of the service of the CS network, and the MSC can According to the location update request, the location update of the UE is completed and the establishment process of the service of the CS network is completed with the UE.
  • the update request module specifically includes:
  • the LA determining unit 9041 is configured to determine a third LAI after the UE falls back to the CS network, where the third LAI is used to indicate the LA of the UE in the CS network.
  • the third LAI can also be considered as the LAI of the cell in which the UE resides in the CS network, because the UE camps in the CS network for a short period of time.
  • the LA determining unit 9041 may acquire the third LAI from the broadcast message of the cell of the CS network, and may obtain the third LAI from other channels, which is not limited herein.
  • the UE indicates that the LA changes in the LTE network before falling back to the CS network, indicating that the first message is sent to the UE.
  • the MSC is likely to be different from the MSC accessed by the UE.
  • the operation of the update request unit 9042 is triggered at this time.
  • the UE does not change in the LTE network before the UE falls back to the CS network, and the MSC that sends the first message to the UE is likely to be the same as the MSC accessed by the UE.
  • the MSC that sends the first message to the UE is the same as the MSC that the UE accesses
  • the MSC that the UE accesses can identify the response of the UE to the first message, and the UE can directly perform the service of the CS network.
  • the update requesting unit 9042 is configured to send a location update request to the MSC accessed by the UE when the second LAI is the same as the third LAI, and the second LAI is different from the first LAI.
  • the update requesting unit 9042 sends a location update request to the accessed MSC according to the LA change information, where the location update request includes indication information of the service of the CS network, so that the MSC
  • the location update of the UE can be completed according to the location update request, and the CSFB roaming forwarding process is initiated to the MSC that sends the first message, and/or the MSC is used to initiate the CSFB roaming to the VLR corresponding to the MSC that sends the first message.
  • the test process is to send a service setup message to the UE, and complete the establishment process of the service of the CS network with the UE.
  • the service establishing module 905 is configured to receive a service establishment message corresponding to the location update request, and complete the establishment process of the service of the CS network with the MSC.
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then sends a service setup message corresponding to the location update request to the UE, and the service establishment module 805 completes the establishment process of the CS network service according to the service setup message and the MSC. .
  • the embodiment provides a more detailed UE on the basis of the embodiment shown in FIG. 8.
  • the LA information module 902 determines LA change information, and the LA change information includes a first LAI and a second LAI.
  • the LAI is used to identify the LA of the UE at the start time of the preset time period
  • the second LAI is used to identify the LA of the UE at the time of termination of the preset time period.
  • the LA determining unit 9041 determines the third LAI. By comparing the first LAI, the second LAI, and the third LAI, it is determined whether the LA of the UE changes in the LTE network.
  • the MSC that sends the first message is different from the MSC that the UE accesses, and the update request unit 9042 The MSC sends a location update request, so that the MSC completes the location update of the UE and the establishment process of the service of the CS network according to the second message.
  • the UE is enabled to estimate the change of the MSC according to the change of the LA, and instructs the MSC to complete the establishment process of the service of the CS network according to the change of the LA, so that even if the MSC that sends the first message is different from the MSC accessed by the UE, the UE It is also possible to complete the establishment process of the CS network service with the accessed MSC, reduce the failure rate of the CSFB process, and meet the communication requirements.
  • the LA change information may also be in other forms.
  • the LA change information may include two values: a first value or a second value. If the LA of the UE changes within the preset time period, the LA information module 902 determines that the value of the LA change information is the first value; if the LA of the UE does not change within the preset time period, the LA The information module 902 determines that the value of the LA change information is a second value. If the value of the LA change information is the first value, the update request unit 9042, after falling back to the CS network, sends a location update request carrying the knowledge information of the service of the CS network to the MSC accessed by the UE.
  • the LA change information may also be in other forms, which is not limited herein.
  • the first receiving module 901 of the UE in the idle state receives the first message, which is in the form of a Paging message, and is used to indicate that the UE performs the called service in response to the calling party of the CS network.
  • the UE detects that the UE satisfies the condition for performing the TAU after receiving the first message, and thus performs TAU.
  • the LA information module 902 records that the LA at the start of the TAU procedure is the first LAI, and the LA at the end of the recording TAU procedure is the second LAI.
  • the fallback execution module 903 falls back to the CS network according to the first message.
  • the LA determining unit 9041 determines that the LA of the initial time after falling back to the CS network is the third LAI, and determines that the third LAI is the same as the second LAI, and the first LAI is different from the third LAI.
  • the trigger update request unit 9042 sends a Location Updating Request carrying the indication information of the calling service to the accessed MSC, and instructs the MSC to complete the location update of the UE and the establishment process of the called service.
  • the service establishing module 905 receives the Setup message corresponding to the Location Updating Request, and completes the establishment process of the called service with the MSC.
  • the embodiment of the present invention further provides another UE, which can also reduce the failure rate of the CSFB process and meet the communication requirements.
  • the basic structure includes:
  • the state judging module 1001 is configured to determine, when the UE satisfies the condition of the HO in the TAU or the LTE network in the LTE network, whether the UE is currently executing the CSFB;
  • the state judging module 1001 judges whether the UE is currently performing CSFB.
  • There are many conditions for performing the TAU or the HO in the LTE network including: the tracking area of the UE is changed, and the changed tracking area is not in the tracking area list saved by the UE, which is not limited in this embodiment.
  • the CSFB process includes the four steps described previously in the application scenario shown in FIG. Wherein, the UE determines whether CSFB is currently being executed, and as long as the UE is currently performing any of the four steps, it determines that CSFB is currently being executed.
  • the trigger task deferral module 1002 performs its respective steps.
  • the task deferring module 1002 is configured to: when the state judging module 1001 determines that the UE is currently performing CSFB, after the CSFB process ends, perform the TAU or LTE intra-network HO process.
  • the task deferring module 1002 performs the TAU or LTE intra-network HO process after the CSFB process ends.
  • the CSFB process ends, which refers to the four steps described before the UE completes the application scenario shown in Figure 1, and returns to the LTE network smoothly.
  • the UE requests the MME of the CS network to fall back to the CS network, and the MME may not accept the request of the UE, and the CSFB fails, and the UE remains in the LTE network, and the CSFB process may be considered as ending.
  • the embodiment is not limited.
  • the state determining module 1001 determines whether the UE is currently executing the CSFB; if the state determining module 1001 determines that the UE is currently executing the CSFB, the task delaying module After the CSFB process ends, the HO process in the TAU or LTE network is performed.
  • the UE does not perform the TAU or the intra HO process in the LTE network when performing CSFB.
  • the UE in this embodiment can reduce the probability that the MSC changes when the UE performs CSFB.
  • the probability that the UE cannot complete the service establishment with the accessed MSC in the CSFB process is reduced, and the success rate of the CSFB is improved, and the communication requirement can be met.
  • the basic structure includes:
  • the second receiving module 1101 is configured to receive the second message in the LTE network.
  • the LTE network is used to provide the UE with the service of the PS network, and when the UE needs to perform the service of the CS network, the second receiving module 1101 receives the second message in the LTE network, where the second message is used to instruct the UE to perform the CS network. Business.
  • the MSC of the CS network sends a Paging Request, and the paging request is sent to the UE in the form of a second message after being processed by the MME. If the UE is in an idle state, the second message is in the form of a Paging message; if the UE is in a connected state, the second message is in the form of a CS Service Notification.
  • the second receiving module 1101 After receiving the second message in the LTE network, the second receiving module 1101 triggers the fallback requesting module 1102 to perform corresponding steps to perform the CSFB process, and then fall back to the CS network to perform the service of the CS network.
  • the fallback request module 1102 is configured to send a third message to the MME before the state determining module 1103 determines whether the circuit domain fallback CSFB is currently being executed;
  • the fallback requesting module 1102 sends a third message to the MME, where the third message is used to indicate that the UE requests to fall back to the CS network to perform the service of the CS network.
  • the third message may be in the form of an extended service request, and the extended service request carries an indication that the UE accepts the service of the CS network.
  • the status determining module 1103 is configured to: when the UE satisfies the implementation of the TAU or LTE network in the LTE network When the condition of the inner HO is determined, it is determined whether the UE is currently executing CSFB;
  • the state judging module 1103 determines whether the UE is currently performing CSFB. There are many conditions for performing the TAU or the HO in the LTE network, including: the tracking area of the UE is changed, and the changed tracking area is not in the tracking area list saved by the UE, which is not limited in this embodiment.
  • the UE since the UE receives the second message in the second receiving module 1101, the UE is currently executing the CSFB.
  • the state determination module 1103 determines that CSFB is currently being executed and triggers the task postponement module 1104 to perform its respective steps.
  • the task deferring module 1104 is configured to: when the state judging module 1103 determines that the UE is currently performing CSFB, after the CSFB process ends, perform the TAU or LTE intra-network HO process.
  • the task delay module 1104 specifically includes:
  • the network fallback unit 11041 is configured to fall back to the CS network when the MME accepts the third message
  • the task execution unit 11042 is configured to: when the network fallback unit returns to the LTE network after the service execution of the CS network is completed, perform a TAU or LTE intra-network HO process; or, when the MME does not accept the third message, perform TAU or LTE HO process within the network.
  • the fallback requesting module 1102 sends a third message to the MME. If the MME accepts the third message, the CSFB is successful, the network fallback unit 11041 falls back to the CS network, and the task execution unit 11042 returns to the LTE network to perform the TAU or LTE intra-network HO process after the UE completes the execution of the CS network service; The third message is not accepted, indicating that the CSFB is unsuccessful, and the UE remains in the LTE network, so the task execution unit 11042 directly performs the HO process in the TAU or LTE network.
  • the UE in this embodiment can reduce the probability that the MSC changes when the UE performs CSFB.
  • the probability that the UE cannot complete the service establishment with the accessed MSC in the CSFB process is reduced, and the success rate of the CSFB is improved, and the communication requirement can be met.
  • the fallback requesting module 1102 may not send the MME to the MME.
  • the third message is sent, so as a further embodiment of the present invention, the UE may not include the fallback request module, but the task delay module of the UE includes a fallback request unit, and after the state determination module determines whether the UE is currently executing CSFB, Send a third message to the MME.
  • the task execution unit 11042 can directly perform the HO process in the TAU or LTE network.
  • the state judging module 1103 determines whether the CSFB is currently being executed, and the MME determines whether to accept the fourth message or the like, it takes a certain time. Therefore, when the MME does not accept the third message, the UE is likely to no longer satisfy the execution of the TAU or the LTE network. HO conditions.
  • the UE may determine whether the condition for performing the TAU or the HO in the LTE network is satisfied, and if yes, perform the TAU or LTE intra-network HO procedure.
  • the second receiving module 1101 of the UE in the idle state receives the second message, which is in the form of a Paging message, and is used to indicate that the UE performs the called service in response to the calling of the CS network.
  • the UE After receiving the second message, the UE sends a third message to the MME, where the third message is in the form of an Extended Service Request, and carries an indication that the UE accepts the service of the CS network.
  • the third message is in the form of an Extended Service Request, and carries an indication that the UE accepts the service of the CS network.
  • the UE determines that the TAU condition is currently met, and the state determination module 1103 determines that the UE is currently executing CSFB. The UE then does not perform the TAU procedure temporarily.
  • the MME accepts the third message, and the network fallback unit 11041 then falls back to the CS network, and the UE completes the execution of the service of the CS network in the CS network.
  • the task execution unit 11042 returns to the LTE network to perform TAU.
  • the embodiment of the present invention further provides another UE, which can also reduce the failure rate of the CSFB process and meet the communication requirements.
  • the basic structure includes:
  • the service requesting module 1201 is configured to send a fourth message to the accessed MSC after the UE falls back from the LTE network to the CS network;
  • the service requesting module 1201 After the UE performs the CSFB, the service requesting module 1201 sends a fourth message to the accessed MSC, and the fourth message is used to request the MSC to perform the service of the CS network.
  • the MSC that the UE accesses in the CS network may be the same as the MSC that sends the CS network service to the UE.
  • the MSC accessed by the UE can accept the fourth message sent by the UE;
  • the incoming MSC may not be the MSC that sends the CS network service to the UE.
  • the MSC accessed by the UE cannot accept the fourth message of the UE.
  • the third receiving module 1202 is configured to receive a fifth message sent by the MSC.
  • the third receiving module 1202 receives the fifth message sent by the MSC, where the fifth message is used to release the connection between the MSC and the UE.
  • the receiving, by the third receiving module 1202, the fifth message may have many scenarios, including:
  • the MSC does not accept the fourth message, the MSC cannot complete the establishment process of the service of the CS network, and the MSC sends a fifth message to the UE, indicating that the UE releases the connection with the MSC, and the third receiving module 1202 receives the fifth message;
  • the MSC accepts the fourth message, establishes the service of the CS network, and completes the execution process of the service of the CS network with the UE, the MSC sends a fifth message to the UE, instructing the UE to release the connection with the MSC, and the third receiving module 1202 receives the fifth message.
  • the third receiving module 1202 receives the fifth message sent by the MSC, which may be other scenarios, which is not limited in this embodiment.
  • the service judging module 1203 is configured to determine whether the UE completes the execution process of the service of the CS network before receiving the fifth message.
  • the third receiving module 1202 receives the fifth message sent by the MSC, but the UE cannot directly learn the scenario in which the MSC sends the fifth message after the fifth message.
  • the service judging module 1203 determines whether the UE completes the execution process of the service of the CS network before receiving the fifth message.
  • the trigger request update module 1204 performs a corresponding operation.
  • the request update module 1204 is configured to send a location update request to the MSC.
  • the request update module 1204 sends a location update request to the MSC.
  • the location update request includes indication information of the service of the CS network, so that the MSC can complete the location update of the UE and complete the establishment process of the service of the CS network with the UE according to the location update request.
  • the service module 1205 is configured to receive a service establishment message corresponding to the location update request, or send a service establishment message corresponding to the location update request to the MSC, and complete a service establishment process of the CS network with the MSC.
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then sends a service setup message (Setup) corresponding to the location update request to the UE, and the UE completes the service establishment process of the CS network according to the service setup message and the MSC. .
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then the UE sends a service setup message corresponding to the location update request to the MSC, and the MSC completes the service establishment process of the CS network according to the service setup message and the UE.
  • the service requesting module 1201 sends a fourth message to the accessed MSC.
  • the third receiving module 1202 receives the fifth message sent by the MSC, where the fifth message is used to release the MSC.
  • the connection with the UE; the service judging module 1203 determines whether the execution process of the service of the CS network is completed before receiving the fifth message; if not, the MSC cannot complete the establishment process of the service of the CS network, requesting the update module 1204 Sending a location update request to the MSC, so that the MSC can complete the location update of the UE and the establishment process of the service of the CS network according to the location update request.
  • the UE can send the location update request to the MSC, so that the MSC
  • the process of establishing the location of the UE and the establishment of the service of the CS network is completed, thereby reducing the probability that the UE cannot complete the service establishment with the accessed MSC in the CSFB process, improving the success rate of the CSFB, and meeting the communication requirement.
  • the establishment service module 1205 receives the service establishment message corresponding to the location update request, and completes the establishment process of the service of the CS network with the MSC. However, in some cases, such as the CS network service, the calling service, etc., in some embodiments of the present invention, the establishing service module 1205 may also send a service establishment message corresponding to the location update request to the MSC, and complete the CS with the MSC.
  • the establishment process of the network business is not limited here.
  • the basic structure includes:
  • the service requesting module 1301 is configured to send a fourth message to the accessed MSC after the UE falls back from the LTE network to the CS network;
  • the UE performs the CSFB, and after the LTE network falls back to the CS network, the service requesting module 1301 sends a fourth message to the accessed MSC, where the fourth message is used to request the MSC to perform the service of the CS network.
  • the fourth message may be in the form of a Paging Response, or may be in other forms, which is not limited in this embodiment.
  • the MSC that the UE accesses in the CS network may be the same as the MSC that sends the CS network service to the UE.
  • the MSC accessed by the UE can accept the fourth message sent by the UE;
  • the incoming MSC may not be the MSC that sends the CS network service to the UE.
  • the MSC accessed by the UE cannot accept the fourth message of the UE.
  • the third receiving module 1302 is configured to receive a fifth message sent by the MSC.
  • the third receiving module 1302 receives the fifth message sent by the MSC, where the fifth message is used to release the connection between the MSC and the UE.
  • the fifth message may be in the form of a Channel Release message or an RRC Connection Release message. If the CS network is a 3G network, the fifth message may be in the form of an RRC Connection Release message.
  • the receiving, by the third receiving module 1302, the fifth message may have many scenarios, including:
  • the MSC does not accept the fourth message, the MSC cannot complete the establishment process of the service of the CS network, and the MSC sends a fifth message to the UE, indicating that the UE releases the connection with the MSC, and the third receiving module 1302 receives the fifth message;
  • the MSC accepts the fourth message, establishes the service of the CS network, and completes the execution process of the service of the CS network with the UE, the MSC sends a fifth message to the UE, instructing the UE to release the connection with the MSC, and the third receiving module 1302 receives the fifth message.
  • the third receiving module 1302 receives the fifth message sent by the MSC, which may be other scenarios, which is not limited in this embodiment.
  • the area determining module 1303 is configured to determine whether the current location of the UE belongs to the preset area.
  • the preset area identifier is saved in the UE, and the preset area identifier is used to identify the preset area.
  • the area determining module 1303 determines whether the current location of the UE belongs to the preset area.
  • the preset area may be manually specified, or may be determined by the UE by default, or determined by the UE according to the indication information of the preset area delivered by the network, which is not limited in this embodiment.
  • the preset area identifier may be in the form of a cell identifier (Cell ID), an LAI, or the like. Other forms are not limited here.
  • the preset area may be used to indicate a range of locations in which the UE is prone to LA change when performing the CSFB process.
  • the LA of the default UE changes.
  • the preset area may have a feature that if the UE performs a TAU procedure in the preset area, the location area identifier LAI of the UE may change; and/or, if the UE performs in the preset area In the HO procedure, the location area identifier LAI of the UE may change; and/or, if the UE falls back from the LTE network to the CS network in the preset area, the location area identifier LAI of the UE changes.
  • the location areas described in the previous paragraph generally exist at the boundaries of different LAs.
  • the UE performs TAU, and the TA is changed from TA 2 to TA 3, and the LA in which the LA is located is also LA 3 changed from LA 2 . Since the UE at the boundary portion of the Cell 4 close to the Cell 5 is likely to enter the Cell 5, the boundary portion of the Cell 4 close to the Cell 5 can be regarded as a preset area.
  • the trigger service judging module 1304 performs a corresponding operation.
  • the service judging module 1304 is configured to determine whether the UE completes the execution process of the service of the CS network before receiving the fifth message.
  • the area judging module 1303 determines that the current location of the UE belongs to the preset area, it is considered that the LA of the UE changes when the UE performs the CSFB process.
  • the TAU, the HO or other processes in the LTE network are the important reasons for the change of the LA of the UE, and the processes such as the TAU and the HO in the LTE network are likely to cause the MSC accessed by the UE to be inconsistent with the MSC that delivers the CS network service to the UE. Therefore, if the LA of the UE changes, it indicates that the MSC accessed by the UE is likely to not accept the fourth message, and the establishment process of the service of the CS network cannot be completed.
  • the service judging module 104 determines whether the UE completes the execution process of the service of the CS network before receiving the fifth message, because the UE cannot directly learn from the fifth message whether the MSC completes the service establishment process of the CS network.
  • the trigger request update module 1305 performs a corresponding operation.
  • the request update module 1305 is configured to send a location update request to the MSC;
  • the request update module 1305 sends a location update request to the MSC, and the location update request is used by the MSC that the UE accesses to send the CSFB roaming to the MSC that sends the CS network service.
  • the forwarding process, and/or the MSC initiates a CSFB roaming retry procedure to the VLR corresponding to the MSC that sends the first message, to send a service setup message to the UE or receive a service setup message sent by the UE.
  • the service module 1306 is configured to receive a service setup message corresponding to the location update request, and complete a service establishment process of the CS network with the MSC.
  • the MSC After receiving the location update request, the MSC completes the location update of the UE, and then sends a service setup message corresponding to the location update request to the UE, and the establishment service module 1306 completes the service establishment process of the CS network according to the service setup message and the MSC. .
  • the area judging module 1303 first determines whether the current location of the UE belongs to the preset area. If so, an operation of judging whether or not the execution process of the service of the CS network is completed is performed. If not, the UE can directly return to the LTE network.
  • the UE provided in this embodiment may determine whether to perform the operation of determining whether the service of the CS network is completed or the location update request to the MSC by determining whether the current location belongs to the preset area by the UE. In the process of reducing the CSFB, the UE can not complete the service establishment with the accessed MSC, improve the success rate of the CSFB, and simplify the process, reduce the burden on the UE and the MSC, and meet the communication requirements.
  • the UE cannot directly learn from the fifth message whether the MSC completes the process of establishing the service of the modified CS network.
  • the fifth message may include redirection information, and is used to indicate that the UE returns to the LTE network. .
  • the received fifth message includes the redirection information
  • the LTE network is returned according to the redirection information; if the redirection information is not included in the received fifth message, the triggering area determining module 1303 or the service is triggered.
  • the decision module 1304 performs the corresponding operations.
  • the determining operation of the area judging module 1303 can also be replaced by other judging operations, and double judgment can also be implemented.
  • the function of the area judging module 1303 may be replaced by: determining whether the TAU or the intra-LTE intra-HO procedure is performed before the UE falls back from the LTE network to the CS network; if the UE is determined to return from the LTE network to the CS network, the TAU or LTE network is executed. Inside HO The triggering service judgment module 1304 performs the corresponding operation. More preferably, the area judging module 1303 can also combine several judgment conditions to implement multiple judgments, which is not limited in this embodiment.
  • the request update module 1305 sends a location update request to the MSC, and the MSC does not complete the establishment process of the service of the CS network within the preset time, the UE returns to the LTE network.
  • the establishment service module 1306 receives the service establishment message corresponding to the location update request, and completes the establishment process of the service of the CS network with the MSC. However, in some cases, such as the CS network service, the calling service, etc., in some embodiments of the present invention, the establishing service module 1306 may also send the service establishment message corresponding to the location update request to the MSC, and the MSC The process of establishing the service of the CS network is not limited here.
  • the UE performs the CSFB, and after the LTE network is dropped back to the CS network, the service requesting module 1301 sends a fourth message to the accessed MSC, where the fourth message is in the form of a Paging Response.
  • the third receiving module 1302 receives the fifth message sent by the MSC, where the fifth message is in the form of an RRC Connection Release message.
  • the preset area identifier is saved in the UE, and the preset area identifier is used to identify the preset area. Since the preset area identifier saved by the UE includes the cell ID of the current cell of the UE, the area determining module 1303 determines that the current location belongs to the preset area.
  • the service judging module 1304 determines that the execution process of the service of the CS network is not completed before receiving the fifth message, so the request update module 1305 sends a Location Updating Request to the MSC, and the location disclosure request includes the indication information of the service of the CS network.
  • the establishment service module 1306 receives the Setup message corresponding to the location update request, and completes the establishment process of the service of the CS network with the MSC.
  • the UE 1400 in the embodiment of the present invention is another. Examples include:
  • the input device 1401, the output device 1402, the processor 1403, and the memory 1404 (wherein the number of the processors 1403 in the UE 1400 may be one or more, and one processor 1403 in FIG. 14 is taken as an example).
  • the input device 1401, the output device 1402, the processor 1403, and the storage device The memory 1404 can be connected by a bus or other means, wherein the bus connection is taken as an example in FIG.
  • the processor 1403 is configured to perform the following steps by calling an operation instruction stored in the memory 1404:
  • the location area LA change information is determined, and the LA change information is used to indicate whether the LA of the UE has changed within the preset time period;
  • the location update request is sent to the mobile switching center MSC accessed by the UE, where the location update request includes the indication information of the service of the CS network.
  • the preset time period is a time period of the preset duration before the UE receives the first message, or the preset time period is a time when the UE receives the first message and a time when the UE falls back to the CS network. The time period between.
  • the processor 1403 is further configured to perform the following steps:
  • the UE performs the tracking area update TAU process, determining LA change information, where the LA change information is specifically used to indicate whether the LA changes at the start and end of the TAU process before the UE falls back to the CS network;
  • the LA change information is specifically determined to indicate whether the LA occurs at the start and end of the HO process in the LTE network before the UE falls back to the CS network. Variety.
  • the LA change information includes a first location area identifier LAI and a second LAI, where the first LAI is used to identify the LA of the UE at the start of the TAU procedure, and the second LAI Used to identify the LA of the UE when the TAU process terminates;
  • the LA change information includes a first LAI, where the first LAI is used to identify the LA of the UE in the LTE network at the start of the HO process, and the second LAI is used to identify The LA of the UE when the HO procedure terminates in the LTE network.
  • the LA change information includes: a first value or a second value
  • the processor 1403 is further configured to perform the following steps:
  • the LA of the UE changes within the preset time period, determine that the value of the LA change information is the first value
  • the LA of the UE does not change within the preset time period, it is determined that the value of the LA change information is the second value.
  • the processor 1403 is further configured to perform the following steps:
  • the third LAI is used to indicate the LA of the UE in the CS network;
  • the location update request is sent to the MSC accessed by the UE.
  • the location update request is used by the MSC to initiate a CSFB roaming forward procedure to the MSC that sent the first message, and/or for the MSC to initiate the VLR corresponding to the MSC that sent the first message.
  • the CSFB roaming retry process to send a service setup message to the UE.
  • Another UE in the embodiment of the present invention is described below from the perspective of hardware processing. Please refer to FIG. 14.
  • Another embodiment of the UE 1400 in the embodiment of the present invention includes:
  • the input device 1401, the output device 1402, the processor 1403, and the memory 1404 (wherein the number of the processors 1403 in the UE 1400 may be one or more, and one processor 1403 in FIG. 14 is taken as an example).
  • the input device 1401, the output device 1402, the processor 1403, and the memory 1404 may be connected by a bus or other means, wherein the bus connection is taken as an example in FIG.
  • the processor 1403 is configured to perform the following steps by calling an operation instruction stored in the memory 1404:
  • the HO process in the TAU or LTE network is executed after the CSFB process ends.
  • the processor 1403 is further configured to perform the following steps before determining whether the circuit domain is falling back to the CSFB.
  • the UE After the UE ends the CSFB process, the UE is also used to execute:
  • the MME accepts the third message, it falls back to the CS network, and returns to the LTE network to perform the TAU or LTE intra-HO procedure after the service execution of the CS network is completed;
  • the TAU or LTE intra-network HO procedure is performed.
  • the processor 1403 is further configured to perform the following steps before determining whether the circuit domain is falling back to the CSFB.
  • the HO process in the TAU or LTE network is performed:
  • the MME accepts the third message, it falls back to the CS network, and returns to the LTE network to perform the TAU or LTE intra-HO procedure after the service execution of the CS network is completed;
  • the TAU or LTE intra-network HO procedure is performed.
  • Another UE in the embodiment of the present invention is described below from the perspective of hardware processing. Please refer to FIG. 14.
  • Another embodiment of the UE 1400 in the embodiment of the present invention includes:
  • the input device 1401, the output device 1402, the processor 1403, and the memory 1404 (wherein the number of the processors 1403 in the UE 1400 may be one or more, and one processor 1403 in FIG. 14 is taken as an example).
  • the input device 1401, the output device 1402, the processor 1403, and the memory 1404 may be connected by a bus or other means, wherein the bus connection is taken as an example in FIG.
  • the processor 1403 is configured to perform the following steps by calling an operation instruction stored in the memory 1404:
  • the fourth message is sent to the accessed MSC, and the fourth message is used to request the MSC to perform the service of the CS network.
  • the fifth message is used to: if the MSC does not accept the fourth message, instruct the UE to release the connection with the MSC; or, if the MSC accepts the fourth message, and completes the service of the CS network with the UE Execution process, instructing the UE to release the connection with the MSC;
  • the preset area identifier is stored in the UE, and the preset area identifier is used to identify the preset area.
  • the processor 1403 determines whether the UE completes the execution of the service of the CS network before receiving the fifth message. The process is also used to perform the following steps:
  • the UE is triggered to determine whether the UE completes the step of performing the service of the CS network before receiving the fifth message.
  • the preset area is characterized by:
  • the location area identifier LAI of the UE changes
  • the location area identifier LAI of the UE changes
  • the location area identifier LAI of the UE changes.
  • the processor 1403 is further configured to perform the following steps before determining whether the UE completes the execution process of the service of the CS network before receiving the fifth message:
  • the UE is triggered to determine whether the UE completes the step of performing the service of the CS network before receiving the fifth message.
  • the location update request is used by the MSC to initiate a CSFB roaming forward procedure, and/or for the MSC to initiate CSFB roaming to the VLR corresponding to the MSC that sent the first message.
  • the disclosed systems and methods can be implemented in other ways.
  • the system embodiment described above is merely illustrative.
  • the division of the unit is only a logical function division, and the actual implementation may have 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.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, module or unit, and may be electrical, mechanical or otherwise.
  • 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 purpose of the solution of the embodiment.
  • 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.
  • the technical solution of the present invention which is essential or contributes 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. .

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Les modes de réalisation de la présente invention concernent un procédé de repli sur un réseau comprenant les étapes au cours desquelles : un équipement d'utilisateur (UE) reçoit un premier message dans un réseau LTE; l'UE se replie sur un réseau à commutation de circuits (CS) après avoir reçu le premier message; l'UE détermine des informations de modifications de zone de localisation (LA) avant de se replier sur le réseau CS; l'UE envoie à un centre de commutation mobile (MSC) auquel l'UE se connecte, une demande de mise à jour de localisation en fonction des informations de modification de LA après le repli sur le réseau CS; et l'UE reçoit la demande de mise à jour de localisation et achève le processus de configuration d'un service du réseau CS avec le MSC. Le procédé de repli de réseau d'après les modes de réalisation de la présente invention permet de réduire le taux d'échec d'un processus de repli sur un réseau CS (CSFB) et de répondre aux exigences de communication. Les modes de réalisation de la présente invention concernent également un équipement utilisateur associé.
PCT/CN2014/093020 2014-12-04 2014-12-04 Procédé de repli sur un réseau et équipement utilisateur associé WO2016086386A1 (fr)

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CN201480072607.9A CN105917685B (zh) 2014-12-04 2014-12-04 一种网络回落方法以及相关用户设备

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