Method and system for returning to long term evolution network and mobile switching center

A method for returning to a long term evolution network, comprising:

• receiving, when a user equipment (UE) is accessed to a second mobile switching center (MSC) due to linking area updating (LAU), a first CSFB indication corresponding to the UE that is sent by a first MSC, wherein the first CSFB indication is sent from a mobility management entity (MME) to the first MSC, and is used for identifying that the UE needs to return to a long term evolution (LTE) network after circuit service of the UE is finished;
• and
• sending, according to the first CSFB indication, a second CSFB indication corresponding to the UE to a radio network controller (RNC)/base station controller (BSC) corresponding to the UE when the circuit service of the UE is finished, wherein the second CSFB indication is used for indicating that the RNC/BSC is to notify the UE of returning to the LTE network.

A method for returning to a long term evolution network, comprising:

• receiving a request message for initiating circuit service fall back (CSFB) by a user equipment (UE);
• and
• sending a first CSFB indication corresponding to the UE to a first mobile switching center (MSC), wherein the first CSFB indication is used for identifying that the UE needs to return to a long term evolution (LTE) network after circuit service of the UE is finished, so that one of the first MSC and a second MSC accessed by the UE due to linking area updating (LAU) sends, according to the received first CSFB indication, a second CSFB indication corresponding to the UE to a radio network controller (RNC)/base station controller (BSC) corresponding to the UE when the circuit service of the UE is finished, wherein the second CSFB indication is used for indicating that the RNC/BSC is to notify the UE of returning to the LTE network, and the second MSC receives the first CSFB indication sent by the first MSC.

A mobile switching center (MSC), comprising:

• a receiving unit, configured to receive a first circuit service fall back (CSFB) indication corresponding to a user equipment (UE) that is sent by a mobility management entity (MME) after the UE initiates CSFB, wherein the first CSFB indication is used for identifying that the UE needs to return to a long term evolution (LTE) network after circuit service of the UE is finished;
• and
• a first sending unit, configured to send, according to the first CSFB indication received by the receiving unit, a second CSFB indication corresponding to the UE to a radio network controller (RNC)/base station controller (BSC) corresponding to the UE when the circuit service of the UE is finished, wherein the second CSFB indication is used for indicating that the RNC/BSC is to notify the UE of returning to the LTE network.

A mobile switching center (MSC), comprising:

• an acquiring unit, configured to receive, when a user equipment (UE) is accessed to the MSC due to linking area updating (LAU), a first CSFB indication corresponding to the UE that is sent by another MSC, wherein the first CSFB indication is sent from a mobility management entity (MME) to the another MSC, and is used for identifying that the UE needs to return to a long term evolution (LTE) network after circuit service of the UE is finished;
• and
• a sending unit, configured to send, according to the first CSFB indication received by the acquiring unit, a second CSFB indication corresponding to the UE to a radio network controller (RNC)/base station controller (BSC) corresponding to the UE when the circuit service of the UE is finished, wherein the second CSFB indication is used for indicating that the RNC/BSC is to notify the UE of returning to the LTE network.

A mobility management entity (MME), comprising:

• a receiving unit, configured to receive a request message for initiating circuit service fall back (CSFB) by a user equipment (UE);
• and
• a sending unit, configured to send, after the receiving unit receives the request message for CSFB, a first CSFB indication corresponding to the UE to a mobile switching center (MSC), wherein the first CSFB indication is used for identifying that the UE needs to return to a long term evolution (LTE) network after circuit service of the UE is finished, so that one of the MSC and another MSC accessed by the UE due to linking area updating (LAU) sends, according to the first CSFB indication, a second CSFB indication corresponding to the UE to a radio network controller (RNC)/base station controller (BSC) corresponding to the UE when the circuit service of the UE is finished, wherein the second CSFB indication is used for indicating that the RNC/BSC is to notify the UE of returning to the LTE network, and the another MSC receives the first CSFB indication sent by the MSC.