Method and system for handling voice and non-voice calls in a CSFB scenario

A method for handling a circuit switched (CS) voice call and a CS non-voice call in a mobility management entity (MME), the method comprising:

• upon receiving a circuit switched fallback (CSFB) call requiring network switching, transmitting a CS service notification to a user equipment (UE), wherein the CS service notification includes a first indication indicating that the CSFB call is the CS voice call or the CS non-voice call;
• receiving an extended service request in response to the CS service notification from the UE;
• identifying whether the CSFB call is the CS voice call or the CS non-voice call;
• based on identifying the CSFB call as the CS non-voice call, identifying a type of the CS non-voice call of the CSFB call;
• responsive to identifying whether the CSFB call is the CS voice call or the CS non-voice call, assigning a priority to the CS voice call;
• after receiving the extended service request, transmitting a UE context modification request including the first indication to an e-node b (eNB), wherein the first indication is delivered to the UE though a radio resource control (RRC) connection release by the eNB;
• receiving a UE context modification response from an eNB in response to the UE context modification request;
• and
• receiving a UE context release request from the eNB after the first indication is transmitted to the UE from the eNB,
• wherein the UE provides one among the CS voice call and the CS non-voice call with a second indication comprising a priority bit to a target radio access network (RAN),
• wherein the priority bit of the second indication indicates to the target RAN that the target RAN is to prioritize the CS voice call ahead of the CS non-voice call.

A user equipment (UE) for handling a circuit switched (CS) voice call and a CS non-voice call, the UE comprising:

• a communication unit configured to communicate with an e-node b (eNB) and a mobility management entity (MME);
• and
• a controller configured to control the communication unit;
• wherein the controller is further configured to:
• upon occurrence of a circuit switched fallback (CSFB) call requiring network switching, receive a CS service notification from the MME, the CS service notification including a first indication indicating that the CSFB call is the CS voice call or the CS non-voice call,
• transmit an extended service request to the MME in response to the CS service notification,
• after transmitting the extended service request to the MME, receive a radio resource control (RRC) connection release including the first indication from an eNB that receives a UE context modification request including the first indication from the MME, and
• after receiving the RRC connection release, provide one among the CS voice call and the CS non-voice call with a second indication comprising a priority bit to a target radio access network (RAN), wherein the priority bit of the second indication indicates to the target RAN that the target RAN is to prioritize the CS voice call ahead of the CS non-voice call;
• and
• provide the target RAN with a third indication indicating a type of the CS non-voice call of the CSFB call based on the CSFB call being the CS non-voice call.

A mobility management entity (MME) for handling a circuit switched (CS) voice call and a CS non-voice call, the MME comprising:

• a communication unit configured to communicate with a user equipment (UE) and an e-node b (eNB);
• and
• a controller configured to control the communication unit,
• wherein the controller is configured to:
• upon receiving a circuit switched fallback (CSFB) call requiring network switching,
• transmit a CS service notification to the UE, wherein the CS service notification includes a first indication indicating that the CSFB call is the CS voice call or the CS non-voice call,
• receive an extended service request in response to the CS service notification from the UE,
• identify whether the CSFB call is the CS voice call or the CS non-voice call,
• based on identifying the CSFB call as a CS non-voice call, identify a type of the CS non-voice call of the CSFB call,
• responsive to identifying whether the CSFB call is the CS voice call or the CS non-voice call, assign a priority to the CS voice call,
• after receiving the extended service request, transmit a UE context modification request including a first indication to an e-node b (eNB), wherein the first indication is delivered to the UE through a radio resource control (RRC) connection release by the eNB,
• receive a UE context modification response from the eNB in response to the UE context modification request, and
• receive a UE context release request from the eNB after the first indication is transmitted to the UE from the eNB,
• wherein the UE provides one among the CS voice call and the CS non-voice call with a second indication comprising a priority bit to a target radio access network (RAN),
• wherein the priority bit of the second indication indicates to the target RAN that the target RAN is to prioritize the CS voice call ahead of the CS non-voice call.