Circuit switched fallback method and device

A first base station in a wireless communication system, comprising:

• a transceiver configured to:
• receive, from a mobility management entity (MME), a user equipment (UE) context modification request message including a circuit switched fallback (CSFB) indicator;
• and
• receive, from a second base station, a radio link failure (RLF) indication message, and
• a controller configured to determine not to trigger a handover procedure based on the CSFB indicator and the RLF indication message.

A method performed by a first base station in a wireless communication system, the method comprising:

• receiving, from a mobility management entity (MME), a user equipment (UE) context modification request message including a circuit switched fallback (CSFB) indicator;
• receiving, from a second base station, a radio link failure (RLF) indication message;
• and
• determining whether to trigger a handover procedure,
• wherein the CSFB indicator indicates that a CSFB procedure has a high priority, and the UE context modification request message further includes an additional CSFB indicator, and
• wherein the additional CSFB indicator indicates whether an information element (IE) in a handover restriction list is used for the CSFB procedure having the high priority.

A first base station in a wireless communication system, comprising:

• a transceiver;
• and
• a processor configured to:
• receive, from a mobility management entity (MME) via the transceiver, a user equipment (UE) context modification request message including a circuit switched fallback (CSFB) indicator;
• receive, from a second base station via the transceiver, a radio link failure (RLF) indication message;
• and
• determine whether to trigger a handover procedure,
• wherein the CSFB indicator indicates a CSFB procedure has a high priority, and the UE context modification request message further includes an additional CSFB indicator, and
• wherein the additional CSFB indicator indicates whether an information element (IE) in a handover restriction list is used for the CSFB procedure having the high priority.