Abstract: Embodiments of the present invention provide an access method and an apparatus. The method includes: receiving, by a converged mobility management network element, an access request of user equipment UE, where the access request is used to request to access a first network; obtaining, by the converged mobility management network element according to the access request, subscription data of the first network corresponding to the user equipment; when failing to obtain the subscription data, updating, by the converged mobility management network element, a continuous cumulative quantity of times; and when the continuous cumulative quantity of times meets a preset condition, sending, by the converged mobility management network element, first indication information to a base station device of a second network.

Abstract: The embodiments of the present application discloses a circuit switched fallback method, a UE, an MSC, and an MME. The method includes: sending, by a UE to an MME, a request message for requesting to perform CSFB; receiving, by the UE, a switch command sent by an eNodeB; releasing or holding a default CS call of the UE after the UE switches to the CS domain according to the switch command, where the default CS call is generated by the UE according to the switch command; and by using an MSC, initiating, by the UE, a CS call or receiving a CS call. According to the circuit switched fallback method, the UE, the MSC, and the MME in the embodiments of the present application, circuit switched fallback can be implement in a manner of switching by a UE from a PS domain to a CS domain, and reduce a delay.

Abstract: Embodiments of the present invention provide an access method and an apparatus. The method includes: receiving, by a converged mobility management network element, an access request of user equipment UE, where the access request is used to request to access a first network; obtaining, by the converged mobility management network element according to the access request, subscription data of the first network corresponding to the user equipment; when failing to obtain the subscription data, updating, by the converged mobility management network element, a continuous cumulative quantity of times; and when the continuous cumulative quantity of times meets a preset condition, sending, by the converged mobility management network element, first indication information to a base station device of a second network.

Abstract: The embodiments of the present application discloses a circuit switched fallback method, a UE, an MSC, and an MME. The method includes: sending, by a UE to an MME, a request message for requesting to perform CSFB; receiving, by the UE, a switch command sent by an eNodeB; releasing or holding a default CS call of the UE after the UE switches to the CS domain according to the switch command, where the default CS call is generated by the UE according to the switch command; and by using an MSC, initiating, by the UE, a CS call or receiving a CS call. According to the circuit switched fallback method, the UE, the MSC, and the MME in the embodiments of the present application, circuit switched fallback can be implement in a manner of switching by a UE from a PS domain to a CS domain, and reduce a delay.