A method, an apparatus, and a system for paging processing and information displaying are disclosed. The paging processing method includes: receiving a paging request message from a Mobile Switching Center (MSC) which a called User Equipment (UE) registers to; and when the called UE is connected, sending a paging notification message to the called UE, and returning a called-UE paging status message to the MSC. In the embodiments of the present invention, after the Mobility Management Entity (MME) receives the paging request message from the MSC, if the called UE is connected, the MME not only sends a Circuit-Switched (CS) paging notification message to the called UE, but also returns a paging status message to the MSC, indicating that the called UE has received the paging notification message.

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). According to an embodiment of the present disclosure, a circuit switched fallback (CSFB) method is provided. The method comprising: receiving, by a first base station, a user equipment (UE) context modification request message from a mobility management entity (MME), wherein the UE context modification request message includes a CSFB indicator; receiving, by the first base station, a radio link failure (RLF) indication message from a second base station; and determining, by the first base station, whether to trigger a handover procedure.

Solution for security negotiation during handover of a user equipment (UE) between different radio access technologies is provided. In the solution, the UE receives non-access stratum (NAS) security information and access stratum (AS) security information which are selected by the target system and then performs security negotiation with the target system according to the received NAS security information and AS security information. As such, the UE may obtain the key parameter information of the NAS and AS selected by a long term evolution (LTE) system and perform security negotiation with the LTE system when the UE hands over from a different system, such as a universal terrestrial radio access network (UTRAN), to the LTE system.

Technology for facilitating circuit switched fallback (CSFB) for a user equipment (UE) is disclosed. A mobility management entity (MME) can receive an optimized CSFB capability indicator from the UE. The MME can receive a requested service type associated with the UE. The MME can initiate a single radio voice call continuity (SR-VCC) handover of the UE to a circuit switched network based on the optimized CSFB capability of the UE. The MME can send an S1 application protocol (S1-AP) request message to an evolved node B (eNB). The S1AP message can include the optimized CSFB capability indicator and a single radio voice call continuity (SRVCC) indicator for the UE. The MME can receive a handover required message from the eNB.

The embodiments of the present invention relate to a method, an apparatus, and a system for selecting a public land mobile network. In an embodiment method an eNodeB acquires PLMN information about a CSFB. The eNodeB then determines a target cell of a packet switching handover according to the PLMN information about the CSFB.

Aspects of the present disclosure provide techniques and apparatus for wireless communication, and more particularly, increasing network coverage using rate adaption. The techniques include adjusting a cell transition threshold based on, for example, maximum packet loss rates (PLRs) for a VOIP terminal, for example, taking into consideration application layer redundancy employed at the terminal. Numerous other aspects are provided.

A portable communication system (100) maintains mission critical functionality. An accessory (120) and a handset (130) are tethered and interoperate such that the accessory operates as the primary controlling device and the handset operates as a secondary device. The accessory (120) contains a main applications processor (102) that handles non-mission critical functions. The accessory further contains a mission critical processor (104) for handling mission critical functions of transmit and receive audio as well as PTT and emergency. In response to a failure of the mission critical processor (104), the mission critical functions are maintained by handing over the mission critical functions to the non-controlling device in a manner transparent to the user. The handover is triggered in response to status changes of the mission critical processor or as a result of battery depletion. Audio paths are re-routed through backup paths (146b, 148) negating reliance on processors of the accessory (120).

Various solutions for avoiding circuit-switched call drop with respect to user equipment and network apparatus in mobile communications are described. An apparatus may transmit a non-access stratum (NAS) message in a NAS signaling connection. The apparatus may receive a NAS response message. The apparatus may initiate a timer to control the NAS signaling connection. The apparatus may further receive a circuit-switched (CS) service notification. The apparatus may stop the timer and execute a CS service procedure.

The present invention provides a voice service processing method and a terminal device. The method includes: sending, by a terminal device, a first message to a network device of a first network, where the first message is used to request a circuit switched fallback CSFB voice service; receiving, by the terminal device, a second message sent by the network device of the first network, where the second message is used to instruct the terminal device to perform network redirection; if the second message carries no frequency information, determining, by the terminal device, a redirection frequency, where the redirection frequency is a frequency supported by a second network; and sending, by the terminal device based on the redirection frequency, a connection request to a network device of the second network, to perform a CS voice service.

Embodiments of the present invention relate to the field of wireless communications technologies, and provide a switching method. The method specifically includes: when user equipment is in idle mode, acquiring a 2G/3G base station candidate set; when initiating a voice service, sending a CSFB request message to an LTE base station; receiving a standard and a frequency of a target 2G/3G base station that are sent by the LTE base station to the user equipment; determining, according to the standard and the frequency of the target 2G/3G base station, whether the 2G/3G base station candidate set includes the target 2G/3G base station; and if the 2G/3G base station candidate set includes the target 2G/3G base station, switching, from the LTE base station to the target 2G/3G base station according to the standard and the frequency of the target 2G/3G base station.