Method for selecting long term evolution LTE network and device

#The present invention relates to the field of communications technologies, and in particular, to a method for selecting a Long Term Evolution (LTE) network after a circuit switched (CS) service ends, and a device.

#A circuit switched (CS) network is a wireless network that provides a circuit switched domain service such as a voice call. A 2nd Generation/3rd Generation 2G/3G) network such as GSM and WCDMA has a wide coverage. Meanwhile, with development of network technologies, a packet switched (PS) network specially providing a data service, for example, a Long Term Evolution (LTE) network, is also deployed on a large scale. Therefore, in a current communications network, the CS network and the PS network coexist, and an operator may provide a circuit switched domain service for a user by using the 2G/3G network and provide a data service for the user by using the LTE network.

#Based on the network coverage manner, a 3rd Generation Partnership Project (3GPP) organization puts forward a “circuit switched fallback” (CS Fallback, CSFB) technology, so that when needing to process a CS service, user equipment (UE) that is registered in an LTE network falls back to a CS domain of a 2G/3G network to complete service processing. After the CS service is completed, an existing protocol further defines a CSFB fallback mechanism, so as to ensure that after completing the CS service, the UE can return to the PS network to perform a PS service. The CSFB fallback mechanism specifically includes: a mobile switching center (MSC)/visitor location register (VLR) releases a connection established for the CS service, and indicates to a base station that the current connection is established for CSFB. When releasing the connection, the base station instructs the UE to obtain LTE frequency band (Frequency) information of the LTE network by reselecting, so that after redirected to a suitable cell supporting the LTE frequency band information, the UE randomly selects an available LTE public land mobile network (PLMN) in broadcast information of the suitable cell.

#To describe the technical solutions in the embodiments of the present invention or in the prior art more clearly, the following briefly describes the accompanying drawings required for describing the embodiments or the prior art. Apparently, the accompanying drawings in the following description show merely some embodiments of the present invention, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

#FIG. 1 is a flowchart of a method for selecting an LTE network according to an embodiment of the present invention;

#FIG. 2 is a flowchart of a method for selecting an LTE network according to another embodiment of the present invention;

#The following clearly describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely some but not all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

#In this specification, an LTE network is an evolved UMTS (Universal Mobile Telecommunications System) terrestrial radio access network (E-UTRAN for short), a 2nd Generation (2G) network is a GSM (Global System for Mobile communications)/EDGE (Enhanced Data Rate for GSM Evolution) radio access network (GERAN for short), and a 3rd Generation (3G) network is a UTRAN network. A PLMN in the LTE network provides only a PS domain service, while the 2G/3G network not only includes a PLMN providing a CS domain service but also includes a PLMN providing a PS domain service.

#In the embodiments of the present invention, user equipment UE may be any one of the following, and the user equipment may be static or mobile. User equipment may include, but is not limited to a station, a mobile station, a subscriber unit, a personal computer, a laptop computer, a tablet computer, a netbook, a terminal, a cellular phone, a handheld device, a cordless telephone set, a personal digital assistant (PDA), a data card, a USB plug-in device, a mobile WiFi hotspot device (MiFi Devices), a smart watch, smart glasses, a wireless modem, a wireless router, and a wireless local loop (WLL) station. The foregoing user equipment may be distributed in an entire wireless network.