Patent ID: 8718653

Claim:
A method for association update, comprising: when a terminal performs Location Area Update (LAU) to a Mobile Switching Center/Visitor Location Register (MSC/VLR) via a Global System for Mobile Communications Enhanced Data Rate for GSM Evolution Radio Access Network/Universal Mobile Telecommunication System Terrestrial Radio Access Network (GERAN/UTRAN), if the terminal has performed combined update or Circuit Switching Fallback (CSFB) attachment in an Evolved Packet System (EPS) network via an Evolved UTRAN (E-UTRAN), then the terminal setting a combined update indication which indicates the EPS network requires combined update when the terminal returns to the E-UTRAN from the GERAN/UTRAN; and when the terminal moves to a registered tracking area of the E-UTRAN from the GERAN/UTRAN, the terminal determining whether the combined update indication which indicates the EPS network requires combined update has been set, if yes, then the terminal initiating combined Tracking Area (TA)/Location Area(LA) Update to a Mobility Management Entity (MME), after receiving a location update request from the MME, the MSC/VLR updating stored association information and re-establishing SGs association with the MME, so that the terminal can receive a Circuit Switching (CS) service while camping in the E-UTRAN; wherein the terminal, a Global System for Mobile Communication (GSM)/Universal Mobile Telecommunication System (UMTS) and the EPS network all support idle-mode Signaling Reduction (ISR) function, and the ISR activated; SGs interface is supported between the MSC/VLR and the MME; Gs interface is not supported between the MSC/VLR and a Serving GPRS Support Node (SGSN), and/or the terminal does not support combined Routing Area (RA)/LA Update.