Modeling and analysis of combined mobility management based on implicit cell update scheme in general packet radio service

General packet radio service (GPRS) is a system for efficient packet-switched data transmission, which is used in conjunction with the global system for mobile communications (GSM) for circuit-switched voice communication. In GPRS, ready, standby, and idle states are defined accommodating packet traffic characteristics, contrary to two states, i.e. busy and idle in GSM. In GSM, location update and paging are performed based on location area (LA). On the contrary, in GPRS, they are carried out based on cell or routing area (RA), which is smaller than LA. Combined RA/LA update and circuit-switched paging via serving GPRS support node (SGSN) have been proposed in 3GPP in order to save the network and radio resources. In this paper, an implicit cell update scheme based on GSM voice call arrivals is proposed and a combined mobile station (MS) state model accommodating both GSM and GPRS states is made based on the implicit cell update scheme and the effect of combined mobility management on the performance of GPRS system is analyzed.