Analysis of GPRS radio channel access delay

We present an analysis of delay encountered in successfully accessing the Random Access Channel (RACH) of General Packet Radio Service (GPRS) Radio Interface by mobile stations that want to initiate data transfer. The process of RACH access is described and the MS state modeled as a discrete-time Markov chain (DTMC) in order to derive the delay. We evaluate the variation of the radio channel access delay with the maximum attempts, inter attempt time interval, number of mobile users, number of backlogged users, radio priority, rate of incoming data and rate of retransmissions. The blocking probability or the probability of complete channel access failure is also evaluated.