Mobile data communications (Internet-mobile communication convergence) seems natural as the popularity of both technologies increase. Our purpose in this article was twofold. First, we reviewed GSM, HSCSD (high speed circuit switched data), GPRS and EDGE (enhanced data rate for GSM evolution). Second, the performance of the packet random access channel (PRACH) was analyzed with respect to quality of service parameters: network access delay, throughput, and failure probability. We derived the overall GPRS traffic channel utilization as a function of the throughput and channel holding time. EDGE introduction will decrease the holding time of GPRS terminals due to multilevel encoding and result in higher throughput. Thus, in order to maintain GPRS channel efficiency, PRACH efficiency must be boosted. Thus packet-capturing is introduced to offset access collisions on (P)RACH and increase its efficiency. We noted that the capture effect decreases with access throughput contrary to access delay and failure rate. These QoS parameters are indicative of network performance, hence crucial for novel network planning.