AbstractGPRS is designed for transmitting packet data and
supposed to take its radio resource from the pool of channels
unused by GSM voice services. The number of channels allocated
to GPRS is a random variable depending on the voice traffic. In
this paper, an approximation method is used for evaluating the
GPRS performance of single-slot service in the variable radio
resource. The method could be used for evaluating the GPRS
performance when the average service time of circuit switched
services is much longer than that of GPRS. The multi-slot
services cause higher blocking probability and longer delay to
the network than the single-slot service. However, those effects
can be reduced by implementing a GPRS resource allocation
scheme with flexible multi-slot services.