B. An Approximation Method for Perfortimiice Evaliiation
The voice services are independent of GPRS. Because GPRS
is mainly designed to transmit intermittent and burst data, the
service time of GPRS is rather smaller than that of voice
services. As an approximation, the decomposition technique
[4] can be used to analyze the GPRS performance. The
essential of this technique is to use the voice services
probability distribution to describe the interaction of voice
services to GPRS. Thus, the GPRS. performance in the
dynamically variable resource is obtained by combining this
distribution with the performance in a fixed resource.
For the voice services, the probability of II users in service is