The field of wireless mobile networking has advanced greatly over the last decade. Different protocols and technologies are in place today to provide wireless and mobility communications in various environments. This paper uses an analytical approach for modeling the mobility effect as well as the data traffic load on the overall system performance in GSM General Packet Radio Service (GPRS) network. An integrated voice/data wireless system with finite buffer for data traffic has been considered as in [1] and based on decomposition of system behavior into short-term and long-term behavior techniques that were introduced in [2]. We used a simplified analytical model to study some performance keys that enable us to evaluate the overall performance in GPRS network and to study how the data services affect the main performance of the GSM network and what is the limit of offered load intensity and mobility that can not be exceeded in order to get an accepted system performance.