In this paper a multi-dimensional markovian chain model is proposed to study the relationship between wireless network performance and key system parameters such as basic parameters of multiple traffic types, wireless network parameters, number of traffic users and voice load in the system. Using Poisson and ON/OFF traffic models to describe the characteristics of voice and data traffic respectively, the proposed model integrates several important aspects including traffic priority, QoS requirements for different kinds of traffic, the transport characteristics of the wireless network, dynamic resource allocation and connection admission control. Simulation results show that this model can well describe the mixture of voice and data traffic in wireless networks, which can be used for transmission design of multiple traffics in wireless networks.