With the development of wireless network, more and more applications require the QoS for message transmission. In order to enhance the QoS service in the dynamic changing wireless networks, this paper proposes two channel allocation schemes to improve the resource utilization of the base station, named FSC and FRC. FSC assigns the available shared channel to the handover call or the reserved channel when the shared channels are fully occupied. FRC, however, assigns the free reserved channel or the shared channel when the reserved channels are fully occupied. We use two-dimension Markov model to analysis the new call blocking probability and handover call dropping probability. Extensive numeric results show that the two schemes have strongly influence on the network resource utilization. In order to improve the performance of base station, the tradeoff between the number of services channel and the QoS of base station must be considered.