Research For CAC Technology With Resource Efficient Allocation In Wireless Network

In wireless network, call admission control (CAC) is one of the key technologies on application level. This thesis admits an emerging Instant Message (IM) service with conventional services for next-generation OFDMA wireless network. According to the different priorities of these services, this thesis proposes a double-threshold guard channel policy which optimizes IM service performance and maintains the performance of conventional services. The simulation results of double-threshold CAC policy shows that the performance of all services can achieve the QoS requirement, and IM service can achieve the optimal performance through adjusting the guard channel numbers dynamically. In the resource shortage system, there is a higher admitting requirement for the service with high QoS. So, in this thesis, we design a multi-service mobility CAC scheme for the guaranteed service. The simulation results of this scheme verify the accuracy of the design. Compared with conventional CAC scheme, this scheme could get the mobility parameter. So this scheme can better conform to the actual situation and has a higher application value. In the cognitive radio network, in order to further improve the performance of delay and resource utilization efficiency, we propose an improved CAC scheme in this thesis. The proposed scheme allocates spare channels to unauthorized users evenly in one slot. Unauthorized users can get more channels and a higher package transmitting rate. So this scheme can reduce delay and improve resource utilization. Through simulating this scheme and compared with traditional policy, the proposed CAC scheme achieves lower delay parameter and higher resource utilization efficiency.