Hybrid channel allocation strategy with group switching and performance evaluation in cognitive radio network

Abstract

Considering the non-real-time traffic in cognitive radio networks and two groups of licensed channels,com-bing the methods of random back-off and control center schedule,a novel hybrid channe allocation strategy with channel group switching mechanism was proposed.Taking into account the total number of the cognitive packets and the numbers of the primary packets on each group channels,a three-dimensional Markov model was constructed,some cogniti user measures in terms of the blocking ratio,the packet loss ratio and the average delay were derived accordingly.Numerical results with analysis and simulation show that,as the back-off time changes,a tradeoff exists between different perfor-mance measures.Therefore,by minimizing the system cost,the back-off time can be optimized.

Keywords

• cognitive radio network;hybrid spectrum allocation;group switching;Markov model;back-off time