基于QoS的分布式认知无线电网络多信道MAC协议

摘要

在分布式认知无线电网络中,动态资源利用不足和中心控制单元的缺失使其MAC层协议的设计面临很多挑战.针对认知无线电网络的特点,提出了一种新的MAC协议,该协议通过在信道预约阶段优先考虑对时延要求较高的应用,来保证网络对这类应用的QoS;同时还解决了认知无线电网络中频谱的利用率低和隐藏终端两个热点问题.为分析研究该协议的性能,首先提出了一种新的分析模型.然后将这种新的MAC协议与两种典型的MAC协议进行了仿真对比,结果表明该协议提高了网络的吞吐量.最后通过数值分析和仿真证实了本协议设计简单高效,具有较高的频谱利用率,不但满足了时延敏感性应用的QoS需求,而且还能有效地解决多信道隐藏终端的问题.%The insufficence of dynamic resource availability and the lack of central control unit offer many challenges when designing MAC protocol for a distributed cognitive radio network.In this paper,we proposed a novel MAC design for distributed cognitive radio network which provides an efficient approach to address quality of service (QoS) requirements of delay sensitive applications by defining higher priority to such applications during channel reservation.It also combats other major challenges such as low utilization of spectrum and multi-channel hidden terminal problem.We developed an analytical framework to study the performance of the proposed protocol.We then compared the performance of proposed protocol with those of two existing protocols.Comparison results show that the proposed MAC outperforms the existing protocols by providing better throughput.The results achieved from the analytical model and validated by simulations show that our simple yet efficient design identifies and fulfils the QoS requirements of delay sensitive applications,achieves excellent spectrum utilization and handles multi-channel hidden terminal problem effectively.