带睡眠机制的IEEE 802.15.4 MAC协议性能分析

针对IEEE 802.15.4中的周期性睡眠机制,提出了一种IEEE 802.15.4 MAC协议实时应用中完全基于时隙分析的精确建模方法.该方法把IEEE 802.15.4的睡眠机制以及载波侦听多址接入/冲突避免(CSMA/CA)机制同时纳入考虑,将整个超帧以退避时隙为单位进行划分.通过对2个机制精确到时隙的建模,分析了网络负载以及占空比特别是睡眠机制对能耗、吞吐量及平均服务延迟等网络性能的影响.NS-2仿真结果表明,该模型可准确预测实时应用中IEEE 802.15.4网络性能,且在相同数据率条件下占空比适当的睡眠机制可使得能量消耗以及网络吞吐量达到最优值.

Performance Evaluation of IEEE 802.15.4 MAC with Sleep Mechanism

An exactly slot based and thus accurate model for IEEE 802.15.4 protocol with sleep mechanism in real time application was proposed. The model explicitly takes into account both the sleep mechanism and CSMA/CA mechanism of IEEE 802.15.4. By dividing the superframe into backoff slots and modeling the two mechanisms with a precision of slot, it analyzes the energy consumption, throughput, and service time delay of the protocol and discusses the impact of network traffic, duty cycle, especially sleep mechanism on protocol performance. The NS 2 simulations show that the model can accurately predict the performance of IEEE 802.15.4 networks. At the same time, under the same packet arrival rate, a proper duty cycle could optimize both the energy consumption and network throughput.