在应用IEEE802.16e协议的无线城域网中,为了节约移动终端的电池能量,可以采用空闲模式节能机制;文中分析了IEEE802.16e协议中的空闲模式的节能机制,并且为了更进一步节约电池能量,引入关闭期,建立了带启动期和关闭期的多重休假Geom/G/1排队系统;使用嵌入Markov链方法,推导出排队模型的性能指标,得到IEEE802.16e中空闲模式节能方案中相应的数据帧平均响应时间、平均数据帧数、系统切换率及能量节省率;并且利用数值例子刻画了性能指标和系统配置参数之间的关系。
In wireless metropolitan area network applicating IEEE 802. 16e protocol, idle mode energy--saving mechanism can he used to save battery power of mobile stations. For the idle mode energy saving mechanism of IEEE 802.16e protocol, a Geom/G/1 queue with setup time, close time and multiple vacations is built. The performance measures of the queue model are deduced by using an embedded Markov chain method. Further, average response time of frame, mean number of frame, system switch rate and energy saving rate are derived for i die mode in IEEE 802.16e. Finally, the dependency relationships between the system performance measures and the system parameters are showed by numerical examples.