Abstract: The queueing priority exhausting station polling protocol that has been declared is introduced based on normal polling protocol.The proposed protocol optimizes the delay performance of central station.By the imbedded Markov chain and the generating function of queue length，the mean queue length in statistical equilibrium is obtained，and the formula is verified by simulation.Meanwhile the delay performance of this protocol is gained by simulation.The simulation results show that the proposed protocol incurs a short delay of the central station queue with heavy load.

Key words: polling protocol, central station, queue length, delay, Markov chain

摘要： 在基本轮询协议的基础上介绍了已有的排队优先权站点耗尽型轮询协议的操作原则，该协议可以优化中心站的延迟特性。通过嵌入马尔科夫链和构造队列母函数的方法，求解出了平衡状态下中心站的队列长度，并通过仿真进行了验证，同时通过仿真方法获得了系统的延迟特性。仿真结果表明，该协议在系统业务量强度较大时，中心站也具有良好的延迟特性。

关键词: 轮询协议, 中心站, 队列长度, 延迟, 马尔科夫链