一种移动即时通讯消息重传改进机制

An improved message retransmission mechanism of mobile instant messaging

为应对移动即时通讯(instant messaging,IM)消息频繁重传给服务器和网络造成的负荷,基于随机过程的更新理论,提出移动即时通讯消息重传模型来研究消息重传性能。仿真实验结果表明,平均消息重传数为1.22次,与重传模型分析结果 1.25次非常接近,取得比同类型模型更好的描述能力。基于建模分析结果提出一种移动即时通讯消息重传改进机制,采用固定重传间隔,设置重传计数器控制最大尝试次数,相关仿真结果表明该机制能有效减少消息重传次数,同时又不显著增加消息传递时间。最后利用概率论中独立同分布的中心极限定理分析消息重传机制如何影响移动即时通讯消息传递的总体服务质量,并给出调整重传间隔参数等服务优化建议。

Frequent instant message retransmissions significantly increase server load and network traffic. We analyze the message retransmission process, define the stochastic events, do the timing analysis, and propose an analytic model to investigate the performance of message retransmission by update theory of stochastic processes. Simulation results show that average message retransmissions is 1.22 times. The result is veryclose to the retransmission model result, 1.25 times. This comparison illustrates the retransmission model can achieve the better ability to describe the retransmission process than the same type of models. We improve the retransmission mechanism based on the modeling analysis results. The new mechanism takes the fixed retransmission interval and uses the retransmission counter to control the maximum number of attempts. The simulation results show the new mechanism can effectively reduce message traffic without significantly increase message delivery time. Finally, we use the central limit theorem with independent and identical distributions in probability theory to analyze how the retransmission mechanism affects the service quality of mobile instant messaging. We give some optimization suggestions such as adjusting retransmission interval.