不饱和负载802.15.4网络MAC层信道竞争延时优化机制  

Channel Contention Delay Optimization Mechanism for 802. 15. 4 Network MAC Layer with Unsaturated Load

作　　者：程宏斌[1] 王晓喃[1] 孙霞[1] 乐德广[1] 

机构地区：[1]常熟理工学院计算机科学与工程学院,江苏常熟215500

出　　处：《计算机工程》2016年第10期124-128,共5页Computer Engineering

基　　金：国家自然科学基金资助项目(61202440);江苏省自然科学基金资助项目(BK20141230)

摘　　要：为减少IEEE802.15.4网络媒体访问控制层信道竞争延时,设计一种针对不饱和负载的节点竞争信道机制,并对其进行数学建模和推导,得到节点主要工作状态的稳态概率。基于该模型的结果对信道状态转换过程建模并推导节点信道接入延时的分析式。研究参数λ,NB和min BE对节点信道竞争延时性能的影响,并与饱和负载网络的延时性能进行对比。分析结果表明,该模型能够较好地描述和评价网络MAC层信道竞争机制,提出的优化机制能够有效降低信道的竞争恶化程度,且可改善节点信道竞争延时性能。To reduce the delay of channel contention at the Medium Access Control（MAC） layer for IEEE 802.15.4 networks, a channel contention mechanism for nodes, with unsaturated load is designed. A mathematical model is built and a derivation is carried on to obtain the. steady-state probability of the main state. According to the result of the model, the formula of channel access delay is derived based on the modeling of channel state conversion process. The impact of protocol parameters such as A ,NB and minBE on the performance of node access delay is researched, and it is compared with the delay performance of the saturated load network. Analysis results show that the new model can describe and evaluate the mechanism of channel contention access very well, and the competition optimization mechanism can reduce effectively the deterioration degree of channel. Moreover, settings of protocol parameters can improve the performance of channel contention delay.

关 键 词：延时 媒体访问控制 信道竞争 不饱和 马尔科夫链 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]