摘要
无线传感器网络协议设计依赖于网络环境中的链路特征.在实际环境中,链路易受外界环境的影响而产生剧烈的变化.但是,目前只有少量的链路模型涉及多频道传输可靠性及其时间变化特征.以丢包率描述链路的可靠性,针对链路可靠性在频道和时间上的变化特征,提出了统计建模的方法,引入丢包率(PDR)和丢包序列(PDS)定量刻画出了链路可靠性与频道、时间的关系.通过在钢铁厂车间、学校实验工厂对2.4GHz的IEEE802.15.4模块进行测试及统计分析,发现数据丢包率服从logistic或log-logistic分布;在一个确定丢包率下,两次数据丢包之间的间隔服从lognormal分布.在此基础上,通过分析干扰链路可靠性的原因,提出了一种工业无线传感器网络链路可靠性模型,并基于此模型对IEEE802.15.4e的两种提案进行了评估和分析.
Wireless sensor network protocol design is highly depended on the link characteristics of the network environment. In real application field, link reliability is vulnerable to environment interferences. But there are little works which reveal the temporal variation and multi-channel difference characteristics of the link reliability. The authors present a statistics approach according to the temporal and frequency characteristics of link reliability in industrial environment. Two variables, i.e. packet drop rate （PDR） and packet drop sequence （PDS） are introduced to describe the relationship of link reliability with time and frequency. Through the measurements in typical environments like iron and steel factory and experimental factory in USTB with IEEE 802. 15.4 compliant transceivers, it is found that the PDR of a certain range follows logistic distribution or log- logistic distribution, and the interval between two dropped packets for a given PDR follows lognormal distribution as well. Furthermore, based on the analysis of the link reliability, a link layer statistical model is presented and two proposals for IEEE802.15.4e are evaluated on the new model. The simulation results show that the network reliability can be improved when taking the statistic characteristics of the link variations into consideration in the design of high reliable protocols.
出处
《计算机研究与发展》
EI
CSCD
北大核心
2009年第12期1971-1984,共14页
Journal of Computer Research and Development
基金
国家"八六三"高技术研究发展计划重大基金项目(2007AA041201)
国家"八六三"高技术研究发展计划基金项目(2007AA04Z169)
国家自然科学基金项目(50674010)~~
