The Synchronized Peer-to-Peer Framework and Distributed Contention-Free Medium Access for Multihop Wireless Sensor Networks

[摘要] IEEE 802.15.4 is a low-power, low-rate MAC/PHY standardthat meets most of the stringent requirements of singlehopwireless sensor networks. Sensor networks with nodalpopulations composed of thousands of devices have been envisionedin conjunction with environmental, vehicular, militaryapplications, and many others. However, such large sensornetwork deployments necessitate multihop support as wellas low power consumption. In the light of the standard'sextremely limited joint support of the two aforementionedattributes, this paper presents two essential contributions. First,a framework is proposed to implement a new IEEE 802.15.4operating mode, namely, thesynchronized peer-to-peermode.This mode is designed to enable the standard's low-powerfeatures in peer-to-peer multihop-ready topologies. The secondcontribution is a distributed GTS(dGTS)management schemedesigned to function in the newly devised network mode. Thisprotocol provides reliable contention-free access in peer-to-peertopologies in a completely distributed manner. Assumingoptimal routing, our simulation experiments reveal perfectdelivery ratios as long as the traffic load does not reach orsurpass its saturation threshold. dGTS sustains at least twicethe delivery ratio of contention-based access under suboptimaldynamic routing. Moreover, the dGTS scheme exhibits minimumpower consumption by eliminating the retransmissionsattributed to contention, which, in turn, reduces the number oftransmissions to a minimum.

[学科分类] 自动化工程