Opportunistic flooding in low-duty-cycle wireless sensor networks with unreliable links
Shuo Guo, Yu Jason Gu, Bo Jiang, Tian He · 2009
Intended for network-wide dissemination of commands, configurations and code binaries, flooding has been investigated extensivelyinwirelessnetworks. However,littleworkhasyetbeendone on low-duty-cycle wireless sensor networks in which nodes stay asleep most of time and wake up asynchronously. In this type of network,abroadcastingpacketisrarelyreceivedbymultiplenodes simultaneously, a unique constraining feature that makes existing solutions unsuitable. Combined with unreliable links, flooding in low-duty-cycle networks is a new challenging issue. In this paper, we introduce Opportunistic Flooding, a novel design tailored for low-duty-cycle networks with unreliable wireless links and predetermined working schedules. The key idea is to make probabilistic forwarding decisions at a sender based on the delay distribution of next-hop nodes. Only opportunistically early packets are forwarded using links outside the energy optimal tree to reduce the flooding delay and redundancy in transmission. To improve performance further, we propose a forwarder selection methodtoalleviatethehiddenterminalproblemandalink-qualitybased backoff method to resolve simultaneous forwarding operations. We evaluate Opportunistic Flooding with extensive simulation and a test-bed implementation consisting of 30 MicaZ nodes. Evaluation shows our design is close to the optimal performance achievable by oracle flooding designs. Compared with improved traditionalflooding,ourdesignachievessignificantlyshorterflooding delay while consuming only 20 % ∼ 60 % of the transmission energy invarious low-duty-cycle networksettings. Categories andSubject Descriptors