WSNs Coverage Hole Partial Recovery by Nodes' Constrained and Autonomous Movements Using Virtual alpha-chords
Ali Rafiei, Mehran Abolhasan, Daniel Robert Franklin, Farzad Safaei · UTS ePRESS (University of Technology Sydney) · 2012
Abstract—In WSNs, in order to recover from coverage holesand to mitigate their indirect/direct effects on networks’ perfor-mance, different recovery strategies such as increasing proximatenodes’ transmission range and/or relocation of nodes towardscoverage holes seem to be appropriate solutions. Since the major-ity of a mobile node’s energy is consumed by movement and sincenodes’ residual energy may be affected by damage events, nodemovements should be performed sparingly. Conventional nodes’information exchange in real-time applications with security andinterference concerns are neither practical nor secure. Therefore,for the aforementioned scenarios, at the price of possible node col-lisions, disconnections, and reasonable compromises, promisingdistributed and autonomous node movement algorithms based onlimited 1-hop neighbour knowledge are proposed. Our proposedautonomous and constrained node movement model based on anode’s 1-hop perception provides a feasible and rapid recoverymechanism for large scale coverage holes in real-time and harshenvironments. Our model not only maintains moving nodes’connectivity to the rest of network to some extent, but also offersemergent cooperative recovery behaviour among autonomousmoving nodes. Our movement model based on virtual chordsformed by nodes and their real and virtual 1-hop neighbours,not only confines node movement range, but also takes the issueof moving nodes’ connectivity into account. Suitable performancemetrics for partial recovery via constrained movement are intro-duced to compare the performance and efficiency of our modelwith conventional Voronoi-based movement algorithms. Resultsshow that our proposed model’s performance is comparable withVoronoi-based movement algorithms.Index Terms—Coverage holes; autonomous and constrainedmovements; Wireless sensor networks; virtual chord.