Homology-Based Distributed Coverage Hole Detection in Wireless Sensor Networks

Abstract

International audienceHomology theory provides new and powerful solutions to address the coverage problems in wireless sensor networks (WSNs). They are based on algebraic objects, such as Čech complex and Rips complex. Čech complex gives accurate information about coverage quality, but requires a precise knowledge of the relative locations of nodes. This assumption is rather strong and hard to implement in practical deployments. Rips complex provides an approximation of Čech complex. It is easier to build and does not require any knowledge of nodes location. This simplicity is at the expense of accuracy. Rips complex cannot always detect all coverage holes. It is then necessary to evaluate its accuracy. This work proposes to use the proportion of the area of undiscovered coverage holes as performance criteria. Investigations show that it depends on the ratio between communication and sensing radii of a sensor. Closed-form expressions for lower and upper bounds of the accuracy are also derived. For those coverage holes that can be discovered by Rips complex, a homology-based distributed algorithm is proposed to detect them. Simulation results are consistent with the proposed analytical lower bound, with a maximum difference of 0.5%. Upper-bound performance depends on the ratio of communication and sensing radii. Simulations also show that the algorithm can localize about 99% coverage holes in about 99% cases

Decentralized Computation of Homology in Wireless Sensor Networks Using Spanning Trees

“…which is built on connectivity information. As shown in [26], under assumption P3, there are no holes inČ(V ) if there are no holes in R(G N ). The absence of holes in the Rips complex therefore guarantees the coverage of domain D.…”

“…To mitigate this problem, partitioning of large networks using divide-and-conquer method has been proposed [21][22][23][24]. This led to more pragmatic approaches of coverage verification where holes in the Rips complex are detected by local message flooding or systematic network reduction [25,26]. To the best of our knowledge, all known algorithms assume certain topological limitations, most notably the demand for a circular fence made of specially designated and configured nodes.…”

A Novel Nonlinear Multitargetk-Degree Coverage Preservation Protocol in Wireless Sensor Networks

“…At the moment, all those nodes will enter sleep states. Although this state can reduce the node energy consumption, there are still some deficiencies; the reason for this is that once perceiving neighbour nodes enter sleep state, there will be large coverage blind area in monitored region; therefore the coverage quality is decreased [34][35][36][37]. In order to avoid such kind of situation, NMCP algorithm uses a mechanism that once a node enters sleep state, it wakes up its neighbour nodes immediately and converts them into wait states.…”

Distributed Hole Detection Algorithms for Wireless Sensor Networks

“…Yao et al [8] used connectivity information gathered from onehop neighbors for coverage hole detection in distributed manner. Yan, Martins and Decreusefond [9] presented a technique for detecting coverage hole using a connectivity based technique. They used two simplicial complexes, Rips complex and Cech complex, to model the network around hole and then used connectivity graph and concept of the Hamiltonian cycle to find nodes in the hole boundary.…”