Hop-based approach for holes and boundary detection in wireless sensor networks

In wireless sensor networks (WSNs), sensors are frequently prone to failure because of their limited batteries lifetime and external spatio-temporal events. Consequently, coverage and communication holes may appear preventing reliable and durable routing pathways. To efficiently deal with the effects of holes and prevent their expansions, it is unavoidable for any solution to detect their boundaries. This issue had been addressed by several works, many of which are based on topological approaches where sensor nodes´ connectivity is used. The authors propose a topological approach for the detection of the boundaries of holes. The approach also allows for the detection of the boundaries of the sensor network which is an important concern when sensors are deployed randomly in harsh, remote areas. The approach is based on the identification and the checking of the connectivity of the x-hop neighbours surrounding every node. The results of our simulations conducted on randomly and uniformly deployed WSNs demonstrate high accuracy and reduced requirements in terms of network connectivity degree and communication overhead compared to other existing approaches.