Void Handling Techniques in Wireless Sensor Networks

Abstract

In extreme regions like war zones, forests, and islands, it is much easier to establish a newlinewireless sensor network than a wired network. Wireless sensor networks reduce network newlineestablishment costs significantly. But it has some drawbacks, like limited battery life and a newlinesmall amount of memory for storage. Due to these limitations, the routing algorithm for wired newlinenetworks, which demands more energy and memory, is not appropriate for wireless sensor newlinenetworks. newlineThe sensor nodes may lose their energy and become dead if not used energy-efficiently. newlineTherefore, the wireless routing has to be energy-efficient. However energy-efficient any newlinewireless routing is, it cannot sustain sensor nodes to remain live throughout. The region newlinewhere no live node remains is called the void region. The unpredictable occurrence of dead newlinenodes and void regions in the network creates a significant challenge for the routing newlinealgorithm. So, wireless routing needs some energy-efficient invalid handling techniques to newlinebypass these holes. We propose three different methods for void handling in a wireless sensor newlinenetwork. newlineThree methods GGG, SRG, and two-hop-based greedy approaches have been proposed to newlinebypass void regions. The GGG is a dynamic approach that considers the size of the void as a newlineparameter and selects the degree of shift accordingly. The SRG approach applies a static newlinemethod with minimal computation. The SRG approach is simplistic and needs only local newlineinformation, making it more scalable. The number of voids and the size of the void region newlinedepend on the sensor node density in the network. The number of holes increases with a newlinedecrease in the network density. We performed simulations over both high- and low-density newlinenetworks, i.e., dense and rare, to validate the efficiency of the proposed methods. newlineThe proposed GGG and SRG methods are compared with the state-of-the-art approaches of newlineGAR and CS. The GGG approach is more energy efficient than the SRG approach. Its energy newlineconsumption does not increase more than 19%, with a five-fold increase in the size of the newlinevoid. newlineThe two-hop greedy approach is a void avoidance-based approach. It detects the holes well newlinebefore selecting the optimal path to reach the goal. It collects its two-hop neighbor newlineinformation to find the neighbor with the minimum projected cost. It has three stages: the first newlineprojected cost estimation phase, the second propagation phase, and the third termination newlinephase. Initially, the projected cost of the neighboring source node is calculated and forwarded newlineto a node with the minimum projected cost. It proceeds this way until the projected cost newlinebecomes zero, at which point the process terminates. We conducted a simulation experiment newlineto validate its efficiency with other cost-based approaches, such as VAA and DUA. The newlinesimulation results show that it is better than the comparative approaches. newline