A fuzzy logic node relocation model in WSNs

A Tuned Fuzzy Logic Relocation Model in WSNs Using Particle Swarm Optimization

“…A large proportion of relocation and movement algorithms in the literature [3], [6], [7], [8], [9], [10], [11], [12], [13], [14], [15] are devoted to currently deployed nodes in order to give the network more flexibility, swiftness to react autonomously in the environments where centralized control and supervision are not feasible. Each of these algorithms are aimed at different and overlapping goals such as network connectivity [13], lifetime [12], re-alignment of unbalanced deployments [7], coverage increase [7], recovery of small and large scale coverage holes [6], [9], [14].…”

“…Although fuzzy logic relocation model shown to be candidate solution to address such a uncertainty for the autonomous moving nodes [10], among indefinite choices, proper and justifiable fuzzy parameters and membership functions should be selected. In proposed model, the proper fuzzy parameters in fuzzy logic relocation model can be obtained by applying PSO technique locally with different ranges and globally over the given deployed area.…”

“…In proposed model, the proper fuzzy parameters in fuzzy logic relocation model can be obtained by applying PSO technique locally with different ranges and globally over the given deployed area. similar to [10] with different angular, boundary conditions and movement strategies, the efficiency and performance of the given model in terms of coverage, uniformity and movement are also compared with distributed Self-Spreading Algorithm (DSSA) [7] which benefited from expected global node density.…”

“…p is the total number of rules. Similar to [10] two different fuzzy inference systems are used: fuzzy radial pair force and fuzzy angular force. Both fuzzy radial pair force system and fuzzy angular force system have one input as distance with 3 gaussian functions, one z-function and one s-function memberships (Table II) and one crisp output, pressure which can take the fuzzy values push hard, push, no action, pull and pull hard.…”

“…Force exerting node n f v is considered as vertex of angle α = (n 1 , n f v , n 2 ) (0 < α ≤ 180 • ) with each pair of its neighbours n 1 ,n 2 . Angular force strategies in [10] based on exerted forces from node's neighbours can be considered as:(A 1 )-Smallest Angular Movement Strategy, among exerted angular forces from node's neighbours, the one is selected that causes smallest node angular movement. (A 2 )-Closest Neighbour Movement Strategy, among exerted angular forces from nodes' neighbours, the closest neighbour is selected as the exerting angular nodes.…”