Novel relay node placement algorithms for establishing connected topologies

Abstract

This paper addresses the problem of placing the least number of fixed-range relay nodes (RNs) in order to establish multi-hop paths between every pair of terminals. We derive an optimal solution for the case of three terminals and for the cases of more than 3 terminals, we present three novel heuristics, namely, Optimized Triangle Selection based on Minimum Spanning Tree Triangulation (OTS-MST), Incremental Optimization based on Delaunay Triangulation (IO-DT) and hybrid approach. These heuristics take advantage of the optimal threeterminal based solution by forming connected sub-graphs for steinerized sets of three terminals and then connecting these sub-graphs via steinerized edges. OTS-MST considers triangles that have two mst edges and picks the subset of these triangles which provides the highest reduction in the total number of required RNs as compared to a solution that is based on steinerized mst edges.

A Straight Skeleton Based Connectivity Restoration Strategy in the Presence of Obstacles for WSNs

“…According to the classification of the cost, there exist two major types of restoration strategies [ 1 ]. One utilizes the least number of relay devices (i.e., RNs and MDCs) to federate disconnected components [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], while the other one pursues the minimum energy consumption influenced by realistic terrains [ 19 , 20 , 21 , 22 , 23 ].…”

“…Recently, Wang et al [ 9 ] proposes a 3- algorithm based on the center of mass and 3- . There are some efficient algorithms without giving approximation ratios [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Lee et al propose efficient algorithms in [ 13 , 15 ], respectively, to deploy RNs toward the center of the deployment area.…”

“…[ 12 ] employ the straight skeleton as the relay node deployment route. In [ 11 ], Senel et al. design two efficient algorithms.…”

“…In previous works, there exist two methods of representative selection. The first one [ 2 , 4 , 5 , 6 , 7 , 8 , 10 , 11 , 12 , 17 , 18 ] is randomly choosing a node within a component to represent it, while the second one [ 9 , 13 , 15 ] chooses a number of nodes, one from each component, closest to each other as corresponding representatives. If the is used to find an MST, then it is obvious that the latter one will result in a shorter MST.…”

“…We call all approaches , if they either randomly choose a node from each component as the corresponding representative or select a number of nodes, each from a component, closest to each other as representatives [ 2 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 15 , 17 , 18 ]. Let denote the length of an MST built by .…”