A Connectivity-Aware Approximation Algorithm for Relay Node Placement in Wireless Sensor Networks

Abstract

Abstract-In two-tiered wireless sensor networks (WSNs), relay node placement is one of the key factors impacting the network energy consumption and the system overhead. In this paper, a novel connectivity-aware approximation algorithm for relay node placement in the WSNs is proposed to offer a major step forward in saving system overhead. In particular, a unique local search approximation algorithm (LSAA) is introduced to solve the relay node single cover (RNSC) problem. In this proposed LSAA approach, the sensor nodes are allocated into groups and then a local set cover (SC) for each group is achieved by a local search algorithm. The union set of all the local SCs constitutes a SC of the RNSC problem. The approximation ratio and the time complexity of the LSAA are analyzed by rigorous proof. In addition, the LSAA approach has been extended to solve the relay node double cover problem. Then, a relay location selection algorithm (RLSA) is proposed to utilize the resulting SC from the LSAA in combining RLSA with the minimum spanning tree heuristic to build the high-tier connectivity. As the RLSA searches for a nearest location to the sink node for each relay node, the high-tier network built by the RLSA becomes denser than that by existing works. As a result, the number of added relay nodes for building the connectivity of the high-tier WSN can be significantly saved. Simulation results clearly demonstrate that the proposed LSAA outperforms the approaches reported in literature and the RLSA-based algorithm can noticeably save relay nodes newly deployed for the high-tier connectivity.Index Terms-Wireless sensor networks, relay node placement, geometric disc cover, network connectivity, approximation algorithm.

PSH: A Pruning and Substitution Based Heuristic Algorithm for Relay Node Placement in Two-Tiered Wireless Sensor Networks

“…As SPTiRP [23] is the latest algorithm to the single-tiered DCRNP problem and there are no two-tiered DCRNP algorithms in literature, we combine the greedy-graph algorithm (GGA) [27] and the SPTiRP to solve the two-tiered DCRNP problem and compare this work with GGA-SPTiRP so as to evaluate the effectiveness of the proposed PSH. Besides, we also compare the PSH with the local search approximation algorithm (LSAA) which is proposed in [20] for the two-tiered RNP problem. The simulations are carried out under two scenarios, the homogeneous scenario, i.e., r ¼ R ¼ 10, and the heterogeneous scenario, i.e., r ¼ 10; R ¼ 15 and r ¼ 10; R ¼ 20.…”

“…Then, they respectively proposed two algorithms with O(1)-approximation ratio and O(ln n)-approximation ratio under different settings for 2CRNDC problem, where n is the number of SNs. Ma et al [20] proposed a local search based approximation algorithm to deploy RNs so as to fully cover SNs and a minimum spanning tree based algorithm to connect each previously deployed RN to the sink.…”

“…However, different from the RNP problem that has been extensively studied [8][9][10][11][12][13][14][15][16][17][18][19][20], the works on the DCRNP problem are very limited [21][22][23][24][25]. Moreover, published works only concentrate on the DCRNP problem in single-tiered WSNs.…”

Delay constrained relay node placement in two-tiered wireless sensor networks: A set-covering-based algorithm

“…Due to the high costs of RNs, a minimum number of RNs are expected to be placed for building the connectivity, which is termed as the Relay Node Placement (RNP) problem. In recent years, the RNP problem has been extensively studied (Lin and Xue, 1999;Ma et al, 2016a;Cheng et al, 2007;Lloyd and Xue, 2007;Misra et al, 2010;Srinivas et al, 2009;Yang et al, 2012;Han et al, 2010).…”

Research on Pseudo-Node Detection Algorithm in Wireless Sensor Networks

“…As to node authentication in practical application, the enemy captures sensor nodes for relevant information, and clones the pseudo node into the network in order to obtain, tamper, and forge network information, and even to carry out various malicious attacks on the network and disable the network [6][7]. Aiming at correctly identifying pseudo nodes in sensor networks so as to guarantee the security of WSN, a joint-ranging-based replication attack detection protocol has been designed in this paper to check the existence of pseudo-nodes in WSN by means of inter-node ranging.…”