Sensor Capacity Based Relay Node Placement in Heterogeneous Wireless Sensor Networks
P. Rachelin Sujae, Thangavelu Saravanan, Saravana Kumar.S · 2014
This research addresses the problem of deploying relay nodes to provide fault tolerance with higher network connectivity in heterogeneous wireless sensor networks, where sensor nodes possess different transmission radii. Depending on the level of desired fault tolerance, such problems can be categorised as 1) full fault-tolerant relay node placement, which aims to deploy a minimum number of relay nodes between every pair of sensor and/or relay nodes and 2) partial fault-tolerant relay node placement, which aims to deploy a minimum number of relay nodes between every pair of sensor nodes. The problems are further complicated by the existence of two different kinds of communication paths, one-way and two-way paths, along which wireless communications exist in both directions; and one-way path, along which wireless communications exist in only one direction. Assuming that sensor nodes have different transmission radii, while relay nodes use the same transmission radius, this paper comprehensively analyzes the range of problems introduced by the different levels of fault tolerance (full or partial) coupled with the different types of path (one-way or two-way). The analysis is based on the range of problems introduced by the different levels of fault-tolerance coupled with the different types of paths. Approximation algorithms are used and the results are derived for improving the connectivity in the network.