Approximation algorithms for two optimal location problems in sensor networks

Abstract

This paper studies two problems that arise in optimization of sensor networks: First, we devise provable approximation schemes for locating a base station and constructing a network among a set of sensors each of which has a data stream to get to the base station. Subject to power constraints at the sensors, our goal is to locate the base station and establish a network in order to maximize the lifespan of the network.Second, we study optimal sensor placement problems for quality coverage of given domains cluttered with obstacles. We assume "line-of-site", sensors, that sense a point only if the straight segment connecting the sensor to this point (the "line-of-site") does not cross any obstacle. so obstacles occludes area from Using line-of-site sensors, the goal is to minimize the number of sensors required in order to have each point "well covered" according to precise criteria (e.g., that each point is seen by two sensors that form at least angle α, or that each point is seen by three sensors that form a triangle containing the point).

Review of Optimization Problems in Wireless Sensor Networks

“…As presented in (Efrat et al, 2005), the problem is a version of the Art Gallery problem, which is known to be NP-hard. The Art Gallery problem involves placing the smallest number of guards in an area such that every point in it can be surveyed by the guards.…”

Optimal Placement of Multiple Interconnected Gateways in Heterogeneous Wireless Sensor Networks

“…However, they assume the gateway is always reachable within a single hop. General sensor-sink paths are considered in [15] where an approximated algorithm aims to maximize the lifetime of a single-sink WSN.…”

“…Even if many routing approaches have been proposed to balance the load among nodes and prolong the overall network lifetime, it is quite evident that nodes closer to the sink are anyway the most critical ones since they are required to relay all traffic generated by the other nodes and headed to the sink. For this reason, several methods have been proposed for optimizing the sink position in WSN design [13,15].…”

Deployment adviser tool for wireless sensor networks

“…R.N provides the path from the sensor nodes to the base station and vice-versa. The location of all these nodes have to be estimated carefully to achieve the best performance, but often the question of how to deploy the nodes so that they ensure connectivity and at the same time optimize the performance is a very tough problem and has been shown to be NP-Hard [1][2][3]. The way to overcome this problem is to propose a heuristic design and to find suboptimal solutions.…”