Section: New Results

Data gathering and coverage in WSN

Participants : Nathalie Mitton, Tahiry Razafindralambo, Arunabha Sen.

Data availability is one of the main goals and challenges in Future Ubiquitous Network and especially in Wireless Sensor Networks. Indeed, gathering and collecting data in a mobile environment is a very challenging task. In [12] , the authors uses data mules to organize the data collection from the sensor in the field. The results presented in [12] are based on some new and unique assumptions. First, it is assumed that the mules are mobile but also the sensors that generate the data to be collected. Second, we collection time is not the first optimization criteria. The focus of the paper is on minimizing the number of mules given a time contraints. The problem is shown to be NP complete and a transformation of the problem into a minimum flow problem allow the computation of optimal solution using Integer Linear Programming.

The results presented in [5] use the assumption of a mobile objects tracked by some other mobile objects as in [12] . In the case of [5] the focus in on coverage of mobile targets by mobile Unmanned Aerial Vehicle. The paper takes two major assumptions regarding the limited energy of UAV and the observation range. These two constraints are linked with each other since when the UAV increase its altitude, it consumes more energy but also increase its observation range. The problem under consideration is mathematically represented by defining mixed integer non-linear optimization models. Heuristic procedures are defined and they are based on restricted mixed integer programming (MIP) formulation of the problem. A computational study is carried out to assess the behavior of the proposed models and MIP-based heuristics.