Beyond Localization: Communicating Using Virtual Coordinates
Thomas Watteyne (Orange Labs & CITI Lab, University of Lyon, France), Mischa Dohler (Centre Tecnològic de Telecomunicacions de Catalunya (CTTC), Spain), Isabelle Augé-Blum (CITI Lab, University of Lyon, France) and Dominique Barthel (Orange Labs, France)
Copyright: © 2009
This chapter deals with self-organization and communication for Wireless Sensor Networks (WSNs). It shows that nodes do not always need to know their true physical coordinates to be able to communicate in an energy-efficient manner. They can be replaced by coordinates which are not related to their geographical position, yet are easier to obtain and more efficient when used by routing protocols. The authors start by analyzing the techniques used by a node to infer its geographical location from a small number of location-aware anchor nodes. They describe how nodes can use their geographical locations to self-organize the network. The authors then present an anchor-free positioning algorithm in which nodes acquire virtual coordinates. Through a continuous updating process, virtual coordinates of neighbor nodes are brought close together. Although not related to the nodes’ geographical location, routing using these coordinates outperforms routing using true physical coordinates. This chapter hence shows that localization algorithms are not per se required when considering communication in a WSN. A better strategy is to use geographic routing protocols over non-physical virtual coordinates which are easier to obtain.