English

Abstract

This paper relates to a generic solution for localization and tracking applications usingWireless sensor network in confined areas where the GPS technology is no longer functional. The proposed solution exploits node mobility by allowing stations to come into contact with other fixed or mobile stations to collect, transmit and pass around their knowledge, which is a collection of ’contact events’. Each contact event being a way to record the fact that a node has been in range of an another node. This event can also refer to a geographical location. The amount of contact events that have been created depends on the effectiveness of the contact detection mechanism and on the performance of the WSN medium access method. This leads us to study the performance of IEEE 802.15.4 unslotted CSMA/CA when the offered load of a cell is only broadcast traffic. Frames are not always received because of collisions or of unsuccessful transmission attempts. This leads to a rupture of the current contact involving the creation of useless contact events for the same situation of proximity between entities. The results obtained by simulation, determine the capability of a cell in terms of number of mobiles and size of the exchanged frames for an acceptable rate of false contact detection.