A Traffic Reducing Method for Multiple Targets Localisation in an IEEE 802.15.4 Based Sensor Network

Abstract

Many applications of wireless sensor networks require to process data cooperatively and to combine information from multiple nodes simultaneously. One of such applications is localisation and tracking where information from many nodes is processed at the same time to accurately estimate targets' positions. However, in case of centralised localisation and tracking applications based on received signal strength indicator (RSSI), where the anchor nodes forward their measured RSSI information to a control centre, the narrow bandwidth of wireless communication link limits the amount of data being forwarded to the control centre. As a result, it cannot receive all the data from the anchor nodes as the number of target nodes increases, and therefore cannot estimate all targets' positions. Thus, we propose a traffic reducing method based on limiting the RSSI information being forwarded and evaluate the proposed method by localising target positions in real environments using maximum likelihood estimation. The results show between 50% and 80% traffic load reduction without severely affecting the estimation accuracy. In addition, the location estimation accuracy is improved at some cases.