On Robustness of Centralized-based Location Determination using WSN

A study on robustness of location determination techniques using wireless sensor network (WSN) is presented in this manuscript. The location estimation technique used by the wireless sensor network is based on location fingerprinting technique. Theoretically, the robustness of the location estimation depends on the availability of the number of sensor nodes in the system. The degradation of location precision performance is proportional to the decrement of number of nodes in the WSN. The analysis of this study is derived from the real deployment and measurement of a test bed in a building that is deployed with TelosB mote based wireless sensor network. The preliminary results suggest that an outage of a large number of sensor nodes has detrimental effect on the performance of the location determination system. In our case, the WSN with 17 nodes yields 82% of locations accurately estimated within 4 meters. After the outage occurred in the network and the number of sensor nodes was reduced to 9 nodes, the location precision was reduced to 35% of those. This shows a dramatically decreasing in precision performance by 47%. Thus, the number of sensors nodes is one of the significant factors that contribute to the performance of any location systems.