An Effect of Anchor Nodes Placement on a Target Location Estimation Performance

Many indoor localisation and tracking techniques in wireless sensor networks assume placing anchor nodes on a ceiling. However, placing the nodes on the ground can improve target localisation estimation accuracy based on received signal strength indicator as we show in this work. The presented results are based on an experiment conducted in a hall under two sets of conditions. In one case, people were present in the hall and in the other one, the hall was empty. For the case when people were present in the hall, the location estimation performance improved from 3.7 meters root-mean square error (RMSE) when using only the anchor nodes fixed to the ceiling to 2.2 meters RMSE when using only the anchor nodes placed on the ground. For the case when the hall was empty, the location estimation performance improved from 4.1 meters RMSE when using only the anchor nodes fixed to the ceiling to 2.4 meters RMSE when using only the anchor nodes placed on the ground. The target location estimation accuracy improved by 40% for both conditions