A Dual Distance Measurement Scheme for Indoor IEEE 802.11 Wireless Local Area Networks

In this paper, the authors address the problem of distance measurement in indoor IEEE 802.11 WLANs. The Received Signal Strength Indicator (RSSI) and the Signal Propagation Time (SPT) have been widely used for distance estimation in indoor WLAN deployments. However, neither approach by itself is accurate. Moreover, there is no mean by which WLAN nodes know whether the estimated distance is accurate or not. In this paper, they propose a multi-measurement approach. Specifically, they combine an RSSI and a propagation time - based schemes and utilize both results for mutual cross-validation to improve the estimation accuracy and reduce the number of false decisions based on errored estimations.