A low-cost robust localization scheme for WLAN

Localization in WLAN networks has been an active area of research recently. However, most of the previous schemes in this area do not consider the presence of any malicious user within the network. The growing interest in location based services would necessitate the development of a low-cost localization scheme which is robust against the attacks from these malicious users. In this paper, we propose such a low-cost secure localization scheme. The proposed scheme is based on the current access point (AP) capability of transmitting at different power levels. The main idea here is to leverage this capability of APs so that a unique set of the messages transmitted by various APs can be received at every location in the system. The client is expected to transmit back the received messages to the AP it is associated with. The location of the client is then estimated using the set of messages received from the client. In this paper we focus more on the performance of this scheme while discussing briefly its inherent security capabilities. We also describe the implementation of this message based scheme. We then perform extensive experiments and observe that this scheme has similar or better localization accuracy as compared to the traditional signal strength based localization schemes.