DOA versus TOA based Localization services in IEEE 802.11 networks

Abstract — In this paper we introduce an innovative technique for localization services in IEEE 802.11 networks. The location estimate is based on the measures provided by at least three Reference Nodes (RNs). By triangulation process, the algorithm calculates the mobile Node (MN) position. Two different cases based on TOA (Time Of Arrival) and DOA (Direction of Arrival), respectively, are considered. The paper deals with modifications on physical and MAC layers of IEEE 802.11a/g, in order to introduce localization services in indoor environment using either DOA or TOA mode of operation. As TOA requires an appropriate synchronization between MT and RNs, DOA only needs a particular antenna design, as the RN are adaptive antenna array with a variable number of elements