Wireless Pers Commun (2010) 54:155–168 DOI 10.1007/s11277-009-9719-y DOA and TOA Based Localization Services Protocol in IEEE 802.11 Networks Alessandro Neri · Alessandro Di Nepi · Anna Maria Vegni Published online: 28 March 2009 © Springer Science+Business Media, LLC. 2009 Abstract In this paper we introduce an innovative technique for localization services in IEEE 802.11 networks. We introduce a localization protocol that can make use of either Time Of Arrival or Direction Of Arrival measurements. The proposed architecture integrates the classical Basic Service Set topology with a set of Location Service Support nodes, that measure those parameters related to a pre-selected localization algorithm. A fast and accu- rate Time Of Arrival estimator, operating directly on the output of the OFDM demodulator, is also presented. The whole procedure has been designed with the intent of weaken the requirements on temporal synchronization among nodes, at the expenses of a small increase in the protocol overhead and a small accuracy loss. Keywords Localization services · TOA · DOA · IEEE 802.11 1 Introduction The location techniques are the basis of a new class of services, called as Location Based Services (LBS), providing appropriate contents to the user, to the right place and in the most simple and rapid way. An increasing number of mobile and smart phones allow peo- ple to access the Internet, wherever they are and whenever they want. This new scenario This work was originally presented at the 10th International Symposium on Wireless Personal Multimedia Communications, Jaipur (India), on 3–6 December 2007. Then, this work has been partially funded by RadioLabs Consortium. A. Neri (B ) · A. Di Nepi · A. M. Vegni Department of Applied Electronics, University of Roma Tre, via della Vasca Navale 84, 00146 Rome, Italy e-mail: neri@uniroma3.it A. Di Nepi e-mail: dinepi@uniroma3.it A. M. Vegni e-mail: avegni@uniroma3.it 123