Creating and sharing knowledge for telecommunications

Palestra - Location determination in 802.11 networks

on 22-11-2004


A.S. Krishnakumar, Director de Investigação de Sistemas em Rede, Avaya Labs, USA

Abstract: With the increasing use of wireless networking, especially
802.11-based wireless systems in enterprise networks, the
thrust now is to develop services that provide more than
untethered network access. An important class comprises those
services that use end-user location information. Such services
include location-aware content delivery, emergency location,
services based on the notion of closest resource, and location-based
access control. Techniques that can estimate location in
indoor environments, preferably without client changes, are
important to enable such services in enterprises. Traditional
GPS methods cannot be used for this since they have problems
working indoors. Further, the use of techniques such as
angle of arrival, Time difference of arrival etc. require client
modifications or substantial changes to the infrastructure. Therefore, we focus our discussion on methods based on received
signal strength measurements.

We will discuss the basic ideas and some recent work in this area.
Implications for deployment and maintenance of such systems will
also be considered. We will present experimental results from
deployed systems and compare the results from the literature.
This leads us to the question of fundamental limits to location
estimation accuracy and we will outline a theoretical analysis
that addresses this.

Local: Instituto Superior Técnico - Av. Rovisco Pais - Lisboa
Anfiteatro Complexo Interdisciplinar - 14:30H

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