WLAN Location Sharing through a Privacy Observant Architecture

In the last few years, WLAN has seen immense growth and it will continue this trend due to the fact that it provides convenient connectivity as well as high speed links. Furthermore, the infrastructure already exists in most public places and is cheap to extend. These advantages, together with the fact that WLAN covers a large area and is not restricted to line of sight, have led to developing many WLAN localization techniques and applications based on them. In this paper we present a novel calibration-free localization technique using the existing WLAN infrastructure that enables conference participants to determine their location without the need of a centralized system. The evaluation results illustrate the superiority of our technique compared to existing methods. In addition, we present a privacy observant architecture to share location information. We handle both the location of people and the resources in the infrastructure as services, which can be easily discovered and used. An important design issue for us was to avoid tracking people and giving the users control over who they share their location information with and under which conditions

SVGOpen Conference Guide: An overview

Context-aware applications are emerging on a daily basis and location information proves to be one of the key components in this domain. This stems from the fact that location information enables and facilitates reasoning about what users are doing (user's behavioural patterns) and what users are interested in. Availability of campus-wide WLAN infrastructure at University of Twente (UT) and the fact that SVGOpen 2005 was scheduled to be held at UT, were two strong driving forces towards building a location-aware conference guide. In this paper, a privacy-sensitive, location-aware service architecture is presented, which utilizes a calibration-free localization technique. The presented architecture uses existing WLAN infrastructure for cost efficiency, and uniquely incorporates the location information into Jini service discovery platform. Vector graphics provide better support for highly dynamic interface. Among all available vector formats, SVG proves to be a better choice to design the dynamic user interface and hence it was used in our implementation

Using time-of-flight for WLAN localization: feasibility study

Abstract. Although signal strength based techniques are widely employed for WLAN localization, they generally suffer from providing highly accurate location information. In this paper, we first present the general shortcomings of the signal strength based approaches used for WLANbased localization and then state reasons why time-of-flight could be an attractive alternative. We subsequently analyze the feasibility of using time-of-flight technique for WLAN localization by synchronizing the clock using Network Time Protocol (NTP) as well as measuring the time at (i) network layer level, (ii) data link layer level, and (iii) firmware level. We conclude that at present using TOF is not a feasible approach because of the limitation of current hardware and protocols.