DemoGeoloc

802.11 Geolocation

In the past few years, the IEEE 802.11 wireless technology (also known as Wi-Fi) has become one of the most popular way to access to the Internet. Nowadays, wireless LANs are available in many companies, universities and public locations. Similarly to the first methods of radio-navigation, a geographical position of a particular device can be calculated from Wi-Fi signal intensity analysis (either from the wireless cards of the device or access points).

According to its solid background in wireless network domain, the Network Research Group provides a 802.11 geolocation system to the users of the Osiris network, which is the Wi-Fi network of the University of Strasbourg. There are several motivations behind this deployment:

• The validation of the positioning system.
• The study of user mobility.
• The measurements of routing metrics for wireless meshed networks.

Deployment

The weFiND project is a set of geolocation tools, which allow to:

• Scan the wireless environment.
• Test several positioning algorithms.
• Visualize your own position.
• Manage a centralized geolocation server.

Experimentations have been made inside the ICube building to estimate the accuracy of the geolocation system. This vidéo illustrates the movement of four laptops equipped with a wireless card. The measurements show an accuracy better than 10 meters. As part of a large scale experimentation, the geographical location of all access points of the Strasbourg university campus have been recorded. Therefore, each user of the University of Strasbourg Wi-Fi network can retrieve his current position.

The online application of weFiND allows to simulate positioning with previously recorded traces.

Community

In order to give a social dimension and to create a community to the weFiND project, a geolocation exchanger plug-in has been created for the instant messaging client Jitsi (ex SIP-Communicator). The coordinates are exchanged between all the contacts of the same account with the Jabber protocol.