Building Your Own Infrastructure Based 802.11 Fingerprinting Service

Indoor positioning is a basic requirement of Intelligent Environments. It is a building block for providing context-aware computing. Infrastructure based WiFi fingerprinting positioning technology (IBWFP) is one way of satisfying such requirement. In IBWFP, the basic landmarks for positioning are fixed 802.11 access points with a well known location. And it is infrastructure based because it refers to the fact that access points devote some computing capacity to collect 802.11 packets from other 802.11 mobile devices. Such information enables positioning a 802.11 mobile device indoors. This paper is a proposal for an inexpensive IBWFP. Its main contributions are a detailed accounting on how to build the physical system (business logic within the routers, configuration of the network in terms of number and location) and how to deploy and maintain the service on top of the physical system (i.e. Site survey, location engine creation, validation and management) with enough accuracy to exploit it. To the best of our knowledge, this is the first attempt to give a guideline to build your own inexpensive IBWFP technology covering all these practical aspects. Our intent is to push forward this technology by sharing our experience using it.