Integrity monitoring in WLAN positioning systems

Indoor Positioning Systems using WLANs have become very popular in recent years. These systems are spawning a new class of applications like activity recognition, surveillance, context aware computing and location based services. While Global Positioning System (GPS) is the natural choice for providing navigation in outdoor environment, the urban environment places a significant challenge for positioning using GPS. The GPS signals can be significantly attenuated, and often completely blocked, inside buildings or in urban canyons. As the performance of GPS in indoor environments is not satisfactory, indoor positioning systems based on location fingerprinting of WLANs is being suggested as a viable alternative. The Indoor WLAN Positioning Systems suffer from several phenomena. One of the problems is the continual availability of access points, which directly affects the positioning accuracy. Integrity monitoring of WLAN localization, which computes WLAN positioning with different sets of access points is proposed as a solution for this problem. The positioning accuracy will be adequate for the sets which do not contain faulty or the access points which are offline, while the sets with such access points will fail and they will report random and inaccurate results. The proposed method identifies proper sets and identifies the rogue access points using prediction trajectories. The combination of prediction and correct access point set selection provides a more accurate result. This paper discusses about integrity monitoring method for WLAN devices and followed by how it monitors and developing the application on mobile platforms.