Indoor antispoofing cooperative localization in cellular networks

Because global positioning system (GPS) users receive a very low power signal outdoors, it is difficult for users to find their location indoors using GPS. Cooperative localization attempts to solve this problem by using information from surrounding users in an ad hoc scenario. Unfortunately this makes the localization system vulnerable to spoofing attacks because manipulating the more accessible cooperative localization transmitters is much easier than manipulating the GPS satellites or the cellular base stations. This paper shows that the effects of spoofing attacks can be effectively minimized by processing information from seven or more cooperative localization users instead of the main stream approach of using only three or four information transmitting users or anchors (base stations). By filtering the extreme estimates resulting from the spoofing attack, users are able to estimate their locations close to the location estimate in the spoof-free case.