DFPS: A Distributed Mobile System for Free Parking Assignment

Cruising for vacant curbside parking spaces causes waste of time, frustration, waste of fuel, and pollution. This problem has been addressed by centralized solutions that perform parking assignments and communicate them to drivers’ smart phones. These solutions suffer, however, from two intrinsic problems: scalability, as the server has to perform intensive computation and communication with the drivers; and privacy, as the drivers have to disclose their destinations to the server. This article proposes DFPS, a distributed mobile system for free parking assignment. DFPS solves the scalability problem by using the drivers’ smart phones to cooperatively compute the parking assignments, and a centralized dispatcher to receive and distribute parking requests to the network of smart phones. The phones of the parked drivers in DFPS are structured in a K-D tree to serve parking requests in a distributed fashion. DFPS removes the computation from the dispatcher and substantially reduces its communication load. DFPS solves the privacy problem through an entropy-based cloaking technique that runs on drivers’ smart phones and conceals drivers’ destinations from the dispatcher. The evaluation demonstrates that DFPS is scalable and obtains better travel time than a centralized system, while protecting the privacy of drivers’ destinations.