Smart Navigation in Intelligent Transportation Systems: Service Performance and Impact on Wireless Networks

Wireless communications are nowadays considered as enablers of innovation in the field of smart mobility in smart cities. In this work, we focus on the smart navigation service, which is aimed at providing drivers with the best route to destination taking into account real time traffic conditions. Smart navigation is increasingly used today and expected to reduce traffic congestions, but the real impact on travel time and the cost in terms of wireless network resources are still open issues. These aspects are here discussed starting from the objectives and the outputs of the Italian project PEGASUS. More specifically, to what extent this application can reduce the travel duration and how frequently traffic information must be updated will be firstly discussed; then, the impact on wireless networks of both the uplink collection of traffic information and the downlink transmission to vehicles is shown, focusing on the UMTS cellular technology; finally, the use of short range IEEE 802.11p wireless communications technology is investigated to offload cellular networks. Through simulations performed in a dense urban scenario, it is shown that 30% to 50% travel time can be saved, that the needed information exchange might reduce the cellular network capacity available for other services of 20% or more, and that the deployment of few road side units and multi-hop transmissions can be effectively used to offload cellular networks.