The Influence of User Mobility on Vehicular Internet Access via IEEE 802.11 Access Points

In this study we evaluate the ability of isolated wireless LAN access points to serve fast moving mobile users under a suitable mobility model for vehicular movement. For this purpose the random waypoint city model is used with five different city maps. The focus lies on the difference in performance resulting from the distinct stationary user distributions of four real city maps and an artificial Manhattan grid. Detailed packet-based simulations using the network simulator ns-2 show the importance of assessing the stationary user distribution before fixing the locations of the wireless access points. The compared factors that are influencing the system´s performance include mean data rates, number of users in hotspots as well as mean sojourn-times in hotspots and times in-between coverage. Although the resulting performance of the scenarios is quite diverse, the use of wireless LAN as an access technology for sporadic vehicular Internet usage is possible in all of them