Cost-Effective Vertical Handoff Strategies in Heterogeneous Vehicular Networks

Abstract

Vehicles are able to access Internet via cellular networks GPRS/UMTS/LTE. The IEEE has also released 802.11p standard for vehicle ad hoc network (VANET) that can connect vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) using a dedicated spectrum. Other prominent wireless technology is Wi-Fi (IEEE802.11) that is used as an alternative for short distances. Currently vehicular communication relies on single type of wireless network, e.g., for safety applications utilizes 802.11p and for infotainment applications, Internet is accessed via cellular networks. Wi-Fi technology is always an attractive solution for increase in data demand in mobile network because high data rate can be achieved with low cost. In order to improve network performance and to reduce the data transfer cost and time, Wi-Fi is used as complementary network to deliver data that was transmitted via cellular network. Communication through above two different networks is called heterogeneous vehicular network (HVN). Frequent switching occurs from one network to other particularly when vehicle moves across overlapping heterogeneous network. Such switching is called vertical handover (VHO). Efficient VHO is needed to minimize the data transfer cost and time. Three cases have been considered in this paper, first Cellular network interworking with Wi-Fi with fixed inter-distance between Wi-Fi Access points (AP), second with statistical inter-distance between Wi-Fi-APs in urban, semi-urban, and rural areas, and third the combination of cellular, Wi-Fi, and VANET which outperforms compared to above two cases.