Scanning and address allocation delays in vehicular communications

WLAN-based roadside-to-vehicle communications is an increasingly popular research trend. This paper examines the applicability of WLANs in the Intelligent Transportation Systems with focus on reducing the scanning phase delay and the address allocation delay. The handover delays become intolerable when the indoor WLAN Access Poins are accessed from by the outdoor mobile nodes at vehicular speeds. In this work, we propose a baseline scheme which calls for passively scanning only the orthogonal channels to reduce the scanning phase delay in the overall handover latency. We argue that the interference free orthogonal channels are ideal for conveying time critical information in vehicular environments. Secondly, this paper evaluates the delays incurred by the Dynamic Host Configuration Protocol (DHCP) in the handover process. The focus on establishing the amount of delay contributed by each DHCP phase and make some meaningful comments at the end. The conclusions made in this paper are based on real-world experiments and tests.