Measuring disruption in vehicular communications

Recent studies have shown that roadside wireless local area network (WLAN) access points (APs) can provide network access from vehicles. However, the unplanned deployment of WLAN APs is the main hurdle in the provision of continuous network services. Because of this unplanned deployment, a mobile node moving at vehicular speed experiences periods of connectivity and disruption as it exploits roadside WLAN APs. Although several works have studied the performance of WLAN APs in providing network services at vehicular speed, very little has been reported on their mathematical interpretation. This paper proposes a hidden Markov model (HMM) to represent a typical roadside-to-vehicle communication. The proposed model is based on the experimental findings and is used to quantify the probabilistic measure of disruption. To the best of the authors' knowledge, this is the first effort that quantifies the aggregate amount of disruption in 802.11-based roadside-to-vehicle communications.