Narrow Results

Providing seamless connectivity during transit in vehicular ad hoc networks (VANETs) is the most promising and challenging task. In VANET, the vehicles are able to communicate with other vehicles and also with the infrastructure units such as road side unit (RSU). The coverage range of RSU is not sufficient to cover the whole road. The vehicle can drive to an area which is not covered by any of the RSUs, and it is termed as congested zone (CZ). This will extremely lead to traffic congestion and maximize blocking probability. In order to provide connectivity between the road segments and to avoid long delay in message transmission, unmanned aerial vehicles (UAVs) are placed in CZs, which act as relay nodes. To enhance the connectivity of the vehicles, a fuzzy-based UAV-assisted handoff scheme (F-UAV-HO) is proposed in this work. By adopting fuzzy, the unwanted participation of UAV is limited in non-congested traffic, thereby saving the battery resource. To validate the proposed work, the simulations are executed in Network Simulator 2.35. The proposed system outperforms other conventional UAV-assisted schemes in congested traffic in terms of average end-to-end delay, PDR and throughput.

This paper proposes five Key Performance Index (KPI) and abnormal/Exception Information Diagnosis of road side units (RSU)-based Real-time Traffic Database System (RTDS) to identify the KPI of RSU system and abnormal conditions of RSUs. The purpose is to validate the location of unreasonable operation values of RSUs. The RSUs contain Vehicle Detector (VD), Closed Circuit Television (CCTV), Changeable Message Sign (CMS), Automatic Vehicle Identification (AVI), and Road Section (RS). The five KPI are defined as follows: the rate of well-prepared completeness of information, maintenance of equipment, instant proper data of equipment, equipment completeness, and file linkage trends. The rate of proper data of equipment abnormal data is identified simultaneously. Then, the five effective KPI index of the whole island area can also be obtained. This system offers the rate of file linkage to check the resource unit on the compliance of government published traffic standard v1.1, regulating five kinds of equipment and 13 file styles.