The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We design an application-layer overlay-network solution to deliver live video streaming for inter-vehicle communication (IVC) and vehicle-to-roadside communication (VRC). This solution includes a distributed clustering method called DVAC and an efficient peer-to-peer relay method called VAPER DVAC performs the distributed and message-driven procedures for cluster formation and maintenance. The design...
In this paper, we report the first complete version of a multi-hop broadcast protocol for vehicular ad hoc networks (VANET). Our results clearly show that broadcasting in VANET is very different from routing in mobile ad hoc networks (MANET) due to several reasons such as network topology, mobility patterns, demographics, traffic patterns at different times of the day, etc. These differences imply...
Vehicular ad-hoc networks (VANETs) promise to enable many novel applications in transportation systems including accident avoidance, congestion sensing, traffic metering, and general in-car information services. Yet implementing multi-hop vehicular communications is highly challenging due to the highly time-varying nature of vehicles. In addition to node mobility and the impediments of wireless communication,...
In this paper, we study connectivity benefits of using a multihop relaying strategy for improved Internet access in a WiFi-based vehicular environment relative to the common strategy that allows only direct communication between vehicles and access points (APs). We use real AP location data and realistic and detailed vehicular mobility traces for our study. Our results show that multihop relaying...
In [1] we show how vehicles can opportunistically exploit infrastructure through open access points (APs) to efficiently communicate with other vehicles. We also highlight the importance of the use of a correct mobility model, since the advantages that may derive from the use of an infrastructure may not be appreciated because of a lack of accuracy. We continue our study based on realistic vehicular...
In this paper, we propose a hybrid wireless data access algorithm in mobile hotspots, which enables ubiquitous Internet access in vehicular networks. We first introduce a novel architecture with proxy cache (PC) for strongly consistent wireless data access and investigate the trade-off relationship between a PC-based poll-each-read (P-PER) algorithm and a PC-based callback (P-CB) algorithm. We then...
Building a wireless sensor network in a car has important benefits in terms of cost reduction, having an open architecture, and fuel efficiency. One option for implementing such an intra-car wireless network is to use RFID technology. In this paper, we report the results of extensive experiments carried out at Carnegie Mellon University in collaboration with General Motors for understanding the capabilities...
This paper proposes an ITS system that uses not only integrated cellular and ad hoc relaying technologies, but also users' mobility profiles. It focuses on a subsystem where cellular bandwidth is used mostly for control signals, and an ad hoc distribution network (ADN) is used for file downloading and video streaming. The paper formulates an optimization problem with the objective being to maximize...
Vehicle-to-vehicle communication protocols may be broadly classified into in three categories; bounded-delay safety alerts, persistent traffic warnings and streaming media for telematics applications. We focus on the first category of time-critical messaging as is it of greatest value to the driver and passengers. Safety alerts are transmitted from a vehicle during events such as loss of traction,...
This paper presents a novel code allocation scheme for multicasting in infrastructure-to-vehicle CDMA-based wireless networks. In a CDMA-based cellular network, to maximize the utilization of bandwidth and to minimize the overhead under varying channel conditions, the proposed scheme discusses how cellular and vehicular networks can collaborate in multicasting. Multiplexing is achieved by assigning...
We consider the problem of adjusting transmission power for vehicle-to-vehicle broadcast safety communication in vehicular ad hoc networks. Given a target communication range designated by a vehicle safety application, the power control algorithm is designed to select a transmission power no greater than necessary for the targeted range. The power control algorithm results in higher communication...
In performance studies of vehicular ad hoc networks, the underlying mobility model plays a major role. In this paper, we investigate the influence of three mobility models on the performance of ad hoc network routing protocols (AODV and GPSR). As a benchmark, we use the popular random waypoint mobility model. Our second model is based on a vehicular traffic simulator that we proposed in earlier work...
Through a field implementation of vehicular ad hoc networks (VANET), we report the observation of a monotonic dependence of maximum relative velocity between two vehicles and their separation, for typical suburban driving. We introduce a hierarchical phenomenological model of driving behavior to describe this observation. As an example, we illustrate how we use this model to predict the expected Doppler...
IEEE- and ASTM-adopted dedicated short range communications (DSRC) standard towards 802.lip is a key enabling technology for the next generation of vehicular safety communication. Broadcasting of safety messages is one of the fundamental services in DSRC. In this paper, requirements and channel design of vehicular ad hoc networks for safety applications are addressed. Performance of vehicle-to-vehicle...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.