Article

Cooperative Intelligent Transport Systems: 5.9-GHz Field Trials

Cohda Wireless Pty. Ltd., Adelaide, SA, Australia
Proceedings of the IEEE (Impact Factor: 6.91). 08/2011; DOI: 10.1109/JPROC.2011.2105230
Source: IEEE Xplore

ABSTRACT The mobile outdoor radio environment is challenging for vehicular communications. Although multipath propagation offers diversity and benefits in non-line-of-sight (NLOS) conditions, simultaneous multipath and mobility results in a doubly-selective fading channel. In practice, this means that the channel parameters vary significantly in both time and frequency within the bandwidth and typical packet durations used in 802.11p/WAVE standards for short-range vehicular communications. This paper presents the results of extensive field trial campaigns conducted in several countries, totaling over 1100 km. These field trials are scenario based, focusing on challenging low-latency, high-reliability vehicle-to-vehicle (V2V) safety applications including intersection collision warning, turn across path, emergency electronic brake light, do not pass warning, and precrash sensing. Vehicle-to-infrastructure (V2I) applications are also considered. The field trials compared the performance of off-the-shelf WiFi-based radio equipment with a more advanced 802.11p compliant radio employing more sophisticated channel estimation and tracking. Field trial results demonstrate significantly improved performance using the advanced radio, translating into greatly increased driver warning times and stopping distances. In fact the results show that off-the-shelf WiFi equipment fails to provide sufficient stopping distance to avert accidents in some cases. During the field trials, channel sounding data were also captured. Analysis of these channel measurements reveals the critical importance of accurate channel estimation, tracking the channel in both time and frequency within each packet. Delay spread and Doppler spread statistics computed from the channel measurements validate previously reported results in the literature. The results in this paper, however, provide the first instance of channel measurements performed simultaneously to application performance evaluation. The objective is to-
-
firmly establish the link between radio channel characteristics and the performance of critical V2V safety applications.

0 Bookmarks
 · 
76 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Using vehicles as sensors for traffic and environment monitoring is a new paradigm that opens the way to worthwhile applications. Data collected on board are usually delivered through the cellular network, with the consequent overloading risk. This paper focuses on the alternative adoption of short range vehicle-to-vehicle (V2V) and vehicle-to-roadside (V2R) communications, with particular reference to the wireless access in vehicular environment (WAVE)/IEEE802.11p technology. Specifically, we propose and validate, through simulations in a urban scenario, a simple but effective routing algorithm to forward data through V2V and V2R communications. The benefits are quantified in terms of the amount of data that can be transmitted without using cellular resources. Furthermore, we present an urban field trial, deployed to test our proposed multi-hop algorithm, through the adoption of low cost hardware and open source software.
    Communications Workshops (ICC), 2013 IEEE International Conference on, Budapest HU; 06/2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: We consider the problem of information propagation for traffic management applications of Intelligent Transportation Systems in urban areas. In this paper is described a system for measurement of communication range of vehicular wireless communications, method for processing and interpreting the measured data and the initial results. The measurement system is designed to provide an estimate on radio propagation and coverage in vehicular applications in urban areas and the focus is on evaluation of the communication coverage for IEEE 802.11 and IEEE 802.15.4 standards based wireless communication systems. The data collected with the described test system are made available online at http://project-bay.eu/v2x-dataset.
    Intelligent Transportation Systems (ITSC), 2012 15th International IEEE Conference on; 01/2012 · 0.25 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Wireless communications are nowadays considered as enablers of innovation in the field of smart mobility in smart cities. In this work, we focus on the smart navigation service, which is aimed at providing drivers with the best route to destination taking into account real time traffic conditions. Smart navigation is increasingly used today and expected to reduce traffic congestions, but the real impact on travel time and the cost in terms of wireless network resources are still open issues. These aspects are here discussed starting from the objectives and the outputs of the Italian project PEGASUS. More specifically, to what extent this application can reduce the travel duration and how frequently traffic information must be updated will be firstly discussed; then, the impact on wireless networks of both the uplink collection of traffic information and the downlink transmission to vehicles is shown, focusing on the UMTS cellular technology; finally, the use of short range IEEE 802.11p wireless communications technology is investigated to offload cellular networks. Through simulations performed in a dense urban scenario, it is shown that 30% to 50% travel time can be saved, that the needed information exchange might reduce the cellular network capacity available for other services of 20% or more, and that the deployment of few road side units and multi-hop transmissions can be effectively used to offload cellular networks.
    International Journal On Advances in Telecommunications. 06/2013;

Full-text

View
2 Downloads
Available from