Developments in Wireless Technologies for Intelligent Transport Systems

Practical trials of intelligent transport systems (ITS) have begun in countries around the world, even as developers of the various electronic elements of these systems continue to evolve and refine functions and boost performance. Renesas is working steadily on technologies like UWB and WAVE that will play a major role in the implementations that will eventually be mass-produced and installed in vehicles and roadways. We share the view of all ITS developers that this technology will reduce accidents and injuries by promoting safe driving and will enable better management of public transport systems.

Intelligent transport systems (ITS) appear destined to bring microcomputer-generated intelligent features to vehicles and roads to promote safe driving, help drivers avoid congestion, and more efficiently manage public-transport infrastructures. Companies developing solutions for ITS applications — including Renesas — are working to incorporate a diverse range of functions and services into next-generation ITS products, and rapid progress is being made in this application. In fact, prototype ITS equipment is now being tested in practical trials on an international scale.

ITS designs use high-speed wireless links for data communication within and between vehicles and between vehicles and the road, primarily "Wireless Access in Vehicular Environments" (WAVE) and ultra-wide band (UWB) types. WAVE has been developing and this achievement is accelerating many of the ITS advances being made today. Especially, it has enabled and is being carefully evaluated in one of the trials currently being conducted in countries around the world. In that trial and others, WAVE is being applied in the exchange of data between nearby vehicles (vehicle-to-vehicle communications) and between vehicles and traffic signals and other roadway infrastructure elements at intersections (road-vehicle communications).

WAVE is a wireless LAN technology that complies with IEEE802.11p, a standard that is still being finalized. It provides the speed and capacity needed for transferring image and other data and is considered ideal for short-range applications such as road-vehicle communications. Renesas was quick to put in place the development technology for using WAVE in the on-board units (OBUs) mounted in vehicles and the roadside units (RSUs) installed at bus stops, intersections, and other locations. Today we are working to incorporate this technology into a special-purpose SoC for use in future ITS trials.

Renesas is also playing a strong role in the area of UWB technology, which can form ad-hoc wireless area networks with a mesh topology. Additionally, UWB links can be used to provide seamless communications inside vehicles. Our R&D engineers have developed a UWB evaluation system for ITS testing that can perform one-to-three multicast streaming of image data with high-throughput, up to 330Mbps.

Europe has taken the initiative in putting ITS concepts to the test. A large-scale public demonstration trial of ITS was carried out by the C2C_CC (Car to Car Communication Consortium) in autumn of 2008. The C2C_CC consortium was established in 2005, primarily by European vehicle manufacturers, and Renesas is acting as a member. The aim of the consortium is the development of systems to support safe driving and it has selected WAVE for road-to-vehicle and vehicle-to-vehicle communications.

The trial was conducted at the Opel test track at Dudenhofen in Germany and used OBUs supplied by Renesas. Vehicles fitted with these OBUs (see photograph) tested the road-to-vehicle transmission of warnings in the vicinity of road repair operations and similar situations. The OBUs also performed vehicle-to-vehicle communications to warn of things like accidents or nearby emergency vehicles. The results of this trial confirmed the effectiveness of using ITS to support driving, while also highlighting the strength of the technology Renesas offers.

Similar ITS initiatives are evident in Asia. For example, joint projects are being set up to develop next-generation ITS systems in China, Taiwan, and other Asian countries, and plans for conducting trials are underway.

In Japan, a project involving full-scale ITS trials was conducted in April 2009 at Yokohama in Kanagawa Prefecture. Figure 1 shows an overview of this trial system and the tests that were carried out. Renesas supplied the WAVE RSUs installed on bus stops, traffic signals, and other roadside infrastructure. We also provided the WAVE OBUs that were installed on the buses.

Renesas continues to actively promote the use of WAVE wireless technology in ITS systems, not only in Europe, but also through its involvement in various Asian trials.