Japanese OKI Electric Industry Company Limited is testing its Dedicated Short Range Communications technology which rapidly exchanges location information about vehicles with mobile phones, assuming both are equipped with the technology. The OKI test is one of several supported by the Japanese government as part of an initiative aimed at deploying advanced communication systems across the country beginning in 2011 to lower the number of pedestrians killed in traffic accidents. The pedestrians and vehicles create a DSRC wireless communications area, which has a radius per device of several hundred meters. Each device sends out its location information at a regular time interval within the area. When a pedestrian device and vehicle device come close and the received power from each device exceeds a specific value that indicates a high possibility of a collision, the devices warn their users.
Pedestrians are warned through the vibration function on their phones, while drivers receive voice guidance from their vehicle communications system. The technology can gather information about surrounding vehicles, perform the necessary calculation to identify impending collisions and warn pedestrians with DSRC-enabled mobile phones "in less than one second," according to OKI. Such a quick response is possible because the system is able to send each vehicle"s current GPS position and map its location against other devices in the area within milliseconds. The system warns the mobile phone user when a vehicle is within 150 meters, but the technology allows the distance from a vehicle to a phone user to be set freely. Although the trial DSRC system currently uses the 5.8 GHz frequency range, OKI plans to achieve compatibility with IEEE 802.11p, the international DSRC standard based on the 5.9 GHz band.