Japan is testing a Safety Mobile Phone technology that could help pedestrians avoid being hit by vehicles.
In the OKI test, pedestrians use mobile phones with an integrated DSRC module, while vehicles are equipped with communication systems embedded with the same technology, as well as GPS (Global Positioning System).
The pedestrians and vehicles create a DSRC wireless communications area, which has a radius per device of several hundred metres. 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 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.
DSRC 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,” says 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 Japanese company adds.
The system warns the mobile phone user when a vehicle is within 150 metres, but the technology allows the distance from a vehicle to a phone user to be set freely, according to OKI.
The short-range service is designed to provide very high data rates in situations where minimizing latency in the communication link and isolating relatively small communication zones are important, according to a description of the protocol by the Institute of Electrical and Electronics Engineers (IEEE), which helped standardize it.
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.
The OKI development appears to be part of a growing trend to use mobile phones as safety devices. For instance, Finnish mobile phone maker Nokia Corp. has applied for a U.S. patent for a lightning detector system designed for use in mobile phones.