In Sweden, Ambulances testing system to jam car radios
(Source: BBC News via Richard Langley)
Ambulances in Stockholm are testing a system that interrupts in-car audio systems to warn drivers that they need to get through.
The solution was developed by students at the KTH Royal Institute of Technology in the city.
It broadcasts a voice warning, while a text message also appears in the radio display.It uses an FM radio signal to jam drivers' speakers and stop music playing.
It will only be able to alert cars that have their radios turned on. It can also interrupt CDs and music connected via Bluetooth.
The radio transmission is sent from the emergency vehicle to nearby FM tuners that are equipped with RDS, a communications protocol for embedding small amounts of digital information in FM radio broadcasts. It is most commonly used to display the station or song title.
["]The city will begin testing the system in a limited number of ambulances and fire engines, with plans to expand across the country later this year.
The warning system can work out how far in advance messages need to be heard depending on the speed of traffic.