Car key fobs, like lots of other everyday technology, use radio spectrum to operate. On rare occasions, faulty or unauthorised equipment can interfere with nearby technology and prevent it from working properly – such as in the case of these customers’ fobs.

Ofcom’s Spectrum Management Centre, based in Baldock, Hertfordshire, provides a 24-hour service to industry and to members of the public, by monitoring the radio spectrum. This service also allows people to report radio interference.

On Friday 26 February, an officer from Hertfordshire Police contacted us to make us aware of the problems at the supermarket car park.

Due to the nature and scale of the problem, we assigned this as a high priority case, and sent out a local engineer who was soon on the scene to investigate the problem.

Within 30 minutes, our spectrum engineer arrived at the car park to investigate the problem. To do this, we use a spectrum analyser – a piece of equipment that measures the airwaves and detects any radio signal which shouldn’t be there. However, at that particular moment, the problem wasn’t actually happening, and customers were able to lock and unlock their vehicles successfully. So, we asked staff at the supermarket to get in touch if any more customers reported further issues over the weekend.

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