Leicestershire Police is running a pilot of a service from mobile operator Orange to supplement its Airwave communications system.
The police force is looking to ensure it has a contingency plan for additional or replacement communication services in the event of network problems or maintenance work on Airwave.
To provide a back-up, it is using Orange Talk Now, a group calling system based on push-to-talk technology. The service is run as an independent network that can operate separately from Airwave should the need arise.
The trial is using the Talk Now service with 130 Sagem MYX5 handsets.