End is in sight for Police use of Tetra Airwave service in the UK.
http://www.theregister.co.uk/2015/01/08/airwave_tetra_switch_off_gov_services_onmishambles/
According to the article at The Register, the Police radio service will be replaced by 4G, but that won’t work well in rural locations. We think they need a new hybrid device with Tetra & 4G to have a system approaching anything workable & more modern.
Any system that uses the newly available 700MHz spectrum in the UK will need new masts & control network, so would cost just as much as Tetra to run, but would at least work pretty well everywhere like Tetra.
Cheapest option, in our humble opinion, would be to make a secure Police Force app for Android & iPhone though with strong certificates & encryption & keep Tetra handsets for direct handset-to-handset secure communications (assuming they’ve been paid for & that doesn’t require a mast).