Update on the United Kingdom (UK) Terrestrial Trunked Radio (TETRA) upgrade to ESN

Currently in the United Kingdom (UK) the Police, Fire and Ambulance Services communicate using a dedicated Terrestrial Trunked Radio (TETRA) radio system.
From the House of Commons Committee of Public Accounts on “upgrading emergency service communications” reference HC 770 published on 25 January 2017, we can read that the UK Home Office is planning to replace the dedicated TETRA radio system with a new system called the Emergency Services Network (ESN).  The ESN will be shared across an existing commercial 4G mobile data network.
This technology move from a dedicated TETRA radio system to a new shared system has not yet been adopted in any other country and has hence been subject to delays in the commercial launch. In 2017 the National Audit Office estimated that the programme was between five and ten months behind schedule.
From the further update by the Public Accounts Committee on Emergency Services Network progress review, reference HC 886 held on Wednesday 21 February 2018 we can read that the new ESN solution should be online and operational by March 2020 and that there will be a transition period between the existing dedicated TETRA system and the new ESN commination network.