From TETRA to ESN: A Fleet Manager's Migration Planning Guide

For the organisations managing emergency services vehicles and communications infrastructure, the transition from TETRA to the Emergency Services Network is no longer a distant planning item. ESN is live, forces are actively deploying it alongside Airwave, and the Airwave shutdown date of 31 December 2029 is close enough to appear in current capital planning cycles. This article sets out the practical antenna specification implications for fleet managers working through the transition.

The Dual-Band Requirement

The single most important planning conclusion is this: any vehicle fitted with communications equipment between now and the Airwave shutdown needs to support both TETRA and ESN. Specifying a vehicle with TETRA-only antenna infrastructure and planning to retrofit ESN later adds cost and disruption that is entirely avoidable with the right specification at the outset.

TETRA operates in the 380–400 MHz band. ESN uses EE's LTE network on Band 20 (800 MHz), Band 3 (1800 MHz) and Band 1 (2100 MHz). These frequencies are far enough apart that no single antenna can cover all of them without significant performance compromise. Dual-system vehicles need either separate antennas for TETRA and LTE, or a multi-band antenna explicitly designed and characterised for the combined frequency range.

Antenna Options for the Transition Period

For most emergency services vehicle fits, the practical options are: a separate TETRA antenna and a separate wideband LTE antenna, co-located on the roof; or a dual-purpose antenna designed to cover the TETRA band and the principal LTE bands simultaneously. Multi-band designs exist that cover 380–400 MHz for TETRA and 700–2700 MHz for LTE in a single unit. Performance must be independently verified — marketing claims about ‘wideband’ performance are not a substitute for measured VSWR and gain data across the specified frequency range.

Planning the Fleet Retrofit Schedule

For organisations with large fleets, a phased retrofit schedule that aligns antenna upgrades with planned vehicle servicing cycles is the most cost-effective approach. Vehicles already scheduled for re-fit in the next 24 months should be specified with the dual-band requirement immediately. Vehicles not in the re-fit cycle need a decision: retrofit now, or defer and accept the risk of a rushed implementation as the shutdown deadline approaches.

Body-Worn and Handheld Equipment

Vehicle antenna planning is only one part of the picture. Body-worn ESN devices have their own antenna requirements. For in-vehicle use, a vehicular antenna cradle with a connection to a roof-mount antenna significantly improves both coverage and battery life for ESN handhelds compared to relying on the device's internal antenna. These cradle systems require a correctly specified vehicle antenna as their foundation.

Contact Renair to discuss TETRA and ESN antenna solutions: renair.co.uk/contact-us.

Frequently Asked Questions

Can one antenna cover both TETRA and ESN?

Some multi-band designs claim to cover both, but performance across the full range must be carefully verified. A solution that shows acceptable VSWR at 400 MHz but poor performance at 1800 MHz is not fit for purpose. Ask for measured data across the full frequency range before specifying.

What is the Airwave shutdown date?

The current planned Airwave TETRA network shutdown date is 31 December 2029. This is subject to programme progress and has already been revised from earlier targets. However, planning on the basis that it will occur on or around this date is the prudent approach for capital procurement cycles.

Should we wait for ESN to mature before committing to new vehicle antenna infrastructure?

No. The dual-band requirement is known and fixed by the frequencies the two networks operate on. Whether ESN's rollout is fast or slow, any vehicle fitted today needs to support both bands to avoid a costly retrofit later. The right time to specify correctly is now.