Broadband terminals cannot talk to a narrowband radio network on their own, and replacing the whole PMR estate to fix that is an investment most organisations cannot justify. The gateway is the third option.

• Two-way calling between PMR (DMR, TETRA, PDT, analogue) and PoC, LTE and 5G endpoints — group, private and emergency calls, plus messaging
• Group mapping and identity mapping — ISSI, TEI and DMR ID matched to HyTalk and PoC IDs, under common dialling rules and numbering
• Vocoder conversion between the two worlds
• Encryption and QoS carried across the bridge rather than terminating at it

Bridging audio is the straightforward half. What determines whether a mixed estate is usable is whether a radio ID and a broadband user ID resolve to the same person under one dialling plan. Without that, a dispatcher maintains two directories describing one workforce, and the mistakes happen at the boundary.

Public safety, transport, energy and utilities, industry, logistics and corporate security — anywhere a working PMR network exists and part of the workforce has moved to broadband terminals.

Which features must carry across. Voice and group calls carry reliably; advanced data services and vendor-specific features generally do not. Writing that scope down at design time is what keeps the project measured against what it can actually do. See radio network integration.