Operators of Land Mobile Radio (LMR) systems can derive substantial benefits from the early adoption of Mission-Critical Services (MCX) built upon open 3GPP standards. This white paper explores the opportunities and challenges of interworking LMR networks with 4G/5G-based MCX solutions by leveraging the standard-defined Interworking Function (IWF). The aim of this integration is to strengthen communication capabilities, achieve seamless interoperability, and enable a gradual adoption of broadband technologies.
The document provides a detailed assessment of interworking functionalities and technical requirements, exploring both standardised and proprietary architectural models to connect LMR networks with MCX services. TETRA is presented as a representative case, though the same principles apply to other technologies such as APCO P25. Depending on the specific architecture of the LMR system, interworking may be implemented natively through integrated software componentsin the LMR and MCX systems or via an external IWF.