This article contributes to the evolution of public safety communication systems by specifying a novel solution for integrating WLAN and Terrestrial Trunked Radio (TETRA) networks. The specified solution allows TETRA terminals to interface to the TETRA Switching and Management Infrastructure (SwMI) over a broadband WLAN radio access network, instead of the conventional narrowband TETRA radio network. These terminals are fully interoperable with conventional TETRA terminals and can employ all TETRA services, including group calls, short data messaging, packet data, and so forth. In addition, however, such terminals can support a range of brand new capabilities enabled by the WLAN, such as broadband data services, true concurrent voice and data services, simultaneous reception of many group calls, reduced call setup and voice transmission delays, improved voice quality, and so forth. The specified solution is solely based on IP multicast and Voice-over-IP (VoIP) technologies and thus fits ideally to the all-IP architecture being introduced by the MESA project for the next generation of public safety and disaster relief communication systems.