Although several different architectures are possible, a typical one is essentially comprised of three tiers: the CCT (Control Centre Terminal), the IMT (Intermediate Mobile Terminal) and the all-important HUT (Handheld User Terminal) worn as a backpack. A GPS satellite monitors the HUT equipped firefighter, who can transmit his position to a ground station managed by the IMT, a transportable terminal with no need for terrestrial infrastructure. The IMT, in turn, transmits to a telecommunications satellite, which then passes the data to the CCT. The CCT acts as the main headquarters and is equipped with high bandwidth communications for voice and data.
A more advanced configuration has the HUT transmitting directly to a satellite and then to the CCT via a ground station and the Internet. Earth Observation satellites are also involved in both configurations, providing real-time information to all components.
The entire system is equipped with a variety of file storage and transfer capabilities, including email and fax, Internet, voice communication and point-to-point video in real time. REMSAT II provides several data rates for each tier from 512 kbps to 1.2 kbps, through VHF local radio networks.