Overview of terrestrial mobile radio networks and infrastructures
A land mobile radio system is the primary voice communication tool for officers and agents to communicate with each other and with dispatchers and typically includes the following :- subscriber units: portable radios used for portable operation and mobile radios in vehicles;
- repeaters: can be portable or fixed and are used to extend the range of radio communications;
- fixed site equipment: used to provide single site and wide area coverage for radio operations and includes routers, antennas and towers;
- key management capabilities: used to provide new over-the-air (OTAR) key to enable encrypted communications. CBP's OTAR system is located at NLECC and generates, distributes, and manages national voice and data encryption keys for DHS agencies as well as other federal, state, and local law enforcement agencies.