Logic Trunked Radio (LTR) is a
radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmi ...
system developed in the late 1970s by the
E. F. Johnson Company.
LTR is distinguished from some other common
trunked radio system
A trunked radio system is a two-way radio system that uses a control channel to automatically assign frequency channels to groups of user radios. In a traditional half-duplex land mobile radio system a group of users (a ''talkgroup'') with mobi ...
s in that it does not have a dedicated
control channel. Each
repeater
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Som ...
has its own controller and all of these controllers are coordinated together. Even though each controller monitors its own channel, one of the channel controllers is assigned to be a master and all the other controllers report to it.
Typically on LTR systems, each of these controllers periodically sends out a
data burst (approximately every 10 seconds on LTR Standard systems) so that the subscriber units know that the system is there. The idle data burst can be turned off if desired by the system operator. Some systems will broadcast idle data bursts only on channels used as home channels and not on those used for "overflow" conversations. To a listener, the idle data burst will sound like a short blip of static like someone keyed up and unkeyed a radio within about 1/2 second. This data burst is not sent at the same time by all the channels but happen randomly throughout all the system channels.
References
External links
Logic Trunked System article from 'Monitoring Times'*
E.F. Johnson Company website
{{Trunked radio systems
Radio electronics
Radio resource management
Radio networks