| LTR is a method of channel management that gives all users of the system automatic access to all channels. This results in minimum waiting to make a call and the most efficient use of the available channels. Trunking is controlled by logic circuitry in the mobile transceivers and the repeaters. This circuitry continually monitors the system and generates data messages which update the mobiles and repeaters as to which repeaters are free.
LTR systems usually do not have a dedicated control channel. Each repeater in LTR systems have there own controller, and all of the controllers are synchronized. Each controller sends out a "data burst" approximately every 10 seconds so that the subscriber unit knows that the system is there. This is one way to tell that the system is a LTR system.
With LTR radio systems, hang-time is not used for dispatch (mobile-to-mobile) calls. A channel is held for only the length of the transmission so that the time between transmissions can be used by others making calls. The only time this is used in LTR trunking is when making telephone calls. |
