Motorola BC796D, APCO25 manual Understanding Banks and Channels, LTR Trunking

LTR Trunking

LTR® (Logic Trunked Radio) systems are trunking systems used primarily by business or private communications service providers, such as taxicabs, delivery trucks, and repair services. These systems encode all control information as digital subaudible data that accompanies each transmission, so there is no separate control channel. Users on an LTR system are assigned to specific talkgroups, which are identified by the radio as six digit numbers. These numbers are in the form AHHUUU, where:

A= Area code (0 or 1)

H= Home repeater (01 through 20)

U= User ID (000 through 254)

When the scanner receives a transmission on a channel set to the LTR mode, it first decodes the LTR data included with the transmission. In the ID Search mode, the scanner stops on the transmission and displays the talkgroup ID on the display. In the ID Scan mode, the scanner only stops on the transmission if the LTR data matches a talkgroup ID that you have stored in the bank’s talkgroup ID list and have not locked out.

LTR systems are frequently programmed so that each radio has a unique User ID.

LTR systems also need to be programmed into your scanner in channel-order.

Since many LTR systems use only odd-numbered channel slots, you would program these systems using only the corresponding odd-numbered channels in a bank (for example, you would program a system with channels at 1, 3, 5, and 9 into Trunk 2 channels 101, 103, 105, and 109).

Understanding Banks and Channels

The memory in your scanner is organized into 10 banks of 100 channels each. Each bank can contain conventional channels as well as 1 trunking system. For each trunking system, each bank can also store 10 groups of 10 talkgroup ID’s (100 per bank).

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