Motorola PM400 manual Conventional Radio Systems, Trunked Radio Systems, LTR Trunked Systems

INTRODUCTION

Your PM400™ radio can operate on both LTR® trunked and conventional radio systems. This radio combines the very latest in two-way technology while delivering outstanding functionality at the touch of a button.

CONVENTIONAL RADIO SYSTEMS

Conventional typically refers to radio-to-radio communications through a single channel. Conventional systems also allow radio users to extend communication coverage by relaying their messages through a repeater. To ensure coordinated use by multiple users, each radio user must monitor the channel or repeater before transmitting to verify that the system is not currently busy.

TRUNKED RADIO SYSTEMS

A trunked radio system allows a large number of users to share a relatively small number of frequencies or repeaters without interfering with each other. The airtime of all the repeaters in a trunked system is pooled, which maximizes the amount of airtime available to

any one radio and minimizes channel/ talkgroup congestion.

Some of the benefits of trunked two-way radio systems are:

•No channel/talkgroup monitoring required prior to transmission

•Improved system access

•Automatic channel/talkgroup selection

•Increased privacy among members of the same group

LTR Trunked Systems

LTR (Logic Trunked Radio) is a transmission- based trunking protocol developed by the E. F. Johnson Company for primarily single-site trunking applications. In transmission trunking, a repeater is used for only the duration of a single transmission. Once a transmission is completed, that repeater becomes available to other users. This means that a conversation comprised of many transmissions may occur over several different channels/talkgroups within the LTR system. This method of trunking provides system efficiency by making repeaters available to all users after every transmission.

When an LTR trunked radio user wants to communicate with another radio, the user’s

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INTRODUCTION

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