EFJohnson 3000 SERIES - Manual (Page 15)

2-1
3000 SERIES SWITCH
SECTION 2 3000 SERIES SWITCH
2.1 INTRODUCTION
A Multi-Net radio system is a combination of
several key elements that together make up a commu-
nication system. By using the basic elements of a
Multi-Net system as building blocks, a Multi-Net
system can be designed to meet the communication
needs of almost any type of user. Elements of a Multi-
Net system are:
• Backbone
This consists of repeater site equipment including
the links to the Switch.
•
Control Consoles
Used for dispatch operators.
•
Switch
Provides the interface between the Backbone and
Control Consoles.
•
RF Equipment
Consists of mobiles, control stations, and handheld
portables.
Each Multi-Net site is an independent trunking
system that processes calls between RF units, main-
tains fleet partitioning, and provides priority access
control. The backbone elements are interconnected by
either microwave, fiber optics, RF links or private tele-
phone lines equivalent to a 4-Wire voice grade phone
circuit.
A Switch contains a Channel Interface Module
(CIM) for each repeater it controls, a Telephone Inter-
connect Module (TIM) for each telephone line used
for interconnect calls, an Intelligent Dispatch Module
(IDM) or Multi-Net Console Module (MCM) for each
dispatch console and others described in this section.
A single Switch can control up to 30 repeater channels
all at one site or divided among a combination of sites
(e.g. 3-10 channel Localities on one Switch). Each
repeater has an identical Switch interface/logic panel
that performs the call processing for the channel. The
Switch provides interface between the Locality equip-
ment and the control consoles and directs all activity
in Multi-Net site applications.
RF units in the coverage area of one repeater site
can communicate with RF units in the coverage area
of other repeater sites through the Switch. Where more
than 30 channels are required, multiple Switches can
be used with communication between them to direct
calls. Wide area radio coverage is provided to allow a
mobile to talk to another mobile using a repeater
hundreds of miles away. That repeater may be part of
the same Multi-Net system or another Multi-Net
system with phone lines or some other type of link that
provides the communication path.
One or more dispatch consoles can be connected
to the Switch using; direct connection, phone lines, or
some other type of link. Depending on the capabilities
of the particular console, the dispatcher can perform
such functions as; place calls to specific mobiles, place
calls to other dispatchers, and make a patch between
two mobiles.