Motorola M3097 Service Manual download pdf (Page 12)

Introduction

A cellular mobile telephone system divides

the service area into small, low power radio

frequency coverage areas called cells. A cel-

lular system consists of a more or less con-

tinuous pattern of these cells, each having a

1 to 40 mile radius (typically 5 - 10 miles).

Within each cell is a centralized cell site with

an elevated antenna and a building. The

building houses a base station with trans-

ceivers and related control equipment for the

channels assigned to that cell. All the cell

sites within a system are then connected ei-

ther by dedicated land lines, microwave links,

or a combination of both to a central control

site called the central controller or switch .

The switch controls the entire cellular sys-

tem and serves as the interface between the

cellular telephone user and the landline net-

work. Each cell site operates on an assigned

access channel, and may have any number

of paging and voice channels assigned to it.

A BAND CHANNELS

Primary Control Channels (21): 313 - 333

Secondary Control Channels (21): 688 - 708

Voice Channels... 001 - 312,

(395 AMPS / 1185 NAMPS): 667 - 716, and

991 - 1023

B BAND CHANNELS

Primary Control Channels (21): 334 - 354

Secondary Control Channels (21): 737 - 757

Voice Channels... 355 - 666 and

(395 AMPS / 1185 NAMPS): 717 - 799

NOTE:

In NAMPS applications, each AMPS voice channel

provides space for three NAMPS voice channels.

Digital cellular multiplexes voice channels to allow for the

possibility of several additional conversations on a single channel.

Figure 1. Channel Assignments

Cellular Overview

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Motorola M3097 Service Manual Page 12