Codan Radio Radio Repeater Systems Training Guide - Manual (Page 19)

RADIO REPEATER SYSTEM | TRAINING GUIDE
Chapter 2: Repeater System Confi gurations Page 11
LINKED REPEATER SYSTEMS
There are various methods of linking (or chaining) repeaters together. An expression that is often used
to describe the repeater that connects to the mobiles and base stations is “drop”, or local coverage
repeater. The expression “linking” is used in preference to “trunking” because the latter is more often
used to describe a different technology. In the following diagrams the term “drop repeater” describes
a repeater that transmits and receives simultaneously and is used to talk to mobiles, base stations,
aircraft, etc. The term “switched link” describes a repeater that does not function simultaneously but is
switched to transmit or receive at any one time (controlled by incoming signals). It is used to connect
one site to another. The term “repeating link” repeater describes a repeater that transmits and receives
simultaneously, just like a “drop” repeater, but unlike a “drop” it is an inexpensive method of linking to
a number of other sites.
Figure 2-3 represents two repeaters linked together (two linked repeaters). Note that in this system
three pairs of frequencies are required.
Figure 2-3: Two Linked Repeaters
REPEATER 1 REPEATER 2
To / From Mobiles and
Base Stations
To / From Mobiles and
Base Stations
Drop
Repeater
Switched link
Repeater
Tx-F1
Rx-F2
Tx-F3
Rx-F4
Drop
Repeater
Switched link
Repeater
Tx-F4
Rx-F3
Tx-F5
Rx-F6