User Manual

ADCP-75-179 • Preliminary Issue A • September 2004 • Section 1: Overview
Page 1-8
© 2004, ADC Telecommunications, Inc.
In some applications, it may be desirable or necessary to combine the forward and reverse path
optical signals from multiple HU’s and RU’s onto a single optical fiber. This can be
accomplished by using an active Coarse Wavelength Division Multiplexer (CWDM) system. Up
to four Digivance systems may be configured to operate over a single optical fiber. A CWDM
module is mounted with each HU and RU. An example of a typical CWDM application is
shown in Figure 1-9.
Figure 1-9. Coarse Wavelength Division Multiplexer Application
A Free Space Optics (FSO) system (that meets the Digivance LRCS data rate performance and
BER requirements) may be used in applications where it is desirable or necessary to bridge an
open span and where it is impractical to lay a fiber optic cable. One FSO transceiver unit may be
mounted on the HU side of the open span and the other FSO transceiver unit may be mounted
on the RU side of the open span. A system diagram of an FSO application is shown in
Figure 1-10. FSO systems are available from various equipment manufacturers.
Figure 1-10. Free Space Optics Application
18528-A
FIBER OPTIC
LINK
HOST UNIT 1
REMOTE
UNIT 1
CWDM
A
CWDM
A
HOST UNIT 2
REMOTE
UNIT 2
CWDM
B
CWDM
B
HOST UNIT 3
REMOTE
UNIT 3
CWDM
C
CWDM
C
HOST UNIT 4
REMOTE
UNIT 4
CWDM
D
CWDM
D
FORWARD AND
REVERSE PATH
HOST UNIT
18530-A
REMOTE
UNIT
FORWARD PATH
FSO
TX/RX
FSO
TX/RX
FREE SPACE OPTICS LINK
REVERSE PATH
FORWARD PATH
REVERSE PATH