User Manual

ADCP-75-150 • Preliminary Issue A • March 2003 • Section 1: Overview
Page 1-7
© 2003, ADC Telecommunications, Inc.
Figure 1-6. Standard Fiber Optic Transport
In some applications, it may be desirable or necessary to combine the forward path and reverse
path optical signals onto a single optical fiber. This can be accomplished by using a pair of
passive bi-directional Wavelength Division Multiplexers (WDM). The optical wavelengths used
in the system are 1550 nm for the forward path and 1310 nm for the reverse path. Because
different wavelengths are used for the forward and reverse paths, both signals can be combined
on a single optical fiber. One WDM is mounted with the HU and the other WDM is mounted
with the RU as shown in Figure 1-7. The WDMs are available as accessory items.
Figure 1-7. Wavelength Division Multiplexer Application
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 20 Watt systems may be configured to operate over a single optical fiber. A CWDM
module is mounted with each HU and RU as shown in Figure 1-8. The CWDM system converts
the optical signal transmitted by each HU and RU to a new optical wavelength that is unique for
each unit. This allows the CWDM system to distinguish between the optical signals generated
by each HU and RU and therefore to distribute those signals to the appropriate destination. The
CWDM system is available separately as an accessory item.
HOST UNIT
18526-A
REMOTE
UNIT
FORWARD PATH
REVERSE PATH
FIBER OPTIC
LINK
HOST UNIT
18527-A
REMOTE
UNIT
FIBER OPTIC
LINK
WDM
WDM
FORWARD AND
REVERSE PATH