User Manual

ADCP-75-136 • Issue 1 • November 2002
Page 2
© 2002, ADC Telecommunications, Inc.
DRU
DRU
DRU
DRU
DRU
DRU
DRU
DRU
DRU
DRU
DRU
DEU
DEU
DHU
LOCAL INTERFACE
DEVICE
REMOTE INTERFACE
DEVICE
REMOTE
BTS
LOCAL
BTS
RF
18108-A
RF
Figure 1. System Overview Functional Block Diagram
1.4 Digital Fiber Optic Transport
The DHU is connected to each DRU unit over a pair of either multi-mode or single-mode
(depending on the type of optical transceiver specified) optical fibers. One fiber is used to
transport the forward path optical signal. The other fiber is used to transport the reverse path
optical signal. Because the optical signal is digital, no adjustments to the optical signal level
are required at the DRU or the DHU as long as the BER is adequate. Either 62.5 or 50 micron
core multi-mode optical fiber; or 9 micron core single-mode optical fiber may be used for the