User's Manual

ADCP-75-187 • Issue 1 • September 2005 • Section 2: DESCRIPTION
Page 2-7
© 2005, ADC Telecommunications, Inc.
3 REMOTE UNIT
The RU is available in either a single-band or a dual-band version. Both versions of the RU
provide the following basic functions:
• Convert the digitized forward path optical signals to digitized RF signals.
• Convert the digitized forward path RF signals to composite RF signals.
• Digitize the reverse path composite RF signals.
• Convert the digitized reverse path RF signals to digitized optical signals.
• Provide an RF interface (antenna port) for the remote antenna(s).
• Provide an optical interface for the HU.
• Transport alarm, control, and monitoring information to the HU via the optical interface.
• Accept AC power input.
• Provide a visual indication of unit status
3.1 Primary Components
Depending on the version, the RU consists of either two or four electronic assemblies mounted
within an environmentally-sealed cast-aluminum enclosure. The Spectrum Transport Module
(STM) provides optical-to-RF and RF-to-optical conversion and digitizing functions; alarm,
control, and monitoring functions; power conversion functions; and RF filtering and interface
functions. The Linear Power Amplifier (LPA) works in conjunction with the STM to amplify
the forward path RF signal. The aluminum enclosure provides a mounting point for the
electronic assemblies, controls RF emissions, seals out dirt and moisture, and provides passive
cooling. The electronic assemblies are not user replaceable or accessible. All connectors and
indicators are mounted on the bottom of the RU enclosure for easy access.
The single-band version of the RU, shown in Figure 2-3, consists of one STM and one LPA
mounted within the same enclosure. The dual-band version consists of two STM’s and two
LPA’s mounted within the same enclosure. The dual-band version makes it possible to support
two separate frequency bands with a single RU.
19 ALARM OUTPUT Screw-type terminal
connector (14–26
AWG )
Connection point for an external alarm system.
Includes normally open (NO), normally closed
(NC), and common (COM) wiring connections.
20 FWD (PORT 1) UPC/SC connector
(flat single-mode)
Output connection point for the forward path
optical fiber.
21 REV (PORT 2) UPC/SC connector
(flat single-mode)
Input connection point for the reverse path opti-
cal fiber.
22 Chassis ground stud Connection point for a chassis grounding wire.
Note: A more detailed description of LED operation is provided in Section 4.
Table 2-1. Host Unit User Interface, continued
REF
NO
USER INTERFACE
DESIGNATION
DEVICE
FUNCTIONAL
DESCRIPTION