User's Manual
ADCP-75-158 • Issue 1 • July 2003 • Section 2: Description
Page 2-4
© 2003, ADC Telecommunications, Inc.
Figure 2-1. Host Unit
2.3 Fault Detection and Alarm Reporting
The HU detects and reports various faults including host unit fault, optical fault, power fault,
temperature fault, and RF fault. Various front panel Light Emitting Diode (LED) indicators turn
from green to red or yellow if a fault is detected. A set of alarm contacts (normally open and
normally closed) are provided for reporting an alarm to an external alarm system when a fault is
detected. Both major alarm (system operation seriously affected) and minor alarm (system
operation not affected or only slightly degraded) contacts are provided.
The status of the HU, the alarm state (major or minor), and other alarm information is
summarized and reported over the service interface, the CAN interface, and also over the optical
interface to the RU. In addition, the state of the RU is received over the optical fiber and reported
over the service interface and the CAN interface. This detailed information may be accessed
remotely through the NOC/NEM interface or locally through the EMS software GUI.
2.4 RF Signal Connections
The RF signal connections between the HU and the BTS are supported through two N-type
female connectors. One connector is used for the forward path RF signal. The other connector is
used for the reverse path RF signal. The current 20 Watt system does not support a diversity
reverse path. In most installations, it is usually necessary to install a Conditioning Panel and/or
Duplexing Panel (accessory items) to support the interface between the HU and the BTS. The
HU should be as close as possible to the BTS to minimize cable losses.
2.5 RF Signal Level Adjustments
The HU is equipped with several attenuators for adjusting the signal levels of the forward and
reverse path RF signals. The attenuators provide an attenuation adjustment range of 0 to 31 dB
and can be set in 1 dB increments. The attenuators are software controlled and are adjusted
through the NOC/NEM interface or the EMS software GUI.
17.2 INCHES
(437 mm)
3.5 INCHES
(89 mm)
11.4 INCHES
(290 mm)
15.3 INCHES
(389 mm)
FRONT PANEL
CABLE MANAGEMENT
TRAY
MOUNTING
BRACKET
(BOTH SIDES)
18531-A