User's Manual

ADCP-75-187 • Issue 1 • September 2005 • Section 2: DESCRIPTION

Page 2-2

1 INTRODUCTION

This section describes the basic components of a typical Digivance 800/900 MHz SMR SCS

system including the Host Unit (HU), Remote Unit (RU), element management system, and

accessories. The system specifications are provided in a table at the end of this section.

2 HOST UNIT

The HU, shown in Figure 2-1, provides the following basic functions:

• Provides a limited adjustable RF interface with the BTS.

• Provides a fiber optic interface with the RU.

• Digitizes the two forward path composite RF signals.

• Converts the two digitized forward path RF signals to a digital optical signal.

• Converts the digitized reverse path optical signal to two digitized RF signals.

• Converts the two digitized reverse path RF signals to two composite RF signals.

• Sends alarm information to an external alarm system through relay contact closures

• Provides an RS-232 interface for connecting the EMS computer.

• Provides a CAN interface for networking multiple HUs.

2.1 Primary Components

The HU consists of an electronic circuit board assembly and a fan assembly that are mounted

within a powder-paint coated sheet metal enclosure. The enclosure provides a mounting point

for the circuit board and fan assemblies and controls RF emissions. The only user-replaceable

component is the fan assembly. The HU is designed for use within a non-condensing indoor

environment such as inside a wiring closet or cabinet. The RF connectors, optical connectors,

alarm output connectors, DC power terminal strip, and grounding lug are mounted on the HU

rear panel. The On/Off power switch, LED indicators, service interface connector, and

Controller Area Network (CAN) connectors are mounted on the HU front panel.

2.2 Mounting

The HU is intended for rack-mount applications. A pair of reversible mounting brackets is

provided that allow the HU to be mounted in either a 19-inch or 23-inch EIA or WECO

equipment rack. When installed, the front panel of the HU is flush with the front of the rack.

Screws are provided for securing the HU to the equipment rack.