User Manual

ADCP-75-179 • Preliminary Issue A • September 2004 • Section 1: Overview

Page 1-3

2.2 Enhanced Base Transceiver Station Interface

The HU is interfaced with an EBTS over coaxial cables as shown in Figure 1-2. The EBTS

provides the RF channel inputs and outputs for a designated sector. In the forward path, the HU

receives two RF inputs from the EBTS. The HU digitizes the RF signals and then converts them

to digital optical signals for transport to the RU. In the reverse path, the HU receives digital

optical signals from the RU. The HU converts the digital optical signals back to two RF outputs

which are supplied to the EBTS over the coaxial cable interface.

Figure 1-2. EBTS/HU Interface

2.3 Handset Interface

The RU interfaces with the handsets (cell phones) through an antenna. In the reverse path, the

RU receives RF signals from each handset (see Figure 1-1). The RU digitizes the RF signals and

then converts them to digital optical signals for transport to the HU over the optical fiber link. In

the forward path, the RU receives digital optical signals from the HU. The RU converts the

optical signals to RF signals for transmission to the handsets. The RU is connected to an

antenna (not provided) which transmits and receives the handset RF signals.

2.4 Local Interface

Communications with an individual Digivance system is supported through a local interface

capability as shown in Figure 1-3. A local interface requires a PC-type computer loaded with

the Digivance Element Management System (EMS) software. EMS provides the various control

and monitoring functions required to locally manage a Digivance system. The EMS computer

can be directly connected to either the HU or RU through the computer’s RS-232 port.

Operation is implemented through the EMS Graphical User Interface (GUI). The GUI consists

of a series of screens from which the user selects the desired option or function. An RS-232

service port is provided on both the HU and the RU for connecting the EMS computer.

20008-A

HOST UNIT

ENHANCED

BASE

TRANSCEIVER

STATION

FORWARD

PATHS

REVERSE

PATHS