System Functional Overview; Basic System Components; Interface With Bts; Interface With Cellular Phones - ADC Digivance Installation And Operation Manual

1 SYSTEM FUNCTIONAL OVERVIEW

The Digivance ICS is a digitally distributed antenna system that provides in-building coverage
for cellular analog (AMPS) and digital (TDMA and CDMA) phone systems operating within
the 800 MHz frequency bands. Large buildings typically interfere with the transmission or
reception of cellular phone system signals by imposing high attenuation losses on RF signals.
The Digivance ICS is designed to overcome the attenuation losses that make cellular
communications within buildings or structures difficult or impossible. With the Digivance
ICS, cellular phone RF signals can be distributed to the interior areas of any building or
structure to eliminate dead spots and improve reception.

1.1 Basic System Components

The basic components of the Digivance ICS and their functions are shown in Figure 1. The
basic system consists of the Digital Host Unit (DHU), Digital Remote Unit (DRU), and when
additional capacity or longer fiber runs are required, the Digital Expansion Unit (DEU). In
addition, two accessory items, the High Power Conditioning Panel (HPCP) and the Remote
Interface Unit (RIU) may be used as needed to interface the DHU with the cellular system
Base Transceiver Station (BTS).

1.2 Interface With BTS

The DHU interfaces, either locally or remotely, with the BTS. As referenced in this
publication, the BTS could be either a microcell or a cell site base station. When the BTS is
co-located (microcell interface) with the DHU, a local interface over coaxial cable is possible.
An interface device, such as the HPCP, may be used to provide the proper input RF signal
level to the DHU. When the BTS is not co-located (cell site base station interface) with the
DHU, a remote interface using a donor antenna is required. An interface device, such as the
RIU, is used to provide the proper input and output RF signal levels between the donor
antenna and the DHU.
In the forward path, the DHU receives RF signals from the BTS. The DHU digitizes the RF
signals and then converts them to digital optical signals for transport to the DEU's and
DRU's. In the reverse path, the DHU receives digital optical signals from the DRU's and
DEU's. The DHU converts the optical signals back to the original RF signal format for the
interface with the BTS.

1.3 Interface With Cellular Phones

The DRU interfaces (through an external antenna) with the cellular phones. In the reverse
path, the DRU receives RF signals from each cellular phone. The DRU digitizes the RF
signals and then converts them to digital optical signals for transport to the DHU. In the
forward path, the DRU receives digital optical signals from the DHU. The DRU converts the
optical signals back to the original RF signal format for transmission to the cellular phones. A
small external antenna is connected to the DRU to transmit and receive RF signals to and from
the cellular phones.
ADCP-75-130 • Issue 3C • August 2006
© 2006, ADC Telecommunications, Inc.
Page 1