ADC 75-192 - Manual (Page 14)

ADCP-75-192 • Issue 2 • June 2007
Page 2
© 2007, ADC Telecommunications, Inc.
The Hub is a rack assembly containing electronic equipment. Included are two types of
Compact PCI (cPCI) “chassis” containing “electronic modules.” The two types of cPCI chassis
are the Digital Chassis and the RF Chassis. The electronic modules include CPU boards, optical
to RF data converters, an optical interface board, and so on. The Hub rack also contains other
separately mounted system equipment including high power attenuators, base station interface
modules, a power distribution unit, an Ethernet hub, and a Hub reference module that provides a
system clock.
The RAN is weather-resistent, pole- or pad-mount cabinet containing a cPCI shelf similar to the
Hub chassis and a similar set of electronic modules and supportive system equipment as
required for the more limited functions required at the RAN. The CXD RAN and the NXD
RAN have different sets of electronic modules, but the basic function is the same.
1.3 Data Flow (Forward and Reverse Paths)
Digivance CXD/NXD is a multi-frequency, multi-protocol Distributed Antenna System (DAS),
providing microcellular SMR, Cellular, and PCS coverage via its distributed RF antennas.
Figure 2 shows the RF signal path through a three-band CXD Digivance system. In the forward
direction, the signal starts from the base station sector on the left and moves to the right. In the
reverse direction, the RF path starts at the antenna and then flows from the RAN to the Hub and
to the base station sector receiver(s).
Figure 2. Digivance CXD System Block Diagram (Three Bands Shown)
21879-C
FBHDC FSC
HUC RSC
STF2 CPU
RDC2
RUC
FIC FIC
RFA
800/
900
800 MHz
BTS
900 MHz
BTS
800/900
DUPLEXED
OUTPUT
1900
DUPLEXED
OUTPUT
RFA
1900 1900 MHz
BTS
HUB
CXD
RAN
FBHDC FSC
HUC RSC
FBHDC FSC
HUC RSC
RDC2
RUC
800
RX
900
RX