User Manual

ADCP-XX-XXX • November 2000 • Section 2: WMTS Description
Page 2-18
 2000, ADC Telecommunications, Inc.
connection. The C&F card is always located next to the host card. The card communicates
with the other system assemblies via the internal CPCI bus. An internal system bus is used for
on-card intra-board data transfer. This bus structure separates data flow and provides better
bus performance and traffic throughput.
4.3.2 Downstream Card
The downstream card, together with the universal card, is part of the downstream module. The
transmission module core includes the forward error correction (FEC) modulation circuit. The
modulator card is based on a transmitter/processor and an IF generator. The downstream IF
output is nominally centered at 44 MHz, and it supports QPSK, 16QAM, and 64QAM
modulation schemes.
4.3.3 Upstream Card
The demodulator card, together with the universal card, is part of the upstream module. The
demodulator card is based on a burst receiver and an IF demodulator for QPSK only. The
upstream IF input is 5 MHz to 68 MHz.
4.3.4 Host Card
The host cards provide bus arbitration, system clock and timing. A secondary host card can be
installed for backup of these functions.
4.3.5 Downstream Application
The downstream application is loaded by the host card into the universal card, which is part of
the downstream module. The application provides the composite IF signal to be converted by
the modulator for the downstream channel.
4.3.6 Upstream Application
The upstream application is loaded by the host card into the universal card, which
is part of
the upstream module. The application provides the demodulated input signal.
4.3.7 C&F Application
This application is the overall WMTS controller. The controller manages the entire WMTS
and runs the SNMP, which is the administrator management interface program. It provides the
100BaseT interface, which connects the WMTS to the Internet backbone via a switch and the
ISP router. The C&F card is always the closest one to the host card.