Cisco Model GS7000 4-Port Node 1 GHz with 42 54 Split Installation Guide

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Chapter 2    Theory of Operation 
 
 
 
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OL-29643-02 
 
 
4-Way Forward Path Signal Routing 
GS7000 Node 4-way forward path signal routing functions are described below. 
Stage Description 
1310 nm or 1550 nm optical signals from the headend are applied to 
receiver module 1 (and/or modules 2, 3, and 4, if used) in the GS7000 
Node. 
The receiver module detects the signal on the optical carrier applied to it 
and outputs an electrical RF signal to the node Optical Interface Board 
(OIB). 
The RF signals travel across the OIB and cables to the Forward 
Configuration Module (FCM). The FCM determines how RF signals 
from the different receiver modules are routed to the four independent 
forward amplification paths in the RF amplifier module. The 1X4 FCM 
splits the RF signals entering it equally between the four forward 
amplification paths in the RF amplifier module. 
Each of the forward amplification paths in the RF amplifier module is 
composed of one input amplification stage and one interstage 
amplification stages in series followed by a power doubler output 
amplification stage. This topology provides one driven output port for 
each of the forward amplification paths in the RF amplifier module, for a 
total of four driven node output ports. 
Each of the forward amplification paths in the RF amplifier module also 
contains padding, trimming, thermal compensation, equalization, and 
filtering circuitry. 
Node signal directors are present at two of the nodes forward output 
ports and allow the signals at those ports to be redirected to the nodes 
auxiliary output ports or split equally between the primary and auxiliary 
node output ports. In this way, the node can be configured to have up to 
six output ports.