The Cisco® GS7000 High-Output 4-Way Segmentable Node with 42/54 MHz Split is the latest-generation 1-GHz optical node platform designed to support fiber deep applications of up to 60 dBmV. This platform allows independent segmentation and redundancy for both the forward and reverse paths in a reliable, easily configurable, technician-friendly package.
The forward path of the Cisco GS7000 4-Way Segmentable Node launch amplifier can be initially deployed in nonsegmented mode with a single broadcast optical receiver distributing common RF services to either four output ports (all high level) or six output ports (two high level and four lower level). The forward path can also be fully segmented by using four independent optical receivers that each feeds its own output port, or left/right segmented by using two independent optical receivers that each feeds half of the node's output ports. Forward path optical redundancy is also supported using optional redundant optical receivers. The type of forward path segmentation and/or redundancy is determined by the type of Cisco GS7000 Forward Configuration Module installed.
The Cisco GS7000 Node's reverse path is equally flexible. Reverse traffic can be segmented or combined and routed to a maximum of four Fabry-Perot (FP), distributed feedback (DFB), coarse wavelength-division multiplexing (CWDM), or dense wavelength-division multiplexing (DWDM) reverse optical transmitters, or to the Cisco GS7000 Enhanced Digital Reverse (EDR) optical transmitters as part of the EDR system. Reverse path optical redundancy is supported using optional redundant optical transmitters. The type of reverse path segmentation and/or redundancy is determined by the type of Cisco GS7000 Reverse Configuration Module installed. A Reverse Input Port is also provided for high-frequency (5-210 MHz) reverse signal injection.
All optical transmitters and optical receivers used in the Cisco GS7000 platform have new high-profile module covers that include both a self-contained fiber pigtail storage area and an integrated pull ring for easier module installation and removal. Additionally, the GS7000 optical receiver has a new low-current design that dissipates less power, and incorporates a two-state interstage RF attenuator switch for performance optimization.
• Standard accessories in the Cisco GainMaker® style (for example, attenuator pads, equalizers, diplexers, and crowbar)
• Field-accessible plug-in forward interstage linear equalizers, forward and reverse configuration modules, and signal directors
• Three-state reverse switch (on/off/6-dB) allows each reverse input to be isolated for noise and ingress troubleshooting (status monitoring or local control module required)
• Auxiliary reverse injection (5-210 MHz) configurable on up to two ports
• Positions for up to four optical receivers and four optical transmitters in housing lid
• Optional low-cost local control module may be installed with a redundant forward configuration module to allow optical path redundancy when no status monitor is required
• Optional status monitoring using a DOCSIS transponder (using standard HMS MIBs)
• Fiber entry ports on both ends of housing lid
• Fiber management tray and track provides easy access to fiber connections
• Primary and redundant power supplies with passive load sharing
• Spring-loaded seizure assemblies allow coaxial connectors to be installed or removed without removing amplifier chassis
• Dual/split AC power
Node Block Diagrams
Figures 2, 3, and 4 provide block diagrams of different node configurations.
Figure 7. Receiver RF Output Level and Transmitter OMI: Rx Switch in -6 dB Setting
Figure 8. Receiver RF Output Level and Transmitter OMI: Rx Switch in 0 dB setting
Notes for Optical Section Specifications:
1. Receiver (Rx) has a 2-position RF attenuator switch (-6 dB and 0 dB). The -6 dB setting is used for 0 to +2 dBm optical Rx power, and the 0 dB setting is used for -3 to 0 dBm Rx power.
2. For forward receiver module only. Does not include frequency response contributions from forward optical transmitter.
3. Minimum receiver RF output level for the stated transmitter percent OMI per channel, with receiver optical input power of 0 dBm, and specified Rx attenuator setting. To determine RF output levels at other optical input power, add (or subtract) 2 dB in RF level for each 1 dB increase (or decrease) in receiver optical input power.
For reverse optical transmitter and link performance, see the "Analog Reverse Optical Transmitters with Thermal Compensation" data sheet.
Unless otherwise noted, specifications reflect typical performance and are referenced to 68° F (20° C). Specifications are based upon measurements made in accordance with SCTE and ANSI standards (where applicable), using standard frequency assignments.
RF Section Specifications
Tables 2, 3, and 4 list RF section specifications.
Table 2. RF Section General Station Performance
General Station Performance
Units
Forward
Reverse
Notes
Pass Band
MHz
54-1002
5-42
Input/Output Port Return Loss
dB
17
16
Hum Modulation at 12 A
dB
70 (54-870 MHz)
60 (871-1002 MHz)
60 (5-10 MHz)
70 (11-42 MHz)
Hum Modulation at 15 A
dB
65 (54-870 MHz)
60 (871-1002 MHz)
60 (5-10 MHz)
65 (11-42 MHz)
Test Points (± 0.5 dB)
dB
-20
-20
Table 3. RF Section Forward Station Performance
Forward Station Performance
Units
15 dB I/S EQ with 0.5 dB I/S Pad
Notes
Amplifier type
-
GaN
Operational gain (minimum)
dB
34
1
Frequency response
dB
± 0.5
1
Internal tilt (±1 dB)
dB
14.5
1, 2
Port to port isolation with full segmentation
dB
60 (54-750 MHz)
55 (751-1002 MHz)
1
Port to port isolation with left/right segmentation
dB
65 (54-750 MHz)
55 (751-1002 MHz)
1
Noise figure at: 54 MHz
1002 MHz
dB
14.0
13.5
1
Reference output levels at: 1002 MHz
870 MHz
750 MHz
650 MHz
550 MHz
55 MHz
dBmV
60
58
56.2
54.5
53
45.5
3
Reference output tilt (55-1002 MHz)
dB
14.5
2, 4
78 NTSC channels (CW) with digital
7
Composite triple beat
dB
60
5
Composite second order (high side)
62
5
Cross modulation
dB
52
5, 8
Composite intermodulation noise (CIN)
dB
51
5
Table 4. RF Section Reverse Station Performance
Reverse Station Performance
Units
Reverse
Notes
Amplifier type
-
GaAs FET
Operational gain (minimum)
dB
-2
6
Frequency response
dB
± 0.5
6
Internal tilt (+/- 1 dB)
dB
0
6
Path to path isolation
dB
55
6
Noise figure
dB
7.5
6
Notes for Tables 3 and 4:
1. Forward performance is for station from output of optical Rx to node RF output port, with 0 dB pad in optical interface board (OIB), any forward configuration module, 0 dB interstage (I/S) pad, 15 dB linear I/S EQ, factory select output pad, and signal director jumper. Includes OIB losses.
2. Reference output tilt and internal tilt are both "linear" tilt.
3. RF Output Levels are referenced to an Optical Input Level at -1 dBm for 1550 nm at 3.0% OMI or 1310 nm at 3.5% OMI.
4. The forward reference output tilt specified is achieved via field installation of appropriate linear I/S EQ, in conjunction with the internal tilt of the launch amplifier and the tilt associated with the optical link (transmitter/receiver combination).
5. Stated distortion performance is for launch amplifier section operated at reference output levels and tilts. Full station performance can be determined by combining optic performance and launch amplifier performance.
6. Reverse performance is for station from reverse input port to input of reverse optical transmitter module, with 0 dB reverse input pad.
7. Loaded with 78 NTSC CW carriers from 55-550 MHz. "Digital" refers to 550 - 1002 MHz loading with QAM carriers at -6 dB relative to analog video carrier levels.
8. X-mod (at 15.75 kHz) specified using 100% synchronous modulation and frequency-selective measurement device.
Data in Table 7 is based on stations configured with a status monitoring transponder. AC currents specified are based on measurements made with typical CATV type ferroresonant AC power supply (quasi-square wave).
DC supply has a fixed under-voltage lockout of 33 VAC.
Table 8. Environmental and Mechanical Specifications
Environmental
Operating temperature range
-40 - 140°F (-40 - 60°C)
Relative humidity range
5% to 95%
Mechanical
Housing Dimensions
21.3 in. L x 11.6 in. H x 11.1 in. D
(541 mm x 295 mm x 282 mm)
Weight
Station with 4 RX, 4 TX, 2 power supplies: 50.0 lbs.
(22.7 kg)
Ordering Information
The Cisco GS7000 Node is available in a wide variety of configurations. The GS7000 Ordering Matrix provides ordering information for configured node stations.
Table 9 contains ordering information for required and optional accessories. Please consult with your Account Representative, Customer Service Representative, or Applications Engineer to determine the best configuration for your particular application.
Table 9. Cisco GS7000 Node Accessories
Required Accessories
Part Number
Plug-in Pads (attenuators): Available in 0.5 dB steps from 0 to 20 dB
• 1 required for each Optical Receiver Module installed in the node (for Optical Interface Board)
• 1 required for each Optical Transmitter Module installed in the node (for Optical Interface Board)
• 1 required for each Reverse input path activated (for Launch Amplifier)
589693 (0 dB) sequentially thru 589734 (20.5dB)
Optional Accessories
Plug-in Forward Linear Equalizers: Available in 1.5 dB steps from 0 to 21 dB.
• Node shipped with 15 dB Linear Equalizers (4)* installed for 14.5 dB of tilt to 1002 MHz (*4008787)
4007228 (0 dB)
see table below
Plug-in Signal Directors - 2 required
Node shipped with Jumpers installed to activate 4 RF output ports
• Optional 2-Way Splitters are required to activate 5 or 6 RF output ports
4011907
4011908
Note: Configured nodes ship without reverse input pads and any of the pads on the OIB. All other standard accessories are shipped from the factory. Forward Launch Amplifier attenuator pads, (4) 15 dB linear EQs, and (2) signal director jumpers are shipped with every configured node.
