Specifications

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Cisco Cable Modem Termination System Feature Guide
0L-1467-02
Chapter 3 Spectrum Management for the Cisco Cable Modem Termination System
Benefits
Intelligent Frequency Hopping • Proactively changes upstream frequency for an interface before noise conditions
become severe enough to force cable modems offline.
• Dedicated hardware intelligent performs “look-ahead” to choose new upstream
frequency to find a stable channel.
• Flexible priority configuration allows hopping decision criteria to be tailored to the
individual cable plant environment.
• Improves responsiveness to ingress impairments, by matching the hopping decision
criteria to the fluctuating plant conditions.
• Pinpoints CNR variations with per-modem accuracy to isolate problematic cable
modems.
• Sustains or even improves subscriber online percentages through user-programmable
proactive channel management techniques.
Dynamic Upstream Modulation • Reduces the risk associated with switching between QPSK and QAM-16 modulation
in the upstream to respond to ingress noise, so that subscribers remain online and
connected.
• Checks the current upstream signal to ensure that it can support the configured
modulation scheme, and proactively adjusts to the secondary, more robust modulation
scheme when necessary.
• Improves DOCSIS upstream channel availability and provides maximum RF spectrum
utilization efficiency.
• Eliminates unnecessary frequency hopping by switching modulation profiles to one
that allows cable modems to remain online while using the currently assigned
upstream.
• Provides assurance that subscribers remain online and connected during periods of
return path impairments
SNMP Interface • Provides a way to remotely obtain the current status of noise on an upstream. This
information can then be inserted into third-party or custom reporting and graphing
applications.
• Provides visibility to ingress and impulse noise under the carrier frequency on a
per-port basis.
• Provides an easy-to-use, distributed method to remotely gather real-time display of the
DOCSIS upstream spectrum for individual cable modems and set-top boxes (STBs).
• Reduces the reliance on costly spectrum analyzers at every headend or hub.
• Quickly provides spectrum views through an intuitive interface, without the
complicated setup time of a spectrum analyzer.
• Allows the technician to troubleshoot the network remotely, as opposed to having to
be physically present to connect and use a spectrum analyzer.
• Supports the DOCSIS Cable Modem Test Analyzer (DCMTA) from Acterna Corp.
1. The Cisco uBR10012 universal broadband router using Cisco IOS Release 12.2(8)BC2 supports a subset of these features. See the “Cisco uBR10012
Router and Cisco IOS Release 12.2(8)BC2 Support” section on page 3-19 for more details.
Table 3-4 Benefits of Advanced Spectrum Management Features (Cisco uBR-MC16S Card) (continued)
Advanced Spectrum
Management Feature Benefits
1