Chapter 2: C4/C4c CMTS Features
STANDARD Revision 1.0
C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved.
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The DOCSIS 2.0 standard greatly improves performance in the upstream path of the cable network. The growing demand
for peer-to-peer file sharing, interactive gaming, and voice over IP telephony increases the need for upstream bandwidth.
The following enhancements are available to CMTSs and CMs that comply with the 2.0 standard while maintaining all the
DOCSIS 1.1 and 1.0 functionality:
Enhanced upstream capacity
Greater maximum upstream throughput — up to 30.72 mbps per channel
Greater upstream channel width — up to 6.4 Mhz
New upstream channel modulation rates: 8QAM, 32QAM, and 64QAM
Longer preamble to facilitate synchronization — up to 1536 bits
Higher powered preamble — QPSK-1
Enhanced noise cancelation and error correction
Synchronous-Code-Division Multiple Access (SCDMA) operation along with the standard TDMA and ATDMA techniques
for combining CM signals onto a given upstream channel.
DOCSIS 3.0 Compliance
In May 2008, the C4 CMTS received DOCSIS® 3.0 Bronze-level requalification by CableLabs®in Certification Wave 58.
The following features were added to the ARRIS C4 CMTS as part of the DOCSIS 3.0 initiative while maintaining total
compatibility with deployed pre-3.0 DOCSIS devices:
Independent Scalability of Upstream and Downstream Channels
Management of Multiple Upstream and Downstream Channels per MAC Domain
Enhanced Cable Plant Infrastructure Management
Cable Modem Topology Resolution
Downstream Channel Bonding
IPv6 Management of CMs and Forwarding of CPE Traffic
Enhanced Operations Support System Interface.
The ARRIS C4c CMTS is a compact DOCSIS 3.0 CMTS based on the proven hardware and software of the larger C4 CMTS
solution.