Technology - Infrastructure - Last Mile 9 - HFC - Principles, DOCSIS 1-x & 2-0

Synopsis

Hybrid Fibre Coax cable systems with cable modems are a widely deployed, highly standardised, broadband access technology. We discuss HFC’s unique characteristics including upstream bandwidth limits and stringent maintenance requirements. The cable modem standards DOCSIS 1.0, 1.1, 2.0 are discussed in detail.

Table of Contents

• 1. Synopsis
• 2. Introduction
  • 2.1 General characteristics
  • 2.2 Large-scale deployment
• 3. HFC’s stringent design and maintenance requirements
  • 3.1 Network design
  • 3.2 Services and frequencies
  • 3.3 A shared medium
  • 3.4 Lifeline support
  • 3.5 Purpose designed broadband network
  • 3.6 Upstream limitations for HFC Internet
  • 3.7 Limiting ‘overuse’ of HFC and other broadband Internet services
• 4. DOCSIS 1.x and 2.0
  • 4.1 DOCSIS 1.0
  • 4.2 DOCSIS 1.1 - QoS and update security
  • 4.3 DOCSIS 2.0
    • 4.3.1 Increased upstream data rate
    • 4.3.2 Limitations imposed by upstream noise
    • 4.3.3 6.4MHz upstream channels
    • 4.3.4 A-TDMA
    • 4.3.5 Adaptive equaliser with 24 taps
    • 4.3.6 Improved burst acquisition
    • 4.3.7 FEC improvements
    • 4.3.8 Ingress cancellation
    • 4.3.9 A-CDMA
    • 4.3.10 Resistance to impulse interference
    • 4.3.11 Tight timing requirements
  • 4.4 Upstream bandwidth problems remain
• 5. Related reports