Cable Modems in the UK

1
Cable Modems in the UK

• Craig Catto
• Head of Broadband and Digital Engineering
• Telewest Communications

2
Agenda

• Broadband HFC Network Basics
• Common misconceptions
• Cable Modems
• Cable Modems in a DTV STB
• The Evolution of Euro-DOCSIS
• DVB-RCCL vs. Euro-DOCSIS
• Creation of Euro-DOCSIS Specification
• Euro-DOCSIS Standardisation
• Certification

3
Broadband HFC Network Basics

• The HFC network is a bi-directional RF pipe
• The Customer Premise Equipment sees all of the
  services coming down the pipe
• The customer selects what they want

4
Network Architectures
5
Downstream Frequency Plan
6
Bandwidth Calculation

• Symbol rate 6.952Msymbols/sec in 8MHz
• 8bits/symbol for 256QAM
• Data rate 51.25Mbps net of overheads
• With 80 carriers 4 Gbps net downstream
• Shared between 500 homes 8Mbps each with 100
  penetration concurrent usage
• Shared medium applies no straight jacket
• Upstream approximately 80Mbps
• Now is the worst time for most cable operators

7
Unlocking the Bandwidth

• The key to securely unlocking the capacity is the
  MAC layer - tuned to the service
• Video DVB-C
• IP DVB-RC but DOCSIS leads the way
• The MAC layer adds TDM to FDM
• pseudo point to point connectivity with an
  individual customer
• The usual argument against Cable Modem is that it
  is 30Mbps shared
• Stop press! 80 such cable modem channels
  simultaneously supported to a node

8
The Birth of Euro-DOCSIS

• Telecom over Cable Operators Forum initiated July
  1999
• Analyse and define common technical and
  commercial strategies for cable delivered
  services
• Rapid and profitable deployment of a single data
  cable modem and Digital set-top box standard
• Boosting the penetration of fast internet and
  other interactive services
• Support of new applications such as VoIP and iDTV
• Improve the business economics

9
TOCOF - Founding Members
Homes passed gt 25 million Subscribers gt 12
million Cable Modem deployment 2000 650K
modems 2002 2.3M modems
10
DOCSIS vs. DVB-RC

• DOCSIS
• US standard
• Internet/IP driven
• Complete specification
• Mature
• High vendor and chip supplier involvement
• Products already available
• Roadmap to QoS/VoIP
• Not adapted to all European cable plant!!!

• DVB-RC
• New standard
• DVB/ATM driven
• less complete - time to market???
• low vendor involvement
• unspecified roadmap towards VoIP
• adapted to European cable plants

TOCOF members decide to adopt DOCSIS, with
minor Europe specific modifications
Euro-DOCSIS Re-use of DOCSIS components and
chipsets Economy of Scale ? Low prices Low
risk Short Time to Market ? Early Deployment
11
European Operators Vendors considering DOCSIS

• Best Data
• NetGem
• Cisco Systems
• Nortel Dasa NS
• Com21
• Nortel Networks
• Daewoo
• Pace
• Daphne
• Philips
• Dassault AT
• Samsung
• DeltaKabel (Lucent)
• Sharp
• Dx Antenna
• Sohoware
• ELSA
• Sony
• Ericsson

• A2000
• Ono
• CWC
• RTD
• CableLink
• StjarnTV
• Caboisao
• TeleCable
• Euscaltel
• TeleKabel Wien
• Gr. G de C
• Telenor
• Avidi
• JancoMulti.
• Telenet
• Kabelplus
• Telewest
• NetGame

• Lyonnaise
• Telia
• Stofa
• Madritel
• Time Warner
• Media Res.
• United Telec
• Menta
• UPC other
• NetCologne
• Videopole
• NTL
• 3Com
• Mitsui
• Alcatel
• Motorola
• Arris
• Interactive

• BAS
• TONNA
• General Instrument
• Toshiba
• GVC
• Tratek
• High Speed Surfing
• TurboComm
• Jahong
• ZyXEL
• Kathrein
• Future Net
• Thomson MM
• Gadline
• NetGear
• NEC
• Askey
• Tearyon

12
Progress of Euro-DOCSIS

• DOCSIS defined by US cable operators
• ITU-T adopt DOCSIS 1.0 as Rec.J.112AnnexB
• TOCOF create Euro-DOCSIS as an option in the
  DOCSIS Radio Frequency Interface (RFI)
  Specification
• DVB downstream and FEC (ETSI EN 300 429)
• wider upstream frequency range to 5-65 MHz
• levels in line with CENELEC standards
• CableLabs added Euro-DOCSIS to version 1.1 of
  DOCSIS as Annex N

13
Progress of Euro-DOCSIS

• Exactly the same version of DOCSIS 1.1
• Approved by SCTE in US
• Adopted as ETSI Standard ES 201 488 V1.1.1
• Submitted to ITU-T as an upgrade to DOCSIS 1.0
• So DOCSIS can be considered to be a common
  world-wide standard
• Certification to encourage the market
• Current deployments, and therefore certification
  are DOCSIS 1.0 with Euro-DOCSIS
• Work on adaptation to STBs progressing

14
Standards Convergence in ITU-T

• ITU-T allows 3 options for bi-directional systems
  over cable, the Annexes to Rec.J.112, which all
• Are bi-directional systems for HFC networks.
• Can support CM and STB environments.
• Are consistent with the DVB Return Channel
  reference model embodied in ITU-T J.110.
• Consistent with the DVB network independent
  protocols embodied in ITU-T J.111.
• Deliver IP and support QoS.
• Have defined Management Information Bases to the
  IETF.

15
DOCSIS 1.1 Enhancements

• Baseline Privacy Plus enhanced security
  authentication
• 16 Service levels, each of which can have a
  different class
• Fragmentation to even out payload for CBR and
  guaranteed bandwidth QoS