Network Access Technology Options

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Network AccessTechnology Options

• Jeremy Sharp
• UKERNA
• Advanced Technologies Manager
• J.Sharp_at_ukerna.ac.uk

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Network Access

• Often referred to as
• Local Loop
• Last Mile
• Defined as the network between you and the local
  exchange/hub/base station

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Network Access Issues

• A Monopoly! Traditional local loop
  infrastructure owned by BT
• Local loop is most of the cost of a broadband
  network
• In rural areas number of users are low, therefore
  business case in these areas for broadband is
  weak
• High prices deter take up

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Technology Options
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ADSL

• Features
• Always on
• Different download and upload speeds
• Suitable for business and home users
• Strengths
• Dedicated connection (better security)
• Standards based
• Flexible options
• Weaknesses
• Limited range
• Problems with co-location and unbundling
• Contended service

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ADSL from BT

BT products and pricing April 2002
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Cable Modems

• Features
• Use a shared medium (Ethernet)
• Download 10Mbit/s shared, Upload 768kbit/s or
  3Mbit/s shared
• Shared between up to 2000 homes designed to
  deliver 256kbit/s at peak times
• Targeted at residential users
• Strengths
• High speed
• Bundled with content
• Low price
• Weaknesses
• Shared medium (poor security)
• Separate standards in Europe and US

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Broadband Wireless

• Features
• Possible speeds range from 500kbit/s to 155Mbit/s
  (realistically 100s kbit/s to 5Mbit/s)
  Symmetric or Asymmetric
• Architectures based on either point to multipoint
  (LMDS) or multipoint to multipoint (mesh radio)
• Strengths
• Quick to deploy
• Independent of incumbents
• Cost proportional to number of subscribers
• Weaknesses
• Lack of spectrum (timeframe for allocation at
  40GHz unclear)
• High cost of user end equipment
• Nodes mounted on customer premises a problem if
  in a conservation area

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Fibre to the Building

• Strengths
• Increasing pervasiveness of fibre (BT CW, NTL)
• User end equipment low cost
• Use existing wiring in a building
• Weaknesses
• High cost of getting fibre to the location

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Satellite

• Features
• Satellite receive with wire return available
• 2-way satellite based products are emerging
  (Tiscalisat BT Openworld)
• Different download and upload speeds
• Strengths
• Ubiquitous
• Weaknesses
• Expensive
• User requirement for a sky view
• Long latency wont be suitable for some
  applications

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Provider Strategies

• Provider strategies depend on
• Target customers (size and location/density)
• Regulatory issues (Licence availability and local
  loop unbundling)
• Provider technology preference
• xDSL Incumbents and new entrants if unbundled
  loops
• Cable modems Cable TV operators

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JANET ADSL Pilot
VPN from customer end into JANET
2Mbit/s downstream
155Mbit/s
JANET
BTs ATM Network
256kbit/s upstream
Authentication Server (Radius technology)

• Uses BTs Business 2000 plus product

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JANET ADSL Pilot

• JANET Product (customer interaction with JANET
  Customer Services and Operations desk)
• Pilot started with 24 sites aim to complete in
  November 2002
• Pilot aims to
• Access requirement
• Determine feasibility of providing a JANET ADSL
  service
• Access the technology

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Further Information

• http//www.ja.net/development/network_access/index
  .html