Technology - Infrastructure - Last Mile 7 - FTTC, VDSL Principles

Synopsis

‘Fibre to the Curb’ with VDSL2 is the highest performing broadband last-mile technology short of Fibre to the Premises (FttP). We introduce the technical principles of Very High Rate Digital Subscriber Line, the nature of the cables it works over and discuss some early standards, including IEEE 802.3ah’s Ethernet in the First Mile adoption of VDSL.

Table of Contents

• 1. Synopsis
• 2. Introduction
  • 2.1 Historical background
    • 2.1.1 Triple play demand
• 3. Single and multi-carrier modulation techniques
  • 3.1 QAM or CAP - Carrierless Amplitude Phase
    • 3.1.1 CAP’s difficulty with multipath
• 4. DMT - OFDM
  • 4.1 Multiple sub-carriers and long symbol times
  • 4.2 Impulse rejection
  • 4.3 Narrowband interference rejection
  • 4.4 Minimising outgoing interference
  • 4.5 Adapting to noise conditions
  • 4.6 Digital duplexing
• 5. Early, non-ITU, standards
  • 5.1 Fast and slow channels
  • 5.2 ETSI TM 06
  • 5.3 ANSI T1.424
  • 5.4 Ethernet in the First Mile - IEEE 802.3ah
    • 5.4.1 Bonding and multiple lines
    • 5.4.2 EFM VDSL applications
  • 5.5 ITU G.993.1
• 6. Related reports