Technology - Infrastructure - Last Mile 8 - FTTC, VDSL2 Technical Standards

Synopsis

We discuss the frequency plans and technical details of the ITU’s promising new G993.2 VDSL2 standard. We discuss ADSL compatibility, Dynamic Spectrum Management and Packet Transfer Mode. Finally we consider the competition challenges of VDSL2 deployment, and the DSL forum’s proposal to use Ethernet rather than ATM transport for future ADSL systems.

Table of Contents

• 1. Synopsis
• 2. Frequency plans
  • 2.1 Lower limit
  • 2.2 Upper limit
  • 2.3 G.993.1 band-plans
  • 2.4 Attenuation and crosstalk
• 3. ITU G.993.2 VDSL2
  • 3.1 Trellis coding
  • 3.2 VDSL2 profiles
  • 3.3 ADSL compatibility
  • 3.4 Transmit power backoff
  • 3.5 Bonding
  • 3.6 Dynamic Spectrum Management
  • 3.7 Vectoring and MIMO - Multiple In Multiple Out
  • 3.8 Packet transfer mode
  • 3.9 Short packets and pre-emption
• 4. Ethernet rather than ATM for DSL
  • 4.1 Multicast IP
  • 4.2 Architectural diversity
  • 4.3 Broadband Loop Carriers (BLC)
• 5. Competition implications
  • 5.1 Centralised spectrum management
  • 5.2 Synchronisation precludes multiple DSLAMs
  • 5.3 Power and installation space
• 6. ADSL2+/VDSL Futures
• 7. Related reports

• Table 1 – ITU VDSL band-plans
• Table 2 – G.993.2 VDSL2 profiles

• Exhibit 1 – Access node deployment scenarios