Members of the ITU have accorded first-stage approval of G.fast, the new ITU broadband standard capable of achieving access speeds of up to 1 Gbit/s over existing telephone wires. Within 250-metre range of a distribution point, G.fast’s fibre-like speeds give service providers a tool to supplement and further monetise fibre to the home (FTTH) strategies with the customer self-installation benefits of ADSL2.
G.fast, within the fibre to the distribution point (FTTdp) architecture, combines the best aspects of fibre and ADSL2. Consumers will have an over-the-counter solution, self-installed without a technician’s assistance, but equipped to support bandwidth-intensive services such as Ultra-HD ‘4K’ or ‘8K’ streaming and IPTV, advanced cloud-based storage, and communication via HD video.
The physical-layer protocol aspects of G.fast defined by Recommendation ITU-T G.9701 ‘Fast Access to Subscriber Terminals – Physical layer specification’ have reached the point of stability required to initiate the standard’s approval procedure. Chip manufacturers will now scale-up G.fast chip design and testing efforts, feeding results of this work into ITU-T Study Group 15 in the interests of finalising G.fast as early as April 2014.
Dr Hamadoun I. Touré, Secretary-General, ITU, noted that from ADSL in 1999 to G.fast in 2014, ITU-standardised DSL solutions had multiplied access speeds by a factor of 125 over the past 15 years. “It is to the credit of ITU’s membership and the dedication of engineers working in our study groups that ITU standards continue to maximize returns on investment in legacy ICT infrastructure.”
ITU-T G.9701 is on track to achieving final approval in conjunction with ITU-T G.9700, which specifies methods to ensure that G.fast equipment will not interfere with broadcast services such as FM radio.
The G.fast project has attracted active participation from a large number of leading service providers, chip manufacturers, and system vendors. Companies involved in its development have already confirmed the standard’s gigabit-per-second capability through lab and field trials using prototype equipment based on mature drafts of the standard.
According to the ITU, service providers will benefit from ‘zero touch’ operations, administration and management; easing migrations to G.fast and increasing the speed of new-service rollouts. G.fast is designed to coexist with VDSL2, enabling service providers to play to the strengths of each standard in different environments; switching customers between G.fast and VDSL2 in line with dynamic business models. The standard will complement FTTH strategies, serving the many scenarios where G.fast is more cost-efficient than FTTH.
Tom Starr, Chairman of Working Party 1, ITU-T Study Group 15, the expert group overseeing ITU-T standardisation of access solutions, said that G.fast’s development had followed an intensive work plan, meeting ambitious time-to-market objectives. “The standard will enable service providers to deliver fibre-like performance more quickly and more affordably than with any other approach.”
Les Brown, Associate Rapporteur of the G.fast Experts Group added that G.fast provided the speed of fibre with the ease of installation of ADSL2. “The solution is as compelling to consumers as it is to service providers, coexisting with VDSL2 and complementing FTTH.”
The development of the G.fast standard has been coordinated with Broadband Forum’s system architecture project, Fibre to the Distribution Point (FTTdp). Broadband Forum has begun developing a testing suite for G.fast systems, which will include test plans for interoperability events, system performance and functional testing; alongside a framework whitepaper, and possibly also a certification programme. ITU-T and Broadband Forum have been working in close collaboration to ensure that G.fast solutions can be quickly placed into FTTdp deployments.