The International Telecommunication Union (ITU) says that the physical-layer protocol aspects of G.fast – which is expected to be the technology that brings the ability to support 500 Mbps or more to copper-based broadband access networks – have reached the stability required to initiate the standard’s approval procedure.
Recommendation ITU-T G.9701 “Fast Access to Subscriber Terminals - Physical layer specification” has reached first-stage approval, the ITU announced. This will enable chip developers to work on G.fast chip design and testing efforts more aggressively, the organization says. Communicating the results of these efforts to ITU-T Study Group 15 should hasten finalizing G.9701 and lead to finalizing G.fast as early as April 2014, the ITU adds.
That timeline would see G.9701 receive final approval in conjunction with ITU-T G.9700, which will specify methods to ensure that G.fast equipment will not interfere with broadcast services such as FM radio.
The ITU standardization work also parallels the Broadband Forum’s Fibre to the Distribution Point (FTTdp) system architecture project, which will define an architecture that would bring fiber close enough to subscriber to let existing copper lines do the rest via G.fast. The 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. The Broadband Forum also is working on a framework whitepaper, and possibly also a certification program, the ITU says.
The final specification is expected to address three speed/reach scenarios:
- 500 Mbps at 100 m (300 ft)
- 200 Mbps at 200 m
- 150 Mbps at 250 m.
Meanwhile, systems houses have already experimented with increasing G.fast data rates to 1 Gbps. For example, Alcatel-Lucent says it can support 1-Gbps data rates over 70 m (see “Notes from Alcatel-Lucent’s Technology Symposium”).
For more information on G.fast and how it might affect the prospects for fiber to the home (FTTH) deployments, see “Will FTTN advances delay FTTH?” from the July/August 2013 issue of Lightwave.
For more information on FTTx equipment and suppliers, visit the Lightwave Buyer’s Guide.