The Broadband Forum has said that the number of certified Gfast products has increased from seven to 24 in the three months since certification began. The BBF said that ADRAN, EXFO and Viavi have had passed the certification process, which is being conducted by the University of New Hampshire’s InterOperability Laboratory (UNH-IOL).
The BBF heralds the news as a sign that the Gfast mass market has arrived. Whether that is true or not cannot yet be said with certainty. However, it is clear that Gfast, the name has been streamlined from the ungainly G.fast, will play a valuable role as telcos seek to keep speeds reasonably close to cable operators’ coaxial cable and the increasing capability of fiber and wireless options. The allure of Gfast is that it can do this without requiring legacy copper infrastructure to be replaced.
“Gfast is progressing nicely,” wrote Gfast chip vendor Sckipio Co-Founder Michael Weissman in response to questions emailed by IT Business Edge. “We now have over 100 operators working towards deployment of Gfast. The largest service providers in the world such as BT, DT, AT&T, CenturyLink and others are rolling out Gfast or are publicly discussing their plans. We have interoperability across chips and equipment vendors - about 5 years ahead of VDSL at this stage. So, good progress.” Sckipio introduced the 23000 family of high-speed Gfast chipsets on September 18.
Before DSL, Gfast and other copper-enhancing technologies, telcos faced a Hobson’s choice: Use an inherently slower and at that point seemingly antiquated approach – twisted pair copper -- or go through the extraordinary cost and dislocation of moving to fiber. Neither choice was ideal, so the industry developed a third and a fourth: Radically speed both wireless and copper. The initial approach was digital subscriber line (DSL). Weissman pointed out that Gfast is a discrete new technology, not a refinement of DSL.
Current Gfast systems are based on the initial 106a profile, using 106MHz of spectrum to carry data over the twisted pairs at speeds of several hundred Mbps. Lincoln Lavoie, senior engineer for UNH-IOL, says the forthcoming Gfast profiles use 212MHz of spectrum and will reach data rates exceeding 1Gbps, by taking advantage of increases in processing power on board the chipsets. These next-generation chipsets will also be able to leverage all the ground work laid down by the Gfast Certification Program."
Across the Digital Divide
Gfast is fast enough to bring broadband to multi-dwelling units and underserved areas where copper already is but where it is not viable to bring fiber. This will be especially valuable when the faster profile rolls out.
“The benefits this will have are on the provisioning of multi-dwelling and multi-tenant locations without disruption and serving wider communities alongside the current Gfast. This technology will begin emerging later in 2018,” wrote Broadband Forum CEO Robin Mersh.
The ability of Gfast to team with fiber to create hybrid networks will greatly increase the flexibility of network operators. The technology is a valuable tool as carriers deal with variables such as distance from the fiber termination to the premises, the number of premises served from that termination point, and the amount of bandwidth required per premise.
Gfast, in short, becomes a partner and enabler of fiber, not a competitor.
“Gfast also forms a key part in service providers' strategies on the way to ubiquitous fiber deployment, providing a cost-effective alternative to fiber-all-the-way by making use of existing infrastructure to eliminate for deployment and disruptive installations,” Mersh wrote.
Gfast is rolling out quickly. For instance, in late August, AT&T made the technology available to multiple dwelling units (MDUs) in Boston, Denver, Minneapolis, New York City, Philadelphia, Phoenix, Seattle and Tampa. The technology is actually on sale to end users in 14 other metro areas.
The current version of Gfast is impressive. The coming version, in which speed is doubled, is not far off: “Productized solutions will be available from FTTdp/G.fast suppliers like ADTRAN closer to year end with field deployments and their subsequent symmetric Gigabit services rolling out in the second half of 2018,” said Kurt Raaflaub, the head of Global Product Marketing for ADTRAN.
The bottom line is that Gfast appears to have arrived. In some instances, it will greatly increase the capacity of end-to-end twisted pair copper circuits and in others, it will provide more flexibility of various variations of fiber-dominated approaches by increasing capacity of the non-fiber portion of the connection. “It comes down to picking the item from the toolbox to reach the most subscribers in the most cost-effective way,” Lavoie said.