A DSL standard that combines fiber and copper to reach gigabit speeds was approved today by the International Telecommunication Union (ITU).

The next step for the new G.fast standard is certifying chipsets and equipment. To that end, the Broadband Forum industry consortium is holding a plugfest in January to test interoperability of products, with a beta trial of a certification program to follow in mid-2015. "Certified G.fast implementations are expected to appear on the market before the end of 2015," the ITU said.

G.fast relies on fiber to reach neighborhoods, with data sent over copper the rest of the way. This is similar to AT&T's 45Mbps fiber-to-the-node deployments, but the new DSL standard allows for much greater speed to consumers' homes.

The new standard is "designed to deliver access speeds of up to 1Gbps over existing telephone wires," the ITU said. "Within 400 meters of a distribution point, G.fast provides fiber-like speeds matched with the customer self-installation of DSL, resulting in cost-savings for service providers and improved customer experience."

G.fast operates on higher frequencies than today's DSL, requiring shorter transmission distances, so the gigabit speeds won't be available at the outer range of that 400 meters. Within 250 meters, G.fast speeds top out at 150Mbps, according to the ITU. In the US, successful G.fast deployments would probably require a fiber expansion, though without the expensive step of bringing fiber into each home. AT&T's current fiber-to-the-node deployments place fiber about 600 to 900 meters from homes.

But early demonstrations suggest that G.fast has great promise. Alcatel-Lucent's Bell Labs developed its own extension of G.fast called XG.FAST and said it could hit 10Gbps over 30 meters of copper and 1Gbps over 70 meters of copper. BT is testing service that hits nearly 800Mbps, and Broadcom in October previewed chips for back-end systems and consumer gateways that can push up to a gigabit per second.