ITU-T doubles G.fast standard speed to 2 Gbps, addresses VDSL2, coax coexistence

copper wiring legacy networks

The ITU-T Study Group 15 has given the green light for the 2 Gbps iteration of the G.fast standard, doubling the access speeds achievable with the first generation of the standard that promised up to 1 Gbps speeds over very short copper wire loops.

RELATED: G.fast to reach nearly 30M homes, businesses by 2021, says research group

As the third amendment of ITU-T G.9701 G.fast standard, ITU-T doubles the aggregate net data rate capacity to 2 Gbps using spectrum up to 212 MHz. The update to the standard maintains spectral compatibility with VDSL2. By enabling the coexistence of G.fast and VDSL2, service providers gain the agility required to switch customers between G.fast and VDSL2 as business operations demand.

Besides offering higher speeds, ITU-T is also enabling G.fast to be applied to coax cable, enabling the coexistence of G.fast and satellite signals in coaxial cable infrastructure.

The amendment also specifies a mechanism for dynamic time assessment, functionality that enables upstream or downstream transmission to exploit G.fast’s full aggregate net data rate. This functionality will improve users’ broadband experience by increasing upload or download speeds in line with the demands of the applications in use.

Having this second standard option in place should be music to the ears of service providers like CenturyLink and BT, which are currently conducting G.fast trials.

A recent Ovum report, commissioned by Australia’s NBN and BT, forecast that G.fast will serve nearly 30 million subscriber homes and businesses worldwide by 2021. The research firm said that the first commercial G.fast services won’t launch in a meaningful way until next year.

Out of the top United States-based telcos, it’s clear that CenturyLink has taken an aggressive stance with G.fast.

In September CenturyLink announced that it installed G.fast technology in 44 multi-dwelling units (MDUs) in Platteville, Wisconsin, or nearly 800 apartments. For this initial deployment, CenturyLink is leveraging its own mix of existing copper and coax cable – assets it gained as a result of a cable overbuild by its predecessor Qwest. 

CenturyLink isn’t the only U.S.-based telco that’s moving ahead with their G.fast plans. Fellow telco Windstream previously began a field trial targeting MDUs with G.fast in Lincoln, Nebraska. Using Calix's G.fast nodes and GigaFamily solutions, Windstream said it will increase broadband speeds to residential customers in what it says is a "select" number of buildings. However, it has not revealed what parts of the city will be the first to get the service.

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