The last year has seen a ramp up in the number of research claims surrounding DSL, as vendors market to telcos that are losing slow DSL customers to cable
and can't afford to deploy fiber to the home
, but have convinced themselves they can milk copper infrastructure for another decade. In April, Alcatel Lucent announced they'd achieved speeds of 800 Mbps
using a pair of traditional DSL lines and something called "phantom mode," which involves creating a third "phantom" channel to supplement the two physical wires common with bonded DSL -- then vectoring to reduce noise.Last fall
, Hauwei announced they were experimenting with similar "SuperMIMO" technology, capable of offering 700 Mbps over 1,300 feet. The only real difference from Alcatel's approach is that Hauwei's technology uses four pair instead of two. Nokia-Siemens also jumped into the party, announcing last October
that their implementation of "Phantom DSL" is capable of 825 Mbps over 1,300 feet. With the ink barely dry on these promises, Stanford professor John Cioffi
, whose research contributed to many of these four-pair DSL advances, is cooking up a new DSL variation called "Triple V" that someday could be capable of delivering speeds up to 2 Gbps over short distances
They doubted when John Cioffi outlined in 2004 how four wires could deliver a gigabit one day. In 2010, Alcatel and others demonstrated 700+ megabits. Now, his ASSIA colleague Ken Kerpez shows a path to two gigabits. It requires 300 MHz, four wires and goes only a short distance. Presumably it's many years away. But Triple-V could deliver 2 gig to Jennie's 9th apartment from the basement. France Telecom is looking for an alternative for buildings they hope not to run fiber to each apartment. My mother in her old neighborhood and 20 attached homes could receive a gig and a half.
As noted, it's once again distance constrained making it more useful for multi-tenant building runs to each apartment, and not necessarily helping rural telcos provide next-gen connectivity. It's not even clear that many of the multi-hundred megabit-per-second copper-based solutions will reach market anytime soon, and this even faster DSL variant isn't even in the lab yet. DSL hardware vendors hope that some of these advancements will provide a profitable way to help rural telcos maintain DSL relevance, but most of these advancements will be focused on multi-tenant dwellings.