spacer 2Telebyte Gfast Testing Guide 320

gfast map nov

Dark Green: Firm commitments from incumbent: BT (10M), Belgacom, Australian NBN, Swisscom,  Austria, Bezeq Israel, Chunghwa Taiwan, Telus Canada, Telekom South Africa, SK Korea, (U.S.) AT&T, Century, Frontier, Windstream, Belgium, Omantel

Mid Pink: Smaller carriers in Germany, Norway, Finland, Japan

Light Green: Incumbent likely:  France, Germany, Italy

Stonehenge Wikipedia 320Pioneers get arrows in their back and schedules do slip. technology is rapidly improving, with Amendment 2 and Amendment 3 chips delayed until the second half of 2017. BT had originally promised to start their 10M home rollout late this year or early next. In particular, BT wants 48 or 96 ports while today's tech only supports 16-24 ports. They also want the higher power and longer reach of the Amendment 2/3 chips. That's particularly important. Their last goal (350 megabits down at 350 meters) is beyond the current state of the art. It may be impossible, but that's unclear.

The original plan, promised by CEO Gavin Patterson, would go to local distribution points for speeds generally 500+ megabits. The 500 meg promise was part of Gavin's attempt to persuade OFCOM not to break up BT because they would deliver great Internet to "nearly all of Britain by 2025." Then the bean counters jumped in and said they wouldn't pay for the high speed. Using the existing cabinets brings the cost so low it fits into the existing capex budget but also reduces the speed.

Some very good BT engineers redesigned the project for 300 meters rather than 100 meters.

They brought the changes (more power, more bits/signal) to the ITU standards committee. Broadcom and Sckipio, the main chipmakers, went to work. They tell me it's been challenging, especially with the heat and power budget. In addition, vectoring 48-96 ports requires massive processing power, adding heat. Adtran's solution, which works well for VDSL, is to move the vectoring engine into an external module, the SLV. That's inspired a debate about whether vectoring need to be onboard or can be external. The Adtran SLV isn't ready for in any case.  

I'm going to call the downstream speed 200+ megabits, rather than the "up to 330" in the BT pr. It's time to use actual speeds that most users can achieve. Anything else is false advertising. BT's regulator, OFCOM, has promised to clamp down on false claims. So have the FCC in the U.S. and BnetzA in Germany. So far, they've all been afraid to take on the telcos. Deutsche Telekom has been particularly egregious, building a vectored VDSL network designed for 30-50 megabits to many as "up to 100." Frontier isn't even vectoring, but also claiming "up to 100." 

They are expanding the trials to 140,000 homes. Light Reading expects that by March. If BT concentrated on apartment buildings, the 500 meg is easily achieved already. But Brits love their gardens, and only about 11% live in MDUs.

BT's speeds can be increased by an important 100 megabits by eliminating the VDSL carveout.


The Site for gfast 230 News

I’m still working through remarkable presentations from the Broadband Forum events. Michael Weissman, Bernd Hesse and team did a remarkable job choosing the speakers.

Deutsche Telecom: 35b Supervectoring Delayed to 2019
Broadcom is now over 3 years late. DT briefed German reporters after their financial call and revealed 35b was now delayed until 2019. 35b should deliver 200+ meg downloads 500-600 meters, a crucial tool for DT, which is losing share to cable. Cable now covers about 70% of Germany and is expanding. DT now only offers 50-100 megabit DSL while cable is often 400 megabits, going to a gigabit. 

The problem is software; the hardware is shipping and supposedly will work. DT says 35b is not ready to turn on. Broadcom in 2015 said 35b was in "production" in the press release below. Alcatel in early 2016 said to expect complete systems very soon. "35g is very similar to 17a so there should be little delay."

Broadcom's problems are leading major telcos and vendors to have a plan B, using Sckipio DT itself is planning extensive deployments in 2019, mostly in apartment buildings.

Gigabit 100 Meters - Unless the Wires are Lousy
Speeds are fine, "Unless there's a line problem." I've been reporting for three years that ~10% of lines have problems. In the chart by Rami Verbin of Sckipio, he finds goes ~130 meters on good lines. Poor lines have about half the reach. 

His chart roughly matches the reports from Swisscom, Belgacom, and England for both & vectored DSL. The 10% with problems can cause the majority of the line-related complaints to support. The angry customers drive up cost.

Rami's solution to reach the gigabit is bonding, supported on the Sckipio chips. Verbin made some additional points:

  • 4 gigabits is possible by bonding two decent 2 gigabit lines.
  • Even in a service from remote cabinets, ~25% are close enough to get a full gigabit."
  • cDTA and iDTA are practical ways to deliver much higher upstream by switching some bandwidth from downstream to upstream only when needed.
  • 35B will probably be similar but Deutsche Telecom doesn't expect to deploy until 2019.

AT&T Wants Coax 2-5 Gigabit Very Soon.
AT&T faces intense competition from cable, talking about 10 gigabits in both directions. (Cable will only be 1 gig down, ~100 meg up, until ~2021.) AT&T wants something to brag about as well.

AT&T gained millions of lines of coax as part of the DirecTV deal. Alcatel and Huawei are leading the development of G.mgfast. That uses 424 MHz, full duplex, to achieve ~2.5 gigabits in both directions. The reach on telco twisted pair is only about 30 meters. On coax, those speeds can probably extend far enough to service most apartment buildings. Using 848 MHz, speeds can reach 5 gigabits. The ITU standards group has been aiming for 2019-2020 for G.mgfast, too slow for AT&T's marketers. David Titus wants a high-speed standard for coax "early in 2018." He believes that is "doable."

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