100 meter G.fast doesn't go far enough or serve larger buildings. Perhaps the telcos want something with more reach than G.fast (100 meters, ~500 megabit,) and more speed than DSL Vectoring (~100 megabit, 800 meters.) Chipmaker Lantiq was the first to announce 200+ meg products,
Lantiq tweaked existing high end VDSL2 chip - and the pr. VDSL2 30 MHz profile 30a is generally described as 100 meg down, 100 meg up. Combine the two for your press release and you're at "200 megabits." Tweak a few parameters and you can claim "300 Mbps VDSL Right Now." Lantiq did that. Besides one-upmanship, it provides a way to telcos to advertise "300 megabits" to counter cable promises of 200, 400 and even a gigabit. Aethra, working with Lantiq, has delivered units to Orange Poland. I believe Broadcom is doing similar. < Kabel Deutschland CTO Lorenz Glatz two years ago explained his company strategy. "Whatever speed Deutsche Telekom, we'll offer twice the speed at the same price." Euro-DOCSIS 3 easily goes to 400 shared and delivers > 200 meg 95+% of the time. In 12-24 months, DOCSIS 3.1 will take that to a gigabit. Deutsche Telekom, building a 50-100 megabit VDSL network, fears they'll be left behind. Vendors are listening and hence promising a new class, Midi-DSL, mid-range bet G.fast and G.vector, promising higher speeds. Alcatel, Huawei and Adtran have all announced products. For now, Midi-DSL is slideware.
No one has shown equipment publicly although Huawei claims tests in customer labs.
Midi-DSL isn't limited to 16 connections. 100 or more homes can be served. It may be years before G.fast can do more than 16 homes. There are problems with space, heat and design. Midi-DSL is planned for cabinets which have more room for heat sinks and boards.
Much of the improved speed is hype: DSL has always been discussed based on download speed (6 meg for ADSL1, 24 meg for ADSL2 ...) The Midi-DSL folks add the upstream speed to get more impressive numbers. Since some of the upstream capacity in G.fast can be switched to downstream giving the combined figure isn't totally deceptive. But it's darn confusing. I'll keep reporting downstream & upstream numbers for now.
Higher speeds require using more spectrum, becoming more efficient, or reducing interference. G,vector is standardized to 30 MHz but most deployments only use the lower 17. I have separate articles on Lantiq, Adtran, aethra, Alcatel and Huawei with more details.