G.Fast – A Technology To Prevent A Fiber Monopoly?

Fiber connectivity is moving closer and closer to people's homes. Some, like me in Paris, are fortunate enough to get a fiber line right into the apartment and enjoy speeds of well beyond 250 Mbit/s in downlink and 50 Mbit/s in uplink. That's something the good old telephone line can't do today by a wide margin. Even cable modems that use the TV cable can't match those speeds at the moment, particularly in the uplink direction which is a must for hosting services at home. In a previous post I have thus speculated that the network operator that is first willing to deploy a real fiber to people's homes is likely to become the next monopoly operator in an area. That's not good news for consumers in the long run. Any hope the good old copper line might catch up?

At the moment, VDSL2 Vectoring is the best there is for phone lines. With the technology, speeds of 100 Mbit/s in the downlink and 40 Mbit/s in the uplink are possible. Easy to beat for fiber. G.Fast has promise to be the next step and offers theoretical top speeds of 500 Mbit/s to 1 Gbit/s. Have a look at this Wikipedia entry for further details. The problem is, however, that such high speeds are only possible for cable lengths shorter than 100m. A lot of outdoor DSLAM locations used for VDSL2 and VDSL2 Vectoring today are not that close to subscriber's homes which means earthworks are also necessary to replace the copper cable from the outdoor cabinets that are used by VDSL today with a fiber strand into buildings. But at least it removes the requirement to deploy fiber inside buildings.

When copper cables get longer, speeds drop quickly. At copper cable lengths of 200 meters, top speeds already drop down to 200 Mbit/s. 250 meters and you are down to 150 Mbit/s. Again, fiber already tops those numbers today easily.

So as fast as G.fast sounds, to get the promised speeds, that fiber needs to go to the building and that requires unloved earth works. And that might bring us right back to the fiber monopoly. So I remain skeptical.