Gfast map

gfast map copy


In 2016, looked very promising.
Thousands worked at developing and deploying.
It wasn't enough. 
Most carriers are investing
in fiber or 5G instead.


Dark Blue: 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 Blue: Smaller carriers in Germany, Norway, Finland, Japan

Light Blue: Incumbent likely:  France, Germany, Italy

G.Fast performance per AlcatelG.Fast speeds. Larger version below  Update 7/13 I've since learned the BT target speed is 250 megabits because they don't intend to deploy enough fiber for higher speeds. From January: If a 4,000 home summer trial goes well, 3/4ths of the country will covered over a decade.  Gavin Patterson's plan goes far beyond anything even rumored in any other country. Trevor Linney and BT were among the first testing At that time they were part of the gigabit hype. Patterson's announcement this time is far more realistic, speaking of "hundreds of megabits" for now. In fact, BT's talk of 400 metres suggests they are looking at one of the Midi-DSL versions rather than today's

  • "speeds of a few hundred megabits per second to millions of homes and businesses by 2020. Speeds will then increase to around 500 Mbps as further industry standards are secured and new kit is developed." 

A few hundred megabits is closer to the current state of the art, especially if you measure download speeds. It's realistic to expect improvements to over time.  The current designs only use 106 MHz but the standard allows up to 212 MHz. Alcatel and other engineers are confident that non-linear precoding will be a major improvement but non-linear wasn't ready for the current version of the standard. I believe the noise-cancellation (vectoring) in the earlier chips will have room for improvement.

Huawei supplied the gear for the earlier BT testing, Their HiSilicon subsidiary is working on a chip but I don't know if it's ready. If HiSilicon isn't available, both Sckipio and Broadcom are promising chips for trials in the summer. 


G.Fast performance per Alcatel
Particularly interesting is BT's comment

  • During the trials we will be testing new ‘micro cabinets’ that are about the size of a biscuit tin and can be attached to telegraph poles, walls of buildings or placed in footway boxes. Max range 400m, possibly further. 

Attributed to a BT spokesman by Techcrunch. At 400 metres, today's version would top out below 50 megabits. Midi-DSL sacrifices speeds over 500 megabits in return for better performance, perhaps 200 megabits, at distances of 300-400 metres. Adtran, Alcatel and Huawei have proposed versions of Midi-DSL but none are close to market. It's much cheaper to locate cabinets at 300-400 meters. BT hopes many of the existing cabinets can be repurposed. 

200 megabits sounds good to me.

Here's the announcement 


DC15-035                                                         30 January 2015 

BT CEO sets out ultrafast broadband vision

“” to deliver speeds of up to 500Mbps to most homes 
Premium fibre services of up to 1Gbps to be developed 

BT CEO Gavin Patterson today set out the company’s ambition to transform the UK broadband landscape from superfast to ultrafast. 

He revealed that BT plans to deliver much faster broadband for homes and small businesses via a widespread deployment of “”. This is an innovative technology that BT will test in two pilot locations starting this Summer. will help BT deliver ultrafast speeds of up to 500Mbps to most of the UK within a decade. Deployment will start in 2016/17, subject to the pilots being successful. 

Early tests show is capable of delivering a range of speeds depending on how close the technology is to a customer’s premises. BT expects to offer initial speeds of a few hundred megabits per second to millions of homes and businesses by 2020. Speeds will then increase to around 500Mbps as further industry standards are secured and new kit is developed. 

“BT is a world leader when it comes to fibre innovation and we are excited about the next stage in our story,” Patterson said today. “We believe is the key to unlocking ultrafast speeds and we are prepared to upgrade large parts of our network should the pilots prove successful. That upgrade will depend however on there continuing to be a stable regulatory environment that supports investment. 

“The UK is ahead of its major European neighbours when it comes to broadband and we need to stay ahead as customer demands evolve. will allow us to do that by building on the investment we have made in fibre to date. It will transform the UK broadband landscape from superfast to ultrafast in the quickest possible timeframe.” 

The two pilots will start this Summer in Huntingdon, Cambridgeshire and Gosforth, Newcastle. Around 4,000 homes and businesses will be able to participate in the pilots which will explore what speeds can be delivered using at scale. 

The pilots will build on recent tests at BT’s world renowned innovation centre at Adastral Park, Suffolk. These have shown that has the potential to deliver significant speed increases from existing and new fibre street cabinets as well as from other points closer to the customer. This is an important development as it means the technology can be deployed in a more efficient and rapid manner than previously thought. 

BT is likely to deploy from various points in the network, with the pilots allowing it to assess various roll out options. It is also planning to develop a premium fibre broadband service for those residential and business customers who want even faster broadband, of up to 1Gbps. 

BT is currently expanding the reach of its fibre network by working with the public sector across the UK. Its network already passes almost 22 million premises – around three quarters of the UK – and is open to all communications providers on an equal basis. Its expansion will help the UK to boast 95 per cent coverage for fibre broadband within the next few years. 

The UK is already ahead of Germany, France, Italy and Spain when it comes to superfast broadband coverage and take-up 1 , and BT’s plans will ensure the UK stays ahead and joins the ranks of world leaders such as Japan and South Korea.