CHICAGO -- Big Telecom Event -- UK incumbent telco BT Group plc (NYSE: BT; London: BTA) and access network technology vendor Allied Telesis highlighted two options for the next phase of fixed broadband rollouts here at BTE on Tuesday.

BT's vision was outlined by Colin Bannon, CTO of BT's Wholesale division, who gave a keynote presentation to hundreds of attendees about the potential of G.fast and how that new technology is exceeding BT's expectations and promising an extended life for its copper access lines. (See A Guide to G.fast.)

Bannon noted how, following more than two years of lab and live network trials, G.fast had exceeded initial expectations and had become an "economic game-changer," enabling BT to plan an ultrafast broadband services future that does not have to involve taking fiber all the way to customers' homes and businesses, something that would be a major challenge (economically and operationally) for the operator.

Figure 1: Faster, Faster!! BT Wholesale CTO Colin Bannon states the case for using G.fast to boost the speed of fixed broadband services over copper lines.

That's because BT had already shown in its labs that G.fast, initially considered to be suitable for deployment at distribution points within 100 meters, was potentially viable at longer distances.

Bannon said BT had identified a number of particular ways in which G.fast could be improved, including:

"We are aggressively pursuing additional standards," noted the BT man.

What this all means for BT is that it can now plan to offer broadband speeds of hundreds of megabits per second, compared with the 80 Mbit/s it can currently offer over copper tails, by adding G.fast technology to its 88,000 street cabinets, which already have the relevant power and electronics from the operator's FTTC vectoring rollout, as well as at select distribution points where needed. (See BTE 2015: G.fast Is a Game-Changer, Says BT Exec.)

BT also realizes offering faster broadband speeds, coupled with the introduction of services such as ultra high-definition video -- BT just announced it will launch the first 4K channel in Europe in August, BT Sport Ultra HD, and will also introduce a new BT TV Ultra HD set top box -- will put pressure on its transmission network.

"The bottleneck at the edge will disappear, but what about the core?" Bannon asked rhetorically. BT is happy with what it can do with its current transport infrastructure too. "We have tested up to 3 Tbit/s on our existing fiber plant... This gives us the potential to leverage our existing investments." (See BT, Huawei Boast 3Tbit/s Transmission Trial.)

Check out all the news and views from the 2015 Big Telecom Event at Light Reading's dedicated BTE show news channel.

WDM-PON is back in town
While BT is focused on sweating its copper assets even more, Allied Telesis Inc. is all about helping the Gigabit brigade take that full 1 Gbit/s service to their customers.

The vendor, best known for its active Ethernet platform for FTTH deployments, was on the BTE show floor demonstrating its new EtherWAVE system, which is designed as a WDM-PON upgrade for operators using GPON to deliver high-speed broadband services.

The big trend in fixed broadband currently is to promote Gigabit services -- see our coverage from the recent Gigabit Cities Live! Event -- but if GPON, which is a shared medium, is used then customers can't be guaranteed to get a full 1 Gbit/s at any time.

If network operators want to offer and deliver a guaranteed Gigabit broadband service over a GPON network architecture (usually with a 1:32 split ratio), they can upgrade to WDM-PON, which delivers a dedicated wavelength to each customer. "This is targeted at high-density MDUs [multi-dwelling units] that want to offer Gigabit broadband. And if service providers want to offer a guaranteed 1 Gbit/s over a PON infrastructure, this is the only way to do it," said Philip Yim, senior vice president of Global Program Management at Allied Telesis.

WDM-PON was a hot topic about five years ago but the costs were deemed prohibitive. But this year the technology has been cropping up again in conversations, with some mobile operators looking at the technology for fronthaul and backhaul as wireless networks move towards high-density 5G topologies.

But is it still cost-prohibitive for retail and/or business fixed broadband deployments? Yim says it doesn't cost much more than active Ethernet to deploy. "The cost to an operator should be not much more than $400 per household and that includes the CPE," stated Yim.

Allied Telesis was showing a 4K video stream as an example of an application that runs superbly over a dedicated Gigabit wavelength. But even if a home had five 4K devices, would any home need a guaranteed 1 Gbit/s connection? Well, there are more applications coming down the line that might just create demand for such guarantees. (See Gigabit Cities: I've Seen the Future.)

— Ray Le Maistre, , Editor-in-Chief, Light Reading