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Unbundling the future of broadband

Will a standard being developed by industry ensure that there's still competition for our business on next-generation broadband networks?

The recent UK Comprehensive Spending Review demonstrated the importance the government attaches to fast Internet access for economic growth, especially in rural areas. Even as Chancellor of the Exchequer George Osborne was cutting department budgets left and right, he still found £530m to bring next-generation access (NGA) to parts of North Yorkshire, Cumbria, Herefordshire and the Highlands and Islands.

These areas need the subsidy because it is otherwise uneconomic for operators to bring them high-speed Internet access. In urban areas, it is going to be easier: you may already have seen the kerbside cabinets that Openreach (the access division of BT) is installing to enable its Infinity service, or you may have been offered a 50Mbit/s connection by Virgin. But the issue of enabling service competition still has to be addressed: no one wants to see the introduction of NGA leading to new monopolies.

The solution relies on a combination of technical, business and regulatory factors. The problem is that enabling NGA competition is not as straightforward as it was for current broadband services.

Technology issues

Many UK broadband subscribers get their service over phone lines supplied by BT, TalkTalk or Sky. The line runs to a street cabinet, where it is aggregated with lines from other homes onto a cable connected to the exchange. At the exchange, an ADSL modem provides the signal that your home modem interprets as a broadband connection. UK telecoms regulator Ofcom ensured that BT did not monopolise home broadband by requiring it to 'unbundle' its lines by making room in its exchanges for third parties to install their own ADSL modems. Ofcom also required BT to charge its retail arm and its competitors the same for unbundled access. The result is today's competitive broadband market.

For Ofcom, the ideal competitive landscape for NGA would see multiple providers bringing independent connections to homes. This is why Ofcom has ruled that BT must offer third parties access to its ducts and poles, so they can string their own fibre to premises.

Gavin Young, head of strategy and planning for architecture, design and economics at Cable&Wireless Worldwide, says the purest form of competition is to have competing infrastructure 'but it is not economic for five or six operators to dig up the same road'.

Given that few homes are likely to get multiple fast connections, Ofcom wants to ensure that competition can still thrive even when one company owns the last-mile connection to homes.

The problem with NGA is that it's more difficult to find a physical point at which a third-party provider can get 'passive access' to NGA infrastructure, where they can install their own equipment and so minimise their dependence on the infrastructure provider.

For example, Openreach is rolling out next-generation access in two ways: fibre to the cabinet (FTTC) and fibre to the premises (FTTP).

In FTTC, Openreach takes a high-bandwidth fibre connection to a street cabinet, and then uses VDSL modems to carry high-bandwidth traffic over the short distance to the home. Third parties who don't want to buy wholesale access to this network from Openreach would have to build their own street cabinets alongside those of Openreach, install VDSL modems, connect to the phone lines in the Openreach cabinet - and arrange backhaul.

In the FTTP approach, individual fibres are routed to each home, and then grouped so that one set of optical equipment can service, say, 32 homes at once. This passive optical networking (PON) approach saves costs, but makes it more difficult to unbundle individual fibre connections.

Passive vs active

Passive access schemes have other benefits, according to Ofcom, apart from minimising reliance on the infrastructure provider. They give their users end-to-end control of their offering and the quality of service, as well as control of when and where they introduce it and how its features evolve. But there are problems.

Installing your own street cabinet and rack of VDSL modems is costly, especially if you can't be sure how many subscribers you'll get for your service. In the case of PONs, according to Oliver Thorp, principal systems engineer at Fujitsu Telecommunications Europe: 'The thing is that you have to operate all of the fibres.'

Jason Roissetter, chief technology officer of Cardiff-based Independent Fibre Networks Ltd, which specialises in providing FTTP networks on new-build estates, adds: 'Passive access is much harder to scope than one thinks. How big should I make my equipment room, the power supply, and how many service providers do I think I'll be serving?"

The problems with passive access prompted Ofcom to call for the development of a standard approach to active line access (ALA), in which infrastructure providers offer third parties a wholesale connection to end users on their NGA networks.

This Ethernet-based standard is being finalised by NICC, an industry body spun out from Ofcom to work on technical standards and interoperability.

ALA is meant to be neutral to applications, higher-level protocols and the underlying physical implementation, so that third parties can offer the same service regardless of how it is delivered. It should also make it easier for third parties to access new customers. Roissetter adds: 'For consumers, there's a lead time for getting new services with a passive approach, compared with the ability to choose between services at the click of a button with active access.'

According to Thorp, Ofcom passed the standardisation work to NICC because it didn't want to set detailed technical standards itself. NICC has in turn drawn on standards set by the ITU, the Broadband Forum (BBF) and the Metro Ethernet Forum (MEF). 'The intent is not to reinvent anything that has been invented before,' he says.

According to Young at Cable&Wireless Worldwide: 'ALA consolidates requirements and means we'll have a consistent service description.'

Ofcom also wants the standard to be highly scalable, and to support features such as security, quality of service management, multicast, and flexibility about the choice of communication providers and interconnect points.

According to David Thorne, chief broadband and access strategist at BT Innovate and Design, the standards work is progressing well. The service specification and user network interface definitions are in the last phase of review, the architecture document is out for a two-week review and the network to network interface spec 'is so simple no one has got around to writing it down yet'. Thorne says the NICC team aims to have all four documents published by Christmas, although it will then take time for the standard to propagate into the product development cycles that will see it embedded in new equipment.


The as-yet unresolved issue is the extent to which Openreach's Generic Ethernet Access, the wholesale NGA product that BT is retailing as Infinity and that Talk Talk has said it will use for its high-speed broadband offering, will conform to the ALA standard.

According to Thorne, although the deployment of GEA is underway before the ALA standard has been settled, the service has been defined with the same stakeholders who are contributing to the ALA work: 'GEA is already fairly close to where ALA is going and the gap is expected to narrow as new products are developed.'

Once ALA is formalised, the idea is to try and define GEA as a subset (or profile) of the standard: 'There's clearly an intention to be compliant.'

Mike Hoban, head of NGA regulation for Openreach, points out that Openreach's customers within BT might be buying NGA access from third parties using ALA and so will expect the offering from Openreach and others to meet the same standards.

George Williamson, director of strategic network design at Openreach, adds that it has been trialling its GEA offering with customers for three and a half years 'and there's quite a high level of consensus on core features and attributes'.

So what benefits does ALA bring? According to Young, without ALA there would be a variety of physical approaches and the way that each ISP would interconnect would be different: 'If 40 companies are building NGA and they all [provide wholesale access] in a different manner the overhead is huge. It means 40 times the testing, trials and certification.'

According to Roissetter, the emergence of ALA will enable companies to compete on the services they offer, perhaps producing products that trade maximum bandwidth for contention ratios and quality of service, or that can guarantee a certain quality of service for HD videoconferencing applications .

'Some of the restrictions in first-generation networks have been removed so service providers will have the ability to innovate,' he says.

For Young, the development of ALA may be useful to other parts of Cable&Wireless's business: 'We can also use ALA for business customers, for example by offering quality of service enhancements, combined with our voice services, and hosted applications in our cloud. That's the beauty of these standards.'

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