Optical fibre is ultimately the preferred technology for next generation UK broadband and works extremely well for the provision of services to large businesses in central London. However, there are considerable hurdles to overcome if it is to be seen as an alternative to BT's local access network in residential areas, according to Chris Smedley, Chief Executive of Geo. His comments come on the back of today's announcement that Ofcom will investigate whether the roll-out of fibre to the door of homes and businesses can be accelerated by using the UK's alternative utility infrastructures, including the sewers.

Geo is well placed to comment on the issue. As well as providing dedicated fibre networks to broadband suppliers such as Carphone Warehouse and Tiscali based on the long-term lease of optical fibre infrastructure, it operates an 80km (and growing) optical fibre network based in Thames Water's London sewer system, having owned the network since 2006. It is the only sewer-based optical fibre network in London.

Smedley comments: "The large trunk sewer network in London's Victorian sewer system is ideal for the installation of high-speed optical fibre. There's plenty of headroom down there for installation and the cables can be pinned to the ceiling of the sewers out of harm's way, making it very secure. It's also low cost, quick to install and avoids the public disruption which comes from digging up the streets. The end result is a very secure network built well away from other optical fibre networks dug in street trenches alongside other networks such as gas, electricity, water and traffic management and all the disruption and loss of service which results. This makes a sewer-based fibre network an ideal solution for large businesses."

However, Smedley says it is unproven whether sewer-based networks will deliver these same advantages in for residential areas. Geo points out that the sewer systems in outer London and other cities, not to mention suburban and rural locations, are a very different proposition as they're much smaller or, in some cases, non-existent.

Smedley adds: "It's reasonable to anticipate that most of the sewer infrastructure near domestic areas will present far more challenges when it comes to the installation of optical fibre as opposed to commercial developments. Equally, operating an optical fibre network in the water network isn't entirely straightforward and as we've learnt through our own relationship with Thames Water, it requires significant planning before installation and a very high level of co-operation throughout the maintenance of the network. The sewer companies will not tolerate new network deployment if it impairs their own ability to provide services."

Nevertheless, Geo believes that sewer-based networks may have a role to play, alongside more traditional road digs, in helping develop next generation networks in the UK. It may also help address the other (and more immediate) challenge for improving broadband speeds - the high cost of the so-called "middle mile" for optical fibre services between core networks such as Geo's and BT Openreach's access network.

Smedley says: "It's also important for Ofcom to investigate the status of the duct networks owned by BT and Virgin Media. Upgrading these to optical fibre is the most likely way of rolling out a next generation national network to UK homes and businesses."

In addition to its network in the London sewers, Geo also operates a 2,500km national network around the UK and is building a high-speed optical fibre network in partnership with the Welsh Assembly Government in Wales.

About Geo

Geo is the only company in the UK to design and build bespoke dedicated fibre network solutions. Geo's revolutionary and flexible approach means that for the first time, organisations can own and control their networks, ensuring that security, high bandwidth and resilience are guaranteed. Geo provides an extensive range of solutions including fully managed networks, dark fibre, lit fibre and co-location services. Geo.National enables network solutions on a national scale, and Geo.Metro provides users with an Ethernet service within the London area. Customers include mobile operators, service providers, major banks and the public sector. Please visit http://www.geo-uk.net for more information.