Down the sewer to inspect Geo's fibre

Down the sewer to inspect Geo's fibre

Summary: The fibre broadband company Geo took ZDNet UK down an east London sewer to inspect the cabling it uses to deliver high-capacity connectivity to the capital's businesses


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  • Climbing down a sewer manhole

    Geo is a super-fast broadband company that sells dark-fibre connectivity, mostly to businesses.

    On Tuesday, Geo took ZDNet UK underground near the London 2012 Olympics site to see the sewer-based cabling that carries the company's fibres under the capital. Geo has 107km of cabling in London and around 3,000km overall across parts of the UK.

    Geo does its initial connection planning using Google Earth, which helps it figure out where the customer's building is, how far the network is from those premises, and where the best manhole access to the sewers is to be found.

    Photo credit: David Meyer

    See more photo stories on ZDNet UK.

  • Sewer with cables

    Geo's cables are installed around shoulder height. This is partly to ensure that they are most convenient for standard sewer entry points for such cabling, and partly because of the dangers that lie lower down in the sewers.

    The London-based company is toying with the idea of installing loose-lying cable, rather than bracketing the cable to the sewer wall. However, loose-lying cable would be threatened by the jetters that are used to clear sewer blockages.

    Jetters blast the blockages — which usually consist of solidified fat from nearby restaurants — with high-pressure water, then scoop back the loosened material. It is during the scooping that loose-lying cables would run the risk of getting tangled.

    Tangling would be disastrous for fibre-optic cable. Even excessive bending would disrupt the passage of the light, which is why so few junctions are used in Geo's sewer systems.

    Photo credit: David Meyer

    See more photo stories on ZDNet UK.

Topics: Broadband, Networking

David Meyer

About David Meyer

David Meyer is a freelance technology journalist. He fell into journalism when he realised his musical career wouldn't pay the bills. David's main focus is on communications, as well as internet technologies, regulation and mobile devices.

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