Saturday, 12 May 2012

How close is the fibre to you?

If your broadband connection is delivered down your copper 'phone line, your speed is fundamentally limited by the length of the line to the exchange (or where BT has rolled out FTTC, to the cabinet). Exact performance depends on many factors, but there is a fundamental inverse square law, and typical limits are of the order of 300m for 100Mb/s, 1km for 10Mb/s, 3km for 1Mb/s.

Some 85% of homes in the UK have more than 800 neighbours within 700 metres. We build maps that highlight such compact communities that are far from fibre. For example, most of Porthleven is more than 3km from the nearest exchange, as are substantial parts of East Kilbride, Nitshill and Hartlepool (these links should open in a new tab).

Google maps will only show a small number of hotspots at a time – and there are thousands of them. To explore your area, you can examine our hotspot maps on Google Earth, which can cope with large data sets. Clicking on the link should download a .kml file that can be opened in Google Earth. In Chrome, you can instruct the browser to "Always Open Files of this Type", or just open this one. For more detailed instructions see below.

The hotspots on these maps are likely to be not-spots. Hopefully many of these areas will be served by FTTC, and we'll be happy to update the maps if someone can provide positions of FTTC cabinets - or any other NGA provision.

If, however, you live in a hot not-spot, you should find out what plans there are to bring fibre to your community. You won't get NGA (say > 20 Mb/s) over more than 1km of copper
phone line - and for 100Mb/s speeds your copper ration is < 400m. You can see what BT's 'Superfast' Broadband plans are (as of April 2012) by clicking on the pin representing each exchange.


If you live in a less-densely populated community (with fewer than 800 neighbours within 700 metres) then you might want to plan a community network to bring NGA to your homes and you should be asking where you can access affordable fibre backhaul nearby.

Caveats

Our distance computations were based on Sam Knows data, from which some exchanges are missing - so in a few instances you may find an exchange marked inside a 'hotspot'. The Open Reach data does not always plot the exchanges accurately. Some are a few hundred metres from their true positions. The Sam Knows data has similar (but different) errors.

Because there is no publicly available dataset of cabinets, we cannot plot your distance from the cabinet. Likewise, we have no data on the Virgin network. You may be getting superfast access from within one of our hotspots – in which case lucky you! Do let us know, in the comments below.

More detail

When you import the .kml file into Google Earth, you should see a new entry appear in the GE sidebar. Zoom in to your area of interest. Once you zoom in far enough your local exchanges should appear. Click on the 'pushpin' to see BT's plans for SFBB at this exchange.

Click on the triangle to open the 'Digital Britain?' folder.

Open the 'Compact Communities' folder to see, and select, the various heatmaps available.



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