Figuring out the speed people are likely to get from a FTTC based roll-out, i.e. the bulk of BDUK spending in the UK is something that has vexed people for a long time and the Public Accounts Committee meeting and report has simply brought it even more sharply into focus.
We now have the situation where BT is on the record as saying it has no objections to map data showing where projects will be delivering being released, and then projects releasing their various phase maps, which both please and annoy to equal measure. Some Counties maps require almost forensic level image processing to recognise specific areas and very few counties release any information at the postcode level. As far as we are aware NONE of the county projects have identified exactly which cabinets will be enabled, even when postcode information is released, while not a problem for many as a postcode is served by a single cabinet, there are people with exchange only lines and no cabinet, or postcodes served by two cabinets.
We thought we might be able to do something, and possibly help answer the question about how much of an area will be superfast or not.
The above map shows two cabinet locations (Binfield Heath in Oxfordshire to be exact), an area where residents raised money to get the two BT green street cabinets enabled, and we have then plotted all the postcodes that lie within a 2km radius of each cabinet, and used our table of distance versus speed for FTTC to estimate what speed range a postcode will fall into. We multiple the radial distance from the cabinet by square root of 2 to give an approximate road distance.
- GREEN, Superfast with a speed >= 30 Mbps
- YELLOW, speed is > 2 Mbps but less than 30 Mbps
- RED, speed is <= 2 Mbps
- BLACK, estimated distance of 3km and VDSL2 assumed to not work.
The problem now is that while it is easy enough to identify a postcode at a certain distance from a cabinet, identifying whether it is served by that particular cabinet is more problematic. This is where local knowledge comes to the fore and some common sense, so we are very confident that the yellow and red postcodes in Caversham are served by different cabinets. Those yellow postcodes in Dunsden Green we are not so sure about. If we knew the location of all the cabinets in that map area we would have no problem plotting speed to the closest cabinet, but that also has its faults, as people are not always connected to the closest cabinet.
So while this system is not perfect, it has a degree of use and nothing stopping us from plotting the map using more colour to highlight the variation in speeds.
I may regret saying this, but if there are community projects who know where their BT cabinet is located and accept the caveats above we can produce data for other areas, not overlaid onto a map, but a basic list of postcodes with the expected speed then email me. Compared to the information coming from the councils and BT themselves we believe it would be useful.
I should point out no secret BT data was used to produce this map, and if BT really wanted to help inform the broadband speed debate we would like to invite them to provide us with lat/lng (or postcode) information for the 85,000 cabinets in the UK and a postcode to cabinet cross-reference. If BT were to do that we might accept a caveat of not releasing the cabinets exact location, though of course people could guess it based on the spread of speeds, or heaven forbid notice it as they walk/drive/jog by them in their local area.