Today I will be adding proximity based results to the Better Internet Dashboard. This allows the Better Internet Dashboard to provide “hints” of which ISPs may be serviceable without having a checker for that ISP.
Of course the data must come from somewhere and that’s the Think Broadband coverage maps.
How it Works
A map is generated based on a very zoomed out view of the United Kingdom. On this map, each provider gets a unique colour, they are layered on top of each other to produce what looks like a random mess. Note, in reality we produce 3 maps (in a single file, side by side) since each map can only contain 32 unique bits.
When we want to lookup an area, we take the lookup coordinates and form a box of 5 kilometres around where the target would be and crop to an ellipse. The output is then a radius around where we want to check filled with a bunch of colours.
The checker then runs over every pixel, one by one, identifying the colours and determining what they map to. This list is then returned to the user. If a checker does not exist on the Better Internet Dashboard for any of the results, they’re now displayed as “local”.
Since Better Internet Dashboard is entirely serverless, this approach means we can process this data by keeping the state of UK broadband deployments in small files.
This process takes takes about 200 milliseconds per request and the dataset is fully refreshed every night.
Because the Better Internet Dashboard already contains checkers for the larger providers in the United Kingdom, the results from this new API should mostly remain very relevant to the user’s search. It’s not going to list an Openreach property 3 miles away for example since we can already definitively say if a property is serviceable.