“Cell Tower Distribution” is a web application that visualizes the location of base stations around the world as grains of light. I actually tried “Cell Tower Distribution” to check the status of signal coverage in various regions.
https://alpercinar.com/open-cell-id/

This can let us see a clear visual map to know which area has a better signal. My home country Taiwan has a really nice signal among the world.
Underneath the map display of Cell Tower Distribution, the developer, Alper Cinar, gives a technical description of the system, explaining that it uses Brotli as the database compression algorithm and Leaflet as the map display library.