But, when you do an install of electric wire towers on a mountain, you might not have cell connectivity. Most apps get by this by saving data locally, and then transmitting on the next connection.
Generally: The thick concrete walls, exposed rebar, and intentional and unintentional geometric structural elements combine to form a giant Faraday-esque electromagnetic exclusion zone. Even with wifi repeaters on each floor you aren't assured a connection.
I worked for LATISTA as a product designer and spent a significant amount of time on-site speaking with users about this exact problem. It's getting better, especially with the larger construction management / development firms, but it's not a solved problem (unless your firm spends a significant amount on portable IT infrastructure).