Tsunagaroom Maps the Places Where Your Phone Actually Works

Field notes

The database groups readings by building, floor, municipality, carrier, and download-speed band rather than relying on broad coverage maps. Contributors select a place and run an automatic phone measurement after disabling Wi-Fi, allowing the result to appear on the relevant page. The homepage reports 251 cumulative readings across 169 locations and 74 municipalities, with carrier entries ranging from the four major Japanese networks to brands such as ahamo, povo, and LINEMO.