You need to be careful with long range radio solutions. Radio waves sources are very easy to locate with cheap equipment. Wifi/Bluetooth is perhaps better since it's already everywhere, but the range isn't good.
It's sometime a bit more difficult: with spread spectrum technologies for example, widely used wireless technologies that work well in dense usage. It works also on cellular networks (2G, 3G, 4G, 5G).
Just so people don't get a false sense of security with some solutions.