Performance of a radio device is optimized by estimating if the device is inside a building. One or more sensors on the radio device are used to measure an environmental quantities relating to the environment of the radio device. The likelihood of the radio device being inside a building is inferred from these measurements. The operation of the radio device then is controlled accordingly. For example, if the radio device is determined to be inside a building, a low operating frequency may be selected for the radio device if a wide area network connection is required, while a high operating frequency may be selected if a local connection is required. An environmental quantity may be, for example, a satellite signal, ambient light, temperature, RF energy, or the response to a test signal emitted by the radio device.