Assertion: mobile phone | /r/CapableOf | emit radio signals
Facets:
value: on its control channel
type: LOCATION
value: periodically
type: TEMPORAL
Source sentences:
text: Even when it is not being used, unless it is turned off, a mobile phone periodically emits radio signals on its control channel, to keep contact with its cell tower and for functions like handing off the phone to another tower if the user crosses into another cell.