A cordless telephone consists of a handset and a base unit wired to a landline and a electrical current. A communication is transmitted from the handset to the base unit by AM or FM radio signals. From the base unit the communication is transmitted over wire, the same as a regular telephone call.
A cordless phone always uses the same channel in the same small area; thus, these phones are much easier to target by eavesdroppers. Nearby users with the same frequency channel pair can listen to their neighbors’ calls simply by listening with their own cordless units. The radio portions of these telephone calls also can be intercepted with relative ease using standard AM radios.