Cordless telephones

摘要

An incoming call initiates selection by a base station of a free channel and transmission of call set-up signalling comprising a long (non-unique) signalling identification signal followed by a short security code unique to that base. The handset, when idle, scans the allocated channels for signalling identification signal and only if this is found does it then check the security code for correspondence with its own stored code. This procedure permits intermittent handset operation for power economy-whilst still meeting acceptable call-set up times.