US Patent 7933397 Telephone system that notifies caller of called party's state

A telephone system that has the ability to provide a caller with additional information (beyond a busy signal or a ring tone) concerning the called party when the called party's line is busy: The called party can control the amount and type of additional information provided to the calling party. In one embodiment, when the called party is notified that someone is trying to place a call (by a mechanism such as by conventional caller ID) the called party has the option of providing the calling party with a variety of different information, such as whether or not the called party is on a conference call and the number (and name if available) of the party to whom the called party is speaking.