Nortel Networks Corporation

Randolph Wheatley

Greg Osterhout

Raymond Paul Dell

A telephone feature can be implemented within a Digital Multiplex Switch (DMS) in order to mute a telephone handset's voice path at the telephone network level. In this DMS, a Digital Tone Multi-Frequency (DTMF) receiver monitors for a predefined sequence of DTMF buttons being pressed on the particular handset, that being the * button followed by two other digits. When the DMS detects such a code, it interrupts the transmit path of the particular handset by opening a switch within the cross-connection switch matrix, therefore removing from the telephone session any background acoustic noise at the particular muted telephone handset and any electrical noise within the transmission line between the muted handset and the DMS. This feature is particularly useful during teleconferencing sessions, in which numerous parties are not contributing to the call, but must listen to the discussion.

Growing community of inventors

Richardson, TX, United States of America

Randolph Wheatley