Network based call mute

US6721409B1 · kind B1 · utility

Assignee

• Nortel Networks Limited · CA

Inventors

• Raymond Paul Dell · Arlington, US
• Greg Osterhout · Coppell, US
• Randolph Wheatley · Richardson, US

Key dates

• Filing date: Dec 21, 1998
• Grant date: Apr 13, 2004
• Expiry date: Dec 21, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04M3/568
• WIPO field: Telecommunications
• WIPO sector: Electrical engineering

Abstract

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.