Patent US4675219A successfully refreshed from Google Patents.
US5870397A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and a system for silence removal in a voice signal transported through a communication network
Assignee: Cisco Technology Inc
•
Filing: 1996-08-06
•
Granted: 1999-02-09
•
Expires: 2016-08-06
Abstract
Abstract A method and an apparatus for removing the silence from the digitalized voice signals conveyed through packets or cells switching networks. The silence samples are neither packetized nor sent over the network but are regenerated at the output of the network. The silence samples generated are white noise samples, where the level is adapted to the background noise of the silence samples received at the input node of the network. For long periods of silence, the white noise level is periodically refreshed to be adapted to the last silence samples received at the input node of the network. The method provides also a control of packet or cell loss. The method uses are not control packets; in the later case, it can be used for ATM networks with AAL1. The method is implemented as a program executed in a Digital Signal Processor located on adapter cards dedicated to voice processing in the network access nodes.
Inventors
- 👤 Pascal Chauffour
- 👤 Bernard Pucci
- 👤 Gerard Richter
- 👤 Maurice Duault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:20
CPC Classifications
G; G10; G10L; G10L19/00; G10L19/012; H; H04; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q11/0478; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/44; H04B1/46; H04L; H04L12/00; H04L12/54; H04L12/56; H04L12/5601; H04L2012/5614; H04L2012/5616; H04L2012/5638; H04L2012/5646; H04L2012/5647; H04L2012/5652; H04L2012/5671; H04Q2213/00; H04Q2213/13034; H04Q2213/13056; H04Q2213/13166; H04Q2213/13201; H04Q2213/13216; H04Q2213/1329
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
154 words
A method for transporting a stream of packets between a transmitting side and receiving side through a communication network, said stream including voice packets corresponding to detected speech periods and silence packets corresponding to detected silence periods, characterized in that it comprises: at the transmitting side, detecting the ends of speech periods, transmitting voice packets corresponding to the speech periods followed, for a first period of time after the end of each speech period, by silence packets, calculating following the end of a speech period, a white noise level corresponding to the background noise of at least one following silence packet and transmitting to the receiving side, a control packet including said white noise level, at the receiving side, receiving the voice, silence and control packets, reading the white noise level in the control packet, and reconstituting said stream by interleaving between the voice packets received from the transmitting side, received white noise packets.
Claim 2
Independent Claim
154 words
A method for transporting a stream of packets between a transmitting side and receiving side through a communication network, said stream including voice packets corresponding to detected speech periods and silence packets corresponding to detected silence periods, characterized in that it comprises: at the transmitting side, detecting the ends of speech periods, transmitting voice packets corresponding to the speech periods followed, for a first period of time after the end of each speech period, by silence packets, calculating following the end of a speech period, a white noise level corresponding to the background noise of at least one following silence packet and transmitting to the receiving side, a control packet including said white noise level, at the receiving side, receiving the voice, silence and control packets, reading the white noise level in the control packet, and reconstituting said stream by interleaving between the voice packets received from the transmitting side, received white noise packets.
Claim 3
Dependent Claim
48 words
The method according to claim 1 characterized in that it comprises at the receiving side: if no packet is received and if the last received packet is not a control packet, repeating in the packet stream reconstituted by the receiving side, the last received packet at least once.
Claim 4
Dependent Claim
44 words
The method according to claim 1 characterized in that it comprises at the receiving side: if no packet is received and no end of speech is detected, repeating in the packet stream reconstituted by the receiving side, the last received packet at least once.
Claim 5
Dependent Claim
79 words
The method according to claim 2, characterized in that it comprises at the transmitting side, starting a timer having a second period of time at the end of the first period, when the timer is expired and if no voice packets are to be transmitted, calculating a new white noise level corresponding to the background noise of silence period and sending a new corresponding control packet which is used by the receiving side for generating refreshed white noise packets.
Claim 6
Dependent Claim
78 words
The method according to claim 3 characterized in that it comprises: at the transmitting side: starting a timer having a second period of time at the end of the first period, when the timer is expired and if no voice packets are to be transmitted, sending a burst of silence packets and at the receiving side, receiving the burst of silence packets and calculating a new white noise level which is used for generating refreshed white noise packets.
Claim 7
Dependent Claim
39 words
The method according to any one of claim 5, characterized in that it comprises: calculating with a linear interpolation algorithm and for a third period of time, the progressive values of the next white noise packets to be generated.
Claim 8
Independent Claim
212 words
A system for transporting a stream of packets between a transmitting side and a receiving side through a communication network, said stream including voice packets corresponding to speech periods and silence packets corresponding to silence periods, said system comprising: a transmission system including a voice activity detector for detecting voice periods and silence periods, control logic for transmitting voice packets representing voice periods and, for a first period of time following the end of voice packets, silence packets representing silence periods following the represented voice periods, a background noise calculator for calculating, following the end of a voice period, a white noise level corresponding to the background noise of one or more of the silence packets representing the silence period following the voice period, a control packet generator for generating control packets including the white noise level, and a transmitter for transmitting voice packets, silence packets and control packets to a receiver system; and a receiver system including: receiver circuitry for receiving transmitted voice, silence and control packets, background noise logic for receiving white noise level values carried in received control packets and for generating white noise level packets, and signal reassembly logic for reconstituting voice activity detected at the transmission system by interleaving generated white noise packets with received voice packets.
Claim 9
Independent Claim
212 words
A system for transporting a stream of packets between a transmitting side and a receiving side through a communication network, said stream including voice packets corresponding to speech periods and silence packets corresponding to silence periods, said system comprising: a transmission system including a voice activity detector for detecting voice periods and silence periods, control logic for transmitting voice packets representing voice periods and, for a first period of time following the end of voice packets, silence packets representing silence periods following the represented voice periods, a background noise calculator for calculating, following the end of a voice period, a white noise level corresponding to the background noise of one or more of the silence packets representing the silence period following the voice period, a control packet generator for generating control packets including the white noise level, and a transmitter for transmitting voice packets, silence packets and control packets to a receiver system; and a receiver system including: receiver circuitry for receiving transmitted voice, silence and control packets, background noise logic for receiving white noise level values carried in received control packets and for generating white noise level packets, and signal reassembly logic for reconstituting voice activity detected at the transmission system by interleaving generated white noise packets with received voice packets.
Claim 10
Dependent Claim
141 words
For use in a communications network carrying a stream of packets representing voice activity, a transmission system comprising: a voice activity detector for detecting voice periods and silence periods; a packet generator for generating voice packets representing periods of detected voice and silence packets representing periods of detected silence; control logic for transmitting voice packets and, for a first period of time following the end of voice packets, silence packets; a background noise calculator for calculating following the end of a voice period, a white noise level corresponding to the background noise of one or more of the silence packets representing the silence period following the voice period; a control packet generator for generating one or more control packets carrying the calculated white noise level; and a transmitter for transmitting voice packets, silence packets and control packets into the communications network.
Claim 11
Dependent Claim
141 words
For use in a communications network carrying a stream of packets representing voice activity, a transmission system comprising: a voice activity detector for detecting voice periods and silence periods; a packet generator for generating voice packets representing periods of detected voice and silence packets representing periods of detected silence; control logic for transmitting voice packets and, for a first period of time following the end of voice packets, silence packets; a background noise calculator for calculating following the end of a voice period, a white noise level corresponding to the background noise of one or more of the silence packets representing the silence period following the voice period; a control packet generator for generating one or more control packets carrying the calculated white noise level; and a transmitter for transmitting voice packets, silence packets and control packets into the communications network.
Claim 12
Dependent Claim
130 words
For use in a voice communications network, a method of generating a stream of packets representing voice activity, said method comprising the steps of: detecting periods of speech and periods of silence; generating voice packets representing periods of detected speech and silence packets representing periods of detected silence; transmitting generated voice packets and, for a first period of time following the end of voice packets, generated silence packets; calculating following the end of the voice packets, a white noise level corresponding to the background noise of one or more of the silence packets representing the period of silence following the period of voice activity; generating one or more control packets carrying the calculated white noise level; and transmitting voice packets, silence packets and control packets into the voice communication network.
Claim 13
Dependent Claim
130 words
For use in a voice communications network, a method of generating a stream of packets representing voice activity, said method comprising the steps of: detecting periods of speech and periods of silence; generating voice packets representing periods of detected speech and silence packets representing periods of detected silence; transmitting generated voice packets and, for a first period of time following the end of voice packets, generated silence packets; calculating following the end of the voice packets, a white noise level corresponding to the background noise of one or more of the silence packets representing the period of silence following the period of voice activity; generating one or more control packets carrying the calculated white noise level; and transmitting voice packets, silence packets and control packets into the voice communication network.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-08 | 2002-08-10 | 2003-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-08 | 2006-08-10 | 2007-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-08 | 2010-08-10 | 2011-02-09 | $7700.00 | Window Closed / Lapsed |