Repetitive pattern removal in a voice channel of a communication network

• US 6,144,658 A
• Filed: 12/12/1997
• Issued: 11/07/2000
• Est. Priority Date: 12/20/1996
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Pucci, Bernard, Lebizay, Gerard, Richter, Gerard, Duault, Maurice
• Primary Examiner(s): Hsu, Alpus H.
• Assistant Examiner(s): HO, DUC CHI
• Application Number:
  US08/989,585
• Time in Patent Office: 1,061 Days
• Field of Search: 341/51, 341/60, 341/63, 341/87, 370/352, 370/428, 370/474, 370/477, 370/493, 370/465, 370/528, 375/243, 375/246, 375/253, 375/368, 704/246, 704/253, 704/500, 714/715, 714/716, 714/822
• US Class Current: 370/352
• CPC Class Codes: H04J 3/17 in which the transmission channel allotted to a first user may be taken away and re-allotted to a second user if the first user becomes inactive, e.g. TASI speech analysis or identification G10L
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 2012/6467 Information loss recovery, e.g. error correction, prediction
• CPC Class Codes: H04L 2012/6481 Speech, voice

Abstract

Repetitive packets in a voice/data stream, are detected and suppressed in the transmitting side of a network, after a predefined number of consecutive repetitive packets have been transmitted. Then, at the receiving side of the network, suppressed repetitive packets are reconstituted by filling the resulting gap in the voice/data stream with the repetitive pattern contained in the last received repetitive packet. When the input voice/data stream is compressed, only non-repetitive packets are compressed so that repetitive patterns are not corrupted by compression.

Claims

1. A voice/data traffic managing system in a packet switching network for operating on a voice/data stream, comprising:

a transmitting side with detection means for detecting in said voice/data stream the presence of one or more packets filled with repetitive patterns (repetitive packets), and removal means for suppressing said repetitive packets after a predefined number (N1) of consecutive repetitive packets have been transmitted, such that they are not transmitted, and encoding means for compressing said voice/data stream, but not compressing said predefined number of transmitted repetitive packets; and

,

a receiving side with reconstitution means for replicating the last repetitive packet received from the transmitting side into the portion of said voice/data stream which corresponds to the suppressed data packets, such that said voice/data stream is reconstituted and played out as an output voice/data signal, and decoding means for decompressing said voice/data stream, said decoding means not decoding repetitive packets so that the patterns within repetitive packets are not corrupted by decompression at said receiving side.

2. A system according to claim 1 further comprising refresh means at the transmitting side for sending a certain number of repetitive packets, for transmission errors recovery, after a predefined number (N2) of repetitive packets have been suppressed.

3. A system according to claim 1 comprising a queue at the receiving side for queuing the successive packets received from the transmitting side, means for determining whether said queue is empty or not, and means for storing the repetitive pattern contained in the last repetitive packet received.

4. A system according to claim 3 comprising at said receiving side, means for applying digital speech interpolation to the output signal when said queue is empty and the last received packet is a non-repetitive packet.

5. A system according to claim 4 wherein, means at said receiving side for playing out said stored repetitive pattern when said queue is empty and the last received packet is a repetitive packet.

6. A system according to claim 5 wherein all called for means are implemented in software.

7. A method for transporting an incoming stream of voice/data in a transmitting side to a receiving side of a packet switching network, comprising:

a) detecting in said voice/data stream at the transmitting side the presence of one or more packets filled with repetitive patterns;

b) transmitting from the transmitting side a predefined number (N1) of consecutive repetitive packets after detection of such packets and removing the next repetitive packets such that they are not transmitted;

c) transmitting the non-repetitive packets in a compressed state, and transmitting those repetitive packets in a non-compressed state;

d) decompressing at the receiving side those non-repetitive packets which were transmitted in a compressed state; and

e) replicating the last repetitive packet received from the transmitting side into the portion of the received packets stream which corresponds to the suppressed packets, such that said voice/data stream is reconstituted for being played out as an output voice/data signal.

8. A method according to claim 7 including the step of sending a certain number of repetitive packets for transmission error recovery, after a predefined number (N2) of repetitive packets have been suppressed.

9. A voice/data traffic managing system in a packet switching network for operating on a voice/data stream, comprising:

at the transmitting side,

detection means for detecting in said voice/data stream the presence of one or more packets filled with repetitive patterns (repetitive packets);

removal means for suppressing said repetitive packets after a predefined number (N1) of consecutive repetitive packets have been transmitted, such that they are not transmitted;

refresh means for sending a certain number of repetitive packets, for transmission errors recovery, after a predefined number (N2) of repetitive packets have been suppressed;

at the receiving side,

reconstitution means for replicating the last repetitive packet received from the transmitting side into the portion of said voice/data stream which corresponds to the suppressed data packets, such that said voice/data stream is reconstituted and played out as an output voice/data signal; and

,

error recovery means, responsive to said refresh packets, for recovery from transmission errors in the absence of receiving said refresh packets.

10. A method for transporting an incoming stream of voice/data from a transmitting side to a receiving side of a packet switching network, comprising:

at the transmitting side,

a) detecting in said voice/data stream the presence of one or more packets filled with repetitive patterns (repetitive packets);

b) transmitting a predefined number (N1) of consecutive repetitive packets after detection of such packets and removing the next repetitive packets such that they are not transmitted;

c) sending a certain number of repetitive packets for transmission errors recovery, after a predefined number (N2) of repetitive packets have been suppressed;

at the receiving side,

d) replicating the last repetitive packet received from the transmitting side into the portion of the received packets stream which corresponds to the suppressed packets, such that said voice/data stream is reconstituted for being played out as an output voice/data signal;

e) recovering from transmission errors in response to not receiving those repetitive packets transmitted for transmission errors recovery.

11. A voice/data traffic managing system in a packet switching network for transmitting a voice/data stream, comprising:

a transmitter with detection means for detecting in said voice/data stream the presence of one or more packets filled with repetitive patterns (repetitive packets), and removal means for suppressing said repetitive packets after a predefined number (N1) of consecutive repetitive packets have been transmitted, such that they are not transmitted, and encoding means for compressing said voice/data stream, but not compressing said predefined number of transmitted repetitive packets, so that a receiver having a reconstitution means for replicating the last repetitive packet received from the transmitter into the portion of said voice/data stream which corresponds to the suppressed data packets, such that said voice/data stream is reconstituted and played out as an output voice/data signal, and said receiver further having decoding means for decompressing said voice/data stream, said decoding means not decoding repetitive packets so that the patterns within repetitive packets are not corrupted by decompression at said receiver.

12. A method for transmitting an incoming stream of voice/data onto a packet switching network, comprising:

a) detecting in said voice/data stream at a transmitter the presence of one or more packets filled with repetitive patterns;

b) transmitting by said transmitter a predefined number (N1) of consecutive repetitive packets after detection of such packets and removing the next repetitive packets such that they are not transmitted;

c) transmitting the non-repetitive packets in a compressed state, and transmitting those repetitive packets in a non-compressed state;

d) decompressing at the receiving side those non-repetitive packets which were transmitted in a compressed state; and

e) replicating the last repetitive packet received from the transmitting side into the portion of the received packets stream which corresponds to the suppressed packets, such that said voice/data stream is reconstituted for being played out as an output voice/data signal.