Communications system having distributed control and real-time bandwidth management

• US 6,064,673 A
• Filed: 07/01/1997
• Issued: 05/16/2000
• Est. Priority Date: 08/02/1996
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Gadda, Chris, Anderson, Pehr
• Primary Examiner(s): Pham, Chi H.
• Assistant Examiner(s): Pham, Brenda H.
• Application Number:
  US08/886,687
• Time in Patent Office: 1,050 Days
• Field of Search: 370/392, 370/238, 370/448, 370/404, 370/412, 370/465, 370/350-356, 370/389
• US Class Current: 370/389
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 2012/6454 Random, e.g. Ethernet
• CPC Class Codes: H04L 2012/6475 N-ISDN, Public Switched Telephone Network [PSTN]
• CPC Class Codes: H04L 2012/6481 Speech, voice
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A communications system and method utilizes peer-to-peer architecture to provide "quality" real-time communications in a non-guaranteed, packet-based network. Quality real-time communications in a non-guaranteed, packet-based network is achieved by (i) minimizing packet loss, (ii) minimizing latency, and (iii) minimizing the artifacts caused by packet loss. The system distributes control of functionality to the peer communication devices, thereby eliminating the need for a central processor to establish peer-to-peer communications. Each of the peer communication devices has the capability to respond to variations in network loading to provide quality real-time communications.

Claims

1. A method for achieving peer-to-peer communications in a packet-based communications network, comprising the steps of

providing a plurality of peer communication devices connected via a packet based communications network;

converting raw data into digital data in a sending peer communication device;

encoding the digital data into packets using one or more of the following data processing techniques (a) compression, (b) redundancy, and (c) interleaving;

transmitting the one or more data packets from the sending peer communication device over the network to a receiving peer communication device including reducing the expected time delays associated with the Ethernet exponential backoff algorithm by resetting the normal Ethernet retry algorithm based on a number of collisions or elapsed time;

decoding the data packets into digital data using one or more of the following data processing techniques (a) decompression, or (b) deinterleaving;

converting the decoded packets of digital data into a continuous stream of digital data, including using one or more of the following reconstruction techniques to mask the effects of missing decoded packets of digital data (a) interpolation, or (b) redundancy.

converting the continuous stream of digital data into raw data.

2. The method of claim 1 further comprising the step of optimizing the encoding, transmitting, decoding, and converting steps to (a) minimize packet loss, (b) minimize latency, and (c) minimize artifacts caused by packet loss.

3. The method of claim 1 wherein the peer communication devices include telephones, central office lines, voice mail channels, automated attendant channels, database managers.

4. The method of claim 1 wherein the raw data is audio signals.

5. The method of claim 1 wherein the network is an Ethernet network.

6. The method of claim 5 wherein the Ethernet network is 10BaseT, 10Base2, 100BaseTX, 100BaseVG anylan, or fiber.

7. The method of claim 1 further comprising the step of queuing the data packets of encoded digital data in a playback queue in order to convert the data packets into the contiguous stream of digital data.

8. The method of claim 7 wherein the step of queuing the data packets of encoded digital data further comprises the step of synchronizing the rate at which digital data is removed from the playback queue with the rate at which digital data is added to the playback queue to compensate for clock skew between the sending and receiving peer communication devices.

9. A method for achieving peer-to-peer audio communications in a packetbased communications network, comprising the steps of:

providing a plurality of peer communication devices connected via an Ethernet network;

converting audio signals received via an audio receiver into digital data within a sending peer communication device;

encoding the digital data into packets using one or more of the following data processing techniques (a) compression, (b) redundancy, and (c) interleaving;

adding a header to each packet of encoded digital data;

transmitting the one or more data packets from the sending peer communication device over the network to a receiving peer communication device including resetting the normal Ethernet retry algorithm once based on a number of collisions or elapsed time and dropping one or more packets based on a number of collisions or after an elapsed time after initiating the reset Ethernet retry algorithm;

removing the header from each data packet to obtain the packets of encoded digital data;

decoding the data packets into digital data using one or more of the following data processing techniques (a) decompression, or (b) deinterleaving;

converting the decoded packets of digital data into a continuous stream of digital data, including using one or more of the following reconstruction techniques to mask the effects of missing decoded packets of digital data (a) interpolation, or (b) redundancy;

converting the continuous stream of digital data into audio signals; and

outputting the audio signals via a audio transmitter.

10. The method of claim 9 wherein the Ethernet network is 10BaseT, 10Base2, 100BaseTX, 100BaseVG anylan, or fiber.

11. The method of claim 10 further comprising the step of queuing the data packets of encoded digital data in a playback queue in order to convert the data packets into the contiguous stream of digital data.

12. The method of claim 11 wherein the step of queuing the data packets of encoded digital data further comprises the step of synchronizing the rate at which digital data is removed from the playback queue with the rate at which digital data is added to the playback queue to compensate for clock skew between the sending and receiving peer communication devices.

13. The method of claim 10 further comprising the step of optimizing the encoding, transmitting, decoding, and converting steps to (a) minimize packet loss, (b) minimize latency, and (c) minimize artifacts caused by packet loss.

14. A method for achieving peer-to-peer communications in a packet-based communications network, comprising the steps of:

providing a plurality of peer communication devices connected via a packet based communications network;

encoding digital data into packets within a sending peer communication device;

transmitting the one or more data packets from the sending peer communication device over the network to a receiving peer communication device;

decoding the data packets into digital data within the receiving peer communication device;

converting the decoded packets of digital data into a continuous stream of digital data, including the steps of

(i) queuing the data packets of encoded digital data in a playback queue;

(ii) synchronizing the rate at which digital data is removed from the playback queue with the rate at which digital data is added to the playback queue to compensate for clock skew between the sending and receiving peer communication devices; and

(iii) using one or more of the following reconstruction techniques to mask the effects of missing decoded packets of digital data (a) interpolation, or (b) redundancy.

15. The method of claim 14 wherein the encoding step further comprises using one or more of the following data processing techniques (a) compression, (b) redundancy, and (c) interleaving.

16. The method of claim 14 wherein the decoding step further comprises using one or more of the following data processing techniques (a) decompression, or (b) deinterleaving.

17. The method of claim 14 wherein the transmitting step further comprises utilizing at least one of the following processing techniques (a) reducing the Ethernet interpacket gap time for retransmitted data packets, (b) reducing the expected time delays associated with the Ethernet exponential backoff algorithm, and c) repeating the transmitting step beyond the Ethernet retry limit.

18. The method of claim 17 wherein the expected time delays associated with the Ethernet exponential backoff algorithm are reduced by using at least one of the following techniques:

(i) reduction of the time between retries; and

(ii) resetting the Ethernet retry algorithm based on number of collisions or elapsed time.