Method and apparatus for real time communication over packet networks

• US 6,175,871 B1
• Filed: 10/01/1997
• Issued: 01/16/2001
• Est. Priority Date: 10/01/1997
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: 3Com Corporation (HP Inc.)
• Inventors: Sidhu, Ikhlaq S., Schuster, Guido M.
• Primary Examiner(s): Coulter, Kenneth R.
• Application Number:
  US08/942,446
• Time in Patent Office: 1,203 Days
• Field of Search: 709/231, 709/220, 709/228, 370/252
• US Class Current: 709/231
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 2012/5616 Terminal equipment, e.g. codecs, synch.
• CPC Class Codes: H04L 2012/5647 Cell loss
• CPC Class Codes: H04L 2012/5649 Cell delay or jitter
• CPC Class Codes: H04L 2012/5671 Support of voice
• CPC Class Codes: H04L 2012/5681 Buffer or queue management
• CPC Class Codes: H04L 2012/6429 Terminal adapters
• CPC Class Codes: H04L 2012/6472 Internet
• 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 2012/6483 Video, e.g. MPEG
• CPC Class Codes: H04L 2012/6489 Buffer Management, Threshold setting, Scheduling, Shaping
• CPC Class Codes: H04L 65/764 at the destination reformatting of additional data in video clients H04N21/4355
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

A method and apparatus for communicating a real time media input over a network. The apparatus encodes the input into data packets having a number of frames ordered according to a first variable. A receiving device unpacks and buffers the unpacked data packets for playout according to a second variable. The receiving device generates utility parameters for evaluating a dynamic characteristic of the network that transports the data packets. The receiving device selects a preferred utility parameter and adjusts the first and second variable according to the selected utility parameter. The method includes encoding an analog input into data packets that are transported to a receiving device. The method also includes unpacking the data packets, buffering the unpacked data packets according to a second variable, and generating at least two utility parameters that represent a dynamic characteristic of a network. The method also includes selecting a preferred utility parameter and adjusting the first and the second variables according to the selected preferred utility parameter.

Claims

1. An apparatus for communicating a real time media input comprising:

an encoding device for encoding the media input into a plurality of data packets, each data packet comprising a plurality of frames created according to a first variable;

a receiving device for unpacking the data packets, and buffering the unpacked data frames packets for a playout of the media input according to a second variable, the receiving device generating a plurality of utility parameters for evaluating a dynamic characteristic of a transporting network that transports the data packets from the encoding device to the receiving device, wherein a preferred utility parameter is selected from the plurality of utility parameters, the preferred utility parameter is used to adjust the first and the second variable so that the encoding device and the receiving device adapt to the dynamic characteristic.

2. The apparatus of claim 1, wherein the first variable is a vector of values that define the compression and packetizing scheme.

3. The apparatus of claim 1, wherein the second variable is a vector of values that define the decompression and depacketizing and playout scheme of the receiving device.

4. The apparatus of claim 1, wherein the real time media input is an audio waveform.

5. The apparatus of claim 1, wherein the real time media input is a video waveform.

6. The apparatus of claim 1, wherein the dynamic transporting characteristic is selected from a group consisting of data packet loss, data packet delay, packet burst loss, loss auto-correlation and delay variation.

7. The apparatus of claim 1, wherein the transporting network comprises a packet switched network.

8. The apparatus of claim 5, wherein the packet switched network is selected from a group consisting of Local Area Networks, Internet Protocol Networks, frame relay networks, ATM networks, and Wide Area Networks.

9. The apparatus of claim 1, wherein the transporting network comprises an interconnected switched network of Local Area Networks, Internet Protocol Networks, and frame relays net works, and Wide Area Networks.

10. The apparatus of claim 5, wherein the packet switched network is an Internet.

11. The apparatus of claim 5, wherein the packet switched network is an Intranet.

12. The apparatus of claim 1, wherein the first variable is an actual redundancy parameter.

13. The apparatus of claim 1, wherein the second variable is an actual buffer length parameter.

14. The apparatus of claim 1, wherein a function of the preferred utility parameter is packeted into a feedback packet which is transported to the encoding device by the transporting network.

15. The apparatus of claim 12, wherein the receiving device packets the function of the preferred utility parameter into the feedback packet.

16. An apparatus for communicating a real time media input, the apparatus comprising:

a sender comprising an encoder and a packetizer in which the encoder partitions the real time media input into a plurality of frames and compresses the frames, the packetizer packets the compressed frames into a plurality of data packets according to a redundancy value;

a transporting network that transports the data packets from the sender to a receiver;

the receiver comprising a real decoder and a plurality of computation decoders, the real decoder comprising a real decoder depacketizer and a real decoder buffer wherein the real decoder depacketizer unpacks the plurality of frames, the frames are placed into the real decoder buffer, a buffer depth is controlled by a buffer length variable,

each computation decoder having a utility parameter for evaluating a dynamic characteristic of the transporting network, the computation decoder comprising a computation decoder depacketizer and a computation decoder buffer wherein the computation decoder depacketizer unpacks the plurality of frames, and communicates the frames to the computation decoder buffer,

the receiver selects a preferred utility parameter from the generated utility parameters and communicates a feedback variable to the real decoder buffer, such that the buffer length is adjusted in accordance with a change in the dynamic characteristic.

17. The apparatus of claim 16, wherein the utility parameter is a function of the redundancy variable and the buffer length variable.

18. The apparatus of claim 16, wherein the input is an audio waveform.

19. The apparatus of claim 16, wherein the input is a video waveform.

20. The apparatus of claim 16, wherein a feedback packet is transported by the transporting means to the digital waveform encoder such that the redundancy value is adjusted in accordance with the change in the dynamic characteristic.

21. The apparatus of claim 16, wherein the feedback packet is transported by the transporting means to the packetizer.

22. The apparatus of claim 16, wherein the data packets include a time stamp, a sequence number, a redundancy parameter, a current frame and a plurality of redundant frames.

23. The apparatus of claim 16, wherein the transporting network is a packet switched network.

24. The apparatus of claim 23, wherein the packet switched network is selected from a group consisting of Local Area Networks, Internet Protocol Networks, and frame relay networks, ATM networks, and Wide Area Networks.

25. The apparatus of claim 23, wherein the packet switched network is an Internet.

26. The apparatus of claim 23, wherein the packet switched network is an Intranet.

27. A system for transmitting real time media, the system comprising:

a first calling device for placing a call to a first processing hub, the first processing hub comprising;

an encoder for partitioning the call into a plurality of compressed frames, and

a packetizer for packetizing the frames into a data packet according to a redundancy variable;

a transporting network for transporting the data packet between the first hub and a second hub wherein the second hub comprises;

a decoder for decoding the data packet into the plurality of frames and ordering these frames within a buffer having a buffer depth according to a buffer length variable, the decoder generating a plurality of utility parameters based on the redundancy variable and the buffer length variable, wherein the decoder selects a preferred utility parameter from the generated utility parameters such that the redundancy variable and the buffer length variable are adjusted in accordance with a change in the dynamic characteristic; and

a second calling device connected to the second processing hub.

28. The apparatus of claim 27, wherein the data packets contain a time stamp, a sequence number, a redundancy parameter, a current frame and a plurality of redundant frames.

29. The apparatus of claim 27, wherein a function of the preferred utility parameter is packeted into a feedback packet and transported to the packetizer by the transporting network.

30. The apparatus of claim 27, wherein the redundancy value is adjusted in accordance with a dynamic characteristic of the transporting network.

31. The apparatus of claim 27 wherein the data packets contain a time stamp, a sequence number, a redundancy parameter, a current frame and a plurality of redundant frames.

32. The apparatus of claim 27 wherein the transporting network is a packet switched network.

33. The apparatus of claim 32 wherein the packet switched network is selected from a group consisting of Local Area Networks, Internet Protocol Networks, frame relay networks, ATM networks, and Wide Area Networks.

34. The apparatus of claim 32 wherein the packet switched network is the Internet.

35. The apparatus of claim 32 wherein the packet switched network is an Intranet.

36. A method for communicating a real time media input comprising the steps of:

communicating the real time media input to a sending device;

encoding the media input into a plurality of frames, packetizing the frames into data packets, each data packet comprising an ordered plurality of the frames according to a first variable;

transporting the data packets to a receiving device;

unpacking the data packets at the receiving device;

buffering the unpacked data packets according to a second variable,

generating at least two utility parameters, the utility parameters representing a dynamic characteristic of a transporting network that transports the data packets from the sending device to the receiving device,

selecting a preferred utility parameter from the generated utility parameters; and

adjusting the first and the second variable according to the selected preferred utility parameter.

37. The method of claim 36 further comprising the step of adjusting the sending device and the receiving device to a change in the dynamic transporting characteristic.

38. The method of claim 36 further comprising the step of playing out the analog input.

39. The method of claim 36 wherein the real time media input is an audio waveform.

40. The method of claim 36 wherein the real time media input is a video waveform.

41. The method of claim 36, further comprising the step of selecting the dynamic characteristic from a group consisting of data packet loss, data packet delay, packet burst loss, loss auto-correlation and delay variation.

42. The method of claim 36, wherein the network comprises a packet switched network.

43. The method of above claim 42, further comprising the step of selecting the packet switched network from a group consisting of Local Area Networks, Internet Protocol Networks, and frame relays.

44. The method of claim 36, wherein the transporting network comprises an interconnected switched network of Local Area Networks, Internet Protocol Networks, frame relay networks, ATM networks, and wide Area Networks.

45. The method of claim 36, further comprising the steps of packetizing a function of the preferred utility parameter into a feedback packet, and transporting the feedback packet to the encoding device by the transporting network.

46. A method for communicating a real time media input comprising the steps of:

partitioning and compressing the real time media input into a plurality of frames at a digital waveform encoder;

packetizing the frames into a plurality of data packets according to an actual redundancy variable;

transporting the data packets by a transporting network from the digital encoder to a receiver;

unpacking the transported data packets into the plurality of frames;

arranging the frames within a buffer according to a buffer length variable;

evaluating a plurality of utility parameters for evaluating a dynamic transporting characteristic of the transporting network;

selecting a preferred utility parameter from the utility parameters; and

adapting the buffer length variable according to a change in the transporting characteristic.

47. The method of claim 46, further comprising the step of communicating the unpacked frames to a digital waveform decoder.

48. The method of claim 46, further comprising the step of adopting the actual redundancy variable according to change in the transporting characteristic.

49. The method of claim 46, further comprising the step of playing out the media input.

50. The method of claim 46, wherein the real time media input is an audio waveform.

51. The method of claim 46, wherein the real time media input is a video waveform.

52. The method of claim 46, further comprising the step of selecting the dynamic characteristic from a group consisting of data packet loss, data packet delay, packet burst loss, loss auto-correlation and delay variation.

53. The method of claim 46, wherein the network comprises a packet switched network.

54. The method of above claim 53, further comprising the step of selecting the packet switched network from a group consisting of Local Area Networks, Internet Protocol Networks, and frame relays.

55. The method of claim 46, wherein the transporting network comprises an interconnected switched network of Local Area Networks, Internet Protocol Networks, frame relay networks, ATM networks, and Wide Area Networks.

56. A method for transmitting real time media between a first and a second processing hub comprising the steps of:

placing a call to the first processing hub,

partitioning and compressing the call at the first processing hub into a plurality of frames,

packetizing the frames at the first processing hub into a data packet according to a redundancy value;

transporting the data packet between the first processing hub and the second processing hub by a transporting network;

decoding the data packet at the second processing hub into the plurality of frames;

ordering these frames within a buffer according to a buffer length variable;

generating a plurality of utility parameters based on the redundancy variable and the buffer length variable;

selecting a preferred utility parameter from the generated utility parameters;

adjusting the redundancy variable and the buffer length variable in accordance with a dynamic transporting characteristic of the transporting network; and

receiving the call from the second processing hub.

57. The method of claim 56, further comprising the step of communicating the unpacked frames to a decoder from the second processing hub for a play out of the media input.

58. The method of claim 57, further comprising the step of playing out the media input.

59. The method of claim 56, wherein the real time media input is an audio waveform.

60. The method of claim 56, wherein the real time media input is a video waveform.

61. The method of claim 56, further comprising the step of selecting the dynamic characteristic from a group consisting of data packet loss, data packet delay, packet burst loss, loss auto-correlation and delay variation.

62. The method of claim 56, wherein the network comprises a packet switched network.

63. The method of above claim 62, further comprising the step of selecting the packet switched network from a group consisting of Local Area Networks, Internet Protocol Networks, frame relay networks, ATM networks, and Wide Area Networks.

64. The method of claim 62, wherein the transporting network comprises an interconnected switched network of Local Area Networks, Internet Protocol Networks, frame relay networks, ATM networks, and Wide Area Networks.