Method and apparatus for operating a multicast system on an unreliable network

• US 5,561,670 A
• Filed: 05/13/1994
• Issued: 10/01/1996
• Est. Priority Date: 05/13/1994
• Status: Expired due to Term

• Current Assignee: Apple Computer Incorporated (Apple Inc.)
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Green, Mark A., Hoffert, Eric M.
• Primary Examiner(s): Kizou, Hassan
• Application Number:
  US08/242,138
• Time in Patent Office: 872 Days
• Field of Search: 370/60, 370/60.1, 370/94.1, 370/94.2, 370/94.3, 370/110.1, 370/119, 348/6, 348/10, 348/429, 348/460, 348/461, 348/462, 348/473, 348/474, 348/522, 348/555, 348/467, 380/10, 380/20, 340/825.3
• US Class Current: 370/410
• CPC Class Codes: H04L 12/1868 Measures taken after transmission, e.g. acknowledgments
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04L 65/764 at the destination reformatting of additional data in video clients H04N21/4355
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 21/236 Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream multiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00

Abstract

A multicast network system comprises a data network which provides a medium for data transfer. A media source having a control packet and media packets coupled to the data network broadcasts the control packet and the media packets to the data network and rebroadcasts the control packet in conjunction with the media packets to the data network. A media receiver is coupled to the network and receives the control packet and the media packets from the data network to process the control packet and the media packets to produce a media output.

Claims

1. A method of operating a multicast network comprising the steps of:

transmitting a media packet digital signal on the multicast network; and

transmitting a control packet digital signal on the multicast network, wherein the control packet digital signal includes format information on the media packet digital signal.

2. The method of claim 1 further comprising the steps of:

receiving the control packet digital signal and the media packet digital signal by a media receiver; and

processing the control packet digital signal and the media packet digital signal to produce a media output signal.

3. The method of claim 2, further comprising the step of processing the format information by the media receiver before processing the media packet digital signal.

4. The method of claim 3, wherein the media packet digital signal includes audio samples and video frames and the method further comprises the steps of:

generating datagrams having format information pertaining to the audio samples and the video frames;

broadcasting the datagrams to the multicast network; and

receiving the datagrams and using the datagrams to reconstruct the audio samples and the video frames from the multicast network.

5. The method of claim 4 further comprising the step of outputting the reconstructed audio samples and video frames.

6. The method of claim 2, wherein the format information of the control packet digital signal includes open channel information and open stream information, and further comprising the step of generating an array of the open channel information and the open stream information.

7. The method of claim 2, further comprising the step of storing the control packet digital signal and the media packet digital signal, by the media receiver, in order to produce the media output signal at a later time.

8. The method of claim 2 further comprising the steps of:

transmitting a second control packet digital signal having second format information on the multicast network; and

transmitting a second media packet digital signal on the multicast network that conforms to the second format information.

9. The method of claim 8 further comprising the steps of:

receiving the second control packet digital signal and the second media packet digital signal; and

processing, by the media receiver, the second control packet digital signal and the second media packet digital signal to produce a second media output signal.

10. The method of claim 9, wherein the step of processing the second control packet precedes processing the media packet digital signal.

11. A media device, coupled to a network, comprising:

a receiver, having a data format memory, which receives multiple transmissions of control packet digital signals having media packet digital signal format information, and stores the format information in the data format memory;

a data processor, coupled to the receiver, which receives the media packet digital signal format information enabling media packet digital signals to be processed by the data processor to produce processor output signals; and

an output device coupled to the data processor which receives signals from the data processor corresponding to received media packet digital signals to produce an output signal.

12. The media device of claim 11 further comprising a media packet digital signal storage device which receives and stores media packet digital signals.

13. The media device of claim 11, wherein the receiver receives a second control packet digital signal having second media data format information for storage in the data format memory.

14. The media device of claim 13, wherein the second data format information is stored in the data format memory before the receiver processes the media packet digital signals.

15. An apparatus for operating on a multicast network, comprising:

means for transmitting a media packet digital signal on the multicast network; and

means for transmitting a control packet digital signal on the multicast network, wherein the control packet digital signal includes format information on the media packet digital signal.