Message synchronization over a stochastic network

• US 8,750,409 B2
• Filed: 09/14/2012
• Issued: 06/10/2014
• Est. Priority Date: 08/30/2004
• Status: Active Grant

• Current Assignee: Harmonic Incorporated
• Original Assignee: Harmonic Incorporated
• Inventors: Picco, Martin Raptis, Koren, Noam
• Primary Examiner(s): ODOM, CURTIS B
• Application Number:
  US13/620,479
• Publication Number:
  US 20130010890A1
• Time in Patent Office: 634 Days
• Field of Search: 375/327, 375354-358, 375373-376, 375/295, 370229-235
• US Class Current: 375/295
• CPC Class Codes: H04J 3/0632 Synchronisation of packets and cells, e.g. transmission of voice via a packet network, circuit emulation service [CES] queuing arrangements in packet switching elements H04L49/90; synchronising systems for the synchronous transmission of a pulse code modulated video signal with one or more other pulse code modulated signals H04N7/56
• 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 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/263 Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: H04L 47/43 Assembling or disassembling of packets, e.g. segmentation and reassembly [SAR]

Abstract

Methods and apparatus to communicate between a local component and a remote component, where the local component is connected to the remote component using a non-deterministic communication link. A local clock is synchronized with a remote clock to within a maximum offset. A rate message from the remote component is received at the local component, where the rate message includes a first time stamp. A data rate is adjusted using the rate message when the time of the local clock substantially matches a time determined using the first time stamp. A data message is sent to the remote component using the adjusted data rate, where the data message includes a second time stamp for use in processing data in the data message. In some implementations, the time determined using the first time stamp is also determined using information about a communication link delay and/or a clock offset.

Claims

1. A method comprising:

sending a message including timing information from a processing device to an encoding device;

receiving a data message including a time stamp from the encoding device;

adjusting a data rate associated the data message based on the time stamp and recommended encoding information; and

processing data included in the data message based on the time stamp including determining when to place the data in an output stream.

2. The method of claim 1, where receiving the data message includes receiving an encoded message encoded using an adjusted data rate determined based on the timing information.

3. The method of claim 1, where receiving the data message includes receiving the time stamp indicative of a time at which the data message is sent by the encoding device.

4. The method of claim 3, where determining when to place the data in the output stream includes determining when to place the data in the output stream based on the time at which the data message is sent and at least one of a network delay and an offset associated with a timing difference between a local time of the encoding device and a local time of the processing device.

5. The method of claim 1, where sending the message includes sending a broadcast message to a plurality of encoding devices including the encoding device, the broadcast message including a time stamp and one of an individual bitrate for each encoding device or a single bitrate to be implemented by the plurality of encoding devices.

6. The method of claim 5, where receiving the data message includes receiving a plurality of data messages from the plurality of encoding devices including the encoding device at the individual bitrate or single bitrate, the method further comprising:

combining data in the plurality of data messages into a multiplexed output stream.

7. A non-transitory computer storage device including instructions for performing operations comprising:

sending a message including timing information from a processing device to an encoding device;

receiving a data message including a time stamp from the encoding device;

adjusting a data rate associated the data message based on the time stamp and recommended encoding information; and

processing data included in the data message based on the time stamp including determining when to place the data in an output stream.

8. The non-transitory computer storage device of claim 7, where receiving the data message includes receiving an encoded message encoded using an adjusted data rate determined based on the timing information.

9. The non-transitory computer storage device of claim 7, where receiving the data message includes receiving the time stamp indicative of a time at which the data message is sent by the encoding device.

10. The non-transitory computer storage device of claim 9, where determining when to place the data in the output stream includes determining when to place the data in the output stream based on the time at which the data message is sent and at least one of a network delay and an offset associated with a timing difference between a local time of the encoding device and a local time of the processing device.

11. The non-transitory computer storage device of claim 7, where sending the message includes sending a broadcast message to a plurality of encoding devices including the encoding device, the broadcast message including a time stamp and one of an individual bitrate for each encoding device or a single bitrate to be implemented by the plurality of encoding devices.

12. The non-transitory computer storage device of claim 11, where receiving the data message includes receiving a plurality of data messages from the plurality of encoding devices including the encoding device at the individual bitrate or single bitrate, the operations further comprising:

combining data in the plurality of data messages into a multiplexed output stream.

13. A system comprising:

one or more computer processors; and

one or more non-transitory computer readable devices that include instructions that, when executed by the one or more computer processors, causes the processors to perform operations, the operations comprising;

sending a message including timing information from a processing device to an encoding device;

receiving a data message including a time stamp from the encoding device;

adjusting a data rate associated the data message based on the time stamp and recommended encoding information; and

processing data included in the data message based on the time stamp including determining when to place the data in an output stream.

14. The system of claim 13, where receiving the data message includes receiving an encoded message encoded using an adjusted data rate determined based on the timing information.

15. The system of claim 13, where receiving the data message includes receiving the time stamp indicative of a time at which the data message is sent by the encoding device.

16. The system of claim 15, where determining when to place the data in the output stream includes determining when to place the data in the output stream based on the time at which the data message is sent and at least one of a network delay and an offset associated with a timing difference between a local time of the encoding device and a local time of the processing device.

17. The system of claim 13, where sending the message includes sending a broadcast message to a plurality of encoding devices including the encoding device, the broadcast message including a time stamp and one of an individual bitrate for each encoding device or a single bitrate to be implemented by the plurality of encoding devices.

18. The system of claim 17, where receiving the data message includes receiving a plurality of data messages from the plurality of encoding devices including the encoding device at the individual bitrate or single bitrate, the operations further comprising:

combining data in the plurality of data messages into a multiplexed output stream.

19. A system comprising:

one or more encoding devices for processing data using one or more bitrates; and

a multiplexer in communication with the one or more encoding devices using one or more messages, the one or more messages containing a time stamp and transmission characteristic information that allows the one or more encoding devices to adjust the one or more bitrates for encoding the data such that data encoded with the one or more adjusted bitrates by the one or more respective encoding devices arrive in time to be placed in an output stream within a time limit as determined based on the time stamp.