DYNAMIC BUFFERING AND SYNCHRONIZATION OF RELATED MEDIA STREAMS IN PACKET NETWORKS

• US 20100271944A1
• Filed: 04/27/2009
• Published: 10/28/2010
• Est. Priority Date: 04/27/2009
• Status: Active Grant

• Current Assignee: Arlington Technologies, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Avaya Incorporated
• Inventors: Mohler, David S., Michaelis, Paul Roller
• Granted Patent: US 8,094,556 B2
• Time in Patent Office: Days
• US Class Current: 370/230.100
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 65/752 adapting media to network capabilities
• CPC Class Codes: H04L 65/80 Responding to QoS

Abstract

The present invention is directed to the use of two or more buffers, at a common receiving node, to reduce the effects of jitter, packet loss, and/or packet latency and/or synchronize different types of packets.

Claims

1. A method, comprising:

(a) receiving, at a common receiving node, first and second packets, the first and second packets having common packet durations and common timestamps and/or sequence numbers;

(b) writing, by a processor, the first packet to a first buffer;

(c) writing, by a processor, the second packet to a second buffer; and

(d) selecting, by a control module, at least one of (i) a time to read each of the first and second packets from the first and second buffers, respectively, and (ii) which of the first and second packets to read, wherein, in (ii), only one of the first and second packets is used to fill a gap in a data stream.

2. The method of claim 1, wherein the first and second packets have common source and destination address pairs, wherein a payload of the first packet has no more than a first level of compression, wherein a payload of the second packet has no more than a second level of compression, wherein the first level of compression is less than the second level of compression, and wherein the payload types of the first and second packets are the same.

3. The method of claim 1, wherein (i) is selected, wherein the first and second packets have common source and destination address pairs, and wherein the first and second packets have different types of media payloads.

4. The method of claim 1, wherein (ii) is selected, wherein the first and second packets have common source and destination address pairs, wherein payloads of the first and second packets have differing levels of compression, and wherein the first and second packets have a common type of media payload.

5. The method of claim 2, wherein the first packet is transmitted over a packet-switched network and the second packet is transmitted over a circuit-switched network, wherein (ii) is selected, wherein the first packet is read from the first queue and the second packet is not read from the second queue, and wherein the second packet is removed from the second queue at substantially the same time that the first packet is read from the first queue.

6. A computer readable medium encoded with instructions that, when executed, perform the steps of claim 1 and wherein the computer readable medium is in communication with the processor.

7. A method, comprising:

(a) maintaining, at a receiving node, at least first and second buffers for first and second sets of packets, wherein a selected first member of the first set of packets has at least one of a timestamp and sequence number in common with a selected second member of the second set of packets;

(b) resizing, by a control module and while at least one of the first and second buffers is occupied, the at least one of the first and second buffers, said resizing being a function of at least one of a state of a network over which at least some of the members of the first and/or second sets of packets are transmitted, a time to process members of the first and/or second sets of packets, relative occupancies of the first and second buffers, user requirements, and application requirements.

8. The method of claim 7, wherein the resizing is a function of the state of a network over which at least some of the members of the first and/or second sets of packets are transmitted and wherein the network is a packet-switched network.

9. The method of claim 8, wherein the network state is a function of one or more of the following:

access priority, bandwidth availability, jitter, packet loss, latency, toll quality, cell error ratio, severely errored cell block ratio, cell loss ratio, cell transfer delay, mean cell transfer delay, cell delay variability, average packet offset, and average packet variance.

10. The method of claim 8, wherein a Quality of Service of the network is indirectly related to a capacity of the at least one of the first and second buffers.

11. The method of claim 7, wherein the resizing is a function of a time to process members of the first and/or second sets of packets, wherein membership of the first set of packets is video information, and wherein membership of the second set of packets is audio information.

12. The method of claim 7, wherein the resizing is a function of the relative occupancies of the first and second buffers.

13. The method of claim 7, wherein the resizing is a function of user and/or application requirements and wherein the user and/or application requirements change as a function of time.

14. A computer readable medium encoded with instructions that, when executed, perform the steps of claim 7 and wherein the computer readable medium is in communication with the processor.

15. A system, comprising:

an input operable to receive first and second packets, the first and second packets having common packet durations and common timestamps and/or sequence numbers;

a processor operable to write the first packet to a first buffer and write the second packet to a second buffer; and

a control module operable to determine at least one of (i) a time to read each of the first and second packets from the first and second buffers, respectively, and (ii) which of the first and second packets to read, wherein, in (ii), only one of the first and second packets is used to fill a gap in a data stream.

16. The system of claim 15, wherein the first and second packets have common source and destination address pairs, wherein a payload of the first packet has no more than a first level of compression, wherein a payload of the second packet has no more than a second level of compression, wherein the first level of compression is less than the second level of compression, and wherein the payload types of the first and second packets are the same.

17. The system of claim 15, wherein (i) is selected, wherein the first and second packets have common source and destination address pairs and wherein the first and second packets have different types of media payloads.

18. The system of claim 15, wherein (ii) is selected, wherein the first and second packets have common source and destination address pairs, wherein payloads of the first and second packets have differing levels of compression, and wherein the first and second packets have a common type of media payload.

19. The system of claim 16, wherein the first packet is transmitted over a packet-switched network and the second packet is transmitted over a circuit-switched network, wherein (ii) is selected, wherein the first packet is read from the first queue and the second packet is not read from the second queue, and wherein the second packet is removed from the second queue at substantially the same time that the first packet is read from the first queue.

20. The system of claim 16, wherein the control module resizes, while at least one of the first and second buffers is occupied, the at least one of the first and second buffers, said resizing being a function of at least one of a state of a network over which the first and/or second packets are transmitted, a time to process the first and/or second packets, relative occupancies of the first and second buffers, time varying user requirements, and time varying application requirements.