Packet prioritization and associated bandwidth and buffer management techniques for audio over IP

• US 8,370,515 B2
• Filed: 03/26/2010
• Issued: 02/05/2013
• Est. Priority Date: 09/30/2002
• Status: Expired due to Fees

• Current Assignee: Arlington Technologies, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Avaya Incorporated
• Inventors: Gentle, Christopher R., Michaelis, Paul Roller
• Primary Examiner(s): Tran, Philip B
• Application Number:
  US12/748,094
• Publication Number:
  US 20100182930A1
• Time in Patent Office: 1,047 Days
• Field of Search: 709/231, 709/238, 709223-224
• US Class Current: 709/231
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/12 Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/2408 for supporting different services, e.g. a differentiated services [DiffServ] type of service
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/2433 Allocation of priorities to traffic types
• 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 47/31 by tagging of packets, e.g. using discard eligibility [DE] bits
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation

Abstract

The present invention is directed to voice communication devices in which an audio stream is divided into a sequence of individual packets, each of which is routed via pathways that can vary depending on the availability of network resources. All embodiments of the invention rely on an acoustic prioritization agent that assigns a priority value to the packets. The priority value is based on factors such as whether the packet contains voice activity and the degree of acoustic similarity between this packet and adjacent packets in the sequence. A confidence level, associated with the priority value, may also be assigned. In one embodiment, network congestion is reduced by deliberately failing to transmit packets that are judged to be acoustically similar to adjacent packets; the expectation is that, under these circumstances, traditional packet loss concealment algorithms in the receiving device will construct an acceptably accurate replica of the missing packet. In another embodiment, the receiving device can reduce the number of packets stored in its jitter buffer, and therefore the latency of the speech signal, by selectively deleting one or more packets within sustained silences or non-varying speech events. In both embodiments, the ability of the system to drop appropriate packets may be enhanced by taking into account the confidence levels associated with the priority assessments.

Claims

1. A method for processing voice communications over a data network, comprising:

receiving a voice stream from a first user, the voice stream comprising a plurality of temporally distinct segments associated with a plurality of packets and the voice stream being a part of a session between at least the first user and a second user, wherein the session has an associated at least one of a jitter value, a latency value, a number of missing packets, a number of packets received out-of-order, a processing delay, a propagation delay, a receive buffer delay, and a number of packets enqueued in a receive buffer and

comparing the at least one of a jitter value, a latency value, a number of missing packets, a number of packets received out-of-order, a processing delay, a propagation delay, a receive buffer delay, and a number of packets enqueued in a receive buffer with a predetermined threshold;

(i) when the at least one of a jitter value, a latency value, a number of missing packets, a number of packets received out-of-order, a processing delay, a propagation delay, a receive buffer delay, and a number of packets enqueued in a receive buffer exceeds the predetermined threshold, not transmitting at least some of the plurality of packets and

(ii) when the at least one of a jitter value, a latency value, a number of missing packets, a number of packets received out-of-order, a processing delay, a propagation delay, a receive buffer delay, and a number of packets enqueued in a receive buffer is less than the predetermined threshold, transmitting the at least some of the plurality of packets; and

further comprising at least one of the following steps;

determining whether or not the contents of a selected first segment of the plurality of temporally distinct segments of the voice stream are the product of voice activity and, when the contents are determined not to be the product of voice activity, indicate a level of confidence that the voice activity determination is accurate; and

comparing the selected first segment with a second segment of the plurality of temporally distinct segments to determine a degree of acoustic similarity between the first and second segments, wherein the processing of the first segment is based on at least one of the level of confidence, the type of voice activity, and the degree of acoustic similarity.

2. The method of claim 1, further comprising:

based on the at least one of the level of confidence, type of voice activity and the degree of acoustic similarity, assigning an importance to the first segment.

3. The method of claim 2, wherein the importance is a value marker and further comprising:

incorporating the value marker into a first packet comprising the first segment.

4. The method of claim 2, wherein the importance is a service class assigned to a first packet comprising the first segment.

5. The method of claim 2, wherein the importance is a transmission priority assigned to a first packet comprising the first segment.

6. The method of claim 1, wherein in the processing step a first packet comprising the first segment is not transmitted when the at least one of the level of confidence and the degree of acoustic similarity is one of less than and greater than a predetermined threshold.

7. The method of claim 6, wherein a first packet associated with the first segment is not transmitted and further comprising:

later reconstructing the first segment with a packet loss concealment algorithm.

8. The method of claim 1, wherein the type of voice activity is a plosive.

9. The method of claim 1, wherein the at least one step is the determining step and wherein the level of confidence is based on a degree of similarity of temporally adjacent packets.

10. The method of claim 1, wherein the at least one step is the determining step and wherein the level of confidence is based on the significance of audio in a packet to receiver understanding or fidelity.

11. The method of claim 1, wherein the at least one step is the determining step and wherein the level of confidence permits a voice activity detector to provide a ternary output.