Packet prioritization and associated bandwidth and buffer management techniques for audio over IP
View Patent ↗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.
1. A tangible, non-transitory computer readable medium, having a first voice stream stored thereon, the first voice stream comprising:
a first packet and a second packet, the first packet comprising:
a packet header comprising transmission information;
a payload comprising one or more frames of the first voice stream;
wherein at least one of the packet header and payload comprises a value of a value marker that is indicative of a level of importance of the payload to maintaining a selected quality of the first voice stream;
wherein the value is based on one of a level of confidence or a type of voice activity; and
wherein the value marker identifies the importance of the first packet associated with the first voice stream in comparison to the second packet associated with the first voice stream.
2. The packet of claim 1 , wherein the transmission information comprises the value marker.
3. The packet of claim 1 , wherein the payload comprises the value marker.
4. A memory comprising:
a first voice stream from a voice communication comprising two or more packets, wherein each packet comprises:
a packet header comprising transmission information;
a payload comprising a frame of the first voice stream; and
a value marker storing a value indicative of a level of importance of the payload to maintaining a selected quality of the voice communication stream, wherein the value marker identifies the importance of a first packet associated with the first voice stream in comparison to a second packet associated with the first voice stream, and wherein the value is based on one of a level of confidence or a type of voice activity.
5. The packet of claim 4 , wherein the transmission information comprises the value marker.
6. The packet of claim 4 , wherein the payload comprises the value marker.