Acoustic Prioritization Agent for VoIP Packet Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional VoIP architectures face challenges in maintaining high voice quality due to network congestion, end-to-end delay, and packet loss, particularly with unreliable voice activity detection and limited receive buffer capacity, leading to choppy or clipped audio.
Innovation Solution
A computational architecture that includes a packet protocol interface and an acoustic prioritization agent to dynamically manage transmission bandwidth and receive buffer latency by providing a ternary output for voice activity detection, prioritizing important voice stream segments, and using packet loss concealment algorithms to reconstruct omitted packets, thereby reducing network congestion and improving voice quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If voice activity detection (VAD) is used to conserve bandwidth by preventing transmission of silent packets, then bandwidth efficiency is improved, but voice quality deteriorates due to unreliable silence detection and loss of audio information
Solution Approach 1:
The patent changes the output parameter of VAD from binary (silence/no silence) to a continuous confidence level (0-1 scale). This allows nuanced decision-making where packets with confidence levels between thresholds can be selectively transmitted or dropped based on network conditions, resolving the contradiction between bandwidth efficiency and voice quality by providing flexible control over packet transmission decisions
Solution Approach 2:
The patent introduces dynamic threshold adjustment where the silence detection thresholds are not fixed but can be adapted based on network congestion levels. When network conditions are good, lower thresholds are used to drop more silent packets for bandwidth efficiency. When congestion is detected, thresholds are raised to preserve more packets for voice quality, thus dynamically balancing the contradiction
2Adaptability or versatility
If a receive buffer with limited capacity (around 150 milliseconds) is maintained to handle late packets, then packet arrival flexibility is improved, but voice quality deteriorates when buffer fills to capacity causing packet drops
Solution Approach 1:
The patent applies preliminary action by proactively dropping low-importance packets (identified by low confidence levels or marked as silent) from the receive buffer before the buffer reaches capacity. This prevents the buffer from filling up and causing indiscriminate packet drops, thereby maintaining voice quality while still providing flexibility for late packet arrival
Solution Approach 2:
The patent applies local quality by treating different packets differently based on their importance. Instead of uniformly dropping packets when buffer is full, the system identifies and prioritizes dropping less important packets (silent packets, low confidence packets) while preserving important voice packets, thus resolving the contradiction between buffer flexibility and voice quality
3Reliability
If packet loss concealment algorithms reconstruct missing packets based on temporally adjacent packets, then packet loss recovery is improved, but voice quality deteriorates when adjacent packets are acoustically dissimilar to missing packets
Solution Approach 1:
The patent applies preliminary action by proactively transmitting packets with higher confidence levels and important voice segments before network congestion occurs. This reduces the number and severity of packet losses that would require concealment, thereby improving both recovery effectiveness and voice quality by preventing rather than just repairing damage
Data Source
AI summary
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.