Jitter Buffer Adaptation via Fast Attack Slow Decay Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing packet-switched voice communication systems face challenges in maintaining voice quality due to variable transmission delays and packet loss, particularly in poorly managed networks like the Internet, where jitter buffers often introduce additional packet loss and longer delays.
Innovation Solution
A state-less adaptation control algorithm with a fast attack and slow decay time is implemented to minimize jitter buffer delay, allowing occasional underflow to prioritize minimizing delay over preventing underflow errors, using watermark levels to adjust enqueue and dequeue operations based on network conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed length adaptive buffer is used to prevent underflow errors, then buffer underflow is reduced, but the buffer introduces longer delays and additional packet loss on networks with jitter greater than 40ms
Solution Approach 1:
The patent implements a dynamic jitter buffer that continuously adapts its length based on real-time network conditions. The buffer length is adjusted by comparing the current network jitter level with a target jitter level, allowing the system to optimize between preventing underflow and minimizing delay according to actual network state rather than using a fixed compromise length
Solution Approach 2:
The system changes the buffer length parameter dynamically based on detected network jitter characteristics. By monitoring network conditions and adjusting the buffer length parameter in response to varying jitter levels, the system can prevent underflow on high-jitter networks while minimizing unnecessary delay on low-jitter networks
2Reliability
If a dynamic jitter buffer varies the amount of delay induced according to detected changes in network transmission delay, then perceived network jitter is reduced, but implementation complexity increases
Solution Approach 1:
The patent employs a feedback mechanism where the system detects current network transmission delay characteristics and uses this information to adjust the jitter buffer length. The adaptation algorithm continuously monitors network jitter and modifies buffer parameters in response, creating a closed-loop control system that reduces perceived jitter while maintaining manageable complexity through iterative adjustment rather than complex predictive modeling
3Loss of time
If the jitter buffer minimizes delay within the buffer at the expense of occasional underflow, then buffer delay is reduced, but underflow errors occur more frequently
Solution Approach 1:
The system dynamically adjusts the buffer length parameter based on detected network jitter levels. When network jitter is high, the buffer length is increased to prevent underflow; when network jitter is low, the buffer length is decreased to minimize delay. This parameter adaptation allows the system to optimize the trade-off between delay and underflow prevention according to actual network conditions
Data Source
AI summary
A method of controlling a buffer for reducing jitter in a packet network is provided, with a fast attack and a slow decay time to track delay changes in the network. The principal function of the method for controlling the jitter buffer is to minimize the delay within the buffer and use packet loss compensation in the event that the buffer enters an underflow condition.