Adaptive VoIP Jitter Buffer via RTP Header Modification

Solution Overview

Problem

VoIP networks often suffer from jitter issues, particularly when receiving packets from external or wireless networks, which conventional Session Border Controllers (SBCs) inadequately handle, leading to degraded voice quality due to unnecessary decoding, re-encoding, and processing resource consumption.

Innovation Solution

The implementation of adaptive jitter buffering that modifies Real Time Protocol (RTP) headers of VoIP packets without decoding or re-encoding the payload, allowing for dynamic adjustment of jitter buffer delay by dropping packets or modifying sequence and timestamp values, especially during silence periods to minimize voice quality degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional SBCs decode and re-encode VoIP packets to handle jitter, then jitter correction capability is improved, but processing resource consumption increases and voice quality degrades

Engineering Contradiction:

Improvejitter correction capabilityVSAvoidprocessing resource consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts only the necessary header information (sequence numbers, timestamps) from VoIP packets to adjust jitter buffer delay, rather than decoding and re-encoding the entire packet payload. This selective extraction approach corrects jitter while minimizing processing resource consumption and preserving voice quality.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of the conventional approach of decoding packets to analyze and correct jitter, the patent inverts the approach by directly manipulating RTP headers to achieve jitter correction. This reverse engineering method achieves the same jitter correction goal with significantly reduced processing overhead.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If conventional SBCs decode and re-encode VoIP packets to handle jitter, then jitter correction capability is improved, but voice quality degrades

Engineering Contradiction:

Improvejitter correction capabilityVSAvoidvoice quality degradation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts only the necessary header information (sequence numbers, timestamps) from VoIP packets to adjust jitter buffer delay, rather than decoding and re-encoding the entire packet payload. This selective extraction approach corrects jitter while minimizing processing resource consumption and preserving voice quality.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of the conventional approach of decoding packets to analyze and correct jitter, the patent inverts the approach by directly manipulating RTP headers to achieve jitter correction. This reverse engineering method achieves the same jitter correction goal with significantly reduced processing overhead.

Inventive Principle:

Principle #13The other way round (Inversion)

3Reliability

If jitter buffer delay is increased to handle external network jitter, then jitter tolerance is improved, but voice call quality degrades

Engineering Contradiction:

Improvejitter toleranceVSAvoidvoice call quality

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent dynamically adjusts jitter buffer delay by modifying RTP headers in real-time based on actual network conditions, rather than using a fixed large buffer. This dynamic adjustment allows the system to tolerate jitter when necessary while minimizing delay-induced quality degradation when the network is stable.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the delay parameter of jitter buffer by selectively modifying RTP packet headers, allowing flexible adjustment of buffer delay to match actual network jitter conditions, thereby balancing jitter tolerance with voice call quality.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9313338B2System, device, and method of voice-over-IP communication

Publication Date: 2016.04.12 AUDIOCODES LTD

AI summary

The present invention includes devices, systems, and methods of Voice-over-Internet Protocol (VoIP) communication. For example, a method includes: receiving a data stream comprising a set of VoIP packets; and modifying a Real Time Protocol (RTP) header of at least one of said VoIP packets to modify a jitter buffer delay of said data stream. Optionally, the method includes decreasing the jitter buffer delay by: dropping at least one packet from said data stream; and decreasing a sequence number and a timestamp value in an RTP header of at least one additional packet subsequent to said at least one packet. Optionally, the method includes increasing the jitter buffer delay by: identifying a pair of consecutive packets in the incoming data stream, the pair of consecutive packets having consecutive sequence numbers; and increasing a sequence number in an RTP header of at least a latter packet in said pair of consecutive packets.