MAC Congestion Signaling With Early CE Marking for Low-Latency XR

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current L4S technology relies on ECN marking at the tail of the queue, which is slow and inadequate for low latency and high throughput requirements of extended reality (XR) services, especially in dynamic wireless environments like 5G networks, leading to buffer bloat and increased latency.

Innovation Solution

Implementing a MAC layer-based early congestion indication mechanism that inserts CE codepoints at the head of the queue, allowing for faster feedback and reducing latency by detecting congestion at the MAC layer and providing CE indications through MAC subheaders and control elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ECN marking is implemented at the tail of the queue, then congestion notification is provided, but latency increases and throughput decreases

Engineering Contradiction:

Improvecongestion notification accuracyVSAvoidlatency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by inserting CE codepoints at the head of the queue before packets are transmitted, rather than waiting for congestion to occur at the tail. This early congestion indication allows receivers to prepare for potential buffer bloat and adjust their transmission rates proactively, reducing latency while maintaining accurate congestion notification.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If ECN marking is implemented at the tail of the queue, then congestion notification is provided, but throughput decreases

Engineering Contradiction:

Improvecongestion notification accuracyVSAvoidthroughput

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

By performing congestion indication at the head of the queue rather than the tail, the system enables faster feedback loops that allow receivers to adjust their transmission rates more quickly. This preliminary action maintains accurate congestion notification while improving throughput by reducing the time packets spend in congested queues.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If traditional ECN marking is used, then congestion control is implemented, but fine-grained control is not achieved

Engineering Contradiction:

Improvecongestion control functionalityVSAvoidcongestion control granularity

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies segmentation by introducing MAC control elements that provide fine-grained congestion control at the MAC layer, separate from traditional IP-layer ECN marking. This segmentation allows for more precise and granular congestion management, enabling differentiated control for different traffic flows and quality of service requirements.

Inventive Principle:

Principle #1Segmentation

4Reliability

If queue-based congestion control is used, then buffer management is implemented, but buffer bloat occurs

Engineering Contradiction:

Improvebuffer management capabilityVSAvoidbuffer size

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent implements feedback by having receivers send back congestion indications through MAC control elements that trigger sender to reduce transmission rates. This feedback mechanism prevents buffer bloat by continuously monitoring queue status and adjusting transmission parameters, allowing for more efficient buffer utilization without requiring excessively large buffers.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20260012847A1Technologies for media access control congestion signaling

Publication Date: 2026.01.08 APPLE INC

AI summary

The present application relates to devices and components including apparatus, systems, and methods for media access control congestion signaling in wireless networks.