Uplink Data Rate Detection via MAC Layer Scheduling Feedback

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Solution Overview

Problem

Existing wireless communication systems face challenges in detecting changes in uplink channel data rates, leading to late detection and increased packet loss, which affects conversational quality, especially in congested conditions.

Innovation Solution

Monitoring scheduling information in user equipment to directly detect changes in link data rates and adapt application data rates by determining which service components to support, such as voice, video, or text services, allowing for early adjustment to changes in link data rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If indirect link quality measures (packet loss, signal strength) are used to detect rate changes, then the detection mechanism is simple, but the detection is late and limited in accuracy

Engineering Contradiction:
Improvelink data rate detection accuracyVSAvoiddetection delay
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements a feedback mechanism where the MAC layer monitors scheduling information and power ratio from the base station, directly detects link data rate changes, and provides timely feedback to the application layer. This closed-loop feedback enables early detection of rate changes before packet loss occurs, resolving the contradiction between detection accuracy and detection delay.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces an intermediary detection mechanism at the MAC layer that acts as a mediator between the network layer scheduling decisions and the application layer. This intermediary monitors scheduling information and power ratio parameters, translating them into direct link data rate measurements, thereby achieving both early detection and accurate measurement without relying on indirect packet loss metrics.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If packet buffering is used to handle rate changes, then packet loss is reduced, but transmission delay increases

Engineering Contradiction:
Improvepacket loss reductionVSAvoidtransmission delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the application layer adapt its data rate in anticipation of link conditions changing. The MAC layer detects rate changes early through monitoring scheduling information and power ratio, and notifies the application layer before packet loss occurs. This enables the application to proactively adjust its sending rate, avoiding both packet loss and excessive buffering delay.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the application layer adapts data rate based on packet loss detection, then reliability improves, but the adaptation is slow and conservative

Engineering Contradiction:
Improvedata rate adaptation reliabilityVSAvoidadaptation speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent establishes a direct feedback channel from the MAC layer to the application layer that provides real-time information about link data rate changes. This feedback mechanism enables the application layer to adapt its data rate quickly and accurately based on actual link conditions rather than relying on slow packet loss statistics, thereby improving both reliability and adaptation speed.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP1982478B1Performance optimization for an uplink channel in a wireless communication network
Publication Date: 2019.03.20 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP1982478B1 patent drawingFigure 1
  • EP1982478B1 patent drawingFigure 2
  • EP1982478B1 patent drawingFigure 3

AI summary

User equipment (200) in a wireless communication system monitors scheduling information and locally detects a change in link data rate of the uplink channel based on the monitored scheduling information. In this way, a change in link data rate can be detected directly without significant delay. This direct or early detection of a rate change is then combined with an appropriate system reaction. The information of the detected change in link data rate is preferably utilized for adapting the application data rate of an IP application running in the user equipment. As an alternative, or as a complement, data packets are classified based on relative importance and selected for transfer of information over the uplink channel based on the classification of data packets and in dependence on the detected change in link data rate.