Threshold-Based Scheduling Request for Power-Efficient LTE

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Solution Overview

Problem

Current LTE scheduling request mechanisms are inefficient, leading to high power consumption and increased PDCCH overhead, particularly for low-volume data transmissions and Machine-Type Communication (MTC) devices, where frequent buffer status reports and scheduling requests consume significant energy and resources.

Innovation Solution

Implementing a threshold-dependent triggering mechanism for scheduling requests, where the transmission is postponed until both a data quantity threshold and/or a timer condition are met, and optimizing the monitoring of the downlink control channel by delaying the start of monitoring after a scheduling request is sent, as well as restricting dedicated scheduling request resources based on priority.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequent scheduling requests and buffer status reports are transmitted to ensure timely data delivery, then reliability of data transmission is improved, but power consumption increases

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the parameter of scheduling request transmission from frequent/regular intervals to threshold-based triggering. The UE monitors buffer status and only transmits scheduling requests when buffer occupancy exceeds a predetermined threshold, thereby reducing transmission frequency while maintaining reliable data delivery when actually needed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements periodic buffer status monitoring with threshold-based triggering. Instead of continuous or frequent periodic transmissions, the system uses periodic monitoring combined with threshold comparison to determine when transmission is necessary, reducing overall transmission count while maintaining reliability.

Inventive Principle:
Principle #19Periodic action

2Productivity

If dedicated scheduling request resources are allocated frequently to ensure quick resource acquisition, then productivity of resource request handling is improved, but PDCCH overhead increases

Engineering Contradiction:
Improveresource request handling efficiencyVSAvoidPDCCH overhead
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent changes the parameter of resource allocation from frequent/dedicated to threshold-based/on-demand. By introducing buffer occupancy thresholds, the system dynamically adjusts when scheduling requests are transmitted, reducing the quantity of scheduling requests and corresponding PDCCH overhead while maintaining efficient resource acquisition when needed.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If continuous monitoring of downlink control channel is performed to ensure timely grant reception, then reliability of resource allocation is improved, but power consumption increases

Engineering Contradiction:
Improveresource allocation reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic monitoring with strategic pauses. The UE monitors the downlink control channel periodically at scheduled intervals rather than continuously, pausing monitoring during periods when resource allocation is less likely to occur, thereby reducing power consumption while maintaining reliable grant reception when allocations are made.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies skipping by allowing the UE to skip monitoring intervals during low-activity periods. By strategically skipping certain monitoring opportunities when buffer status indicates no pending data, the system reduces power consumption while ensuring monitoring occurs when resource allocation is actually needed.

Inventive Principle:
Principle #21Skipping (Rushing through)

Data Source

PatentEP4002950B1Threshold-based and power-efficient scheduling request procedure
Publication Date: 2024.10.23 APPLE INC
  • EP4002950B1 patent drawingFigure 1
  • EP4002950B1 patent drawingFigure 2
  • EP4002950B1 patent drawingFigure 3

AI summary

A method executed by a base station, the method comprising: transmitting, to a user equipment, information to set a timer for a logical channel of the user equipment; and receiving a scheduling request transmitted from the user equipment requesting uplink resources, wherein the transmission of the scheduling request from the user equipment to the base station is triggered by the user equipment: determining that a first trigger condition is fulfilled for the logical channel based at least in part on data becoming available in a transmission buffer of the user equipment; starting the timer when the first trigger condition is fulfilled to delay transmission of the scheduling request; and determining that a second trigger condition is fulfilled for the logical channel based at least in part on expiration of the timer