Prioritized Scheduling Request Backoff in Wireless Systems

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Solution Overview

Problem

Current wireless communication systems do not perform backoff for scheduling requests (SR), leading to potential blocking of important access trials during uplink congestion.

Innovation Solution

A method for determining whether to apply a backoff parameter before transmitting an SR, where the decision is based on prioritized access types such as emergency access, high priority access, or specific radio bearers, and the backoff parameter is received from the network via system information or RRC connection reconfiguration messages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If backoff is not performed for scheduling request during uplink congestion, then SR transmission is simple and fast, but important access trials are blocked

Engineering Contradiction:
Improveaccess trial reliabilityVSAvoidSR transmission complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by differentiating SR transmission behavior based on access type. High priority access (e.g., emergency, voice/video) ignores backoff parameters to ensure reliable transmission, while non-prioritized access applies backoff to reduce congestion. This selective application of backoff based on local access characteristics resolves the contradiction between reliability and complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamics by making the SR transmission behavior adaptive rather than static. The UE dynamically determines whether to apply backoff based on the access type and received backoff parameters, allowing the system to flexibly adjust transmission behavior according to current conditions and priority levels, thereby improving reliability without permanently increasing complexity.

Inventive Principle:
Principle #15Dynamics

2Productivity

If backoff parameter is always applied before SR transmission, then congestion is reduced, but important access trials are blocked

Engineering Contradiction:
Improvesystem throughputVSAvoidimportant access reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by making backoff application dependent on the specific access type. High priority accesses (emergency, voice/video, control elements) are exempt from backoff to ensure their reliability, while non-prioritized accesses apply backoff to improve system throughput. This selective approach resolves the contradiction between productivity and reliability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of backoff application from a fixed state to a conditional state. The backoff parameter is received from the network but its application is modified based on access type classification. This parameter change allows the system to optimize throughput for non-prioritized access while protecting the reliability of high-priority access.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If backoff is performed for all SR transmissions, then random access congestion is reduced, but access delay increases

Engineering Contradiction:
Improverandom access efficiencyVSAvoidSR transmission delay
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies local quality by differentiating time treatment based on access priority. High priority accesses experience no backoff delay, maintaining fast access times, while non-prioritized accesses apply backoff to improve random access efficiency. This resolves the contradiction between productivity and time loss by applying delays only where necessary.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2912917B1Method and apparatus for performing backoff for scheduling request in wireless communication system
Publication Date: 2018.12.12 LG ELECTRONICS INC
  • EP2912917B1 patent drawingFigure 1~2
  • EP2912917B1 patent drawingFigure 3~5
  • EP2912917B1 patent drawingFigure 6~8

AI summary

A method and apparatus for scheduling uplink (UL) transmission in a wireless communication system is provided. A user equipment (UE) receives a backoff parameter from a network, and determines whether or not to apply the received backoff parameter before transmitting a scheduling request (SR) to the network via a dedicated channel. Whether or not to apply the received backoff parameter is determined according to a prioritized access, and the prioritized access corresponds to one of emergency access, high priority access, control element/information in media access control (MAC), radio link control (RLC) or packet data convergence protocol (PDCP), data radio bearer (DRB) for voice/video service, signaling radio bearer (SRB) 0, SRB 1, SRB 2, multimedia telephony service (MMTEL)-voice, MMTEL-video, and voice over long-term evolution (VoLTE).