Logical Channel SR Prohibit Timer Mechanism

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Solution Overview

Problem

In wireless communication systems, the existing SR prohibit mechanism fails to manage scheduling requests for logical channels effectively, leading to unnecessary SR transmissions and interference between LTE and NR/NextGen systems, particularly affecting URLLC operations due to excessive PUCCH load and lack of SR transmissions for certain logical channels.

Innovation Solution

Implementing a sr-ProhibitTimer for each logical channel to control SR transmissions independently, ensuring that SRs are only prohibited for channels with active timers, allowing SRs for channels without running timers and prioritizing SRs based on configured resources and priorities, thereby isolating the operation of one logical channel from others.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a single SR prohibit timer is used for all logical channels, then PUCCH load is reduced by preventing excessive SR transmissions, but SR transmissions for certain logical channels (e.g., URLLC) are unnecessarily blocked

Engineering Contradiction:
ImprovePUCCH loadVSAvoidSR transmission reliability for URLLC
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent divides the single SR prohibit timer into multiple logical channel-specific prohibit timers (one timer per logical channel). This segmentation allows each logical channel to have independent SR transmission control, so that URLLC traffic can maintain SR transmissions even when other channels are prohibited, resolving the contradiction between reducing overall PUCCH load and maintaining URLLC reliability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different SR prohibit timer configurations to different logical channels based on their specific requirements. URLLC logical channels can be configured with shorter or no prohibit timers to ensure reliable transmission, while other channels use longer timers to reduce PUCCH load,实现ing localized optimization rather than uniform prohibition

Inventive Principle:
Principle #3Local quality

2Loss of energy

If SR triggering is prevented for certain logical channels to reduce PUCCH load, then unnecessary SR transmissions are reduced, but no SRs are sent at all for those logical channels

Engineering Contradiction:
ImprovePUCCH loadVSAvoidSR transmission efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent implements dynamic SR prohibit timer management where timers are started, stopped, and restarted based on real-time conditions. When a logical channel's timer expires or is stopped, SR transmissions are permitted again. This dynamic approach allows the system to reduce PUCCH load during high-traffic periods while restoring transmission capability when appropriate, maintaining overall SR transmission efficiency

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses periodic timer expiration mechanisms to allow SR transmissions in cycles. Instead of permanent prohibition, the prohibit timer creates periodic opportunities for SR transmission, ensuring that logical channels can send SRs at regular intervals rather than being completely blocked, thus maintaining transmission efficiency while reducing excessive transmissions

Inventive Principle:
Principle #19Periodic action

3Device complexity

If a single SR prohibit timer is shared across all logical channels, then device complexity is reduced, but inter-system mobility between LTE and NR is affected

Engineering Contradiction:
ImproveSR management complexityVSAvoidInter-system mobility capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal SR prohibit timer mechanism that can be applied to multiple logical channels independently while maintaining a unified management structure. Each channel has its own timer instance, but they all follow the same management rules and can be controlled through a common interface, providing multi-functionality without proportionally increasing complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent establishes SR prohibit timer configurations in advance through RRC signaling before actual SR transmissions occur. The network pre-configures which logical channels should have prohibit timers and with what parameters, allowing the UE to automatically manage SR transmissions according to pre-planned rules, thereby simplifying real-time decision-making while supporting complex inter-system mobility scenarios

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3399826B1Devices handling scheduling request for logical channel
Publication Date: 2021.08.18 HTC CORP
  • EP3399826B1 patent drawingFigure 1
  • EP3399826B1 patent drawingFigure 2
  • EP3399826B1 patent drawingFigure 3

AI summary

A communication device for handling a scheduling request (SR) for a logical channel (LC) comprises a storage device storing instructions of transmitting a first SR for a fist LC to a network and starting a first sr-ProhibitTimer associated to the first LC, when the first SR is triggered by the first LC and the first sr-ProhibitTimer is not running; not transmitting the first SR for the first LC, when the first SR is triggered by the first LC and the first sr-ProhibitTimer is running; transmitting a second SR for a second LC to the network and starting a second sr-ProhibitTimer associated to the second LC, when the second SR is triggered by the second LC and the second sr-ProhibitTimer is not running; and not transmitting the second SR triggered by the second LC, when the second SR is triggered by the second LC and the second sr-ProhibitTimer is running.