RACH Occasion Cancellation Configuration for Dynamic Scheduling Conflicts
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Solution Overview
Problem
Wireless communication systems face conflicts between dynamic scheduling and random access resources, leading to decreased performance as RACH procedures can interfere with dynamically scheduled uplink or downlink transmissions, causing collisions and preempting resources.
Innovation Solution
The system configures random access channel (RACH) preamble and uplink data occasions, with indicators for cancellation eligibility, allowing user equipment (UE) to determine when to monitor downlink control channels and transmit RACH messages based on these configurations, avoiding conflicts with dynamic scheduling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If RACH procedures are allowed to use dynamically scheduled resources, then resource utilization efficiency is improved, but collision and preemption between RACH transmissions and dynamic scheduling occur
Solution Approach 1:
The patent segments RACH occasions into two categories: those restricted for cancellation and those not restricted. This segmentation allows the system to protect critical RACH transmissions from dynamic scheduling preemption while still allowing flexibility in non-critical occasions, thereby resolving the contradiction between resource utilization efficiency and RACH transmission reliability
Solution Approach 2:
The patent applies different cancellation restrictions to different RACH occasions based on their local characteristics and requirements. By configuring specific RACH occasions as restricted for cancellation while leaving others unrestricted, the system achieves local optimization that balances reliability requirements with overall resource utilization efficiency
2Reliability
If RACH occasions are restricted for cancellation to prevent collisions, then RACH transmission reliability is improved, but scheduling flexibility is reduced
Solution Approach 1:
The patent divides RACH occasions into restricted and non-restricted groups, allowing the system to maintain scheduling flexibility in non-restricted occasions while ensuring reliability in restricted occasions. This segmentation resolves the contradiction by applying different scheduling policies to different segments of RACH resources
Solution Approach 2:
The patent changes the cancellation restriction parameter for specific RACH occasions based on their importance and timing. By dynamically adjusting which occasions are restricted for cancellation, the system maintains adaptability while ensuring critical RACH transmissions are protected from preemption
3Reliability
If UEs monitor downlink control channels frequently to detect scheduling conflicts, then collision avoidance is improved, but processing overhead increases
Solution Approach 1:
The patent performs preliminary configuration of cancellation restriction indicators for RACH occasions before the actual RACH transmission. By pre-configuring which occasions are restricted for cancellation, UEs can avoid unnecessary monitoring and processing of non-restricted occasions, thereby reducing processing overhead while maintaining collision avoidance capability
Solution Approach 2:
The patent enables UEs to self-determine whether to monitor downlink control channels based on the cancellation restriction configuration. UEs can autonomously identify restricted RACH occasions and adjust their monitoring behavior accordingly, reducing processing overhead while ensuring collision avoidance for critical transmissions
Data Source
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AI summary
Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may perform a random access channel (RACH) procedure with a base station. The UE may receive a message configuring a RACH preamble occasion and an uplink data occasion. The message may be a radio resource control (RRC) message or a system information (SI) message. In some cases, the UE may determine if the RACH preamble occasion, the uplink data occasion, or both are restricted for cancellation based on the message. The UE may determine when to monitor a downlink control channel for dynamic scheduling based on determining which occasions are restricted for cancellation and may transmit a RACH message based on monitoring-or not monitoring-the downlink control channel for dynamic scheduling preempting a RACH occasion. In some other cases, a base station may schedule transmissions to not overlap with configured RACH occasions.