RRC Inactive Data Transmission via Configured Grant Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, there is a challenge in efficiently managing data transmission in RRC INACTIVE states due to limited radio resources and latency issues, particularly in scenarios where timely data transmission is critical.
Innovation Solution
A method and apparatus for a user equipment (UE) to receive a message indicating a change in RRC state from CONNECTED to INACTIVE, where it assesses a time gap between the current time and an uplink grant occasion, triggering a random access procedure for data transmission if the gap is large enough, or using the uplink grant occasion if the gap is small, ensuring efficient data transmission in the RRC INACTIVE state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE triggers a random access procedure for data transmission in RRC INACTIVE state, then the data transmission can be performed, but the transmission latency increases due to the additional random access steps
Solution Approach 1:
The patent dynamically selects between two transmission modes (configured grant-based transmission and random access-based transmission) based on the time gap condition. When the time gap is within the threshold, the UE uses configured grant occasions for immediate transmission; when the time gap exceeds the threshold, the UE triggers random access procedure. This dynamic adaptation resolves the contradiction by optimizing the transmission path based on real-time conditions.
Solution Approach 2:
The patent changes the transmission parameter (transmission mode) based on the time gap parameter. By comparing the time gap between current time and configured grant occasion with a threshold, the system switches between two transmission approaches, thereby adapting to different latency requirements and resolving the contradiction between reliable transmission and low latency.
2Loss of time
If the UE uses configured grant occasions for data transmission, then the transmission latency is reduced, but the radio resource utilization becomes less flexible when the time gap is large
Solution Approach 1:
The system dynamically adjusts the transmission mode based on the time gap condition. When the time gap is small (within threshold), configured grant occasions are used for low-latency transmission. When the time gap is large (exceeds threshold), random access procedure is triggered for flexible resource allocation. This dynamic switching resolves the contradiction between latency efficiency and resource flexibility.
Solution Approach 2:
The patent implements a feedback mechanism where the UE evaluates the time gap between current time and configured grant occasion, compares it with a threshold, and accordingly selects the appropriate transmission mode. This feedback-based decision process ensures that the system adapts to varying resource availability conditions, resolving the contradiction between fixed grant efficiency and flexible resource utilization.
3Speed
If the UE maintains RRC CONNECTED state for immediate data transmission, then the transmission speed is fast, but the radio resource consumption increases
Solution Approach 1:
The patent prepares configured grant occasions in advance during the RRC CONNECTED state, allowing the UE to transition to RRC INACTIVE state while retaining pre-configured transmission resources. This preliminary action enables fast data transmission in INACTIVE state without maintaining continuous connection, thereby reducing ongoing radio resource consumption while preserving transmission speed when needed.
Solution Approach 2:
The patent uses periodic configured grant occasions for uplink transmission in RRC INACTIVE state. Instead of maintaining continuous connected state, the UE can transmit data at predetermined periodic intervals using configured grants, reducing average radio resource consumption while maintaining the capability for fast transmission when data arrives at the scheduled occasions.
Data Source
AI summary
A method for performing data transmission by a user equipment (UE) in a wireless communication system is disclosed. The method comprises steps of receiving a message indicating a change of a Radio resource control (RRC) state from a RRC CONNECTED state to a RRC INACTIVE state, wherein the message includes information related to a configured grant (CG) and a threshold; if a time gap between a current time and an uplink grant occasion associated with the configured grant is larger than or equal to the threshold, triggering a random access (RA) procedure for the data transmission; and performing the data transmission based on the RA procedure in the RRC INACTIVE state, wherein, if the time gap is smaller than the threshold, the data transmission is performed based on the uplink grant occasion associated with the configured grant.