UE Uplink Grant Selection for Configured Grant Latency
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Solution Overview
Problem
Wireless communications systems face latency issues due to misalignment between the periodicity of uplink configured grants and the arrival of uplink data, leading to increased delays and reduced performance, especially when scheduling requests are prohibited.
Innovation Solution
User equipment (UE) dynamically determines whether to use uplink resources associated with a configured grant or a scheduling request based on latency calculations or delay thresholds, choosing the option that provides the soonest-available resources to reduce latency and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the UE waits for the next configured grant transmission opportunity, then the UE can transmit uplink data using pre-configured resources, but the latency increases when the periodicity of configured grants does not align with data arrival
Solution Approach 1:
The patent applies dynamics by enabling the UE to dynamically switch between two uplink transmission modes: configured grant (grant-free) and dynamic grant (scheduling request). The UE evaluates data arrival timing against configured grant periodicity and selectively chooses the optimal transmission path, making the system adaptable rather than static. This resolves the contradiction by allowing the UE to use configured grants when they align with data arrival (low latency) and switch to scheduling requests when misalignment occurs (avoiding excessive latency).
Solution Approach 2:
The patent changes the operational parameter of uplink transmission mode from fixed to variable. The network configures both configured grant parameters (periodicity, time resources) and enables dynamic grant capability, allowing the UE to adjust its transmission approach based on real-time conditions. This parameter flexibility resolves the contradiction between maintaining pre-configured resource efficiency and adapting to variable data arrival patterns.
2Loss of time
If the UE sends a scheduling request to obtain uplink resources, then the UE can get resources allocated sooner when configured grant periodicity is long, but the UE cannot use grant-free transmission which simplifies operation
Solution Approach 1:
The patent introduces dynamic mode selection where the UE transitions between configured grant mode and dynamic grant mode based on data arrival timing. The UE monitors configured grant opportunities and compares them with actual data arrival times, dynamically deciding whether to wait for the next configured grant or initiate a scheduling request. This dynamic approach resolves the contradiction by adapting the transmission mode to minimize latency while managing complexity through automated decision logic.
Solution Approach 2:
The patent implements self-service by enabling the UE to autonomously determine when to use configured grants versus when to send scheduling requests. The UE independently evaluates its data buffer status, calculates timing based on configured grant periodicity, and makes transmission decisions without continuous network intervention. This self-service mechanism resolves the contradiction by allowing the UE to manage its own resource allocation strategy, reducing reliance on network scheduling while maintaining optimal latency performance.
3Ease of operation
If the UE always uses configured grants for uplink transmission, then the UE can transmit without scheduling requests, but latency increases when data arrives between configured grant opportunities
Solution Approach 1:
The patent applies dynamics by making the UE's transmission mode configurable and switchable. The network can configure the UE with configured grants for grant-free operation, but also enables the capability to send scheduling requests when needed. The UE dynamically selects between these modes based on whether data arrival aligns with configured grant opportunities, resolving the contradiction between operational simplicity and latency efficiency.
Solution Approach 2:
The patent implements multi-functionality by designing the uplink transmission system to support both configured grant mode and dynamic grant mode within the same UE configuration. The UE possesses universal capability to perform both grant-free transmission and scheduled transmission, selecting the appropriate function based on real-time conditions. This universality resolves the contradiction by allowing the system to leverage the simplicity of configured grants when applicable while accessing the flexibility of scheduling requests when needed.
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. A wireless device such as a user equipment (UE) may receive a first control message that indicates a set of scheduled uplink communications, where the set of scheduled uplink communications include a set of transmission opportunities for transmitting one or more uplink messages. The UE may calculate a first duration between an availability of uplink data at the UE and a transmission opportunity of the set of transmission opportunities for transmitting the uplink data. The UE may then transmit a scheduling request for the uplink data based on the first duration being greater than a second duration, the second duration being either a duration between sending the scheduling request and receiving an uplink grant, or a latency threshold duration.