Configured Grant Retransmission Timing for Uplink Collision Avoidance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems operating in unlicensed spectrum without listen before talk (LBT), configured grant uplink transmissions from different UEs can collide in the same reception beam of a gNB, leading to systematic retransmission failures due to configured periodicities.
Innovation Solution
Adjusting retransmission timing by introducing an offset value for the retransmission timer associated with a configured grant, allowing UEs to defer retransmissions randomly to avoid collisions, which is configured per device, beam, HARQ process, or traffic class.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If configured grant uplink transmissions are used with configured periodicities, then transmission efficiency is improved, but retransmission collisions occur systematically
Solution Approach 1:
The patent introduces dynamic adjustment of retransmission timing by applying offsets to the configured periodicity. Instead of fixed periodic retransmissions, the system dynamically adapts retransmission timing based on collision detection and offset application, allowing the retransmission schedule to vary and avoid systematic collisions while maintaining overall transmission efficiency.
Solution Approach 2:
The patent changes the timing parameter of retransmissions by applying offsets to the configured grant periodicity. When collisions are detected or anticipated, the system modifies the retransmission timing parameter by adding random or semi-static offsets, transforming the fixed periodic schedule into a flexible timing mechanism that avoids systematic collisions.
2Device complexity
If retransmissions are performed at fixed periodic intervals, then transmission protocol simplicity is maintained, but collision avoidance capability deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-configuring offset values (random or semi-static) before retransmission occurs. The offset is determined in advance and applied to the configured grant timing, allowing the system to proactively avoid collisions before they happen rather than reacting after collision detection.
Solution Approach 2:
The system performs self-service by autonomously adjusting its own retransmission timing using the offset mechanism. The UE independently applies offsets to its configured grant retransmissions without requiring complex coordination with other UEs, allowing each device to self-regulate its timing to avoid collisions.
Data Source
AI summary
Apparatuses, methods, and systems are disclosed for adjusting retransmission timing for a configured grant. One apparatus includes a processor that determines an offset value for a retransmission timer associated with a configured grant for communications between the UE and a mobile wireless communication network. The processor starts the retransmission timer adjusted by the offset value in response to transmission of data corresponding to a transport block (“TB”) on a hybrid automatic repeat request (“HARQ”) process. The processor detects expiration of the retransmission timer associated with the configured grant. In response to detecting expiration of the retransmission timer, the processor determines a transmission resource from a plurality of configured transmission resources for retransmitting a TB.