Dynamic Backoff in Wireless Communication Nodes for PRACH Repetition
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Solution Overview
Problem
Existing random access backoff mechanisms in wireless communication systems, such as those used for PRACH, increase latency and fail to effectively manage cell overload during PRACH repetition, especially in scenarios with high uplink traffic.
Innovation Solution
A dynamic random access backoff mechanism that allows self-adaptive selection of random access resource groups based on a condition set, adjusting the execution time of resource selection to avoid waiting for a fixed backoff time when certain conditions are met, thereby balancing cell load and reducing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed random access backoff mechanism based on backoff time is used, then cell overload issue is solved, but random access latency increases
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed backoff time mechanism to a dynamic backoff mechanism that adapts based on random access success status. When random access fails, the UE waits for a backoff time before retrying; when successful, the UE can immediately attempt again without waiting for the full backoff time, thus optimizing latency while maintaining overload management
Solution Approach 2:
The patent changes the parameter of backoff time from a fixed value to a variable that depends on random access outcome. The system modifies the timing parameter dynamically based on whether the previous random access attempt succeeded or failed, allowing flexible adjustment of retry intervals to balance latency and cell load management
2Reliability
If PRACH repetition is performed to enhance uplink coverage, then uplink coverage is improved, but cell overload condition changes and existing backoff mechanism becomes difficult to apply
Solution Approach 1:
The patent makes the backoff mechanism adaptive to PRACH repetition scenarios by allowing immediate retry when random access succeeds during repetition. This dynamic adjustment enables the system to handle the increased time-frequency resources occupied by PRACH repetition without being constrained by fixed backoff timing, thus maintaining adaptability in changing cell load conditions
Solution Approach 2:
The system uses feedback from random access outcome (success or failure) to adjust the backoff behavior. When PRACH repetition is performed and the access attempt succeeds, the UE receives feedback and can immediately retry without waiting for the full backoff time, making the mechanism responsive to actual access conditions rather than following a rigid timer
Data Source
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AI summary
Disclosed in the present application is a method and an apparatus used in a wireless communication node. The communication node, in response to the first random access process not being completed, selects a second random access resource group; sends a preamble according to the second random access resource group; wherein the execution time of the action of selecting the second random access resource group is related to whether the first condition set is satisfied; if the first condition set is satisfied, the execution time of the selection of the second random access resource group is no later than a first backoff time; if the first condition set is not satisfied, the execution time of the action of selecting the second random access resource group is no earlier than the first backoff time; the first condition set is related to the second random access resource group; the second random access resource group consists of K2 air interface resources, and the K2 is an integer greater than 1. The present application is capable of self-adaptively adjusting the backoff time of the performance of random access resource selection for enhanced PRACH coverage.