Random Access Selection Between Two-Step and Four-Step RACH
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge lies in selecting an appropriate random access method between two-step and four-step RACH mechanisms in a cell that supports both, ensuring efficient resource allocation and minimizing collisions while leveraging the faster access speed of two-step RACH and providing a backup mechanism for fallback.
Innovation Solution
A random access method that involves receiving configuration information with a threshold and priority settings, allowing terminals to select between two-step and four-step RACH based on parameters such as service requirements, signal quality, and channel occupancy, thereby distributing users and reducing collision probabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If two-step RACH is selected for fast access, then access speed is improved, but collision probability increases due to limited capacity
Solution Approach 1:
The patent segments the user population into different groups based on service requirements, signal quality, and channel occupancy. Different segments are assigned to different RACH mechanisms (two-step or four-step) to balance access speed and collision probability. This segmentation allows the system to leverage the fast access of two-step RACH for suitable users while protecting against collisions by assigning other users to four-step RACH.
Solution Approach 2:
The patent changes the selection parameters dynamically based on service requirements, signal quality metrics, and channel occupancy levels. By adjusting these parameters, the system can adaptively select between two-step and four-step RACH to optimize both access speed and collision probability under different conditions.
2Reliability
If four-step RACH is used as backup mechanism, then reliability is improved, but access speed deteriorates compared to two-step RACH
Solution Approach 1:
The patent performs preliminary assessment of service requirements, signal quality, and channel occupancy before selecting the RACH mechanism. This preliminary action allows the system to proactively choose the appropriate mechanism (two-step for speed, four-step for reliability) before the actual access attempt, ensuring both fast access when possible and reliable fallback when needed.
3Device complexity
If all users are allocated to a single RACH mechanism, then device complexity is reduced, but resource utilization efficiency deteriorates
Solution Approach 1:
The patent enables user equipment to autonomously select the appropriate RACH mechanism based on pre-configured criteria including service requirements, signal quality thresholds, and channel occupancy levels. This self-service approach eliminates the need for complex network-side allocation decisions while optimizing resource utilization by matching users to suitable mechanisms based on their specific conditions.
Data Source
Figure 1~4
Figure 5~6
Figure 7
AI summary
The present disclosure provides a random access method and apparatus, and a communications device, and relates to the field of wireless communications technologies. The random access method includes: receiving, by a terminal, random access configuration information from a network side device, wherein the random access configuration information comprises at least a random access threshold; and selecting, by the terminal, a random access manner according to the random access configuration information.