5G Random Access Switching Across Uplink Bandwidth Parts
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Solution Overview
Problem
In 5G mobile communications, there is a challenge in ensuring a high success rate for random access by terminal devices, particularly when conventional 4-step and 2-step random access processes fail, leading to high latency and signaling overheads.
Innovation Solution
A method where a terminal device performs random access in an active uplink bandwidth part, determining a parameter for the duration or number of access attempts, and switches to a different uplink bandwidth part if the parameter exceeds a threshold, utilizing various types of random access (grant-free, 2-step, 4-step) to improve success rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a terminal device performs random access in an active uplink bandwidth part using conventional 4-step or 2-step procedures, then the random access process can be completed, but the success rate is low leading to high latency and signaling overheads
Solution Approach 1:
The patent changes the parameter of bandwidth part selection dynamically. When random access fails in the active uplink bandwidth part (first bandwidth part), the terminal switches to a different uplink bandwidth part (second bandwidth part) with different identifier, performing random access in an alternative frequency resource pool to improve success probability and reduce latency
Solution Approach 2:
The patent introduces a new dimension for random access by switching between different bandwidth parts (frequency resources). Instead of repeatedly attempting access in the same bandwidth part, the terminal moves to a different frequency dimension (second bandwidth part with different identifier) when access fails, providing an alternative path for successful access
2Reliability
If a terminal device repeatedly attempts random access in the same bandwidth part, then the access procedure continues, but the signaling overhead increases and network resources are wasted
Solution Approach 1:
The patent changes the bandwidth part parameter dynamically based on access success. When random access fails in the first bandwidth part, the terminal switches to the second bandwidth part, avoiding repeated failed attempts in the same resource and reducing unnecessary signaling overhead
Solution Approach 2:
The patent extracts the failed random access attempts from the first bandwidth part and relocates them to the second bandwidth part. This separation allows the system to isolate failed access procedures from successful ones, preventing accumulation of redundant signaling in a single bandwidth part
Data Source
AI summary
Embodiments of this application disclose a random access method and an apparatus. The method includes: A terminal device performs first-type random access in a first bandwidth part, where the first bandwidth part is an active uplink bandwidth part; the terminal device determines a first parameter, where the first parameter is duration for performing first-type random access in the first bandwidth part, or the first parameter is a quantity of times of sending a first-type random access message; and the terminal device performs random access in a second bandwidth part if the first parameter is greater than a first threshold, where the second bandwidth part is an uplink bandwidth part, and an identifier of the second bandwidth part is different from an identifier of the first bandwidth part. Through implementation of the method described in embodiments of this application, a success rate of random access can be improved, and the terminal device can access a network in a timely manner.