Adaptive Random Access Backoff for Wireless UEs
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Solution Overview
Problem
Current wireless communication systems, such as 5G NR and LTE, face delays in random access procedures due to ambiguous UE behavior, leading to unnecessary delays in contention-free preamble transmission.
Innovation Solution
A backoff procedure is introduced where user equipment (UE) determines whether to send a contention-free random access (CFRA) preamble during a backoff period based on the type of random access procedure, using a backoff indicator received from the base station (BS), allowing for efficient transmission even when contention-free resources are available.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If UE waits for backoff period to expire before transmitting CFRA preamble, then collision avoidance is improved, but access delay increases
Solution Approach 1:
The patent applies dynamics by making the backoff behavior adaptive rather than static. The UE dynamically determines whether to apply backoff based on the detected random access procedure type (CFRA vs. CBRA). When CFRA is detected, the UE transmits immediately without backoff; when CBRA is detected, the UE applies backoff. This dynamic adaptation resolves the contradiction by optimizing behavior for each specific scenario.
Solution Approach 2:
The patent changes the parameter of backoff duration from a fixed value to a conditional value based on procedure type detection. By monitoring the random access procedure type parameter and adjusting the backoff behavior accordingly, the system achieves both collision avoidance (when CBRA is detected) and reduced delay (when CFRA is detected).
2Speed
If UE transmits CFRA preamble immediately without backoff, then access speed is improved, but collision risk increases
Solution Approach 1:
The patent makes the transmission timing dynamic based on procedure type detection. Instead of always transmitting immediately or always waiting for backoff, the UE adaptively chooses the appropriate behavior by detecting whether the current random access procedure is CFRA or CBRA, thus achieving both speed and reliability when conditions are favorable.
Solution Approach 2:
The patent employs feedback by having the UE monitor and detect the random access procedure type before making transmission decisions. This feedback mechanism allows the UE to adjust its transmission timing based on the detected procedure type, reducing collision risk while maintaining access speed when appropriate.
3Measurement precision
If UE monitors random access procedure type to determine transmission behavior, then transmission accuracy is improved, but processing complexity increases
Solution Approach 1:
The patent extracts only the necessary information (random access procedure type) from the downlink messages to make transmission decisions. By focusing on detecting just the procedure type rather than analyzing all message contents, the UE achieves accurate detection with minimal processing complexity, taking out only the essential parameter needed for decision-making.
Data Source
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AI summary
Certain aspects of the present disclosure provide techniques for a random backoff procedure in a wireless communication network such as a new radio (NR) network. A method for wireless communications that can be performed by a user equipment (UE) is provided. The method includes sending a random access preamble to a base station (BS) during a random access procedure. The method includes receiving a random access response from the BS including a backoff indicator. The method includes determining whether to send a contention-free random access (CFRA) preamble to the BS during the backoff period based, at least in part, on a type of the random access procedure.