Random Access Preamble Selection Using Dynamic Coverage Enhancement Levels

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Solution Overview

Problem

User equipment (UE) may fail to perform a successful random access procedure due to an inappropriate coverage enhancement (CE) level, leading to inefficiencies in wireless communication systems.

Innovation Solution

A communication device that determines a first CE level, selects a random access preamble, performs the random access procedure, and if unsuccessful, determines a second CE level and selects a different preamble group to retry the procedure, allowing for successful communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE performs the random access procedure using a single selected CE level, then the procedure is simple to execute, but the success rate is low when the selected CE level is inappropriate for the environment

Engineering Contradiction:

Improverandom access procedure success rateVSAvoidCE level management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic CE level adjustment by allowing the UE to switch between different CE levels based on the success or failure of random access procedure attempts. The UE starts with an initial CE level determination and can transition to a second CE level if the first attempt fails, creating a flexible, adaptive system rather than a static single-level approach.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the random access procedure by introducing multiple CE levels (first CE level and second CE level) with associated different preamble groups. This parameter change allows the system to adapt to different channel conditions and coverage requirements, improving the likelihood of successful access.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the UE retries the random access procedure with the same CE level, then the procedure remains consistent, but efficiency is reduced due to repeated failures in inappropriate environments

Engineering Contradiction:

Improverandom access procedure efficiencyVSAvoidtime for failed access attempts

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent implements a feedback mechanism where the outcome of the random access procedure (success or failure) informs the next action. If the procedure fails at the first CE level, the UE receives feedback to switch to a second CE level and corresponding preamble group, creating a learning system that adapts based on previous attempts rather than repeating the same failed configuration.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent prepares multiple CE levels and their associated preamble groups in advance before the random access procedure begins. This preliminary preparation allows the UE to quickly switch between configurations without delay when the initial attempt fails, reducing the overall time loss compared to determining new parameters on-the-fly.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If the UE uses multiple CE levels and preamble groups, then the adaptability to different environments improves, but the device complexity increases

Engineering Contradiction:

Improveenvironmental adaptability of random access procedureVSAvoidpreamble selection and CE level management

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the random access procedure into distinct phases with different CE levels and preamble groups. By dividing the procedure into a first random access procedure (with first CE level and first preamble group) and a second random access procedure (with second CE level and second preamble group), the system manages complexity through structured segmentation rather than presenting a monolithic complex choice to the UE.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different quality characteristics to different parts of the random access procedure by associating specific CE levels with specific preamble groups. Each CE level has its own optimized preamble group tailored to that coverage condition, ensuring that the right tools are used for each specific environmental condition rather than a one-size-fits-all approach.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10278212B2Device and method of handling random access procedure

Publication Date: 2019.04.30 HTC CORP

AI summary

A communication device of handling a random access procedure comprises a storage unit for storing instructions and a processing circuit coupled to the storage unit. The processing circuit is configured to execute the instructions stored in the storage unit. The instructions comprise determining a first coverage enhancement (CE) level; selecting at least one first random access preamble from a first preamble group corresponding to the first CE level; performing the random access procedure according to the at least one first random access preamble with a network; determining a second CE level, if the random access procedure performed according to the first access preamble is performed unsuccessfully; selecting at least one second random access preamble from a second preamble group; and performing the random access procedure according to the at least one second random access preamble with the network.