User Equipment Random Access Timer Feedback Mechanism

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Solution Overview

Problem

In LTE-Advanced systems, user equipment returns an RRC connection reconfiguration complete message before the completion of the random access procedure for the secondary base station, making it impossible for the master base station to determine the success or failure of the procedure, leading to inefficient use of network resources and potential throughput limitations.

Innovation Solution

The user equipment activates a timer during the random access procedure for the secondary base station, and if the procedure is not completed before the timer expires, it indicates the incompletion to the master base station, allowing the base station to detect the status of the connection and adjust communication accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the user equipment returns an RRC connection reconfiguration complete message before the completion of the random access procedure, then the communication setup process is accelerated, but the master base station cannot determine the success or failure of the random access procedure

Engineering Contradiction:
Improvetime for communication setupVSAvoidrandom access procedure status
Core Design Contradiction:
Loss of timeVSLoss of information

Solution Approach 1:

The invention introduces a feedback mechanism where the user equipment sends an indication message to the master base station after the random access procedure completes (or times out). This feedback allows the master base station to determine whether the random access to the secondary base station was successful, resolving the information loss problem while maintaining the accelerated setup process.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The user equipment performs the RRC connection reconfiguration complete message transmission in advance, before the random access procedure to the secondary base station is fully completed. This preliminary action accelerates the overall setup process, while the subsequent indication message provides the necessary status information.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If the user equipment transmits uplink data in a bearer configured for the secondary cell without confirming random access success, then data transmission can begin earlier, but network resources are used inefficiently due to undetected configuration failures

Engineering Contradiction:
Improvedata transmission speedVSAvoidnetwork resource efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The indication message sent from user equipment to the master base station provides feedback on random access success. This allows the master base station to determine whether to activate the configured bearer for uplink data transmission, ensuring network resources are not wasted on failed configurations while enabling early data transmission when successful.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts bearer activation based on random access outcome. The master base station can selectively activate or deactivate bearers depending on whether the random access procedure succeeded, optimizing network resource usage while maintaining high productivity when conditions are favorable.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3595395B1User equipment and method
Publication Date: 2021.04.21 NTT DOCOMO INC
  • EP3595395B1 patent drawingFigure 1
  • EP3595395B1 patent drawingFigure 2
  • EP3595395B1 patent drawingFigure 3

AI summary

Techniques are provided for allowing a base station indicating reconfiguration for user equipment 5 to detect whether an RA procedure performed in response to the reconfiguration indication is successful or unsuccessful. One aspect of the present invention relates to user equipment having a dual connectivity function to communicate with a master base station and 10 a secondary base station simultaneously, comprising: a transmission and reception unit configured to transmit and receive radio signals to/from the master base station and the secondary base station; an RA processing unit configured to perform a random access (RA) procedure; 15 and a timer management unit configured to activate a timer upon detecting an RA procedure activation event for triggering activation of the RA procedure for the secondary base station, wherein if the RA procedure performed in response to detection of the RA procedure 20 activation event has not been completed before expiration of the timer, the timer management unit indicates the triggering base station that the RA procedure has not been completed.