Random Access Control in Carrier Aggregation Cell Groups

Solution Overview

Problem

In dual connectivity scenarios, terminal apparatuses need to constantly monitor multiple cell groups to enable low-latency high-capacity data communication, leading to significant power consumption, and there is a need for efficient communication control methods to manage cell group activation and deactivation.

Innovation Solution

The method involves transmitting and receiving random access preambles based on RRC messages and time alignment timers in primary TA groups, allowing the terminal apparatus to determine when to transmit preambles efficiently, reducing unnecessary monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the terminal apparatus constantly monitors multiple cell groups to enable low-latency high-capacity data communication, then communication reliability is improved, but power consumption increases

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic monitoring behavior where the terminal apparatus adjusts its monitoring activity based on the running state of time alignment timers. When the timer is running, the terminal monitors the cell group; when the timer is not running, the terminal suspends monitoring. This dynamic adjustment allows the system to maintain communication reliability when needed while reducing power consumption during periods when monitoring is less critical.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the monitoring parameter (monitoring activity) based on the state of the time alignment timer. By linking monitoring behavior to the timer state, the system dynamically adjusts whether the terminal apparatus performs monitoring operations, thereby balancing communication reliability requirements with power consumption constraints.

Inventive Principle:

Principle #35Parameter changes

2Speed

If the terminal apparatus performs monitoring of multiple cell groups at high frequency, then communication response time is improved, but device complexity increases

Engineering Contradiction:

Improvecommunication response timeVSAvoidmonitoring complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent implements dynamic monitoring behavior where the terminal apparatus adjusts its monitoring activity based on the running state of time alignment timers. When the timer is running, the terminal monitors the cell group; when the timer is not running, the terminal suspends monitoring. This dynamic adjustment allows the system to maintain communication reliability when needed while reducing power consumption during periods when monitoring is less critical.

Inventive Principle:

Principle #15Dynamics

3Use of energy by moving object

If the terminal apparatus stops monitoring cell groups to reduce power consumption, then power efficiency is improved, but communication delay increases

Engineering Contradiction:

Improvepower efficiencyVSAvoidcommunication delay

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent implements dynamic monitoring behavior where the terminal apparatus adjusts its monitoring activity based on the running state of time alignment timers. When the timer is running, the terminal monitors the cell group; when the timer is not running, the terminal suspends monitoring. This dynamic adjustment allows the system to maintain communication reliability when needed while reducing power consumption during periods when monitoring is less critical.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses the time alignment timer as a feedback mechanism to control monitoring behavior. The timer's running state provides feedback information that determines whether the terminal apparatus should continue monitoring or suspend monitoring activities, creating a closed-loop control system that balances power efficiency and communication responsiveness.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12513771B2Terminal apparatus and method for performing random access procedures in carrier aggregation (CA) based networks

Publication Date: 2025.12.30 SHARP KK

AI summary

Provided is a method applied to a terminal apparatus for communicating with a base station apparatus. The method includes the steps of: receiving a first RRC message including a parameter related to a first cell group from the base station apparatus; and transmitting a random access preamble in an SpCell of the first cell group, based on reception of the first RRC message. The random access preamble is transmitted in the SpCell, based on first information being included in the first RRC message and a time alignment timer, in a primary TA group of the first cell group, which is not running.