UE Transmission Power Control for Regulatory Compliance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In regions where transmission power higher than PC3 is not allowed, such as Japan, user equipment supporting higher power classes like PC1 or PC2 face challenges in adhering to local regulations due to lack of notification of maximum transmission power through system information, leading to potential excessive power output during random access procedures before RRC connection.

Innovation Solution

User equipment performs initial access and handover procedures by controlling transmission power according to the notified or default power class regulations, ensuring compliance with the allowed transmission power levels by determining the maximum transmission power based on system information or handover instructions, and applying the appropriate power class settings for each frequency band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If user equipment supports high power classes (PC1 or PC2) for extended coverage, then coverage area is improved, but transmission power may exceed regulatory limits in regions where PC3 is the maximum allowed power class

Engineering Contradiction:
Improvecoverage areaVSAvoidexcessive transmission power
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The user equipment dynamically adapts its transmission power class based on received power class indication information from the base station. When the indicated power class is lower than the supported power class, the UE reduces its transmission power to comply with local regulations, while maintaining the ability to use higher power classes when permitted by the network

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the power class parameter of the user equipment based on network configuration and regulatory requirements. The base station transmits power class indication information that modifies the operating power class parameter of the UE, allowing it to transition between different power classes (PC1, PC2, or PC3) as needed

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If capability information is acquired after RRC connection is established, then device complexity is reduced, but transmission power control precision is insufficient during random access procedure

Engineering Contradiction:
Improvedevice complexityVSAvoidtransmission power control precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The base station transmits power class indication information in system information blocks before the RRC connection is established. This preliminary action allows the user equipment to determine the appropriate transmission power class during the random access procedure, ensuring precise power control from the initial access phase without increasing device complexity

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3522618B1User device and base station
Publication Date: 2024.11.20 NTT DOCOMO INC
  • EP3522618B1 patent drawingFigure 1~2
  • EP3522618B1 patent drawingFigure 3
  • EP3522618B1 patent drawingFigure 4

AI summary

Provided is a power control technique for a user equipment that supports high transmission power. An aspect of the invention relates to user equipment that supports a first power class in a certain frequency band, the user equipment including a transceiver that transmits radio signals to and receives radio signals from a base station; and a transmission power controller that controls transmission power to the base station, wherein, upon accessing the base station in the frequency band provided with, as a default power class, a second power class that is lower than the first power class, the transmission power controller controls the transmission power in accordance with a regulation of the default power class, and the transmission power controller controls the transmission power so that the transmission power becomes less than or equal to maximum output power of the default power class.