Multi-SIM User Equipment RRC Switching With Timed Network Assistance

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Solution Overview

Problem

Current wireless communication systems lack standardized support for multi-SIM devices, leading to increased complexity and unpredictable UE behavior, which degrades user experience and network functionality.

Innovation Solution

A method and UE implementation for multi-SIM operation that allows a UE to transmit an assistance information message indicating a preferred RRC state switch and includes a configuration of a timer, enabling seamless network transitions between SIMs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multi-SIM operation is implemented without standardized support, then device versatility is improved, but system complexity increases and UE behavior becomes unpredictable

Engineering Contradiction:

Improvemulti-SIM operation capabilityVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the multi-SIM operation into distinct states (DSDS mode and DSDA mode) with well-defined transition conditions. The UE operates in one of these two segmented modes, each with specific behavior rules, avoiding the complexity of handling all possible operational scenarios simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of requiring the network to manage all possible UE behaviors in multi-SIM scenarios, the patent inverts the approach by having the UE autonomously manage its own state transitions and network interactions. The UE independently decides when to switch between SIMs and handles the complexity locally.

Inventive Principle:

Principle #13The other way round (Inversion)

2Adaptability or versatility

If multi-SIM operation is implemented without standardized support, then device versatility is improved, but UE behavior becomes unpredictable degrading user experience

Engineering Contradiction:

Improvemulti-SIM operation capabilityVSAvoidUE behavior predictability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent uses parameter changes to define distinct operational modes. By changing the operational parameter (mode selection between DSDS and DSDA), the system achieves predictable UE behavior. Each mode has clearly defined parameters for state transitions, network interactions, and resource management, making UE behavior deterministic and reliable.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If network switches frequently between SIMs, then user experience is improved, but network resources are wasted due to repeated connection establishment

Engineering Contradiction:

Improveuser experienceVSAvoidnetwork resource consumption

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent applies preliminary action by having the UE indicate its intent to switch networks before actually performing the switch. The UE transmits assistance information messages to the network in advance, allowing the network to prepare for the transition and maintain connection state, thereby avoiding repeated connection establishment and reducing resource waste.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback mechanisms where the UE provides assistance information to the network about its switching intentions and preferred RRC states. This feedback loop allows the network to optimize its response, making the switch more efficient and reducing the overhead of repeated connection establishment.

Inventive Principle:

Principle #23Feedback

4Reliability

If UE remains in RRC_CONNECTED state for both SIMs, then connectivity is maintained, but power consumption increases

Engineering Contradiction:

ImproveconnectivityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by allowing the UE to transition between different RRC states (CONNECTED and IDLE) depending on the operational mode and network conditions. The UE dynamically adjusts its state to balance connectivity requirements with power consumption, rather than remaining statically in the CONNECTED state for both SIMs.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12382534B2User equipment and method for multi-SIM operation

Publication Date: 2025.08.05 SHARP KK

AI summary

A user equipment and a method for performing a multi-Subscriber Identity Module (multi-SIM) operation are provided. The method includes connecting to a first network associated with a first Universal Subscriber Identity Module (USIM) of the UE; receiving, from the first network, a first configuration indicating that the UE is allowed to transmit an assistance information message for switching to a second network associated with a second USIM of the UE, the first configuration further including a configuration of a timer; transmitting, to the first network, the assistance information message, the assistance information message including information of a preferred Radio Resource Control (RRC) state associated with the first network to indicate that the UE prefers to switch from an RRC_CONNECTED state associated with the first network to the preferred RRC state; and starting the timer upon transmitting the assistance information message.