Dual SIM RRC Handover Coordination via Auxiliary Signaling

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Solution Overview

Problem

Dual SIM dual standby (DSDS) terminal devices experience unexpected disconnection of RRC connections when one SIM card is in an RRC connected state and the other SIM card needs to perform data transmission, leading to user experience issues and ping-pong handover between RRC connections.

Innovation Solution

A wireless communication method where a terminal device sends a message to an access network device to request the establishment or resumption of an RRC connection with a second subscriber identity, including auxiliary information to determine the release or deactivation of the first RRC connection, thereby optimizing RRC connection handover and reducing signaling overheads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the terminal device switches to the second SIM card to establish an RRC connection when the first SIM card is already connected, then the second SIM card can perform data transmission, but the first RRC connection is unexpectedly disconnected

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidRRC connection stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The terminal device performs preliminary actions by indicating to the network device that it needs to switch to the second SIM card before actually switching. This allows the network device to be prepared and avoid unexpected disconnections when the switch occurs. The indication message is sent in advance to coordinate the connection management.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the terminal device maintains RRC connection with the first SIM card, then the first SIM card can maintain stable connection, but the second SIM card cannot perform data transmission when needing to enter RRC connected state

Engineering Contradiction:

ImproveRRC connection stabilityVSAvoiddata transmission capability

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The terminal device dynamically switches between different SIM cards and RRC connection states based on service requirements. The device can transition from maintaining a stable connection with the first SIM card to enabling data transmission with the second SIM card by sending an indication message to the network device, allowing flexible adaptation to different communication needs.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If the terminal device frequently switches between RRC connections for dual SIM cards, then both SIM cards can access the network, but ping-pong handover occurs between RRC connections

Engineering Contradiction:

Improvenetwork access capabilityVSAvoidRRC connection stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The terminal device uses feedback mechanisms by monitoring the service status of each SIM card and adjusting RRC connection management accordingly. When switching between SIM cards, the device sends indication messages to the network device to coordinate the connection state changes, preventing unnecessary ping-pong handovers by making informed decisions based on actual service needs.

Inventive Principle:

Principle #23Feedback

4Adaptability or versatility

If the terminal device establishes separate RRC connections for each SIM card, then each SIM card can independently communicate, but signaling overhead increases and network resources are consumed

Engineering Contradiction:

Improveindependent communication capabilityVSAvoidsignaling overhead

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The terminal device merges RRC connection management for dual SIM cards by using a single RRC connection to communicate with the network device while managing multiple SIM cards. The indication message mechanism allows the device to coordinate switching between SIM cards over the shared connection, reducing signaling overhead compared to maintaining separate RRC connections for each SIM card.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentEP4024924B1Wireless communication method and device

Publication Date: 2025.01.22 HUAWEI TECH CO LTD

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AI summary

This application provides a wireless communication method and apparatus. The method includes: When a terminal device supporting more than two subscriber identities needs to perform RRC handover, the terminal device sends a first message to a first access network device to request to establish or resume a second RRC connection with a second subscriber identity, where the first message includes auxiliary information. The first access network device may determine, based on the auxiliary information, to release or deactivate a first RRC connection. The first access network device determines to release or deactivate the first RRC connection, and indicates, via a second message, the terminal device to release or deactivate the first RRC connection. Sending a request message including the auxiliary information to an access network device enables the access network device to determine to deactivate or release an RRC connection. This avoids unexpected interruption of data transmission, avoids ping-pong handover occurring when the terminal device establishes an RRC connection with a plurality of subscriber identities, and optimizes user experience.