Dual-SIM RRC Suspend-Resume Coordination for Network Sync
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Solution Overview
Problem
Dual-SIM dual-standby (DSDS) user equipment (UE) devices face network synchronization issues and performance disruptions when suspending and resuming radio resource control (RRC) connections, leading to potential RRC state mismatches and increased latency during transitions between SIMs.
Innovation Solution
Implementing a method where the UE requests the network to suspend the first RRC connection and stores its state, allowing for efficient resumption without timeouts, using a timer to manage the inactive state and ensuring network synchronization through coordinated communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the UE suspends the first RRC connection to perform higher priority communication on the second SIM, then the higher priority communication can be executed, but the RRC connection state may become mismatched with the network and latency increases during resume
Solution Approach 1:
The UE sends an RRC connection suspend request to the network before actually suspending the connection, and receives an RRC connection suspend message in advance. This preliminary action ensures the network is notified and maintains proper state synchronization before the suspension occurs, preventing state mismatches when resuming.
Solution Approach 2:
The UE implements a feedback mechanism where it sends suspend requests to the network and receives confirmatory suspend messages. This feedback loop ensures both the UE and network have consistent understanding of the connection state, maintaining reliability during suspend/resume operations.
2Device complexity
If the UE uses a single receiver architecture for cost savings, then device complexity and cost are reduced, but network synchronization issues occur during SIM suspension and resumption
Solution Approach 1:
The RRC connection suspend message acts as an intermediary communication mechanism between the UE and network. It mediates the state transition by formally notifying the network of the suspension before it occurs, ensuring synchronization is maintained even with a single receiver architecture that requires sequential SIM operations.
3Use of energy by moving object
If the UE transitions RRC connection to inactive state efficiently, then energy consumption is reduced, but state management complexity increases with timer coordination
Solution Approach 1:
The UE autonomously manages its own RRC connection state by initiating suspend requests and coordinating timers independently. The device serves itself by maintaining proper state management without requiring continuous network intervention, enabling efficient transitions to inactive states while managing the complexity of timer coordination internally.
Data Source
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AI summary
Devices and associated methods for operating a dual-subscriber identity module (SIM) dual-standby (DSDS) user equipment device (UE) configured with a first SIM and a second SIM. The UE performs communications with a first cellular network using the first SIM and a first radio resource control (RRC) connection, and receives a request to perform a higher priority communication using the second SIM. In response to the request to perform the higher priority communication, the UE transmits a request to the first network to suspend the first RRC connection. After transmission of the request to suspend the first RRC connection, the UE receives a message from the first network to place the first RRC connection in an inactive state, and initiates a timer, wherein the timer is used to determine whether the first RRC connection remains in the inactive state or transitions to an idle state.