UE Parallel PLMN Search in RRC Connected Mode
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Solution Overview
Problem
Existing wireless communication systems face delays or failures when performing a Public Land Mobile Network (PLMN) search while a user equipment (UE) is in radio resource control (RRC) connected mode.
Innovation Solution
The UE leverages Multi-Subscriber Identity Module (MSIM) and Dual Receive Dual SIM Dual Standby (DR-DSDS) features to perform a PLMN search using a second connection instance while the first connection instance is in RRC connected mode, thereby avoiding search delays or failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the UE performs PLMN search while in RRC connected mode using the same connection instance, then the search can be performed, but the search experiences delays or failures due to resource conflicts
Solution Approach 1:
The patent divides the single connection instance into multiple connection instances (first connection instance and second connection instance). When the first connection instance is in RRC connected mode, the PLMN search is performed using the second connection instance, allowing parallel operation without resource conflicts. This segmentation resolves the contradiction by enabling simultaneous data communication and PLMN search without interference.
Solution Approach 2:
The patent introduces a new dimension of operation by utilizing multiple connection instances simultaneously. Instead of sequentially performing PLMN search after transitioning to idle mode, the system operates in parallel using different connection instances, effectively adding a temporal and operational dimension that eliminates search delays while maintaining connected mode benefits.
2Reliability
If the UE transitions to RRC idle mode to perform PLMN search, then the search can be performed without delays, but the data communication is interrupted
Solution Approach 1:
The patent segments the communication function into multiple connection instances, allowing the first connection instance to maintain RRC connected mode for continuous data communication while the second connection instance performs PLMN search. This eliminates the need to interrupt data communication for PLMN search, resolving the contradiction between search reliability and communication productivity.
Solution Approach 2:
The patent implements multi-functionality where multiple connection instances serve different purposes simultaneously. The first connection instance handles data communication while the second connection instance performs PLMN search, allowing the UE to maintain both active communication and network search operations without mutual interference, thus preserving both productivity and reliability.
3Device complexity
If the UE uses a single connection instance for both data communication and PLMN search, then the device complexity is low, but the search experiences delays or failures
Solution Approach 1:
The patent divides the single connection instance into multiple connection instances to enable parallel operation. Although this increases device complexity slightly, it resolves the reliability issue by allowing PLMN search to proceed without delays or failures caused by resource conflicts in connected mode, achieving a acceptable balance between complexity and reliability.
Data Source
AI summary
Disclosed are methods, systems, and computer-readable medium to perform operations including: receiving, by an access stratum (AS) layer of a user equipment (UE) and from a non-access stratum layer (NAS) layer of the UE, a Public Land Mobile Network (PLMN) search request; determining, by the AS layer, that a first connection instance is in radio resource control (RRC) connected mode; responsively determining, by the AS layer, whether a second connection instance is available; and in response to determining that the second connection instance is available, triggering, by the AS layer, the PLMN search on the second connection instance, wherein the PLMN search comprises one or more frequency scans.