UMTS PLMN Search in RRC Connected Mode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In UMTS systems, mobile stations in RRC connected mode face inefficiencies during periodic PLMN searches, particularly when switching between cells with common PLMN identities, as they must enter idle mode to establish connections, leading to increased signaling activity and resource management challenges.
Innovation Solution
A method that allows mobile stations in CELL_PCH or URA_PCH states to perform periodic PLMN searches and select cells with higher priority PLMN identities without entering idle mode by using a CELL UPDATE procedure if the serving and selected cells share a common PLMN identity, and setting neighboring cell priorities equal to the serving cell's priority to minimize cell changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If mobile stations enter idle mode to establish connections during periodic PLMN searches, then they can select cells with higher priority PLMN identities, but signaling activity increases and UTRAN resources are consumed
Solution Approach 1:
The patent applies dynamics by allowing mobile stations to transition between connected and idle modes based on PLMN priority conditions. When a higher priority PLMN is detected during periodic searches, the MS dynamically enters idle mode to reselect and register with the new PLMN, while maintaining connected mode for normal operations. This dynamic state change enables adaptive resource usage based on network conditions.
Solution Approach 2:
The patent changes the operational state parameter of the mobile station from connected mode to idle mode specifically during PLMN reselection events. This parameter change allows the MS to perform PLMN searches and reselections while minimizing the duration of idle mode entry, thus reducing signaling overhead and resource consumption compared to maintaining continuous idle mode operation.
2Adaptability or versatility
If mobile stations frequently transition to idle mode for PLMN searches, then they can access higher priority networks, but connection establishment time increases
Solution Approach 1:
The patent implements periodic PLMN searches at predetermined intervals while in connected mode, rather than continuously monitoring or frequently transitioning to idle mode. This periodic approach allows the MS to detect higher priority PLMNs at scheduled times and only enter idle mode when necessary for reselection, thereby minimizing the frequency of state transitions and reducing overall connection establishment time.
Solution Approach 2:
The patent performs preliminary PLMN identity checks during periodic searches in connected mode before committing to idle mode transitions. By预先 detecting the presence of higher priority PLMNs and preparing for potential reselection, the system reduces the urgency and frequency of idle mode entries, thereby optimizing connection establishment time while maintaining network selection adaptability.
3Productivity
If mobile stations remain in connected mode during PLMN searches, then resource management is efficient, but they cannot switch to higher priority PLMNs
Solution Approach 1:
The patent creates a dynamic framework where mobile stations operate primarily in connected mode for efficient resource management, but can transition to idle mode when higher priority PLMNs are detected during periodic searches. This dynamic state management ensures that the MS maintains connected mode for most operations (preserving resource efficiency) while retaining the capability to switch PLMNs when necessary (maintaining adaptability).
Solution Approach 2:
The patent maintains continuous connected mode operation for normal data transmission and resource-efficient communication, while superimposing periodic PLMN search actions that temporarily trigger idle mode transitions only when higher priority networks are available. This approach ensures continuous useful action in connected mode while periodically enabling PLMN switching capability.
Data Source
AI summary
A method of performing a periodic public land mobile network (PLMN) search for a mobile station in a CELL_PCH state of radio resource control (RRC) connected mode in a universal mobile telecommunications system (UMTS) is described. The method includes providing a mobile station operating in the CELL_PCH state camping on a serving cell of a PLMN utilizing a first PLMN identity; performing a periodic PLMN search with the mobile station and selecting a cell with a second PLMN identity, the second PLMN identity having a higher network priority than the first PLMN identity; and performing a CELL UPDATE procedure to register the mobile station with the selected cell utilizing the second PLMN identity if the serving cell and the selected cell are each associated with a common PLMN identity.