Multi-SIM PLMN Search Coordination for Power Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mobile communication devices with multiple SIM cards experience increased power consumption due to independent PLMN searches, leading to higher battery drain and inefficient HPLMN search times.
Innovation Solution
Implementing a method where a mobile communication device starts multiple HPLMN timers based on respective timer values for each SIM card, performs a PLMN search at timer expiry, updates a shared PLMN list, and registers to a higher priority PLMN if found, reducing the total number of searches and sharing search results across SIM cards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mobile communication device performs independent PLMN searches for each SIM card according to their respective scanning cycles, then each SIM card can find its HPLMN independently, but the power consumption increases significantly
Solution Approach 1:
The patent merges multiple independent PLMN search operations into a single coordinated search process. When multiple SIM cards are present, the device performs one PLMN search that results are shared across all SIM cards, rather than each SIM card performing separate searches. This combining of search operations maintains the ability to find HPLMN for each SIM while significantly reducing power consumption by avoiding redundant scanning activities.
2Reliability
If the mobile communication device performs PLMN searches at regular scanning intervals for each SIM card, then each SIM card can periodically find higher priority PLMNs, but the time spent on searches increases
Solution Approach 1:
The patent combines multiple PLMN search operations into a single search event that serves multiple SIM cards simultaneously. Instead of each SIM card triggering separate search cycles, the system performs one search when any SIM card's scanning cycle expires, and the results are utilized by all SIM cards. This merging approach maintains proper PLMN priority selection while reducing the total time spent on searches.
3Adaptability or versatility
If the mobile communication device starts HPLMN timers independently for each SIM card, then each SIM card can track its own scanning cycle, but the device complexity increases
Solution Approach 1:
The patent implements a universal timer management mechanism where a single timer can serve multiple SIM cards' scanning cycle requirements. Instead of maintaining completely separate timer systems for each SIM card, the device uses a unified timer approach where the timer is started based on the earliest scanning cycle among all SIM cards, and the same timer expiration triggers a PLMN search that benefits all SIM cards. This reduces device complexity while maintaining adaptability to multiple SIM cards with different scanning cycles.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A mobile communication device including a plurality of Subscriber Identification Module (SIM) cards is provided. In addition, various methods are provided for searching for a Public Land Mobile Network (PLMN) for each SIM card. In one method, the device separately starts a plurality of Home PLMN (HPLMN) timers according to a corresponding plurality of HPLMN timer values stored respectively in the plurality of SIM cards, performs a PLMN search for one of the plurality of SIM cards at an expiry of a corresponding one of the plurality of HPLMN timers, and updates a PLMN list with one or more PLMNs found during the PLMN search. The device then determines, for all of the plurality of SIM cards, whether the PLMN list contains any PLMN with a higher priority than a currently registered PLMN. Also, the device performs, for any SIM card of the plurality of SIM cards in which there is any PLMN with the higher priority than the currently registered PLMN, a location registration in the PLMN with the higher priority. This may reduce the total number of PLMN searches and thus reduce power consumption.