Mobile Device PLMN Reporting Filtering by Frequency Band
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mobile telecommunications systems lack an efficient method to differentiate between Public Land Mobile Networks (PLMNs) that a device can support and those it cannot, leading to unnecessary reporting and potential user confusion or delayed selection of usable networks.
Innovation Solution
A method and apparatus for mobile devices to scan for PLMNs, where system information is used to determine if detected cells operate in supported frequency bands, and only report PLMN identities from bands that the device can support, omitting unsupported bands to prevent false presentation to users and ensure accurate network selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If the mobile device reports all detected PLMN identities regardless of frequency band support, then the completeness of PLMN reporting is improved, but the accuracy of network selection deteriorates due to inclusion of unsupported networks
Solution Approach 1:
The patent segments the PLMN reporting process into two distinct stages: initial detection of all PLMN identities regardless of frequency band, and subsequent filtering to separate supported from unsupported PLMNs. This segmentation allows the system to maintain complete information gathering while ensuring accurate network selection by only reporting PLMNs from supported frequency bands in the final report to the non-access stratum.
Solution Approach 2:
The patent introduces an intermediary filtering mechanism between the access stratum's PLMN detection function and the non-access stratum's network selection function. This intermediary process examines each detected PLMN's frequency band against the device's supported bands and selectively passes only compatible PLMNs forward, thus resolving the contradiction between complete detection and accurate reporting.
2Area of stationary object
If the mobile device scans all frequency bands including unsupported bands, then the coverage of PLMN detection is improved, but the time and resources consumed increase
Solution Approach 1:
The patent applies preliminary action by having the access stratum perform initial scanning of all frequency bands to detect PLMN identities, but then immediately filtering out PLMNs from unsupported bands before completing the full scanning and reporting process. This preliminary filtering prevents wasted time on extensively scanning and processing PLMNs that the device cannot support, while still maintaining comprehensive detection coverage.
Solution Approach 2:
The patent extracts and removes PLMN identities from unsupported frequency bands from the detection results before final reporting. By taking out these irrelevant PLMN entries early in the process, the system maintains broad detection coverage for information gathering purposes while eliminating the time consumption associated with processing and reporting unsupported networks.
3Loss of information
If the mobile device reports PLMN identities from unsupported bands, then the information available for user selection is improved, but the user experience deteriorates due to false presentation of inaccessible networks
Solution Approach 1:
The patent converts the potential harm of reporting unsupported PLMNs into a benefit by using the frequency band support information as a filtering criterion. The system benefits from comprehensive PLMN detection across all bands, then uses the same frequency band data to identify and exclude unsupported PLMNs, transforming what could be harmful misinformation into an opportunity to provide accurate, actionable network selection information to the user.
Data Source
AI summary
A method and apparatus for searching for and reporting Public Land Mobile Networks "PLMNs" in a mobile telecommunications system, the method comprising, at a mobile device: initiating a scan to find Public Land Mobile Networks; when a cell of a PLMN is detected on a frequency, then reading system information to determine one or more PLMN identities of the detected cell; determining whether the detected cell operates in a frequency band supported by the mobile device; when it is determined that the detected cell does not operate in a band supported by the device, omitting adding the associated one or more PLMN identities from a list of PLMNs,and otherwise adding the one or more PLMN identities to the list of PLMNs; and reporting the list of PLMNs.