Auto IMSI Switch SIM Application for Roaming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Auto IMSI Switch SIM applications are limited in updating Forbidden PLMN lists when reject causes are not 'PLMN Not Allowed', and they are inefficient due to limited memory and processing power on SIM cards, lacking a robust criteria for triggering IMSI switches independent of cause codes.
Innovation Solution
A system and method using proactive commands like PROVIDE LOCAL INFORMATION (PLI) to update location parameters and trigger the Auto IMSI Switch SIM application, replacing home IMSI with global IMSI irrespective of the cause code received, enabling seamless service availability in international roaming scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the existing Auto IMSI Switch SIM application uses EF FPLMN to detect PLMN Not Allowed reject cause, then the IMSI switching can be triggered for that specific case, but the application fails to update EF FPLMN values when reject cause is not 'PLMN Not Allowed' resulting in service failures
Solution Approach 1:
The patent changes the triggering parameter from a specific reject cause code ('PLMN Not Allowed') to a general location change detection mechanism using proactive commands. The SIM application now responds to location parameter changes (such as cell ID, tracking area, or PLMN changes) regardless of the specific reject cause, enabling universal adaptability across all rejection scenarios while maintaining reliable service availability.
Solution Approach 2:
The patent makes the Auto IMSI Switch SIM application universally applicable to all types of network rejections by implementing a generic location change detection mechanism. Instead of being limited to handling only 'PLMN Not Allowed' cases, the application now functions across multiple scenarios including but not limited to PLMN rejections, tracking area rejections, and other network rejection causes, achieving multi-functionality and broad compatibility.
2Reliability
If the SIM card stores and processes extensive location parameters and cause codes, then the triggering criteria can be more comprehensive, but the limited memory and processing power on SIM cards reduces efficiency
Solution Approach 1:
The patent extracts only the essential location parameters needed for triggering IMSI switching from the complex set of available network information. Instead of storing and processing extensive location parameters and all possible cause codes on the SIM card, the system extracts key parameters such as location change indicators and basic network identification, reducing the processing burden on the SIM card while maintaining robust switching criteria.
Solution Approach 2:
The patent implements preliminary action by having the network side prepare and send proactive commands with location parameter updates before the SIM card needs to make switching decisions. The network pre-processes the rejection information and sends condensed location change notifications to the SIM card, allowing the SIM card to trigger IMSI switching based on simple pre-processed indicators rather than analyzing complex raw network rejection messages, thereby improving processing efficiency.
3Measurement precision
If the Auto IMSI Switch SIM application triggers switching based on specific cause codes, then the switching can be precise for known scenarios, but it lacks robust criteria for triggering independent of cause codes
Solution Approach 1:
The patent inverts the traditional approach by instead of having the SIM card analyze rejection cause codes to trigger switching, the network sends proactive commands indicating location changes. The SIM card simply responds to these location change indicators without needing to interpret rejection causes, achieving both precision (through network-validated location changes) and independence (from cause code analysis).
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Embodiments of the present disclosure relate to availing at least one service by a user equipment [110] while one of in an international roaming and leaving the international roaming. In a preferred embodiment, a method for automatic IMSI switching by using the proactive commands such as PLI commands, while entering and leaving the international roaming, independent of the cause code sent by any operator and can work regardless of the cause code received is disclosed. The method includes replacing of the home IMSI of the user equipment [110] with the global IMSI in an event the at least one network parameter corresponds to the second location and replacing of the global IMSI of the user equipment [110] with the home IMSI in an event the at least one network parameter corresponds to the first location.