SIM-card Applet

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Video demonstration

Live demonstration of the MultiAccount SIM applet:

  • how to list mobile profiles via SIM menu
  • how a new mobile profile is downloaded on the SIM-card


How it works

This document describes the mobile profile ("account") selection methods to detect if the application ("applet") should switch to another account depending on the settings and current network registration status of the terminal.

The method is based on special information collected by the applet from the terminal and also from some files on the USIM. This information is applied to the special map named "Account MCC/MNC Coverage List", which defines up to 25 MCC/MNC pairs for each account.

Each record of the "Account MCC/MNC Coverage List" contains 85 PLMNs codes the corresponding account IMSI is valid for. The coding of each MCC/MNC pair is according to standard EF(PLMNsel). If an MCC/MNC pair has an MCC value according to EF(PLMNsel), but MNC with 0xFF value, then the MCC/MNC pair is wildcard and is valid for the entire country.

Example:

* T-Mobile Austria has MCC/MNC equals to 23203. The value for "Account MCC/MNC Coverage List" will be 32F230
* MCC/MNC wildcard for Austria will be 232FF. The value for "Account MCC/MNC Coverage List" will be 32F2FF

Some combinations of the wildCard MCC/MNC and exact MCC/MNC are possible:

* if the configuration defines two accounts for the same country (same MCC value) and one of it uses MNC wildcard (FF), then the one without the wildcard will only be used by the algorithm, if the one with the wildcard is contained in a record with a lower index (record index is equal to account number)
* if the MCC/MNC coverage list of an account uses one MNC wildcard, then all other MNC values in the same MCC/MNC coverage list record does not have any influence to the algorithm, if they have the same MCC.


Block diagram

Case 1. Subscription selection logic during Mobile phone startup:

SIMApplet 01.png

Case 2. Subscription selection in case when for the visited country there is one precise and one wildcard subscription is included into the Account MCC/MNC Coverage List:

SIMApplet 02.png