8 SIM/USIM personalisation

22.0223GPPMobile functionality specificationPersonalisation of Mobile Equipment (ME)Release 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

SIM/USIM personalisation is an anti‑theft feature. When a ME is SIM/USIM personalised to a particular SIM it will refuse to operate with any other SIM/USIM. Hence, if the ME is stolen the thief will not be able to use it with another SIM/USIM (see note). While this does not stop the ME being stolen it should make it less attractive to the thief.

NOTE: If the ME and the SIM/USIM to which it has been personalised are stolen together the ME would become unusable once the SIM/USIM is reported stolen and is disconnected.

The ME is SIM/USIM personalised by storing the SIM/USIM code group (which is equivalent to the IMSI) of the relevant SIM/USIM in the ME and setting the SIM/USIM personalisation indicator in the ME to "on". Whenever a SIM/USIM is inserted, or the ME is powered up with a SIM/USIM already in place, the SIM/USIM code group (IMSI) is read from the SIM/USIM and checked against the SIM/USIM code group(s) stored in the ME. If there is no match the ME shall go into emergency calls only mode as described in annex A.2.

The SIM/USIM personalisation feature is controlled by a Personalisation Control Key (PCK). This key is selected by the user at SIM/USIM personalisation and shall be entered into the ME to SIM/USIM de‑personalise the ME.

In order to support the SIM/USIM personalisation feature the ME should have storage for the SIM/USIM personalisation indicator, a (list of) SIM/USIM code group(s) and the PCK.

Multiple instances of SIM/USIM personalisation can be supported, i.e. whenever a SIM/USIM is inserted, or the ME is powered up with a SIM/USIM already in place, the IMSI is read from the SIM/USIM and checked against a list of SIM/USIM code groups stored in the ME.

8.1 Operation of SIM/USIM personalised ME

The SIM/USIM personalisation check described below is performed whenever a SIM/USIM is inserted or the ME is powered up with a SIM/USIM already in place.

The personalisation check is as follows. When more than one personalisation is active in the ME, normal mode of operation includes performing any outstanding personalisation checks:

a) check whether the ME is SIM/USIM personalised: The ME checks its SIM/USIM personalisation indicator, if it is set to "off" the personalisation check shall be stopped and the ME goes into the normal mode of operation, omitting the remaining steps of the check;

b) read IMSI: The ME reads the IMSI from the SIM/USIM;

c) SIM/USIM personalisation check: The ME checks the read IMSI against the (list of) SIM/USIM code group(s) stored in the ME. If no match is found, the ME shall display an appropriate message (e.g. "Insert correct SIM" or "Insert correct USIM") and shall go into emergency calls only mode as described in annex A.2. Otherwise, the ME goes into the normal mode of operation.

8.2 SIM/USIM personalisation cycle

8.2.1 Personalisation cycle

The process of personalisation can only be carried out on a currently unpersonalised ME, i.e., if the SIM/USIM personalisation indicator is set to "off". Access to the personalisation process shall be restricted in order to prevent unauthorised , accidental or unwanted personalisation. Other restrictions are described in clause 13. The personalisation process results in the PCK being set, the SIM/USIM personalisation indicator being set to "on" and the storage in the ME of a (list of) SIM/USIM code group(s) to which the ME is being personalised.

The SIM/USIM personalisation process is as follows:

the SIM/USIM code group(s) is (are)entered into the ME. This may be accomplished by one of the following means :

– the ME reads the SIM/USIM code group (IMSI) from the SIM/USIM and stores it;

– a manufacturer defined process.

b) the ME carries out the pre‑personalisation checks contained in clause 13. If they all pass, the SIM/USIM code group(s) is(are) stored in the ME. If any fail, the personalisation process shall be terminated;

c) to personalise the ME to more than one SIM/USIM and if the reading of the IMSI from the SIM/USIM is used to enter the SIM/USIM code group in the ME, the procedures given in a) and b) shall be repeated;

d) the PCK is then stored in the ME. A single value of PCK shall be used for both single and multiple SIM/USIM personalisation;

e) the SIM/USIM personalisation indicator is set to "on".

8.2.2 De‑personalisation cycle

To de‑personalise the ME, the correct PCK shall be entered. It is optional whether or not a SIM/USIM is inserted in the ME. If a SIM/USIM is inserted, then de‑personalisation shall be offered whether or not the SIM/USIM personalisation check passes or fails.

SIM/USIM de‑personalisation shall be provided by keypad entry. Other de‑personalisation methods may also be provided.

The SIM/USIM de‑personalisation process is as follows:

a) the user enters the PCK in the ME;

b) if the entered PCK is the same as the one stored in the ME, the SIM/USIM personalisation indicator is set to "off".

If the entered and stored PCK values differ, the de‑personalisation process shall be stopped and the ME remain personalised. The stored IMSI and PCK are left unchanged.