Level 2 Service Manual
SIM Lock consists in restricting the use of the terminal to a family of SIM cards. For the SIM Lock, three
principal informations are used. These informations are read from data fields in the SIM card.
1°) IMSI (International Mobile Subscriber Identity), 15 Digits :
Example of IMSI : 208 01 55 12312312
208 = MCC = Mobile Country Code (ex : 208 for France)
01 = MNC = Network Country Code (ex : 01 for FT)
55 = NS = Network Subset
12312312 = Indifferent serial number
2°) Group IDentifier 1 (GID1):
This data field can contain digits or letters which identify a family of SIM
Ex : XX for a type for of prepaid SIM card of Service provider Y
3°) Group IDentifier 2 (GID2) :
same as GID1 to identify a sub family of SIM.
Then, from this information, we have 5 types of latch :
1°) Network Level :
latch on MCC MNC of IMSI of the SIM only
(ex : only the cards 208 01 be able to operate the mobile.
Mitsubishi uses to call this latch NCK (NCK stands for " Network Control Keys" and is the password to lock
the mobile at the network level)
2°) Network Subset Level :
Latch on MCC, MNC and digit 6 and 7 of the IMSI
Ex : latch on 208 01 55, only the SIM cards with an IMSI starting with 208 01 55 will operate the mobile.
Mitsubishi uses to call this latch NSCK (Network Subset Control Key)
3°) Service provider level :
latch on Network (value of MCC MNC) and value of GID1 data field.
Ex : latch on the value "XX" in GID1 and MCC MNC=208 01, only the SIM cards of service provider Y with
XX stored in data field GID1 will operate the mobile.
Mitsubishi uses to call this latch SPCK (Service Provider Control Key)
4°) Corporate Provider Level :
latch on network (value of MCC and MNC) and a value stored in GID2
Mitsubishi uses to call this latch CPCK (Corporate Provider Control Key)
5°) IMSI level
latch on the complete IMSI of one SIM card.
Only one SIM card corresponding to the correct IMSI operates the mobile. Usually, this latch is done in an
automatic way (the first SIM card inserted in the mobile is the only SIM which can be usesd by this mobile).
General information :
To lock /unlock a mobile, you need 8 digits password for each level concerned, and each mobile (one set of
passwords for one IMEI). These passwords are calculated with a special algorithm. You have only 10 attempts
to unlock correctly a mobile. After 10 unsuccessful attempts, the mobile is permanently blocked.
To enter the unlock procedure, you need to access special menus with specific access codes.
Mitsubishi Electric Telecom Europe
ZA le Piquet, 35370 Etrelles
Phone: +33 2 99 75 71 00
Fax: +33 2 99 75 71 47