22.0163GPPInternational Mobile station Equipment Identities (IMEI)Release 17TS
An MS can only be operated if a valid "International Mobile Subscriber Identity" (IMSI) is present. An IMSI is primarily intended for obtaining information on the use of the PLMN by subscribers for individual charging purposes.
Besides the IMSI, the implementation of IMEI is found necessary in order to obtain knowledge about the presence of specific mobile station equipment in the network, disregarding whatever subscribers are making use of these equipment.
The main objective is to be able to take measures against the use of stolen equipment or against equipment of which the use in the PLMN can not or no longer be tolerated for technical reasons.
The IMEI is incorporated in an UE module which is contained within the UE. The IMEI shall be unique and shall not be changed after the ME’s final production process. It shall resist tampering, i.e. manipulation and change, by any means (e.g. physical, electrical and software).
NOTE: This requirement is valid for new GSM MEs type approved after 1st June 2002. However, this requirement is applicable to all 3GPP system compatible UEs from start of production.
The manufacturer implementing the IMEI module in the ME is responsible for ensuring that each IMEI within the allocated range is unique to the ME in which it resides, and is also responsible for keeping detailed records of produced and delivered MEs.