Method of controlling access to a cellular network

A system for controlling access to a cellular communication network, for a terminal (MT) identified by a terminal identifier (IMEI) with a subscription identified by a subscription identifier (IMSI), wherein the system comprises:

• at least one cellular network communication module,
• at least one switching center module (MSC) through which the terminal (MT) is intended to access the cellular communication network,
• data storage means comprising at least one database (DB), the database (DB) comprising at least one record associating a plurality of subscription identifiers comprising at least one subscription identifier with a plurality of terminal identifiers comprising at least one terminal identifier, the plurality of terminal identifiers of the record being formed by at least one of one or more terminal identifiers, one or more ranges of terminal identifiers, and one or more terminal identifier prefixes (TAC), each prefix being deemed to comprise all the terminal identifiers beginning with said prefix (TAC), wherein when the terminal (MT) attempts to access the cellular communication network, the at least one cellular network communication module is configured to:
• receive at least the terminal identifier (IMEI) and the subscription identifier (IMSI) of the terminal (MT),
• verify, at each attempt at connection of said terminal (MT) or said subscription to the cellular communication network, that said terminal (MT), together with said subscription, are authorized to use the cellular communication network, by verifying the presence in the database (DB) of at least one record comprising the subscription identifier (IMSI) of said subscription associated with the terminal identifier (IMEI) of said terminal (MT), the record also comprising a “value mode” that determines how the presence of the terminal identifier (IMEI) of said terminal (MT) is to be verified among the terminal identifiers in the plurality of terminal identifiers of the record, the “value mode” indicating a first modality wherein the terminal identifier (IMEI) of said terminal (MT) must be verified exactly, or the “value mode” indicating a second modality wherein the terminal identifier (IMEI) of said terminal (MT) must be verified by a limited part thereof, and
• wherein the system is configured so that:
• if the result of the verification is positive, then the at least one cellular network communication module sends to the at least one switching center module (MSC) an acknowledgment message, and in response the at least one switching center module (MSC) enables the terminal (MT) to access the cellular communication network and;
• if the result of the verification is negative such that at least one of the subscription identifier (IMSI) and the terminal identifier (IMEI) is not present, then the at least one cellular network communication module does not send to the at least one switching center module (MSC) an acknowledgment message and prevents thereby that the terminal (MT) accesses the cellular communication network through the at least one switching center module (MSC).

A method of controlling access to a cellular communication network, for a terminal (MT) identified by a terminal identifier (IMEI) with a subscription identified by a subscription identifier (IMSI), the cellular communication network comprising at least one cellular network communication module, at least one database (DB) recorded in data storage means and at least one switching center module (MSC) through which the terminal (MT) is intended to access the cellular communication network, the method comprising the following steps performed by means of at least one processor:

• creation, in the at least one database (DB) being recorded in data storage means of at least one record associating a plurality of subscription identifiers comprising at least one subscription identifier with a plurality of terminal identifiers comprising at least one terminal identifier, the plurality of terminal identifiers of the record being formed by at least one of one or more terminal identifiers, one or more terminal identifier ranges, and one or more terminal identifier prefixes (TAC), each prefix comprising all the terminal identifiers beginning with said prefix (TAC), when the terminal (MT) attempts to access the cellular communication network:
• receiving at least the terminal identifier (IMEI) and the subscription identifier (IMSI) of the terminal (MT) at the at least one cellular network communication module,
• checking that said terminal (MT) together with said subscription are authorized to use the cellular communication network, by verifying the presence in the database (DB) of at least one record comprising the subscription identifier (IMSI) of said subscription associated with the terminal identifier (IMEI) of said terminal (MT), said verification being performed at the time of each attempt at connection of said terminal (MT) or of said subscription to the cellular communication network,
• checking for at least one missing identifier among the plurality of subscription identifiers (IMSI) and the plurality of terminal identifiers (IMEI), and
• at least one of authorization of access and refusal of access of said terminal (MT) to said network according to the result of the check:
• if the result of the check is positive, then the at least one cellular network communication module sends to the at least one switching center module (MSC) an acknowledgment message, and in response the at least one switching center module (MSC) authorizing the terminal (MT) to access the cellular communication network and;
• if the result of the check is negative, then the at least one cellular network communication module does not send to the at least one switching center module (MSC) an acknowledgment message, and thereby refusing the terminal (MT) access to the cellular communication network through the at least one switching center module (MSC).