Lawful interception in a wi-fi / packet core network access

An authentication unit configured to allow anchoring of a data packet session of a user entity connected to a wireless access network to a packet core network of a mobile communications network, the user entity using an access identifier allowing the user entity to be identified in the wireless access network, wherein the access identifier is not used in the mobile communications network to identify a subscriber, the authentication unit comprising:

• a receiver configured to receive a request in which access to the wireless access network is requested, wherein the request message contains an MAC address of the requesting user entity,
• a converting unit configured to convert the MAC address in the received request into a sequence of digits used as a mobile subscriber identifier with which the user entity is identified in the mobile communications network, and
• a transmitter configured to transmit a response message accepting the access to the packet core network, the response message including the sequence of digits used as mobile subscriber identifier.

A lawful interception control module configured to collect communication data of user entities in a mobile communications network which comprises a packet core network, the control module comprising:

• a input unit configured for an input of an identifier with which a user entity is identified the communication data of which should be collected, wherein the input unit is configured for an input of an identifier having the format of an MAC address of the user entity,
• a converting unit configured to convert the input identifier into a sequence of digits used as mobile subscriber identifier with which the user entity is identified in the mobile communications network,
• a transmitter configured to transmit the generated sequence of digits as mobile subscriber identifier to all PDN gateways of the mobile communications network.