Signaling mechanism for inter-RAT carrier aggregation

A method in a wireless network control node, the method comprising:

• receiving first and second data units forwarded from one or more wireless base stations, wherein the first data units were transmitted by a mobile station using a first radio access technology and the second data units were transmitted by the mobile station using a second radio access technology that differs from the first;
• receiving, from one of the wireless base stations, a control message associated with one or more of the first and second data units, wherein the control message comprises an N-bit binary mask, where N is the number of carriers in an inter-RAT carrier aggregation for the mobile station and wherein each bit of the N-bit binary mask indicates a RAT type for a corresponding carrier;
• and
• identifying, from the control message, the radio access technology over which the associated one or more data units were transmitted.

A wireless base station, comprising

• a first radio unit configured to receive first data units transmitted by a mobile station using a first radio access technology;
• and
• a MAC processing unit configured to:
• receive the first data units from the first radio unit;
• forward the received first data units to a network control node for further processing;
• and
• send a control message associated with the first data units to the network control node, wherein the control message indicates the radio access technology over which the associated data units were transmitted, wherein the control message comprises an N-bit binary mask, where N is the number of carriers in an inter-RAT carrier aggregation scheme wherein each bit of the N-bit binary mask indicates a radio access technology type for a corresponding carrier.

A wireless network controller, comprising:

• a base station interface unit configured to receive first and second data units forwarded from one or more wireless base stations, wherein the first data units were transmitted by a mobile station using a first radio access technology and the second data units were transmitted by the mobile station using a second radio access technology that differs from the first;
• and
• a protocol processing unit configured to:
• receive a control message associated with one or more of the first and second data units from one of the wireless base stations, via the base station interface unit, wherein the control message comprises an N-bit binary mask, where N is the number of carriers in an inter-RAT carrier aggregation for the mobile station and wherein each bit of the N-bit binary mask indicates a RAT type for a corresponding carrier;
• and
• identify, from the control message, the radio access technology over which the associated one or more data units were transmitted.