Method, System, and Apparatus

A method comprising:

• providing information to a user device capable of operating using carrier aggregation, said information comprising an indication of a first carrier and at least one second carrier to be used for a signalling procedure;
• receiving a transmission from the user device of a first signal of the signalling procedure using at least one of the first carrier and the at least one second carrier;
• and
• causing transmission of a second signal of the signalling procedure from an access point using at least one of the first carrier and the at least one second carrier.

An apparatus comprising:

• at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:
• receive information at a user device capable of operating using carrier aggregation, said information comprising an indication of a first carrier and at least one second carrier to be used for a signalling procedure;
• cause transmission from the user device of a first signal of the signalling procedure using at least one of the first carrier and the at least one second carrier;
• and
• monitor the first carrier and the at least one second carrier for transmission of a second signal of the signalling procedure from an access point.

An apparatus comprising:

• at least one processor and at least one memory including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:
• provide information to a user device capable of operating using carrier aggregation, said information comprising an indication of a first carrier and at least one second carrier to be used for a signalling procedure;
• and
• receive a transmission from the user device of a first signal of the signalling procedure using at least one of the first carrier and the at least one second carrier;
• cause transmission of a second signal of the signalling procedure from an access point using at least one of the first carrier and the at least one second carrier.