An aspect of the invention relates to 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: obtain a system access to a primary cell from a user device, carry out a radio connection setup for the user device for the primary cell in a response to the system access and/or obtain an indication of a system access of the user device to at least one secondary cell from the at least one secondary cell, and carry out a resource configuration for the user device with the secondary cell in response to the obtaining the indication, and carry out a radio connection setup for the user device for the secondary cell based on the resource configuration.