A method and an OCA module of a radio network node (RNN) for handling a request for at least one channel and a method and an OCA module of a core network node (CNN) for providing at least one channel operable by a RNN are disclosed. The OCA module receives, from an RMM module, the request. The OCA module sends, to the OCA module of the CNN, the request and a set of local parameters. The OCA module of the CNN assesses channels to select one or more channels in a first level assessment, wherein the assessment is based on the set of local parameters and a set of global parameters. The OCA module of the CNN sends the one or more channels to the OCA module. The OCA module assesses, in a second level assessment, said one or more channels, to obtain at least one second level channel.