A method for processing an access request from a user equipment, UE , the method performed by an access network node and comprising: receiving an access request message from the UE , wherein the access request message includes information of the UE; selecting a first basic control plane, CP, function node for a common or basic function for slice instances, based on the information of the UE, wherein the first basic CP function node (510-1) is shared by the slice instances, wherein each of the slice instances includes a service-specific or non-common CP function node, which is not shared by other slice instances; transmitting the access request message to the selected basic CP function node (510-1); for change of a basic CP function node for the UE , determined by the first basic CP function node and triggered by network management, change of subscriber information of the UE, location change of the UE or change of service attributes of the UE, receiving, from the first basic CP function node (510-1), a detach/re-attach request message for detach of the UE from the first basic CP function node and re-attach of the UE to another basic CP function node; transmitting the detach/re-attach request message to the UE ; receiving a re-attach request message from the UE , based on the detach/re-attach request message, wherein the re-attach request message includes information of the UE; selecting a slice instance on the basis of the information included within the re-attach request message from the UE ; and selecting a second basic CP function node (510-2) other than the first basic CP function node (510-1), based on the information of the UE, included within the re-attach request message; transmitting an attach - or the re-attach request message to the second basic CP function node (510-2) receiving an access request message from the UE , wherein the access request message includes information of the UE; selecting a first basic control plane, CP, function node for a common or basic function for slice instances, based on the information of the UE, wherein the first basic CP function node (510-1) is shared by the slice instances, wherein each of the slice instances includes a service-specific or non-common CP function node, which is not shared by other slice instances; transmitting the access request message to the selected basic CP function node (510-1); for change of a basic CP function node for the UE , determined by the first basic CP function node and triggered by network management, change of subscriber information of the UE, location change of the UE or change of service attributes of the UE, receiving, from the first basic CP function node (510-1), a detach/re-attach request message for detach of the UE from the first basic CP function node and re-attach of the UE to another basic CP function node; transmitting the detach/re-attach request message to the UE ; receiving a re-attach request message from the UE , based on the detach/re-attach request message, wherein the re-attach request message includes information of the UE; selecting a slice instance on the basis of the information included within the re-attach request message from the UE ; and selecting a second basic CP function node (510-2) other than the first basic CP function node (510-1), based on the information of the UE, included within the re-attach request message; transmitting an attach - or the re-attach request message to the second basic CP function node (510-2) <EOS>