Abstract: There is disclosed an apparatus caused to perform: during or subsequent to performing at least part of an authentication and/or authorisation procedure for a user equipment to access a network slice: signalling. to a charging function, a charging data request, the charging data request comprising an identifier of the user equipment, an identifier of the network slice. and an indication of an event to which the charging data request relates; and receiving, from the charging function, a charging data response.

Abstract: A terminal is assigned to a home radio access network and the access node of the data network is assigned to a second radio access network. An access control function of the access node receives from the terminal a first message containing an authentication code. The access control function of the access node identifies the home radio access network associated with the terminal from the authentication code. The access control function then sends an inquiry message including the authentication code to an access control function of the home radio access network associated with the terminal. From the authentication code, the home radio access network identifies the user as a subscriber of the relevant home radio access network. This is done e.g. by interrogating data from the HLR (Home Location Register) or the HSS (Home Subscriber Server).