Method and apparatus for service charging in a communication network

A charging system node configured for operation in a charging system associated with a communication network, the charging system node comprising:

• communication interface circuitry configured to send messages to and receive messages from one or more other nodes in the charging system or the communication network;
• and
• processing circuitry operatively associated with the communication interface circuitry and configured to:
• receive a credit request for authorizing use of a communication service in the communication network by a user device associated with a user account, the credit request requesting reservation of a first number of service units corresponding to one or more charging intervals, each charging interval defining, according to a charging configuration used in the communication network for the communication service, a second number of service units, with each service unit being a quantum of metered consumption of the communication service;
• authorize the one or more charging intervals in dependence on sufficient credit units being available for reservation among multiple credit containers associated with the user account, including authorizing each of at least one of the one or more charging intervals by reserving a corresponding aggregation of credit units from two or more credit containers among the multiple credit containers, wherein a respective number of credit units reserved from each of the two or more credit containers for the corresponding aggregation of credit units depends on a type-dependent rating function that translates between the service units and the type of credit units contained in the credit container;
• and
• send a credit response indicating a total number of service units corresponding to the authorized charging intervals.