The Offline Charging System (OFCS) is a component of the Policy Control and Charging (PCC) of LTE networks
. The offline charging calculates the costs that the billing system charges to the subscriber from the information about the connections and the mobile services used that it receives from the Policy and Charging Enforcement Function (PCEF). The billing file is called the Charging Data Record (CDR) in mobile networks. The offline charging system is connected to the PECF component via a G interface (Gz).