In a 5.sup.th-Generation (5G) cellular communication network, charging customers for data usage is performed by a network function referred to as a charging function (CHF). A session management function (SMF) of the network repeatedly sends update requests to reserve additional data for a data session. If the CHF is not available and the SMF does not receive a response to an update message, the SMF continues to assign data for the data session, even though it has not received authorization to do so from the CHF. When the CHF becomes available, the SMF sends a request to start a second data session to continue the data connection that was previously supported by the original data session. This request specifies the amount of data that was used in the original data session without being confirmed by the CHF, allowing the CHF to account for this data usage.

Systems and methods may provide for establishing a data usage budget based on one or more of user input and historical usage data, wherein the data usage budget distinguishes between usage types and distinguishes between connection types. Additionally, a data usage of one or more client devices may be monitored in accordance with the data usage budget. In one example, the usage types are designated as one or more of a high bandwidth usage and a low bandwidth usage, and the connection types are designated as one or more of a capped connection and a non-capped connection.

Embodiments of this application provide a charging method. The method includes that a session management function determines, a data flow within a protocol data unit, PDU, session and a charging key corresponding to the data flow within the PDU session, wherein a plurality of user plane functions are involved in the PDU session. For each of the plurality of user plane functions, the session management function sends to an online charging system, a quota request for a charging key without available quota for the UPF.

In a 5.sup.th-Generation (5G) cellular communication network, charging customers for data usage is performed by a network function referred to as a charging function (CHF). A session management function (SMF) of the network repeatedly sends update requests to reserve additional data for a data session. If the CHF is not available and the SMF does not receive a response to an update message, the SMF continues to assign data for the data session, even though it has not received authorization to do so from the CHF. When the CHF becomes available, the SMF sends a request to start a second data session to continue the data connection that was previously supported by the original data session. This request specifies the amount of data that was used in the original data session without being confirmed by the CHF, allowing the CHF to account for this data usage.

A charging method includes: determining, by a control plane function entity (CP), that a data flow that is transmitted by user equipment (UE) on a first data session needs to be migrated to a second data session; charging, by the CP, the data flow on the first UP through a first charging session between the CP and a charging system; obtaining, by the CP, charging information of the data flow before the migration that is counted by the first UP; and determining, by the CP, a quota that is used for the data flow after the migration is necessary to be delivered to the second UP, and delivering the quota to the second UP, thereby charging a service data flow of a user in a case of migration between user planes.

Embodiments of this application provide a charging method. The method includes that a session management function determines, a data flow within a protocol data unit, PDU, session and a charging key corresponding to the data flow within the PDU session, wherein a plurality of user plane functions are involved in the PDU session. For each of the plurality of user plane functions, the session management function sends to an online charging system, a quota request for a charging key without available quota for the UPF.

Example charging methods and apparatus are described. One example method includes sending a service resource create request to a charging system by a charging trigger apparatus. The charging trigger apparatus receives a service resource create response sent by the charging system. The service resource create request is used to request the charging system to create a service resource corresponding to a service in a session. The session is used to provide a data connection service to user equipment. The service resource is used to manage requesting for a quota for the service in the session and/or manage reporting of usage information of the service in the session. The service resource create response includes a first resource identifier, and the first resource identifier is used to identify the service resource that corresponds to the service in the session and that is created by the charging system.

A charging method applied to a network architecture in which network control and data flow forwarding are separated. The method includes receiving, by a control plane (CP) entity, a charging rule delivered by a policy and charging rules function PCRF entity, generating, by the CP, a user plane UP entity reporting policy based on the charging rule, requesting, by the CP from an online charging system OCS, a quota required by a rating group in the charging rule, receiving, by the CP, a quota delivered by the OCS, and generating UP quota information based on the quota; and delivering, by the CP, the generated UP reporting policy and the generated UP quota information to the UP.

This application provide an offline charging call detail record threshold control method and system based on a CUPS protocol. According to the method, after a CP establishes a session, a message that is sent to a UP carries a maximum quantity of charging condition changes. The UP reports charging information to the CP based on an instant query request from the CP or a subscription condition, and calculates a quantity of charging condition changes. If the quantity of charging condition changes is less than the maximum quantity of charging condition changes, the UP continues to accumulate used traffic on the basis of existing accumulated used traffic. If the quantity of charging condition changes is equal to the maximum quantity of charging condition changes, the UP clears charging information and a quantity of traffic containers for an offline charging call detail record on a UP side.

A charging method includes: determining, by a control plane function entity (CP), that a data flow that is transmitted by user equipment (UE) on a first data session needs to be migrated to a second data session; charging, by the CP, the data flow on the first UP through a first charging session between the CP and a charging system; obtaining, by the CP, charging information of the data flow before the migration that is counted by the first UP; and determining, by the CP, a quota that is used for the data flow after the migration is necessary to be delivered to the second UP, and delivering the quota to the second UP, thereby charging a service data flow of a user in a case of migration between user planes.