Abstract: A method for subscribing for Policy Control Function (PCF) binding events for an address range in a 5G system (5GS) includes: subscribing, from the NF Service Consumer to the functional entity, to binding information changes for one or a combination of subscriber parameters; sending, from the functional entity to the NF Service Consumer, a confirmation of the subscription; detecting, by the functional entity, a change of the stored binding information matching one or a combination of the subscriber parameters for one or more subscriber IDs; notifying of the change of the stored binding information, from the functional entity to the subscribed NF Service Consumer, by sending new PDU session binding information associated with the one or more subscriber IDs; and receiving, at the NF Service Consumer, the new PDU session binding information associated with the one or more subscriber IDs.

Abstract: A 5G system (5GS) includes a Network Function (NF) Service Consumer and a functional entity, wherein the functional entity includes binding information stored therein and the binding information includes: Protocol Data Unit (PDU) sessions information and a list comprising one or more subscribers identities (IDs) and/or Policy Control Function (PCF) instance IDs. A method for querying PCF binding information for an address range in the 5GS includes: querying, from the NF Service Consumer to the functional entity, based on one or a combination of query parameters, for all binding information matching the query parameters; and notifying, from the functional entity to the NF Service Consumer, any binding information that matches the query parameters.

Abstract: A communication system includes an external entity and a 5G system (5GS), wherein the 5GS comprises a 5G core (5GC), wherein the 5GC comprises a functional entity, a Unified Data Management (UDM), a Session Management Function (SMF), and a User Plane Function (UPF). A method for setting up expected communication behavior information in the system includes: performing, by the external entity, an Application Programming Interface (API) call via an API of the functional entity and setting up an expected communication behavior for a subscriber or set of subscribers, a data network name (DNN), a 5G virtual network (VN), a slice or a combination thereof that the functional entity is allowed to manage.