Turning now to an example embodiment in which the above-described concepts are applied to a 5G MCN architecture that is based on NFV, the SCEF may be implemented as a NF that exposes an API that allows the third party server to indicate to the MCN that it has data to send to a particular UE. Alternatively, the node that exposes the API may be some other NF. When a UE uses a 5G power savings state, such as the NG POWER-SAVING state, the API may allow the third party server to inform the MCN that the third party server would like to send data to the UE. The MCN may then notify the UE that it should leave the NG POWER-SAVING or RRC Low Energy state because data is buffered at a third party server.

In some cases, when the UE is in NG POWER-SAVING state, the UE may be expected to periodically leave the NG POWER-SAVING state and listen to the network for a page or to perform some procedure with the network (e.g., similar to a TAU) to let the MCN know that the UE is temporarily reachable. The MCN may take this opportunity to page the UE so that the third party data can be buffered, or it can reply to the UE's message (e.g., the TAU message) and inform the UE that data is buffered for the UE in a third party server. The page or indication of buffered data from the MCN may cause the UE to not return to the NG POWER-SAVING state.

When the UE is in RRC Low Energy state, the UE may be expected to periodically listen to the network for a page or perform some procedure with the network (similar to a TAU) to let the MCN now that the UE is temporarily reachable. The MCN may take this opportunity to page the UE so that the 3rd party data can be buffered or it can reply to the UE's message (i.e. the TAU message) and inform the UE that data is buffered for the UE in a third party server. The page or indication of buffered data from the MCN may cause the UE to leave the RRC Low Energy state.