To execute certain events, for example OS upgrade, silent reset at modem or modem software updates (also commonly called as binary updates) there are 3 parties involved: the device, the operator and the application function. Once the UE has downloaded the binary, the time when the UE performs the upgrade is left for the UE implementation, with possibly UE implementations seeking user input. If UEs cannot execute the event (e.g. the storage capacity or the battery level are insufficient), they may delay execution of the event. These UEs become unavailable (i.e. cannot interact with the 5G System) in the order of minutes whenever such operations are performed. As UEs become unavailable without prior knowledge from the core network and/or application function, it can impact critical operations of an application server if it depends on availability of the UE during the unavailability period (i.e. a period of time during which the UE is not available).
The present key issue shall study:
Whether and how an unavailability period is determined in 5GS for a specific UE.
Study the expected UE and/or network actions (if any) based on determined unavailability period.