Call placement to or from satellite UEs is optimized by reducing IMS message exchanges, the originating party has control over QoS parameters; a HPA subscription service is made available, and calls to a terminating satellite UE that is shielded from satellite coverage are completed by selectively employing HPA pages. For a call request without preconditions, an IMS node associated with an originating UE uses the NRSCPA on Offer instead of using the standard terminating node initiated NRSCPA on Answer. An IMS node associated with a terminating UE checks for HPA subscription by the user. If subscribed, the terminating INVITE request is for a “Conversational” or “Interactive” service, and the terminating UE is in PMM_IDLE state, the satellite RAN pages the terminating UE using HPA.