Embodiments of a User Equipment (UE) and methods for operating in a mobile network that supports packet-switched (PS) and circuit-switched (CS) communication are generally described herein. The UE may include hardware processing circuitry to transmit a registration message for registration with the PS node and a CS node of the mobile network and for an establishment of a signaling session between the PS node and the CS node for the UE. The hardware processing circuitry may be further to transmit a periodic registration update message for remaining registered with the PS node. In some embodiments, the periodic registration update message may include a signaling permission indicator for a re-establishment, by the PS node, of the signaling session between the PS node and the CS node for the UE.