Patent ID: 10075991

Abstract:
A method and apparatus for performing a state transition for Device to Device (D2D) communication are provided. The method includes determining whether D2D initiation is required, while a terminal is operating in a first or a second state defined by EPS (Enhanced Packet System) Mobility Management (EMM)-Deregistered and EPS Connection Management (ECM)-IDLE at a Non-Access Stratum (NAS) layer and Radio Resource Control (RRC)-IDLE. If the D2D initiation is required, the method includes transitioning to a third state defined by EMM-Registered and ECM/RRC-Connected and performing the D2D initiation through a mobile communication network. If a deactivation condition is satisfied or a D2D state update is completed in the third state, the method includes transitioning to a fourth state defined by EMM-Registered and ECM/RRC-IDLE, and if a state update or scheduling for D2D communication is required in the fourth state, the method includes transitioning to the third state.