Methods of mobile device based relay for coverage extension

The invention discloses an equipment direct-through system relay state determination method and device. The method comprises the steps that relay user equipment UE acquires relay configuration information and/or receives device-to-device D2D information, and the relay state of the relay UE is determined according to the relay configuration information and/or the D2D information. The device is arranged in the relay user equipment UE and comprises an information acquisition module and a state determination module. According to the method and the device, the UE with the relay capacity can enter the relay second state without accessing of far-end users and enter the relay first state when receiving the request of the far-end users for searching the relay and periodically broadcast the relay information so that switching of the relay state of the relay UE can be realized through the mode, and the objective of power saving can be achieved when the relay UE is in the relay second state.