A USER EQUIPMENT, A NETWORK NODE AND METHODS THEREIN FOR PERFORMING AND ENABLING DEVICE-TO-DEVICE (D2D) COMMUNICATION IN A RADIO COMMUNICATIONS NETWORK

摘要

A method performed by a first user equipment for performing Device-to-Device, D2D, communications with a second user equipment is provided. The first user equipment determines that a valid timing reference is not present in the first user equipment. Also, the first user equipment determines whether a preconfigured timing advance can be used in the D2D communication. Then, when determined that the preconfigured timing advance can be used, the first user equipment transmits a D2D signal to the second user equipment with a timing using the preconfigured timing advance to perform D2D communication. A user equipment, a network node and method therein for enabling D2D communications between user equipments in a radio communications network are also provided.