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 (121) for performing Device-to- Device, D2D, communications with a second user equipment (122)is provided. The first user equipment (121) determines that a valid timing reference is not present in the first user equipment (121). Also,the first user equipment (121) 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 (121) transmits a D2D signal to the second user equipment (122) with a timing using the preconfigured timing advance to perform D2D communication. A user equipment (121), a network node (110)and method therein for enabling D2D communications between user equipments (121, 122) in a radio communications network (100) are also provided.