A method for controlling a device-to-device, D2D, discovery process at a user equipment, comprising: receiving , at the user equipment, from a base station, in broadcasted system information, guiding information on D2D services available in a cell, discovering , at the user equipment, a D2D service according to the guiding information, if the received guiding information is relevant to any D2D service that the user equipment desires to discover, determining , at the user equipment, whether discovery information in a discovering message received from a discovered user equipment is sufficient for performing the D2D discovery process or not; in response to a positive result of the determination, continuing , at the user equipment, the discovery procedure by sending a reply to the discovered user equipment via a direct D2D channel between the user equipment and the discovered user equipment, at least by using the discovery information in the discovering message; in response to a negative result of the determination, sending , from the user equipment, a request to the base station for assistance on further discovery information for performing the D2D discovery process, and receiving , at the user equipment, the further discovery information from the base station, characterized by the determining comprising checking, based on the guiding information and information in the discovering message, whether a discovery type may be judged, and by the continuing comprising continuing the discovery procedure by sending the reply to the discovered user equipment based on the judged discovery type. receiving , at the user equipment, from a base station, in broadcasted system information, guiding information on D2D services available in a cell, discovering , at the user equipment, a D2D service according to the guiding information, if the received guiding information is relevant to any D2D service that the user equipment desires to discover, determining , at the user equipment, whether discovery information in a discovering message received from a discovered user equipment is sufficient for performing the D2D discovery process or not; in response to a positive result of the determination, continuing , at the user equipment, the discovery procedure by sending a reply to the discovered user equipment via a direct D2D channel between the user equipment and the discovered user equipment, at least by using the discovery information in the discovering message; in response to a negative result of the determination, sending , from the user equipment, a request to the base station for assistance on further discovery information for performing the D2D discovery process, and receiving , at the user equipment, the further discovery information from the base station, sending , from the user equipment, a request to the base station for assistance on further discovery information for performing the D2D discovery process, and receiving , at the user equipment, the further discovery information from the base station, characterized by the determining comprising checking, based on the guiding information and information in the discovering message, whether a discovery type may be judged, and by the continuing comprising continuing the discovery procedure by sending the reply to the discovered user equipment based on the judged discovery type. <EOS>