A technology for a user equipment (UE) that is operable to communicate in a device to device (D2D) network. A proximity detection request can be communicated to an evolved packet core (EPC). The proximity detection request can include a window parameter, an identification information of a second UE, and a proximity detection signal indicating whether the proximity detection request is for proximity detection of the second UE or for establishing a D2D connection with the second UE. A proximity alert message can be received from the EPC at the window parameter.