1. A method comprising:instructing a first user equipment (UE) device to transmit a reference signal;
receiving, from a second UE device, device-to-device (D2D) channel characteristic information indicative of a D2D communication link between the first UE device and the second UE device, the D2D channel characteristic information determined from a UE device received reference signal that is the reference signal transmitted by the first UE device as received at the second UE device;
determining, from the D2D channel characteristic information, D2D transmission parameters for transmitting a D2D signal from the first UE device to the second UE device; and
transmitting the D2D transmission parameters to the first UE device.