Methods and apparatus of varying transmit power of signals for increasing system throughput and spectral reuse in an unlicensed spectrum are disclosed. One method includes transmitting from a first mobile device to a second mobile device a request to send (RTS) signal having a first transmit data power level based on a channel gain between the first mobile device and the second mobile device, receiving, at the first mobile device, a clear to send (CTS) signal from the second mobile device, and transmitting data at the first transmit data power level from the first mobile device to the second mobile device.