A signal repeating system for a wireless network includes an antenna configured for transceiving signals between a base station and a user equipment device. Repeating circuitry is coupled to the antenna and defines an uplink path for signals from the user equipment device to the base station and a downlink path for signals from the base station to the user equipment device. The repeating circuitry includes gain circuitry and gain control circuitry that is coupled to the gain circuitry. The gain control circuitry is operable for varying the gain of the repeating circuitry according to a waveform. Measurement circuitry measures the receive power in the uplink path over time from the user equipment device. Processing circuitry cross-correlates the inverted gain variation waveform with the measured receive power for determining the existence of traffic from user equipment devices in the uplink path.