A method of wireless communication includes configuring a virtual SRS transmission to prompt a user equipment to use a shortened uplink transmission format to create a silent period at an end of a subframe. In one embodiment, switching networks S1 and S2 have their respective inputs connected to the FETs’ drains, and are operated with clock signals CLK1 and CLK2, respectively. The control signal monitoring circuit monitors the digital control signal and detects either a heavy load or a light load condition based on characteristics of the digital control signal. If an oscillator okay signal is not detected within another predetermined time, then an oscillator failure signal may be generated.