Abstract Silicon-on-insulator (SOI) waveguide devices are emerging for the realization of optical signal processing systems for the last couple of years. The recent technological advancement in silicon photonics is the main driving force at the back of these devices. Using non-linear optical phenomenon in silicon wires and their compatibility with CMOS devices provide the stage for integrated photonic devices. All-optical signal processing devices are being investigated at present, but the chip-scale solution provided by the silicon photonics is the most promising. In this research we have investigated all-optical signal processing in a 10 mm long SOI waveguide by exploiting well established coupled wave equations. We consider single pulsed pump to analyze frequency shifting by four-wave-mixing (FWM). For the wavelengths 20⿿30 nm far from the pump, the gain overcomes nonlinear losses resulting in higher frequency conversion efficiency.