The formula that relates wavelength to frequency is frequency=speed of light /wavelength. The speed of light is usually approximated to 3*10^3m/s^2. We convert the wavelength to meters (12.24 cm is the same as 0.1224 m), frequency = 300,000,000/0.1224m = 2,450,980,392 Hz, which is about 2.45GHz.
