The standard unit for frequency is the hertz Hz defined as events or cycles per second. The formula used to calculate the frequency is. Because frequency determines the number of times a wave oscillates and it can be expressed as f 1 t.
Every point on the wave returns to the same value after one period since a wave undergoes one oscillation during one period.
For a sinusoidal wave represented by the equation. Angular frequency 2 p period of oscillation. Frequency f is defined to be the number of events per unit time. In long-distance transmission systems the coherence time may be reduced by propagation factors such as dispersion scattering and diffraction.