"""
    c: light's velocity.
    h: Planck's constant.
    l: light's wavelength.
    freq: light's frequency.
    BRef:  reference bandwidth.
    numPolarizations: is used to choose whether one or two polarizations are used to transmit the signal.
        
"""
 
c = 299792458
h = 6.62606957e-34
l = 1550e-9
freq = 193.4e12
BRef = 12.5e9
numPolarizations = 2
