Chapter 7 :Wavelength Division Multiplexing¶

Example 7.1 , Page no:128¶

In [1]:
import math
from __future__ import division

#initialisation of variables
delta_lambda=60e-9;  #delta lambda in m
lambda1=1550e-9;  #wavelength in m
c=3e8;  #velocity of light in m/s
CS=75*1e9;  #Channel spacing in Hz
Power_margin=30;  #power margin in dB
Fiber_loss=0.25;  #fiber loss in dB/Km
channel_capacity=2.5*1e9;  #channel capacity STM-16 in bps

#CALCULATIONS
delta_f=(c*delta_lambda)/lambda1**2;  #frequency bandwidth in Hz
transmission_distance=Power_margin/Fiber_loss;  #Transmission distance in Km
No_channels=(delta_f/CS);  #No. of channels
distance_bitrate_product=No_channels*channel_capacity*transmission_distance;  #distance bitrate product in bpsKm

#RESULTS
print"Frequency bandwidth =",round(delta_f/1e12,5),"x10^12Hz";  #division by  1e12 to convert unit from Hz to 10^12 Hz
print"Transmission distance =",round(transmission_distance,5),"Km";
print"No. of channels=",round(No_channels);
print"Distance bitrate product =",round(distance_bitrate_product/1e12),"Tbits/sKm";  #division by  1e12 to convert unit from bits/sKm to Tbits/sKm

Frequency bandwidth = 7.4922 x10^12Hz
Transmission distance = 120.0 Km
No. of channels= 100.0
Distance bitrate product = 30.0 Tbits/sKm