Files
oopt-gnpy/gnpy/core/utils.py
EstherLerouzic 54a3725e17 Add a -spectrum option to input external file to define spectrum
The option is only set for gnpy-transmission-main.

The spectrum file is a list of spectrum objects, each defining
f_min, f_max and spectrum attributes using the same meaning as SI
in eqpt_config.json for baud_rate, roll_off, tx_osnr. slot_width is
used for the occupation of each carrier around their central frequency,
so slot_width corresponds to spacing of SI.
Unlike SI, the frequencies are defined includint f_min and f_max.
The partitions must be contiguous not overlapping.

Pref.p_span0 object records the req_power, while
ref_carrier records info that will be useful for equalization ie baud_rate.

For now, I have not integrated the possibility to directly use
transceivers type and mode in the list.

User can define sets of contiguous channels and a label to identify
the spectrum bands. If no label are defined, the program justs uses
the index + baud rate of the spectrum bands as label.

Print results per spectrum label

If propagated spectrum has mixed rates, then prints results (GSNR and OSNR)
for each propagated spectrum type according to its label.

Print per label channel power of elements

Per channel power prints were previously only showing the noiseless
reference channel power and only an average power.
With this change, we add a new information on the print:
the average total power (signal + noise + non-linear noise).
If there are several spectrum types propagating, the average per
spectrum is displayed using the label.
For this purpose, label and total power are recorded in each element
upon propagation

Note that the difference between this total power and the existing
channel power represents the added noise for the considered OMS.
Indeed ROADMs equalize per channel total power, so that power displayed
in 'actual pch (dBm)' may contain some noise contribution accumulated
with previous propagation.
Because 'reference pch out (dBm)' is for the noiseless reference,
it is exactly set to the target power and 'actual pch (dBm)' is always
matching 'reference pch out (dBm)' in ROADM prints.

Add examples and tests for -spectrum option

initial_spectrum1.json reproduces exactly the case of SI
initial_spectrum2.json sets half of the spectrum with 50GHz 32Gbauds and
half with 75GHz 64 Gbauds. Power setting is not set for the second half,
So that equalization will depend on ROADM settings.

Signed-off-by: EstherLerouzic <esther.lerouzic@orange.com>
Change-Id: Ibc01e59e461e5e933e95d23dacbc5289e275ccf7
2022-11-09 14:39:25 +01:00

416 lines
11 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
gnpy.core.utils
===============
This module contains utility functions that are used with gnpy.
"""
from csv import writer
from numpy import pi, cos, sqrt, log10, linspace, zeros, shape, where, logical_and, mean
from scipy import constants
from gnpy.core.exceptions import ConfigurationError
def write_csv(obj, filename):
"""
Convert dictionary items to a CSV file the dictionary format:
::
{'result category 1':
[
# 1st line of results
{'header 1' : value_xxx,
'header 2' : value_yyy},
# 2nd line of results: same headers, different results
{'header 1' : value_www,
'header 2' : value_zzz}
],
'result_category 2':
[
{},{}
]
}
The generated csv file will be:
::
result_category 1
header 1 header 2
value_xxx value_yyy
value_www value_zzz
result_category 2
...
"""
with open(filename, 'w', encoding='utf-8') as f:
w = writer(f)
for data_key, data_list in obj.items():
# main header
w.writerow([data_key])
# sub headers:
headers = [_ for _ in data_list[0].keys()]
w.writerow(headers)
for data_dict in data_list:
w.writerow([_ for _ in data_dict.values()])
def arrange_frequencies(length, start, stop):
"""Create an array of frequencies
:param length: number of elements
:param start: Start frequency in THz
:param stop: Stop frequency in THz
:type length: integer
:type start: float
:type stop: float
:return: an array of frequencies determined by the spacing parameter
:rtype: numpy.ndarray
"""
return linspace(start, stop, length)
def lin2db(value):
"""Convert linear unit to logarithmic (dB)
>>> lin2db(0.001)
-30.0
>>> round(lin2db(1.0), 2)
0.0
>>> round(lin2db(1.26), 2)
1.0
>>> round(lin2db(10.0), 2)
10.0
>>> round(lin2db(100.0), 2)
20.0
"""
return 10 * log10(value)
def db2lin(value):
"""Convert logarithimic units to linear
>>> round(db2lin(10.0), 2)
10.0
>>> round(db2lin(20.0), 2)
100.0
>>> round(db2lin(1.0), 2)
1.26
>>> round(db2lin(0.0), 2)
1.0
>>> round(db2lin(-10.0), 2)
0.1
"""
return 10**(value / 10)
def watt2dbm(value):
"""Convert Watt units to dBm
>>> round(watt2dbm(0.001), 1)
0.0
>>> round(watt2dbm(0.02), 1)
13.0
"""
return lin2db(value * 1e3)
def dbm2watt(value):
"""Convert dBm units to Watt
>>> round(dbm2watt(0), 4)
0.001
>>> round(dbm2watt(-3), 4)
0.0005
>>> round(dbm2watt(13), 4)
0.02
"""
return db2lin(value) * 1e-3
def psd2powerdbm(psd_mwperghz, baudrate_baud):
"""computes power in dBm based on baudrate in bauds and psd in mW/GHz
>>> round(psd2powerdbm(0.031176, 64e9),3)
3.0
>>> round(psd2powerdbm(0.062352, 32e9),3)
3.0
>>> round(psd2powerdbm(0.015625, 64e9),3)
0.0
"""
return lin2db(baudrate_baud * psd_mwperghz * 1e-9)
def power_dbm_to_psd_mw_ghz(power_dbm, baudrate_baud):
"""computes power spectral density in mW/GHz based on baudrate in bauds and power in dBm
>>> power_dbm_to_psd_mw_ghz(0, 64e9)
0.015625
>>> round(power_dbm_to_psd_mw_ghz(3, 64e9), 6)
0.031176
>>> round(power_dbm_to_psd_mw_ghz(3, 32e9), 6)
0.062352
"""
return db2lin(power_dbm) / (baudrate_baud * 1e-9)
def psd_mw_per_ghz(power_watt, baudrate_baud):
"""computes power spectral density in mW/GHz based on baudrate in bauds and power in W
>>> psd_mw_per_ghz(2e-3, 32e9)
0.0625
>>> psd_mw_per_ghz(1e-3, 64e9)
0.015625
>>> psd_mw_per_ghz(0.5e-3, 32e9)
0.015625
"""
return power_watt * 1e3 / (baudrate_baud * 1e-9)
def round2float(number, step):
"""Round a floating point number so that its "resolution" is not bigger than 'step'
The finest step is fixed at 0.01; smaller values are silently changed to 0.01.
>>> round2float(123.456, 1000)
0.0
>>> round2float(123.456, 100)
100.0
>>> round2float(123.456, 10)
120.0
>>> round2float(123.456, 1)
123.0
>>> round2float(123.456, 0.1)
123.5
>>> round2float(123.456, 0.01)
123.46
>>> round2float(123.456, 0.001)
123.46
>>> round2float(123.249, 0.5)
123.0
>>> round2float(123.250, 0.5)
123.0
>>> round2float(123.251, 0.5)
123.5
>>> round2float(123.300, 0.2)
123.2
>>> round2float(123.301, 0.2)
123.4
"""
step = round(step, 1)
if step >= 0.01:
number = round(number / step, 0)
number = round(number * step, 1)
else:
number = round(number, 2)
return number
wavelength2freq = constants.lambda2nu
freq2wavelength = constants.nu2lambda
def freq2wavelength(value):
""" Converts frequency units to wavelength units.
>>> round(freq2wavelength(191.35e12) * 1e9, 3)
1566.723
>>> round(freq2wavelength(196.1e12) * 1e9, 3)
1528.773
"""
return constants.c / value
def snr_sum(snr, bw, snr_added, bw_added=12.5e9):
snr_added = snr_added - lin2db(bw / bw_added)
snr = -lin2db(db2lin(-snr) + db2lin(-snr_added))
return snr
def per_label_average(values, labels):
"""computes the average per defined spectrum band, using labels
>>> labels = ['A', 'A', 'A', 'A', 'A', 'B', 'B', 'B', 'B', 'B', 'B', 'B', 'B', 'C', 'D', 'D', 'D', 'D']
>>> values = [28.51, 28.23, 28.15, 28.17, 28.36, 28.53, 28.64, 28.68, 28.7, 28.71, 28.72, 28.73, 28.74, 28.91, 27.96, 27.85, 27.87, 28.02]
>>> per_label_average(values, labels)
{'A': 28.28, 'B': 28.68, 'C': 28.91, 'D': 27.92}
"""
label_set = sorted(set(labels))
summary = {}
for label in label_set:
vals = [val for val, lab in zip(values, labels) if lab == label]
summary[label] = round(mean(vals), 2)
return summary
def pretty_summary_print(summary):
"""Build a prettty string that shows the summary dict values per label with 2 digits
"""
if len(summary) == 1:
return f'{list(summary.values())[0]:.2f}'
text = ', '.join([f'{label}: {value:.2f}' for label, value in summary.items()])
return text
def deltawl2deltaf(delta_wl, wavelength):
""" deltawl2deltaf(delta_wl, wavelength):
delta_wl is BW in wavelength units
wavelength is the center wl
units for delta_wl and wavelength must be same
:param delta_wl: delta wavelength BW in same units as wavelength
:param wavelength: wavelength BW is relevant for
:type delta_wl: float or numpy.ndarray
:type wavelength: float
:return: The BW in frequency units
:rtype: float or ndarray
"""
f = wavelength2freq(wavelength)
return delta_wl * f / wavelength
def deltaf2deltawl(delta_f, frequency):
""" deltawl2deltaf(delta_f, frequency):
converts delta frequency to delta wavelength
units for delta_wl and wavelength must be same
:param delta_f: delta frequency in same units as frequency
:param frequency: frequency BW is relevant for
:type delta_f: float or numpy.ndarray
:type frequency: float
:return: The BW in wavelength units
:rtype: float or ndarray
"""
wl = freq2wavelength(frequency)
return delta_f * wl / frequency
def rrc(ffs, baud_rate, alpha):
""" rrc(ffs, baud_rate, alpha): computes the root-raised cosine filter
function.
:param ffs: A numpy array of frequencies
:param baud_rate: The Baud Rate of the System
:param alpha: The roll-off factor of the filter
:type ffs: numpy.ndarray
:type baud_rate: float
:type alpha: float
:return: hf a numpy array of the filter shape
:rtype: numpy.ndarray
"""
Ts = 1 / baud_rate
l_lim = (1 - alpha) / (2 * Ts)
r_lim = (1 + alpha) / (2 * Ts)
hf = zeros(shape(ffs))
slope_inds = where(
logical_and(abs(ffs) > l_lim, abs(ffs) < r_lim))
hf[slope_inds] = 0.5 * (1 + cos((pi * Ts / alpha) *
(abs(ffs[slope_inds]) - l_lim)))
p_inds = where(logical_and(abs(ffs) > 0, abs(ffs) < l_lim))
hf[p_inds] = 1
return sqrt(hf)
def merge_amplifier_restrictions(dict1, dict2):
"""Updates contents of dicts recursively
>>> d1 = {'params': {'restrictions': {'preamp_variety_list': [], 'booster_variety_list': []}}}
>>> d2 = {'params': {'target_pch_out_db': -20}}
>>> merge_amplifier_restrictions(d1, d2)
{'params': {'restrictions': {'preamp_variety_list': [], 'booster_variety_list': []}, 'target_pch_out_db': -20}}
>>> d3 = {'params': {'restrictions': {'preamp_variety_list': ['foo'], 'booster_variety_list': ['bar']}}}
>>> merge_amplifier_restrictions(d1, d3)
{'params': {'restrictions': {'preamp_variety_list': [], 'booster_variety_list': []}}}
"""
copy_dict1 = dict1.copy()
for key in dict2:
if key in dict1:
if isinstance(dict1[key], dict):
copy_dict1[key] = merge_amplifier_restrictions(copy_dict1[key], dict2[key])
else:
copy_dict1[key] = dict2[key]
return copy_dict1
def silent_remove(this_list, elem):
"""Remove matching elements from a list without raising ValueError
>>> li = [0, 1]
>>> li = silent_remove(li, 1)
>>> li
[0]
>>> li = silent_remove(li, 1)
>>> li
[0]
"""
try:
this_list.remove(elem)
except ValueError:
pass
return this_list
def automatic_nch(f_min, f_max, spacing):
"""How many channels are available in the spectrum
:param f_min Lowest frequenecy [Hz]
:param f_max Highest frequency [Hz]
:param spacing Channel width [Hz]
:return Number of uniform channels
>>> automatic_nch(191.325e12, 196.125e12, 50e9)
96
>>> automatic_nch(193.475e12, 193.525e12, 50e9)
1
"""
return int((f_max - f_min) // spacing)
def automatic_fmax(f_min, spacing, nch):
"""Find the high-frequenecy boundary of a spectrum
:param f_min Start of the spectrum (lowest frequency edge) [Hz]
:param spacing Grid/channel spacing [Hz]
:param nch Number of channels
:return End of the spectrum (highest frequency) [Hz]
>>> automatic_fmax(191.325e12, 50e9, 96)
196125000000000.0
"""
return f_min + spacing * nch
def convert_length(value, units):
"""Convert length into basic SI units
>>> convert_length(1, 'km')
1000.0
>>> convert_length(2.0, 'km')
2000.0
>>> convert_length(123, 'm')
123.0
>>> convert_length(123.0, 'm')
123.0
>>> convert_length(42.1, 'km')
42100.0
>>> convert_length(666, 'yards')
Traceback (most recent call last):
...
gnpy.core.exceptions.ConfigurationError: Cannot convert length in "yards" into meters
"""
if units == 'm':
return value * 1e0
elif units == 'km':
return value * 1e3
else:
raise ConfigurationError(f'Cannot convert length in "{units}" into meters')