Files
oopt-gnpy/gnpy/core/parameters.py
AndreaDAmico 32d8b2a4d8 Simulation Parameters
This change siplifies the structure of the simulation parameters,
removing the gnpy.science_utils.simulation layer, provides some
documentation of the parameters and define a mock fixture for testing in
safe mode.

Jan: while I'm not thrilled by this concept of hidden global state, we
agreed to let it in as a temporary measure (so as not to hold merging of
Andrea's flexgrid/multirate patches). I've refactored this to a more
pytest-ish way of dealing with fixtures. In the end, it was also
possible to remove the MockSimParams class because it was not adding any
features on top of what SimParams can do already (and to what was
tested).

Change-Id: If5ef341e0585586127d5dae3f39dca2c232236f1
Signed-off-by: Jan Kundrát <jan.kundrat@telecominfraproject.com>
2021-10-29 13:14:22 +02:00

241 lines
8.1 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
gnpy.core.parameters
====================
This module contains all parameters to configure standard network elements.
"""
from scipy.constants import c, pi
from numpy import squeeze, log10, exp
from gnpy.core.utils import db2lin, convert_length
from gnpy.core.exceptions import ParametersError
class Parameters:
def asdict(self):
class_dict = self.__class__.__dict__
instance_dict = self.__dict__
new_dict = {}
for key in class_dict:
if isinstance(class_dict[key], property):
new_dict[key] = instance_dict['_' + key]
return new_dict
class PumpParams(Parameters):
def __init__(self, power, frequency, propagation_direction):
self.power = power
self.frequency = frequency
self.propagation_direction = propagation_direction.lower()
class RamanParams(Parameters):
def __init__(self, flag=False, space_resolution=10e3, tolerance=None):
""" Simulation parameters used within the Raman Solver
:params flag: boolean for enabling/disable the evaluation of the Raman Power profile in frequency and position
:params space_resolution: spatial resolution of the evaluated Raman Power profile
:params tolerance: tuning parameter for scipy.integrate.solve_bvp solution
"""
self.flag = flag
self.space_resolution = space_resolution # [m]
self.tolerance = tolerance
class NLIParams(Parameters):
def __init__(self, method='gn_model_analytic', dispersion_tolerance=1, phase_shift_tolerance=0.1,
computed_channels=None, wdm_grid_size=None, f_cut_resolution=None, f_pump_resolution=None):
""" Simulation parameters used within the Nli Solver
:params method: formula for NLI calculation
:params dispersion_tolerance: tuning parameter for ggn model solution
:params phase_shift_tolerance: tuning parameter for ggn model solution
:params computed_channels: the NLI is evaluated for these channels and extrapolated for the others
"""
self.method = method.lower()
self.dispersion_tolerance = dispersion_tolerance
self.phase_shift_tolerance = phase_shift_tolerance
self.computed_channels = computed_channels
self.wdm_grid_size = wdm_grid_size
self.f_cut_resolution = f_cut_resolution
self.f_pump_resolution = f_pump_resolution
class SimParams(Parameters):
_shared_dict = {'nli_params': NLIParams(), 'raman_params': RamanParams()}
def __init__(self):
if type(self) == SimParams:
raise NotImplementedError('Instances of SimParams cannot be generated')
@classmethod
def set_params(cls, sim_params):
cls._shared_dict['nli_params'] = NLIParams(**sim_params.get('nli_params', {}))
cls._shared_dict['raman_params'] = RamanParams(**sim_params.get('raman_params', {}))
@classmethod
def get(cls):
self = cls.__new__(cls)
return self
@property
def nli_params(self):
return self._shared_dict['nli_params']
@property
def raman_params(self):
return self._shared_dict['raman_params']
class FiberParams(Parameters):
def __init__(self, **kwargs):
try:
self._length = convert_length(kwargs['length'], kwargs['length_units'])
# fixed attenuator for padding
self._att_in = kwargs['att_in'] if 'att_in' in kwargs else 0
# if not defined in the network json connector loss in/out
# the None value will be updated in network.py[build_network]
# with default values from eqpt_config.json[Spans]
self._con_in = kwargs['con_in'] if 'con_in' in kwargs else None
self._con_out = kwargs['con_out'] if 'con_out' in kwargs else None
if 'ref_wavelength' in kwargs:
self._ref_wavelength = kwargs['ref_wavelength']
self._ref_frequency = c / self.ref_wavelength
elif 'ref_frequency' in kwargs:
self._ref_frequency = kwargs['ref_frequency']
self._ref_wavelength = c / self.ref_frequency
else:
self._ref_wavelength = 1550e-9
self._ref_frequency = c / self.ref_wavelength
self._dispersion = kwargs['dispersion'] # s/m/m
self._dispersion_slope = kwargs['dispersion_slope'] if 'dispersion_slope' in kwargs else \
-2 * self._dispersion/self.ref_wavelength # s/m/m/m
self._beta2 = -(self.ref_wavelength ** 2) * self.dispersion / (2 * pi * c) # 1/(m * Hz^2)
# Eq. (3.23) in Abramczyk, Halina. "Dispersion phenomena in optical fibers." Virtual European University
# on Lasers. Available online: http://mitr.p.lodz.pl/evu/lectures/Abramczyk3.pdf
# (accessed on 25 March 2018) (2005).
self._beta3 = ((self.dispersion_slope - (4*pi*c/self.ref_wavelength**3) * self.beta2) /
(2*pi*c/self.ref_wavelength**2)**2)
self._gamma = kwargs['gamma'] # 1/W/m
self._pmd_coef = kwargs['pmd_coef'] # s/sqrt(m)
if type(kwargs['loss_coef']) == dict:
self._loss_coef = squeeze(kwargs['loss_coef']['loss_coef_power']) * 1e-3 # lineic loss dB/m
self._f_loss_ref = squeeze(kwargs['loss_coef']['frequency']) # Hz
else:
self._loss_coef = kwargs['loss_coef'] * 1e-3 # lineic loss dB/m
self._f_loss_ref = 193.5e12 # Hz
self._lin_attenuation = db2lin(self.length * self.loss_coef)
self._lin_loss_exp = self.loss_coef / (10 * log10(exp(1))) # linear power exponent loss Neper/m
self._effective_length = (1 - exp(- self.lin_loss_exp * self.length)) / self.lin_loss_exp
self._asymptotic_length = 1 / self.lin_loss_exp
# raman parameters (not compulsory)
self._raman_efficiency = kwargs['raman_efficiency'] if 'raman_efficiency' in kwargs else None
self._pumps_loss_coef = kwargs['pumps_loss_coef'] if 'pumps_loss_coef' in kwargs else None
except KeyError as e:
raise ParametersError(f'Fiber configurations json must include {e}. Configuration: {kwargs}')
@property
def length(self):
return self._length
@length.setter
def length(self, length):
"""length must be in m"""
self._length = length
@property
def att_in(self):
return self._att_in
@att_in.setter
def att_in(self, att_in):
self._att_in = att_in
@property
def con_in(self):
return self._con_in
@con_in.setter
def con_in(self, con_in):
self._con_in = con_in
@property
def con_out(self):
return self._con_out
@con_out.setter
def con_out(self, con_out):
self._con_out = con_out
@property
def dispersion(self):
return self._dispersion
@property
def dispersion_slope(self):
return self._dispersion_slope
@property
def gamma(self):
return self._gamma
@property
def pmd_coef(self):
return self._pmd_coef
@property
def ref_wavelength(self):
return self._ref_wavelength
@property
def ref_frequency(self):
return self._ref_frequency
@property
def beta2(self):
return self._beta2
@property
def beta3(self):
return self._beta3
@property
def loss_coef(self):
return self._loss_coef
@property
def f_loss_ref(self):
return self._f_loss_ref
@property
def lin_loss_exp(self):
return self._lin_loss_exp
@property
def lin_attenuation(self):
return self._lin_attenuation
@property
def effective_length(self):
return self._effective_length
@property
def asymptotic_length(self):
return self._asymptotic_length
@property
def raman_efficiency(self):
return self._raman_efficiency
@property
def pumps_loss_coef(self):
return self._pumps_loss_coef
def asdict(self):
dictionary = super().asdict()
dictionary['loss_coef'] = self.loss_coef * 1e3
dictionary['length_units'] = 'm'
return dictionary