Only propagates carriers that belong to Amp bandwidth

The commit introduces mux/demux functions in amps and ensures that the
propagation is only done on carriers that are in the Amp bandwitdh, ie
with all their spectrum including slot width is in bandwidth.

For consistency, default amp f_min is changed:
Objective is to use amplifiers' band to bound the possible frequencies
to be propagated. Since the current default f_min of Amp in json_io.py is
higher than the SI one, this would result in a different nb of channels
than currently used in tests, and a change in all tests. In order to
avoid this, I preferred to change this value and have consistency
between SI f_min and Amp f_min.

The commits adds a set of functions to make amps band the useable
spectrum on each OMS. Thee OMS generation is changed to use the amp band.

The commit adds filtering functions (demux and mux) to filter out spectrum
which is not in the amplifier band.

Spectrum assignment is also corrected to correctly match the amp bandwidth
constraint with guardband: center frequency index must be within the
usable part of the amp band. This changes a bit the notion of freq_index
and guardband in the functions, but this is transparent to user:
f_min, f_max represent the amp band, while self.freq_index_min/max
represent the center frequency boundary for a reference 50GHz channel.

Signed-off-by: EstherLerouzic <[email protected]>
Change-Id: I225b2b2dc0e1f1992c0460f6e08fa9c9bc641edf

gnpy/core/elements.py

@@ -34,7 +34,7 @@
 from gnpy.core.parameters import RoadmParams, FusedParams, FiberParams, PumpParams, EdfaParams, EdfaOperational, \
     RoadmPath, RoadmImpairment
 from gnpy.core.science_utils import NliSolver, RamanSolver
-from gnpy.core.info import SpectralInformation
+from gnpy.core.info import SpectralInformation, demuxed_spectral_information
 from gnpy.core.exceptions import NetworkTopologyError, SpectrumError, ParametersError
 
 
@@ -1204,5 +1204,10 @@ def propagate(self, spectral_info):
         self.propagated_labels = spectral_info.label
 
     def __call__(self, spectral_info):
-        self.propagate(spectral_info)
-        return spectral_info
+        # filter out carriers outside the amplifier band
+        band = next(b for b in self.params.bands)
+        spectral_info = demuxed_spectral_information(spectral_info, band)
+        if spectral_info.carriers:
+            self.propagate(spectral_info)
+            return spectral_info
+        raise ValueError(f'Amp {self.uid} Defined propagation band does not match amplifiers band.')

gnpy/core/info.py

@@ -11,7 +11,7 @@
 from __future__ import annotations
 from collections import namedtuple
 from collections.abc import Iterable
-from typing import Union
+from typing import Union, List
 from dataclasses import dataclass
 from numpy import argsort, mean, array, append, ones, ceil, any, zeros, outer, full, ndarray, asarray
 
@@ -317,6 +317,56 @@ def create_input_spectral_information(f_min, f_max, roll_off, baud_rate, spacing
                                                  tx_osnr=tx_osnr, tx_power=tx_power, label=label)
 
 
+def is_in_band(frequency: float, band: dict) -> bool:
+    """band has {"f_min": value, "f_max": value} format
+    """
+    if frequency >= band['f_min'] and frequency <= band['f_max']:
+        return True
+    return False
+
+
+def demuxed_spectral_information(input_si: SpectralInformation, band: dict) -> SpectralInformation:
+    """extract a si based on band
+    """
+    filtered_indices = [i for i, f in enumerate(input_si.frequency)
+                        if is_in_band(f - input_si.slot_width[i] / 2, band)
+                        and is_in_band(f + input_si.slot_width[i] / 2, band)]
+    if filtered_indices:
+        frequency = input_si.frequency[filtered_indices]
+        baud_rate = input_si.baud_rate[filtered_indices]
+        slot_width = input_si.slot_width[filtered_indices]
+        signal = input_si.signal[filtered_indices]
+        nli = input_si.nli[filtered_indices]
+        ase = input_si.ase[filtered_indices]
+        roll_off = input_si.roll_off[filtered_indices]
+        chromatic_dispersion = input_si.chromatic_dispersion[filtered_indices]
+        pmd = input_si.pmd[filtered_indices]
+        pdl = input_si.pdl[filtered_indices]
+        latency = input_si.latency[filtered_indices]
+        delta_pdb_per_channel = input_si.delta_pdb_per_channel[filtered_indices]
+        tx_osnr = input_si.tx_osnr[filtered_indices]
+        tx_power = input_si.tx_power[filtered_indices]
+        label = input_si.label[filtered_indices]
+
+        return SpectralInformation(frequency=frequency, baud_rate=baud_rate, slot_width=slot_width, signal=signal,
+                                   nli=nli, ase=ase, roll_off=roll_off, chromatic_dispersion=chromatic_dispersion,
+                                   pmd=pmd, pdl=pdl, latency=latency, delta_pdb_per_channel=delta_pdb_per_channel,
+                                   tx_osnr=tx_osnr, tx_power=tx_power, label=label)
+    return None
+
+
+def muxed_spectral_information(input_si_list: List[SpectralInformation]) -> SpectralInformation:
+    """return the assembled spectrum
+    """
+    if input_si_list and len(input_si_list) > 1:
+        si = input_si_list[0] + muxed_spectral_information(input_si_list[1:])
+        return si
+    elif input_si_list and len(input_si_list) == 1:
+        return input_si_list[0]
+    else:
+        raise ValueError('liste vide')
+
+
 def carriers_to_spectral_information(initial_spectrum: dict[float, Carrier],
                                      power: float) -> SpectralInformation:
     """Initial spectrum is a dict with key = carrier frequency, and value a Carrier object.

gnpy/core/parameters.py

@@ -463,10 +463,10 @@ def asdict(self):
 
 class EdfaParams:
     default_values = {
-        'f_min': 191.3e12,
-        'f_max': 196.1e12,
+        'f_min': None,
+        'f_max': None,
         'multi_band': None,
-        'bands': [],
+        'bands': None,
         'type_variety': '',
         'type_def': '',
         'gain_flatmax': None,
@@ -502,9 +502,11 @@ def __init__(self, **params):
             # Bandwidth
             self.f_min = params['f_min']
             self.f_max = params['f_max']
-            self.bandwidth = self.f_max - self.f_min
-            self.f_cent = (self.f_max + self.f_min) / 2
+            self.bandwidth = self.f_max - self.f_min if self.f_max and self.f_min else None
+            self.f_cent = (self.f_max + self.f_min) / 2 if self.f_max and self.f_min else None
             self.f_ripple_ref = params['f_ripple_ref']
+            self.bands = [{'f_min': params['f_min'],
+                           'f_max': params['f_max']}]
 
             # Gain
             self.gain_flatmax = params['gain_flatmax']

gnpy/core/utils.py

@@ -12,6 +12,7 @@
 from numpy import pi, cos, sqrt, log10, linspace, zeros, shape, where, logical_and, mean, array
 from scipy import constants
 from copy import deepcopy
+from typing import List
 
 from gnpy.core.exceptions import ConfigurationError
 
@@ -458,3 +459,49 @@ def calculate_absolute_min_or_zero(x: array) -> array:
     array([1., 0., 3.])
     """
     return (abs(x) - x) / 2
+
+
+def find_common_range(amp_bands: List[List[dict]], default_band_f_min: float, default_band_f_max: float) \
+        -> List[dict]:
+    """Find the common frequency range of bands
+    If there are no amplifiers in the path, then use default band
+
+    >>> amp_bands = [[{'f_min': 191e12, 'f_max' : 195e12}, {'f_min': 186e12, 'f_max' : 190e12} ], \
+        [{'f_min': 185e12, 'f_max' : 189e12}, {'f_min': 192e12, 'f_max' : 196e12}], \
+        [{'f_min': 186e12, 'f_max': 193e12}]]
+    >>> find_common_range(amp_bands, 190e12, 195e12)
+    [{'f_min': 186000000000000.0, 'f_max': 189000000000000.0}, {'f_min': 192000000000000.0, 'f_max': 193000000000000.0}]
+    >>> amp_bands = [[{'f_min': 191e12, 'f_max' : 195e12}, {'f_min': 186e12, 'f_max' : 190e12} ], \
+        [{'f_min': 185e12, 'f_max' : 189e12}, {'f_min': 192e12, 'f_max' : 196e12}], \
+        [{'f_min': 186e12, 'f_max': 192e12}]]
+    >>> find_common_range(amp_bands, 190e12, 195e12)
+    [{'f_min': 186000000000000.0, 'f_max': 189000000000000.0}]
+
+    """
+    _amp_bands = [sorted(amp, key=lambda x: x['f_min']) for amp in amp_bands]
+    _temp = []
+    # remove None bands
+    for amp in _amp_bands:
+        is_band = True
+        for band in amp:
+            if not (is_band and band['f_min'] and band['f_max']):
+                is_band = False
+        if is_band:
+            _temp.append(amp)
+
+    # remove duplicate
+    unique_amp_bands = []
+    for amp in _temp:
+        if amp not in unique_amp_bands:
+            unique_amp_bands.append(amp)
+    if unique_amp_bands:
+        common_range = unique_amp_bands[0]
+    else:
+        if default_band_f_min is None or default_band_f_max is None:
+            return []
+        common_range = [{'f_min': default_band_f_min, 'f_max': default_band_f_max}]
+    for bands in unique_amp_bands:
+        common_range = [{'f_min': max(first['f_min'], second['f_min']), 'f_max': min(first['f_max'], second['f_max'])}
+                        for first in common_range for second in bands
+                        if max(first['f_min'], second['f_min']) < min(first['f_max'], second['f_max'])]
+    return sorted(common_range, key=lambda x: x['f_min'])

gnpy/example-data/default_edfa_config.json

@@ -5,8 +5,8 @@
   "gain_ripple": [
     0.0
   ],
-  "f_min": 191.35e12,
-  "f_max": 196.1e12,
+  "f_min": 191.275e12,
+  "f_max": 196.125e12,
   "dgt": [
     1.0,
     1.017807767853702,

gnpy/example-data/std_medium_gain_advanced_config.json

@@ -5,8 +5,8 @@
     0.0359549,
     5.82851
   ],
-  "f_min": 191.35e12,
-  "f_max": 196.1e12,
+  "f_min": 191.275e12,
+  "f_max": 196.125e12,
   "nf_ripple": [
     0.4372876328262819,
     0.4372876328262819,

gnpy/tools/json_io.py

@@ -192,7 +192,7 @@ def __init__(self, **kwargs):
     @classmethod
     def from_json(cls, filename, **kwargs):
         config = Path(filename).parent / 'default_edfa_config.json'
-
+        # default_edfa_config.json assumes a DGT profile independantly from fmin/fmax, that's a generic profile
         type_variety = kwargs['type_variety']
         type_def = kwargs.get('type_def', 'variable_gain')  # default compatibility with older json eqpt files
         nf_def = None
@@ -367,6 +367,31 @@ def _update_dual_stage(equipment):
     return equipment
 
 
+def _update_band(equipment: dict) -> dict:
+    """Creates a list of bands for this amplifier, and remove other parameters which are not applicable
+    """
+    amp_dict = equipment['Edfa']
+    for amplifier in amp_dict.values():
+        if amplifier.type_def != 'multi_band':
+            amplifier.bands = [{'f_min': amplifier.f_min,
+                                'f_max': amplifier.f_max}]
+            # updates band parameter
+        else:
+            _bands = [{'f_min': amp_dict[a].f_min,
+                       'f_max': amp_dict[a].f_max} for a in amp_dict[amplifier.type_variety].multi_band]
+            # remove duplicates
+            amplifier.bands = []
+            for b in _bands:
+                if b not in amplifier.bands:
+                    amplifier.bands.append(b)
+            # remove non applicable parameters
+            for key in ['f_min', 'f_max', 'gain_flatmax', 'gain_min', 'p_max', 'nf_model', 'dual_stage_model',
+                        'nf_fit_coeff', 'nf_ripple', 'dgt', 'gain_ripple']:
+                delattr(amplifier, key)
+
+    return equipment
+
+
 def _roadm_restrictions_sanity_check(equipment):
     """verifies that booster and preamp restrictions specified in roadm equipment are listed in the edfa."""
     for roadm_type, roadm_eqpt in equipment['Roadm'].items():
@@ -428,6 +453,7 @@ def _equipment_from_json(json_data, filename):
                 raise EquipmentConfigError(f'Unrecognized network element type "{key}"')
     _check_fiber_vs_raman_fiber(equipment)
     equipment = _update_dual_stage(equipment)
+    equipment = _update_band(equipment)
     _roadm_restrictions_sanity_check(equipment)
     return equipment
 

gnpy/topology/request.py

@@ -16,14 +16,17 @@
 """
 
 from collections import namedtuple, OrderedDict
+from typing import List
 from logging import getLogger
 from networkx import (dijkstra_path, NetworkXNoPath,
                       all_simple_paths, shortest_simple_paths)
 from networkx.utils import pairwise
 from numpy import mean, argmin
-from gnpy.core.elements import Transceiver, Roadm
-from gnpy.core.utils import lin2db
-from gnpy.core.info import create_input_spectral_information, carriers_to_spectral_information
+
+from gnpy.core.elements import Transceiver, Roadm, Edfa
+from gnpy.core.utils import lin2db, find_common_range
+from gnpy.core.info import create_input_spectral_information, carriers_to_spectral_information, \
+    demuxed_spectral_information, muxed_spectral_information, SpectralInformation
 from gnpy.core import network as network_module
 from gnpy.core.exceptions import ServiceError, DisjunctionError
 from copy import deepcopy
@@ -332,14 +335,34 @@ def compute_constrained_path(network, req):
     return total_path
 
 
+def filter_si(path: list, equipment: dict, si: SpectralInformation) -> SpectralInformation:
+    """Filter spectral information based on the amplifiers common range"""
+    # First retrieve f_min, f_max spectrum according to amplifiers' spectrum on the path
+    common_range = find_elements_common_range(path, equipment)
+    # filter out frequencies that should not be created
+    filtered_si = []
+    for band in common_range:
+        temp = demuxed_spectral_information(si, band)
+        if temp:
+            filtered_si.append(temp)
+    if not filtered_si:
+        raise ValueError('Defined propagation band does not match amplifiers band.')
+    return muxed_spectral_information(filtered_si)
+
+
 def propagate(path, req, equipment):
-    """propagates signals in each element according to initial spectrum set by user"""
+    """propagates signals in each element according to initial spectrum set by user
+    Spectrum is specified in request through f_min, f_max and spacing, or initial_spectrum
+    and amps frequency band on the path is used to filter out frequencies"""
+    # generates spectrum based on request
     if req.initial_spectrum is not None:
         si = carriers_to_spectral_information(initial_spectrum=req.initial_spectrum, power=req.power)
     else:
         si = create_input_spectral_information(
             f_min=req.f_min, f_max=req.f_max, roll_off=req.roll_off, baud_rate=req.baud_rate,
             spacing=req.spacing, tx_osnr=req.tx_osnr, tx_power=req.tx_power, delta_pdb=req.offset_db)
+    # filter out frequencies that should not be created
+    si = filter_si(path, equipment, si)
     roadm_osnr = []
     for i, el in enumerate(path):
         if isinstance(el, Roadm):
@@ -385,6 +408,7 @@ def propagate_and_optimize_mode(path, req, equipment):
                                                          baud_rate=this_br, spacing=req.spacing,
                                                          delta_pdb=this_offset, tx_osnr=req.tx_osnr,
                                                          tx_power=req.tx_power)
+            spc_info = filter_si(path, equipment, spc_info)
             roadm_osnr = []
             for i, el in enumerate(path):
                 if isinstance(el, Roadm):
@@ -1225,3 +1249,11 @@ def _penalty_msg(total_path, msg, min_ind):
         else:
             msg += f'\n\t{pretty} penalty not evaluated'
     return msg
+
+
+def find_elements_common_range(el_list: list, equipment: dict) -> List[dict]:
+    """Find the common frequency range of amps of a given list of elements (for example an OMS or a path)
+    If there are no amplifiers in the path, then use the SI
+    """
+    amp_bands = [n.params.bands for n in el_list if isinstance(n, (Edfa))]
+    return find_common_range(amp_bands, equipment['SI']['default'].f_min, equipment['SI']['default'].f_max)