osnr calculation

.gitignore

@@ -60,3 +60,6 @@ target/
 
 # pyenv python configuration file
 .python-version
+
+# MacOS DS_store
+.DS_Store

gnpy/examples/config/config_ex1.json

@@ -5,11 +5,11 @@
             "name": "",
             "description": "Booster_Connection",
             "parameters": {
-                "length": 0.0,
+                "length": 80.0,
                 "dispersion": null,
                 "dispersion_slope": 16.7,
                 "pmd": 0.0,
-                "loss": 0.0,
+                "loss": 0.2,
                 "fiber_type": "SMF-28e",
                 "nonlinear_coef": 0.0
             }
@@ -20,11 +20,11 @@
             "name": "",
             "description": "Booster_Connection",
             "parameters": {
-                "length": 0.0,
+                "length": 100.0,
                 "dispersion": null,
                 "dispersion_slope": 16.7,
                 "pmd": 0.0,
-                "loss": 0.0,
+                "loss": 0.2,
                 "fiber_type": "SMF-28e",
                 "nonlinear_coef": 0.0
             }
@@ -35,11 +35,11 @@
             "name": "",
             "description": "Booster_Connection",
             "parameters": {
-                "length": 0.0,
+                "length": 80.0,
                 "dispersion": null,
                 "dispersion_slope": 16.7,
                 "pmd": 0.0,
-                "loss": 0.0,
+                "loss": 0.2,
                 "fiber_type": "SMF-28e",
                 "nonlinear_coef": 0.0
             }
@@ -110,7 +110,7 @@
                 "channels": [{
                         "manufacturer": "acme corp",
                         "manufacturer_pn": "acme model1",
-                        "frequency": [193.95],
+                        "frequency": 193.95,
                         "modulation": "QPSK",
                         "baud_rate": 32.0,
                         "capacity": 100,
@@ -121,12 +121,12 @@
                         "filter_params": [0.4],
                         "polarization_mux": "interleaved",
                         "osnr": 40.0,
-                        "power": -5.0
+                        "power": -10.0
                     },
                     {
                         "manufacturer": "acme corp",
                         "manufacturer_pn": "acme model1",
-                        "frequency": [194.15],
+                        "frequency": 194.15,
                         "modulation": "QPSK",
                         "baud_rate": 32.0,
                         "capacity": 100,

gnpy/examples/sim_ex.py

@@ -1,22 +1,55 @@
 import matplotlib.pyplot as plt
 import networkx as nx
 import gnpy
+import numpy as np
 from pprint import pprint as pp
 plt.rcdefaults()
 
-
 config_fn = './gnpy/examples/config/config_ex1.json'
 nw = gnpy.Network(config_fn)
 
 
+def db_to_lin(val):
+    return 10 ** (val / 10)
+
+
+def chan_osnr(chan_params, amp_params):
+    in_osnr = db_to_lin(chan_params['osnr'])
+    pin = db_to_lin(chan_params['power']) / 1e3
+    nf = db_to_lin(amp_params.nf[0])
+    ase_cont = nf * gnpy.h * chan_params['frequency'] * 12.5 * 1e21
+    ret = -10 * np.log10(1 / in_osnr + ase_cont / pin)
+    return ret
+
+
+def edge_dict(chan, osnr, d_power):
+    dct = {'frequency': chan['frequency'],
+           'osnr': osnr if osnr else chan['osnr'],
+           'power': chan['power'] + d_power}
+    return dct
+
+
 def calc_path_osnr(nw, opath):
-    print(opath)
-    pp(opath[0].params.channels) 
-    return None
-    for en, chan in enumerate(opath[0].params.channels):
-        for pen, p in enumerate(opath):
-            print(en, type(p), p, pen)
-        print("*** ")
+    for en, leg in enumerate(opath[:-1]):
+        edge = nw.g[opath[en]][opath[en + 1]]
+        suc_class = opath[en].__class__
+        if suc_class == gnpy.network_elements.Tx:
+            for chan in opath[en].params.channels:
+                edge['channels'].append(edge_dict(chan, None, 0))
+        elif suc_class == gnpy.network_elements.Fiber:
+            attn = opath[en].params.length * opath[en].params.loss
+            for inedge in nw.g.in_edges([opath[en]]):
+                pedge = nw.g[inedge[0]][inedge[1]]
+                for chan in pedge['channels']:
+                    edge['channels'].append(edge_dict(chan, None, -attn))
+        elif suc_class == gnpy.network_elements.Edfa:
+            for inedge in nw.g.in_edges([opath[en]]):
+                pedge = nw.g[inedge[0]][inedge[1]]
+                gain = opath[en].params.gain
+                for chan in pedge['channels']:
+                    osnr = chan_osnr(chan, opath[en].params)
+                    edge['channels'].append(edge_dict(chan, osnr, gain[0]))
+        print(leg, edge['channels'])
 
 
 def calc_osnr(nw):
@@ -24,14 +57,17 @@ def calc_osnr(nw):
         for rx in nw.nw_elems['Rx']:
             for opath in nx.all_simple_paths(nw.g, tx, rx):
                 calc_path_osnr(nw, opath)
+                print("*" * 10)
 
 
 calc_osnr(nw)
 
-
-if 0:
-    graph_pos = nx.fruchterman_reingold_layout(nw.g)
-    nx.draw_networkx_nodes(nw.g, graph_pos, node_size=1000, node_color='b', alpha=0.2)
-    nx.draw_networkx_edges(nw.g, graph_pos, width=2, alpha=0.3, edge_color='green')
-    nx.draw_networkx_labels(nw.g, graph_pos, font_size=10)
+if 1:
+    layout = nx.spring_layout(nw.g)
+    nx.draw_networkx_nodes(nw.g, layout, node_size=1000,
+                           node_color='b', alpha=0.2)
+    nx.draw_networkx_labels(nw.g, layout)
+    nx.draw_networkx_edges(nw.g, layout, width=2,
+                           alpha=0.3, edge_color='green')
+    #nx.draw_networkx_edge_labels(nw.g, layout, font_size=10)
     plt.show()

gnpy/network_elements.py

@@ -15,10 +15,6 @@ class Params:
             setattr(self, k, v)
 
 
-class Channels():
-    pass
-
-
 class Network:
     g = nx.DiGraph()
     nw_elems = {}
@@ -38,7 +34,7 @@ class Network:
                 n0 = Utils.find_by_node_id(self.g, gpath[0])
                 for nid in gpath[1:]:
                     n1 = Utils.find_by_node_id(self.g, nid)
-                    self.g.add_edge(n0, n1, channels=Channels())
+                    self.g.add_edge(n0, n1, channels=[])
                     n0 = n1