An approximated version of the GGN is implemented to reduce the computational time enabling fast multi-band transmission simulations
Change-Id: I2951a878aa04b5eb4a33ba86d626a788c4cbb100
The chromatic dispersion and dispersion slope can be provided as a single values evaluated at the fiber reference frequency or in a dictionary containing the dispersion values evaluated at multiple frequencies:
"dispersion": {"value": [], "frequency": []}
Change-Id: I81429484dd373cc49bd9baf013247782ba1912fd
The nonlinear coefficient can be expressed at the reference frequency and will be scaled in frequency using the scaling rule of the effective area
Change-Id: Id103b227472702776bda17ab0a2a120ecfbf7473
1. Effective area scaling along frequency is implemented by means of a technological model.
2. Raman gain coefficient is extended coherently, including the scaling due to the pump frequency.
Change-Id: I4e8b79697500ef0f73ba2f969713d9bdb3e9949c
Co-authored-by: Giacomo Borraccini <giacomo.borraccini@polito.it>
Constant power per slot_width uses the slot width instead of
baud rate compared to PSD.
This is the equalization used in OpenROADM
add tests for constant power per slot width equalization
Signed-off-by: EstherLerouzic <esther.lerouzic@orange.com>
Change-Id: Ie350e4c15cb6b54c15e418556fe33e72486cb134
On a ROADM, the code would previously set the same per-carrier power
regardless of the channel spectrum width. With this patch, carriers are
equalized either by their:
- absolute power (same as before),
- power spectral density (PSD).
Also, it's possible to apply a per-channel power offset (in dB) which
will be applied to a specified channel on top of the selected
power-level or PSD strategy. The same offset can be also selected
through the `--spectrum` option via the `default_pdb` parameter.
The equalization policy can be set via the ROADM model (in the equipment
config) as well as on a per-instance basis.
The PSD is defined as the absolute power over a spectral bandwidth,
where the spectral bandwidth corresponds to the actual spectrum
occupation (without any applicable guard bands), as approximated by the
symbol rate. PSD is specified in mW/GHz. As an example, for a 32 GBaud
signal at 0.01 mW, the PSD is 0.01/32 = 3.125e-4 mW/GHz.
This has some implications on the power sweep and ROADM behavior. Same
as previously (with absolute power targets), the ROADM design determines
the power set points. Target power is usually the best (highest) power
that can be supported by the ROADMs, especially the Add/Drop and express
stages' losses, with the goal to maximize the power at the booster's
input. As such, the `--power` option (or the power sweep) doesn't
manipulate with ROADM's target output power, but only with the output
power of the amplifiers. With PSD equalization, the `--power` option is
interpreted as the power of the reference channel defined in equipment
config's `SI` container, and its PSD is used for propagation. Power
sweep is interpreted in the same way, e.g.:
"SI":[{
"f_min": 191.3e12,
"baud_rate": 32e9,
"f_max":195.1e12,
"spacing": 50e9,
"power_dbm": 0,
"power_range_db": [-1,1,1],
"roll_off": 0.15,
"tx_osnr": 40,
"sys_margins": 2
}],
...and with the PSD equalization in a ROADM:
{
"uid": "roadm A",
"type": "Roadm",
"params": {
"target_psd_out_mWperGHz": 3.125e-4,
}
},
{
"uid": "edfa in roadm A to toto",
"type": "Edfa",
"type_variety": "standard_medium_gain",
"operational": {
"gain_target": 22,
"delta_p": 2,
"tilt_target": 0.0,
"out_voa": 0
}
},
then we use the power steps of the power_range_db to compute resulting
powers of each carrier out of the booster amp:
power_db = psd2powerdbm(target_psd_out_mWperGHz, baud_rate)
sweep = power_db + delta_power for delta_power in power_range_db
Assuming one 32Gbaud and one 64Gbaud carriers:
32 Gbaud 64 Gbaud
roadmA out power
(sig+ase+nli) -20dBm -17dBm
EDFA out power
range[
-1 1dBm 4dBm
0 2dBm 5dBm
1 3dBm 6dBm
]
Design case:
Design is performed based on the reference channel set defined in SI
in equipment config (independantly of equalization process):
"SI":[{
"f_min": 191.3e12,
"baud_rate": 32e9,
"f_max":195.1e12,
"spacing": 50e9,
"power_dbm": -1,
"power_range_db": [0,0,1],
"roll_off": 0.15,
"tx_osnr": 40,
"sys_margins": 2
}],
`delta_p` values of amps refer to this reference channel, but are applicable
for any baudrate during propagation, e.g.:
{
"uid": "roadm A",
"type": "Roadm",
"params": {
"target_psd_out_mWperGHz": 2.717e-4,
}
},
{
"uid": "edfa in roadm A to toto",
"type": "Edfa",
"type_variety": "standard_medium_gain",
"operational": {
"gain_target": 22,
"delta_p": 2,
"tilt_target": 0.0,
"out_voa": 0
}
},
Then the output power for a 64 Gbaud carrier will be +4 =
= lin2db(db2lin(power_dbm + delta_p)/32e9 * 64e9)
= lin2db(db2lin(power_dbm + delta_p) * 2)
= powerdbm + delta + 3 = 4 dBm
Signed-off-by: EstherLerouzic <esther.lerouzic@orange.com>
Change-Id: I28bcfeb72b0e74380b087762bb92ba5d39219eb3
The lumped losses are used in the computation of the loss/gain profile
through the fiber whether the Raman effect is considered or not. The
computed power profile is used to calculate the related NLI impairment.
Using the 'gn_model_analytic' method, the lumped losses are taken into
account as the contribution of an additional total loss at the end of
the fiber span. In case the 'ggn_spectrally_separated' is selected, the
method uses the computed power profile according to the specified z and
frequency arrays. The lumped losses are so considered within the NLI
power evolution along the fiber.
Change-Id: I73a6baa321aca4d041cafa180f47afed824ce267
Signed-off-by: Jan Kundrát <jan.kundrat@telecominfraproject.com>
In this change, the RamanSolver is completely restructured in order to obtain a simplified and faster solution of the Raman equation. Additionally, the inter-channel Raman effect can be evaluated also in the standard fiber, when no Raman pumping is present. The same is true for the GGN model.
The Raman pump parameter pumps_loss_coef has been removed as it was not used. The loss coefficient value evaluated at the pump frequency can be included within the fiber loss_coef parameter.
This change induces variations in some expected test results as the Raman profile solution is calculated by a completely distinct algorithm. Nevertheless, these variations are negligible being lower than 0.1dB.
Change-Id: Iaa40fbb23c555571497e1ff3bf19dbcbfcadf96b
Gamma and the raman efficiency are calculated using the effective area if not provided. Both these parameters are managed as optional in json_io.py for backward compatibility.
Change-Id: Id7f1403ae33aeeff7ec464e4c7f9c1dcfa946827
Jan: only add those parameter which are not being removed in future
patches and which have useful documentation that the user can plausibly
act on.
Change-Id: I02173f500fed8c065a30de5d23e318bce2a90c33
Co-authored-by: Jan Kundrát <jan.kundrat@telecominfraproject.com>
The NF calculated by the preamp model is compliant with the MW-MW noise
mask in the OpenROADM MSA spec. The booster is noise-free, which is
modeled by setting the NF to zero (-inf in dB units). This is obviously
unphysical but it is the simplest way to model the total noise
contribution from a ROADM, including preamp and booster, that is
compliant with the the OpenROADM MSA.
This also introduces two new EDFA type varieties,
"openroadm_mw_mw_preamp" and "openroadm_mw_mw_booster" in the equipment
library. I would prefer to also change the names of the existing
"openroadm" type_def and "standard"/"low_noise" type_variety,
representing an OpenROADM inline-amplifier, for better consistency but
this probably needs to be discussed first.
Signed-off-by: Jonas Mårtensson <jonas.martensson@ri.se>
Change-Id: I7344ff53623f166649efb389c95c04ff92718e35
Signed-off-by: Jan Kundrát <jan.kundrat@telecominfraproject.com>
Co-authored-by: Jan Kundrát <jan.kundrat@telecominfraproject.com>
As Jonas pointed out in Ia2ee3fdde1c4eed0b7ef1de77153959230ba1c01, the
documentation was wrong and the default NF implementation was not the
advanced_model. Let's not describe what the backwards-compatible
behavior is (we do not want our users to rely on that), and instead just
say that "adavnced_model" activates, well, the advanced model.
Change-Id: Ie57340d491a6f73d696d77c07091f85952cb4a08
The numbered list was very hard to read; split that into one sentence
per line. Also do that everywhere else but in the tables (in RST I'm
afraid this would be super-painful).
Change-Id: Ib80c05b66cbc98af2d0dda612943f91d923425b0
Relative links within the source tree work, but they were not being
turned into nice usable hyperlink that go back to GitHub under the
generated documentation.
Reported-by: Melin, Stefan M. <Stefan.Melin@teliacompany.com>
Change-Id: I137ad95fa75a6ee5e1b03a252782e6357d36a3af
This was identified during today's coders call where Andrea asked what
the best place for documentation of `sim_params.json` is. Let's split
docs about tangible equipment from those of global "simulation options".
Of course these options are still done in `eqpt_config.json`, which
might get super-confusing to the user -- so please make sure that this
is correctly explained when adding docs for `sim_params.json` in future.
Change-Id: If43894e8f562ca8a768b0efb6cc6c1afeb4aa514
Thanks to Stefan for reporting this.
Reported-by: Melin, Stefan M. <Stefan.Melin@teliacompany.com>
Change-Id: I9ab3aa5f829ffe3ef722df2d46f1393f748a52dc
