diff --git a/docs/release-notes.rst b/docs/release-notes.rst index ddd1d92c0..842157e3c 100644 --- a/docs/release-notes.rst +++ b/docs/release-notes.rst @@ -5,6 +5,51 @@ Release change log Each release introduces some changes and new features. +v2.9 +---- + +The revision introduces a major refactor that separates design and propagation. Most of these changes have no impact +on the user experience, except the following ones: + +**Network design - amplifiers**: amplifier saturation is checked during design in all cases, even if type_variety is +set; amplifier gain is no more computed on the fly but only at design phase. + +Before, the design did not consider amplifier power saturation during design if amplifier type_variety was stated. +With this revision, the saturation is always applied: +If design is made for a per channel power that leads to saturation, the target are properly reduced and the design +is freezed. So that when a new simulation is performed on the same network for lower levels of power per channel +the same gain target is applied. Before these were recomputed, changing the gain targets, so the simulation was +not considering the exact same working points for amplifiers in case of saturation. + +Note that this case (working with saturation settings) is not recommended. + +The gain of amplifiers was estimated on the fly also in case of RamanFiber preceding elements. The refactor now +requires that an estimation of Raman gain of the RamanFiber is done during design to properly compute a gain target. +The Raman gain is estimated at design for every RamanFiber span and also during propagation instead of being only +estimated at propagation stage for those Raman Fiber spans concerned with the transmission. The auto-design is more +accurate for unpropagated spans, but this results in an increase overall computation time. +This will be improved in the future. + +**Network design - ROADMs**: ROADM target power settings are verified during design. + +Design checks that expected power coming from every directions ingress from a ROADM are consistent with output power +targets. The checks only considers the adjacent previous hop. If the expected power at the input of this ROADM is +lower than the target power on the out-degree of the ROADM, a warning is displayed, and user is asked to review the +input network to avoid this situation. This does not change the design or propagation behaviour. + +**Propagation**: amplifier gain target is no more recomputed during propagation. It is now possible to freeze +the design and propagate without automatic changes. + +In previous release, gain was recomputed during propagation based on an hypothetical reference noiseless channel +propagation. It was not possible to Ā«freezeĀ» the autodesign, and propagate without recomputing the gain target +of amplifiers. +With this new release, the design is freezed, so that it is possible to compare performances on same basis. + +**Display**: "effective pch (dbm)" is removed. Display contains the target pch which is the target power per channel +in dBm, computed based on reference channel used for design and the amplifier delta_p in dB (and before out VOA +contribution). Note that "actual pch out (dBm)" is the actual propagated total power per channel averaged per spectrum +band definition at the output of the amplifier element, including noises and out VOA contribution. + v2.8 ----