Aggiornamento sul programma nazionale italiano di lotta biologica classica al moscerino asiatico dei piccoli frutti, Drosophila suzukii

Vengono presentate le attività del Tavolo tecnico-scientifico nazionale di coordinamento per la lotta al moscerino asiatico dei piccoli frutti, Drosophila suzukii Matsumura, istituito formalmente su indicazione del Comitato Fitosanitario Nazionale nel gennaio 2021. La principale finalità del Tavolo è quella di definire e condividere le attività di contrasto al fitofago invasivo attraverso la programmazione di un piano triennale di controllo biologico classico che prevede l’impiego del parassitoide esotico Ganaspis brasiliensis Ihering. La prima campagna di lanci del parassitoide, partita nell’agosto del 2021 a seguito dell’autorizzazione da parte dell’ex Ministero della Transizione Ecologica (ora Ministero dell’Ambiente e della Sicurezza Energetica), ha visto la partecipazione delle regioni Campania, Emilia-Romagna, Piemonte, Puglia, Sicilia, Valle d’Aosta e Veneto e delle Province autonome di Trento e Bolzano. Nel 2023 si aggiungeranno le regioni Lombardia e Toscana. I risultati dei monitoraggi delle prime due stagioni, eseguiti sul 100% dei siti di lancio tra maggio e novembre di ogni anno, suggeriscono che G. brasiliensissi stia insediando in varie aree del territorio nazionale e ne confermano la specificità nei confronti di D. suzukii, già osservata negli studi di laboratorio

Frequency-Domain Hybrid Modulation Formats for High Bit-Rate Flexibility and Nonlinear Robustness

Since the deployment of the first commercial polarization-multiplexed (PM) QPSK 100G systems, the evolution of coherent optical communications in the last decade has been largely dominated by single-carrier quadrature amplitude modulation (QAM) based modulation of increasing constellation size. However, as the data traffic becomes more dynamic and heterogeneous, an efficient use of the optical link requires more flexible modulation schemes, capable of adapting data-rate and distance with fine granularity. While typical multi-carrier modulation schemes composed of hundreds of subcarriers may be inadequate for optical transmission, namely due its high peak-to-average power ratio and increased nonlinearity penalties, it has been recently shown that few-carrier modulation (with symbol rate in the order of 2-4 GBaud) can provide an increased robustness to nonlinear propagation impairments. In this paper, we exploit the concept of frequency-domain hybrid modulation formats (FDHMF) based on electronic subcarrier multiplexing with the use of different QAM formats on each subcarrier to simultaneously enhance the data-rate flexibility and the nonlinear propagation performance of the optical link. In addition, by properly designing the FDHMF signal, an increased tolerance against optical filtering can also be achieved. Using the enhanced Gaussian noise model, we report a comprehensive theoretical study on the performance of FDHMF, considering independent-and joint-subcarrier forward-error correction strategies, optimization of power ratio between subcarriers, and corresponding impact of fiber nonlinearities. These theoretical insights are then validated by a broad range of wavelength-division multiplexing experiments with per-channel bit-rates in the range of 150G to 250G. The obtained results demonstrate that FDHMF is an effective solution for the implementation of flexible transponders capable of adapting the data rate to the lightpath quality of transmission: An enabling technology for the introduction of future elastic optical networks

Combining probabilistic shaping and nonlinear mitigation: Potential gains and challenges

We experimentally compare different options for transmission at 200G net bit-rate and demonstrate that the benefits of probabilistic shaping and nonlinear mitigation via SRO and/or DBP can be effectively combined to enable propagation reach enhancement of > 40%

Effectiveness of Digital Back-Propagation and Symbol-Rate Optimization in Coherent WDM Optical Systems

We apply DBP to an experimental WDM system where multisubcarrier transmission provides a 12% reach gain vs. single-carrier. DBP provides further gain for both single- and multisubcarrier systems but significantly underperforms ideal theoretical predictions

Low-Complexity Time-Domain DBP Based on Random Step-Size and Partitioned Quantization

We propose and experimentally validate a low-complexity time-domain (TD) digital backpropagation (DBP) algorithm for fiber nonlinearity compensation, targeting an optimized hardware implementation. To counteract the coherent accumulation of numerical quantization errors between DBP steps, we propose a random step-size distribution along the optical link (with pm5% interval around the optimal step-size). In addition, to further reduce the average quantization bit precision requirements, we propose a partitioned quantization technique, enabling to quantize the finite-impulse response (FIR) filter tail coefficients with significantly lower precision. The proposed low-complexity DBP algorithm is experimentally demonstrated over a 2592 km long-haul wavelength division multiplexing transmission system with 21 imes32 GBaud PM-16QAM optical channels. Employing the proposed step-size randomization together with dual-time-slot quantization, we demonstrate penalty-free operation at an average of sim4 b per FIR coefficient, leading to a 60% complexity reduction when compared to the standard TD-DBP implementation

Theoretical and experimental assessment of nonlinearity mitigation through symbol rate optimization

We investigated the reach increase obtained through non-linearity mitigation by means of transmission symbol rate optimization (SRO). We did this first theoretically and simulatively. We show that for PM-QPSK systems at full-C-band the reach increase may be substantial, on the order of 10%-25%, with optimum symbol rates on the order of 2-to-6 GBaud. We extended the investigation to PM-16QAM, where we found a qualitatively similar effect, although the potential reach increase is typically only about half that of PM-QPSK. We then set up an experiment to obtain confirmation of the theoretical and simulative predictions. We demonstrated a reach increase of 11% in a 19-channel, 128Gbit/s per channel, PM-QPSK experiment, when going from single-carrier per channel to multi-subcarrier (up to 16 subcarriers per channel) transmission. The experiment reached 14,100 km over PSCF, with 110 km spans and EDFA-only amplification. The results matched well the model predictions