Journal of Optical Communications and Networking最新文献

{"title":"Analog feedforward equalizer optimization in the context of 50G-PON","authors":"Dylan Chevalier;Pascal Scalart;Gael Simon;Jeremy Potet;Laurent Bramerie;Michel Joindot;Mathilde Gay;Philippe Chanclou;Monique Thual","doi":"10.1364/JOCN.551393","DOIUrl":"https://doi.org/10.1364/JOCN.551393","url":null,"abstract":"We address one of the challenges of 50 gigabit capable passive optical network (50G-PON) implementation induced by the limited bandwidth of low-cost components and signal distortions of fiber transmission and photonic devices. In the context of the broadband access network, and more specifically 50G-PON, the simplest and most affordable solution is usually the best. Implementing an analog feedforward equalizer (AFFE) is not as simple as using digital feedforward equalizer (DFFE) techniques but is relevant from a cost and energy consumption point of view. AFFE has a number of advantages, such as lower power consumption and lower latency, due to the fact that it avoids using an analog-to-digital converter (ADC). In this work, we focus on AFFE optimization techniques to mitigate intersymbol interference (ISI) and chromatic dispersion (CD) and therefore improve signal quality. We model an AFFE in order to reduce a complex problem (because of AFFE’s inter-cells non-uniformity and intra-cells non-linearity, for example) into a simpler formulation that can be solved according to a minimum mean square error (MMSE) approach. This approach is possible when the transmission channel does not fluctuate. Experimental validation through electrical and optical setups demonstrates the effectiveness of the proposed optimization, achieving a significant reduction in the bit error rate (BER) and opening eye diagrams for better signal clarity, thereby offering a viable solution for future optical networks.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 5","pages":"401-411"},"PeriodicalIF":4.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design, prototyping, and polarity management of all-port flipped 19-core fiber splitters for broadcast-and-select-type spatial cross-connects","authors":"Rika Tahara;Yudai Uchida;Kyosuke Nakada;Ryunosuke Sasaki;Masahiko Jinno","doi":"10.1364/JOCN.557230","DOIUrl":"https://doi.org/10.1364/JOCN.557230","url":null,"abstract":"A hierarchical optical cross-connect that combines a spatial cross-connect (SXC) based on spatial division multiplexing technology with a conventional wavelength cross-connect can economically accommodate the continuing exponential growth in Internet traffic. The SXC has a core selective switch (CSS) in a route-and-select configuration. The CSS is a multi-core fiber (MCF)-based optical switch that can switch optical signals on a per-core basis without going through fan-in fan-out (FIFO) devices. To reduce the cost of the SXC, a broadcast-and-select (B&S) configuration is promising, where the ingress CSSs in the SXC are replaced by MCF splitters (SPLs). In this paper, we propose a construction for <tex>${1} times N$</tex> MCF SPLs and a method to manage the polarity and core arrangement flipping when using them for the SXC. In addition, we report experimental results using <tex>${1} times {2}$</tex> all-port flipped 19-core fiber (19-CF) SPLs constructed to verify the effectiveness of the proposed method. The unique feature of the proposed method is that the core arrangement of all MCF output ports is inverted with respect to that of the input port. This cancels the core arrangement flipping that occurs in the egress CSS in the B&S SXC. Furthermore, based on a comparison with MCF-based optical devices, such as the CSS and FIFO, which have polarity, we clarify that MCF SPLs have no polarity, similar to MCF patch cords. Therefore, a single type of MCF SPL can be used without worrying about orientation. Three constructed all-port-reversed <tex>${1} times {2}$</tex> 19-CF SPL prototypes exhibit low loss (<tex>${lt}{7.5};{rm dB}$</tex>), low polarization-dependent loss (<tex>${lt}{0.5};{rm dB}$</tex>), and low total inter-core cross talk (<tex>${lt} {-}35.7;{rm dB}$</tex>) at C-band wavelengths. In addition, no optical signal-to-noise ratio penalty is observed when 100-Gb/s-based wavelength-division-multiplexed signals are input to all cores. Finally, we show that an all-port non-flipped <tex>${1} times {4}$</tex> 19-CF SPL can be constructed by connecting three all-port flipped <tex>${1} times {2}$</tex> 19-CF SPLs in a tree structure.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 5","pages":"378-391"},"PeriodicalIF":4.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quality of transmission optimization in a multi-band optical system: a stepwise multi-device joint configuration algorithm","authors":"Yujia Yang;Yuchen Song;Shengnan Li;Yao Zhang;Min Zhang;Danshi Wang","doi":"10.1364/JOCN.551340","DOIUrl":"https://doi.org/10.1364/JOCN.551340","url":null,"abstract":"Performance optimization in ultra-wideband transmission systems becomes increasingly complex due to the higher number of configurable components and the amplified impact of fiber nonlinearities, such as the stimulated Raman scattering effect. To address these challenges and advance multi-band transmission systems toward comprehensive optimization, we propose a stepwise algorithm to jointly configure multiple devices, enhancing the performance of <tex>${rm S} + {rm C} + {rm L}$</tex>-band transmission systems. This stepwise configuration approach accelerates the identification of optimal configurations by considering various linear and nonlinear effects while incorporating adjustments to multiple devices beyond in-line amplifiers. This flexibility allows for tailored optimizations under varying conditions, achieving improved performance at a reduced cost. A simulation study of an eight-span <tex>${rm C} + {rm L} + {rm S}$</tex>-band link demonstrates that optimizing amplifiers alone using the proposed algorithm achieves a comparable 2.2 dB improvement in generalized signal-to-noise ratio (GSNR) while reducing the optimization time by half compared to traditional methods. Further configuring wavelength-selective switches (WSSs) improves GSNR flatness—reducing the difference between maximum and minimum GSNR values to below 0.2 dB in each band, even under uneven amplifier gain spectra. Additionally, an efficient method for simultaneously configuring WSS in multiple adjacent channels reduces optimization time by approximately tenfold.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 5","pages":"352-362"},"PeriodicalIF":4.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum computing approach for multi-objective routing and spectrum assignment optimization","authors":"Oumayma Bouchmal;Bruno Cimoli;Ripalta Stabile;Juan Jose Vegas Olmos;Carlos Hernandez-Chulde;Ricardo Martinez;Ramon Casellas;Idelfonso Tafur Monroy","doi":"10.1364/JOCN.552061","DOIUrl":"https://doi.org/10.1364/JOCN.552061","url":null,"abstract":"Optimization problems are fundamental in a wide range of fields, including telecommunications, where efficient resource allocation is critical to ensure good network performance and high scalability. In the context of elastic optical networks (EONs), the multi-objective routing and spectrum assignment (MO-RSA) problem represents a key challenge, as it involves selecting a valid path and assigning frequency slots while fulfilling continuity and contiguity constraints and optimizing multiple conflicting objectives. This paper presents a novel, to the best of our knowledge, quantum-based approach to solving the MO-RSA problem. We first formulate the MO-RSA problem as a quadratic unconstrained binary optimization (QUBO) problem and then solve it using the quantum approximate optimization algorithm (QAOA). Our method accounts for both minimizing the total number of used links (or any non-negative additive metric) and maximizing the optical signal-to-noise ratio. For our simulations, we employed the Qiskit framework and IBM’s sampler-based quantum backend to implement and test the proposed approach. Our results demonstrate that by encoding the MO-RSA problem into a QUBO model and optimizing it with QAOA, we achieved an approximation ratio of 88% and a computational complexity of <tex>$O({n^2})$</tex>, which represents a significant improvement over the exponential complexity of traditional integer linear programming methods.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 6","pages":"B15-B27"},"PeriodicalIF":4.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143800763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Building operator-centric digital twins for optical transport networks: from data models to real applications","authors":"Renato Cherini;Nehuen Gonzalez-Montoro;Aldana Gonzalez-Montoro;Luis Compagnucci;Jorge M. Finochietto","doi":"10.1364/JOCN.551477","DOIUrl":"https://doi.org/10.1364/JOCN.551477","url":null,"abstract":"The complexity and heterogeneity of modern optical transport networks (OTNs) demand advanced solutions to enhance their operation and maintenance. This paper presents lessons learned from the design and implementation of a digital twin network (DTN) tailored to network operators’ requirements, integrating hybrid models that combine physical representations with data-driven analysis. By leveraging telemetry data, the DTN can facilitate network operators to perform predictive maintenance, resource optimization, and risk analysis. Through a case study on soft failure detection across 454 optical sections, we analyze the value of transforming theoretical concepts coupled with collected data into actionable insights, reducing operational overhead and enhancing network resilience. This work underscores the potential of hybrid modeling in the context of DTN to create operator-centric solutions for optical transport networks.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 6","pages":"B1-B14"},"PeriodicalIF":4.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143800769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full softwarization in optical access networks [Invited]","authors":"Takahiro Suzuki;Sang-Yuep Kim;Jun-ichi Kani;Tomoaki Yoshida","doi":"10.1364/JOCN.549703","DOIUrl":"https://doi.org/10.1364/JOCN.549703","url":null,"abstract":"Optical access systems are needed to meet the ever-increasing range of requirements from legacy services to new services. The application of network function virtualization (NFV) to access systems is promising for flexible function deployment and agile service creation, while the softwarization of upper-layer functions has been progressing for the optical line terminal (OLT). To maximize the flexibility, the softwarization of lower-layer functions, including media access control (MAC), physical-layer (PHY) functions, and digital signal processing (DSP), is also being studied. Although one-port 10 Gb/s systems with softwarized real-time 10G-EPON physical coding sublayer (PCS) have already been demonstrated, systems with higher output speeds have not been demonstrated. This paper builds a softwarized four-port 10G-EPON PCS, including scrambling and forward error correction (FEC), on a general-purpose server and evaluates its real-time throughput, latency, and power consumption. We build a demonstration platform with four-port service node interfaces (SNIs) and four-port passive optical network (PON) interfaces using polling-based data transfer and multi-threading. The results show that our platform achieves approximately <tex>${4} times {10.3125};{rm Gb/s}$</tex> throughput, 0.5 ms round-trip latency, and a 66% reduction in power consumption per port compared to a single-port implementation.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 7","pages":"C62-C69"},"PeriodicalIF":4.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143800997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Software-defined cloud–optical networks for long-haul geographically distributed machine learning","authors":"Meng Lian;Yongli Zhao;Yike Jiang;Tingting Bao;Yuan Cao;Jie Zhang","doi":"10.1364/JOCN.553555","DOIUrl":"https://doi.org/10.1364/JOCN.553555","url":null,"abstract":"Optical networks enable long-haul geographically distributed machine learning (GDML) by connecting multiple data centers (DCs), offering a solution to overcome limitations of single DC-based training for large models. However, effective coordination is hindered by limited resource sharing among cloud and network entities. In this work, we propose an architecture of a software-defined cloud–optical network (SD-CON). Domain controllers of SD-CON jointly abstract cloud and network resources, while a hyper-domain controller establishes cloud–network service function chains (CN-SFCs) to enhance the cloud–network collaboration. Additionally, we introduce the task scheduling algorithm with a multi-candidate parameter server (MPS) to optimize the CN-SFCs. A 1000 km GDML experiment on the China Environment for Network Innovation demonstrates rapid allocation of cloud and network resources (<tex>${sim}{5.7};{rm s}$</tex> latency) in SD-CON, improving task success rates (over 23.111%) and enhancing resource utilization compared with the baselines.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 5","pages":"363-377"},"PeriodicalIF":4.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resilient single-star and passive double-star fiber links for point-to-multipoint optical networks with switchable path protection","authors":"Takahiro Kodama;Shota Eguchi;Tomoya Nakagawa","doi":"10.1364/JOCN.538664","DOIUrl":"https://doi.org/10.1364/JOCN.538664","url":null,"abstract":"This study focuses on the design of a new, to the best of our knowledge, switchable network with disaster resilience in mind. Specifically, it introduces a redundant link configuration consisting of a single star (SS) type provided to each optical distribution terminal (ODT) as the primary link and a passive double star (PDS) type provided to all ODTs as the secondary link. This configuration allows for a point-to-multipoint (P-to-MP) optical network that can switch between SS and PDS links using an optical switch to achieve rapid recovery and improved reliability during disasters. The study meticulously compares the capital cost and availability of the SS configuration, the PDS configuration, and the SS/PDS switchable configuration with and without variable reflection blocking (VRB). In addition, a bidirectional transmission experiment was conducted using wavelength conversion with two light sources and VRB to address single-link failures. The experimental results unequivocally confirmed that the proposed configuration functions effectively during link failures, ensuring energy-efficient operation and superior capital cost efficiency. Furthermore, it was demonstrated that using VRB at the ODT side allows for bidirectional communication while effectively suppressing reflections, further enhancing the system’s capital and operation cost efficiency. The proposed P-to-MP optical network configuration effectively ensures redundancy and reliability while accommodating the expanded scale of optical fiber deployment in next-generation mobile communication systems.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 4","pages":"324-337"},"PeriodicalIF":4.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design model of a three-stage folded Clos network with a decoupled first stage guaranteeing admissible blocking probability","authors":"Eiji Oki;Ryotaro Taniguchi;Kazuya Anazawa;Takeru Inoue","doi":"10.1364/JOCN.550838","DOIUrl":"https://doi.org/10.1364/JOCN.550838","url":null,"abstract":"Some data center networks have implemented optical circuit switching (OCS) to replace electrical packet switching, achieving reduced power consumption, lower latency, and increased capacity. This paper focuses on designing an OCS network to maximize the switching network size, defined as the number of terminals connected under the constraints of a fixed number of identical <tex>$N times N$</tex> switches and a specified maximum admissible blocking probability. An existing design for a three-stage folded Clos network encounters a limitation where the network size ceases to grow as the number of switches increases beyond a certain threshold. To address this, we propose a design model for a three-stage folded Clos network with the decoupled first stage, named 3dF, to maximize the network switching size while guaranteeing an admissible blocking probability. The 3dF model introduces an input–output layer that combines the first- and second-stage switches into a single, large switch and decouples the switching functions originally handled by a single switch at the first stage into two distinct switches. We formulate this model as an optimization problem and employ an exhaustive search-based algorithm to identify the structure with the largest switching network size in non-increasing order while ensuring that specified constraints, such as blocking probability, are satisfied. We derive theoretical results for three-stage folded Clos variants and, through numerical analysis, show that the 3dF design achieves a larger switching network size than other variants under the SNB condition or a blocking probability guarantee.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 4","pages":"309-323"},"PeriodicalIF":4.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adaptive windowing-based concept drift detection and adaptation framework for human-to-machine applications over future communication networks","authors":"Xiangyu Yu;Lihua Ruan;Jamie S. Evans;Elaine Wong","doi":"10.1364/JOCN.538964","DOIUrl":"https://doi.org/10.1364/JOCN.538964","url":null,"abstract":"Human-to-machine (H2M) applications in future networks have strict low-latency transmission requirements. Thanks to the assistance of machine learning (ML) in future communication networks, ML-enhanced dynamic bandwidth allocation (DBA) schemes have been proposed to effectively reduce uplink latency in H2M applications. Existing methods generally assume that the H2M application traffic stream is stationary, thereby primarily designing an ML model based on a specific H2M application and fixed traffic load. However, future communication networks are expected to support dynamic and heterogeneous H2M applications. As such, incoming H2M data traffic from networks will change over time as different H2M applications have distinct traffic distributions, causing the concept drift in H2M applications. Meanwhile, another challenge in detecting the concept drift of H2M applications is detecting traffic distribution change in dynamic network environments among similar H2M application scenarios, which leads to an incremental drift of H2M application traffic. To tackle the above challenges, we propose an adaptive windowing-based concept drift detection and adaptation (ADA) framework to support H2M applications in dynamic and heterogeneous networks. Unlike existing solutions that mainly use fixed sliding windows, the proposed ADA dynamically changes the sliding window size based on the drift detection results. Hoeffding’s inequality-based drift detection algorithm is employed in ADA to effectively detect incremental H2M application traffic drift in a dynamic network. Comprehensive simulation investigations show that ADA can enhance DBA performance in terms of uplink latency reduction and rapidly responding and adapting to the concept drift in changing H2M applications and traffic load scenarios of 96.51% drift detection efficiency improvement, and over 50% packet delay reduction in model adaptation compared to frameworks are considered.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"17 4","pages":"338-351"},"PeriodicalIF":4.0,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}