We propose methods and an architecture to conduct measurements and optimize newly installed optical fiber line systems semi-automatically using integrated physics-aware technologies in a data center interconnection (DCI) transmission scenario. We demonstrate, for the first time to our knowledge, digital longitudinal monitoring (DLM) and optical line system (OLS) physical parameter calibration working together in real-time to extract physical link parameters for fast optical fiber line systems provisioning. Our methodology has the following advantages over traditional design: a minimized footprint at user sites, accurate estimation of the necessary optical network characteristics via complementary telemetry technologies, and the capability to conduct all operation work remotely. The last feature is crucial, as it enables remote operation to implement network design settings for immediate response to quality of transmission (QoT) degradation and reversion in the case of unforeseen problems. We successfully performed semi-automatic line system provisioning over field fiber network facilities at Duke University, Durham, North Carolina. The tasks of parameter retrieval, equipment setting optimization, and system setup/provisioning were completed within 1 h. The field operation was supervised by on-duty personnel who could access the system remotely from different time zones. By comparing Q-factor estimates calculated from the extracted link parameters with measured results from 400G transceivers, we confirmed that our methodology has a reduction in the QoT prediction errors ( ${pm}0.3;{rm dB}$ ) over existing designs ( ${pm}0.6;{rm dB}$ ).
{"title":"Semi-automatic line-system provisioning with an integrated physical-parameter-aware methodology: field verification and operational feasibility","authors":"Hideki Nishizawa;Giacomo Borraccini;Takeo Sasai;Yue-Kai Huang;Toru Mano;Kazuya Anazawa;Masatoshi Namiki;Soichiroh Usui;Tatsuya Matsumura;Yoshiaki Sone;Zehao Wang;Seiji Okamoto;Takeru Inoue;Ezra Ip;Andrea D'Amico;Tingjun Chen;Vittorio Curri;Ting Wang;Koji Asahi;Koichi Takasugi","doi":"10.1364/JOCN.524669","DOIUrl":"https://doi.org/10.1364/JOCN.524669","url":null,"abstract":"We propose methods and an architecture to conduct measurements and optimize newly installed optical fiber line systems semi-automatically using integrated physics-aware technologies in a data center interconnection (DCI) transmission scenario. We demonstrate, for the first time to our knowledge, digital longitudinal monitoring (DLM) and optical line system (OLS) physical parameter calibration working together in real-time to extract physical link parameters for fast optical fiber line systems provisioning. Our methodology has the following advantages over traditional design: a minimized footprint at user sites, accurate estimation of the necessary optical network characteristics via complementary telemetry technologies, and the capability to conduct all operation work remotely. The last feature is crucial, as it enables remote operation to implement network design settings for immediate response to quality of transmission (QoT) degradation and reversion in the case of unforeseen problems. We successfully performed semi-automatic line system provisioning over field fiber network facilities at Duke University, Durham, North Carolina. The tasks of parameter retrieval, equipment setting optimization, and system setup/provisioning were completed within 1 h. The field operation was supervised by on-duty personnel who could access the system remotely from different time zones. By comparing Q-factor estimates calculated from the extracted link parameters with measured results from 400G transceivers, we confirmed that our methodology has a reduction in the QoT prediction errors (\u0000<tex>${pm}0.3;{rm dB}$</tex>\u0000) over existing designs (\u0000<tex>${pm}0.6;{rm dB}$</tex>\u0000).","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"894-904"},"PeriodicalIF":4.0,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142045133","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}
In satellite optical networks (SONs), laser inter-satellite links (LISLs) are energy hungry to drive pointing, acquisition, and tracking systems and laser devices to maintain fine link pointing and provide communication services. Rechargeable batteries are the sole energy support for satellites in the eclipse region, and unrestrained use of batteries may accelerate battery aging and shorten the satellite operation period. Real-time sleep/activate control on demand is not applicable to reduce the energy consumption of LISLs because waiting for link pointing delay is intolerable for most traffic requests, and aperiodically changing LISLs’ working states may affect the routing reliability in SONs. For the above problem, this paper proposes green LISL planning (GreenLP) to periodically switch LISLs’ working states to prolong the battery lifetime. Considering the possible degradation of network throughput by sleeping LISLs, this paper models GreenLP as a double-objective optimization problem from the perspective of topology design, and two topology features are expanded based on traffic prediction to numerically quantify LISLs’ potential importance. Simulation results indicate that, compared with existing schemes, GreenLP reduces battery lifetime consumption by 8.93% and the probability of request blocking by 5.65%. Numerical analysis shows that the expanded node betweenness centrality has the effectiveness and universality to quantify LISLs’ potential importance on network throughput.
{"title":"Green laser inter-satellite link planning in satellite optical networks: trading off the battery lifetime and network throughput using numerical quantization","authors":"Yu Liu;Xin Li;Daixuan Li;Chenyu Zhao;Shanguo Huang","doi":"10.1364/JOCN.527910","DOIUrl":"10.1364/JOCN.527910","url":null,"abstract":"In satellite optical networks (SONs), laser inter-satellite links (LISLs) are energy hungry to drive pointing, acquisition, and tracking systems and laser devices to maintain fine link pointing and provide communication services. Rechargeable batteries are the sole energy support for satellites in the eclipse region, and unrestrained use of batteries may accelerate battery aging and shorten the satellite operation period. Real-time sleep/activate control on demand is not applicable to reduce the energy consumption of LISLs because waiting for link pointing delay is intolerable for most traffic requests, and aperiodically changing LISLs’ working states may affect the routing reliability in SONs. For the above problem, this paper proposes green LISL planning (GreenLP) to periodically switch LISLs’ working states to prolong the battery lifetime. Considering the possible degradation of network throughput by sleeping LISLs, this paper models GreenLP as a double-objective optimization problem from the perspective of topology design, and two topology features are expanded based on traffic prediction to numerically quantify LISLs’ potential importance. Simulation results indicate that, compared with existing schemes, GreenLP reduces battery lifetime consumption by 8.93% and the probability of request blocking by 5.65%. Numerical analysis shows that the expanded node betweenness centrality has the effectiveness and universality to quantify LISLs’ potential importance on network throughput.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"868-880"},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141809202","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}
Optical networks-on-chip (ONoCs) have emerged as a compelling platform for many-core systems owing to their notable attributes, including high bandwidth, low latency, and energy efficiency. Nonetheless, the integration of microring resonators (MRs) in ONoCs exposes them to vulnerabilities associated with hardware trojans (HTs). In response, we propose an innovative strategy that combines deep-learning-based HT attack prediction with a robust security defense mechanism to fortify the resilience of ONoCs. For HT attack prediction, we employ a multiple-inputs and multiple-outputs long short-term memory neural network model. This model serves to identify susceptible MRs by forecasting alterations in traffic patterns and detecting internal faults within optical routing nodes. On the defensive front, we introduce a fine-grained defense mechanism based on MR faults. This mechanism effectively thwarts HTs during the optical routing process, thereby optimizing node utilization in ONoCs while concurrently upholding security and reliability. Simulation outcomes underscore the efficacy of the proposed HT attack prediction mechanism, demonstrating high accuracy with a loss rate of less than 0.7%. The measured mean absolute error and root mean squared error stand at 0.045 and 0.07, respectively. Furthermore, when compared to conventional coarse-grained node-based defense algorithms, our solution achieves noteworthy reductions of up to 16.2%, 43.72%, and 44.86% in packet loss rate, insertion loss, and crosstalk noise, respectively.
{"title":"Neural-network-based hardware trojan attack prediction and security defense mechanism in optical networks-on-chip","authors":"Xiangyu He;Pengxing Guo;Jiahao Zhou;Jingsi Li;Fan Zhang;Weigang Hou;Lei Guo","doi":"10.1364/JOCN.519470","DOIUrl":"10.1364/JOCN.519470","url":null,"abstract":"Optical networks-on-chip (ONoCs) have emerged as a compelling platform for many-core systems owing to their notable attributes, including high bandwidth, low latency, and energy efficiency. Nonetheless, the integration of microring resonators (MRs) in ONoCs exposes them to vulnerabilities associated with hardware trojans (HTs). In response, we propose an innovative strategy that combines deep-learning-based HT attack prediction with a robust security defense mechanism to fortify the resilience of ONoCs. For HT attack prediction, we employ a multiple-inputs and multiple-outputs long short-term memory neural network model. This model serves to identify susceptible MRs by forecasting alterations in traffic patterns and detecting internal faults within optical routing nodes. On the defensive front, we introduce a fine-grained defense mechanism based on MR faults. This mechanism effectively thwarts HTs during the optical routing process, thereby optimizing node utilization in ONoCs while concurrently upholding security and reliability. Simulation outcomes underscore the efficacy of the proposed HT attack prediction mechanism, demonstrating high accuracy with a loss rate of less than 0.7%. The measured mean absolute error and root mean squared error stand at 0.045 and 0.07, respectively. Furthermore, when compared to conventional coarse-grained node-based defense algorithms, our solution achieves noteworthy reductions of up to 16.2%, 43.72%, and 44.86% in packet loss rate, insertion loss, and crosstalk noise, respectively.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"881-893"},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141807023","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}
This Special Issue contains a collection of invitation-only extensions based on papers presented at the Optical Networks and Systems Symposium at IEEE GLOBECOM held 4–8 December 2023 in Kuala Lumpur, Malaysia. We present a brief introduction followed by an overview of each of the papers.
{"title":"Introduction to the GLOBECOM 2023 Optical Networks and Systems Symposium Special Issue","authors":"Nicola Andriolli;Jerzy Domzal;Elaine Wong","doi":"10.1364/JOCN.539472","DOIUrl":"https://doi.org/10.1364/JOCN.539472","url":null,"abstract":"This Special Issue contains a collection of invitation-only extensions based on papers presented at the Optical Networks and Systems Symposium at IEEE GLOBECOM held 4–8 December 2023 in Kuala Lumpur, Malaysia. We present a brief introduction followed by an overview of each of the papers.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"ONS1-ONS2"},"PeriodicalIF":4.0,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10643137","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142021592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Leading by the development of Starlink, the low earth orbit (LEO) satellite networks are expected to be the customer-grade Internet infrastructure for carrying Internet traffic. In this paper, focusing on network usage fluctuations that are caused by both human activity variations in work and rest time slots and inter-orbital-plane ISL length variations, we introduce the time-zone-based traffic model and the link compensation matrix into the global satellite network. Accordingly, we propose relay routing algorithms to balance the workload of the satellites over different time zones and latitudes, and we also compare the proposed algorithms with the baseline strategies. Then simulation results show that the proposed model and algorithm can achieve a 97.23% reduction in blocking ratio with a 0.29% increase in latency.
{"title":"Latitude- and time-zone-aware load balancing in optical satellite networks","authors":"Kexin Gao;Wei Wang;Yongli Zhao;Yanran Xiao;Xin Zhang;Liyazhou Hu;Jie Zhang","doi":"10.1364/JOCN.525353","DOIUrl":"https://doi.org/10.1364/JOCN.525353","url":null,"abstract":"Leading by the development of Starlink, the low earth orbit (LEO) satellite networks are expected to be the customer-grade Internet infrastructure for carrying Internet traffic. In this paper, focusing on network usage fluctuations that are caused by both human activity variations in work and rest time slots and inter-orbital-plane ISL length variations, we introduce the time-zone-based traffic model and the link compensation matrix into the global satellite network. Accordingly, we propose relay routing algorithms to balance the workload of the satellites over different time zones and latitudes, and we also compare the proposed algorithms with the baseline strategies. Then simulation results show that the proposed model and algorithm can achieve a 97.23% reduction in blocking ratio with a 0.29% increase in latency.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"E61-E72"},"PeriodicalIF":4.0,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142013356","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}
Elastic optical networks (EONs) operating in the C-band have been widely deployed worldwide. However, two major technologies—multiband elastic optical networks (MB-EONs) and space division multiplexed elastic optical networks (SDM-EONs)—can significantly increase network capacity beyond traditional EONs. A one-time greenfield deployment of these flexible-grid technologies may not be practical, as existing investments in flexible-grid EONs need to be preserved and ongoing services must face minimal disruption. Therefore, we envision the coexistence of flexible-grid, multiband, and multicore technologies during the brownfield migration. Each technology represents a tradeoff between higher capacity and greater deployment overhead, directly impacting network performance. Moreover, as traffic demands continue rising, capacity exhaustion becomes inevitable. Considering the different characteristics of these technologies, we propose a robust network planning solution called Progressive Optics Deployment and Integration for Growing Yields (PRODIGY+) to gradually migrate current C-band EONs. PRODIGY+ employs proactive measures inspired by the Swiss Cheese Model, making the network robust to traffic peaks while meeting service level agreements. The upgrade strategy enables a gradual transition to minimize migration costs while continuously supporting increasing traffic demands. We provide a detailed comparison of our proposed PRODIGY+ strategy against baseline strategies, demonstrating its superior performance.
在 C 波段运行的弹性光网络（EON）已在全球广泛部署。然而，两种主要技术--多频带弹性光网络（MB-EON）和空分复用弹性光网络（SDM-EON）--可以显著提高网络容量，超越传统的 EON。一次性全新部署这些灵活光网络技术可能并不现实，因为需要保留对灵活光网络 EON 的现有投资，而且必须尽量减少对现有服务的干扰。因此，我们设想在棕地迁移过程中，灵活网格、多频段和多核技术将共存。每种技术都要在更高容量和更大部署开销之间进行权衡，从而直接影响网络性能。此外，随着流量需求的不断增长，容量耗尽将不可避免。考虑到这些技术的不同特性，我们提出了一种稳健的网络规划解决方案，称为 "渐进式光学部署和集成，促进产量增长"（PRODIGY+），以逐步迁移当前的 C 波段 EON。PRODIGY+ 采用受瑞士奶酪模型启发的前瞻性措施，使网络在满足服务水平协议的同时，还能应对流量高峰。升级策略可实现逐步过渡，最大限度地降低迁移成本，同时持续支持不断增长的流量需求。我们详细比较了我们提出的 PRODIGY+ 策略和基准策略，证明了其卓越的性能。
{"title":"PRODIGY+: a robust progressive upgrade approach for elastic optical networks","authors":"Shrinivas Petale;Aleksandra Knapinska;Egemen Erbayat;Piotr Lechowicz;Krzysztof Walkowiak;Shih-Chun Lin;Motoharu Matsuura;Hiroshi Hasegawa;Suresh Subramaniam","doi":"10.1364/JOCN.525392","DOIUrl":"10.1364/JOCN.525392","url":null,"abstract":"Elastic optical networks (EONs) operating in the C-band have been widely deployed worldwide. However, two major technologies—multiband elastic optical networks (MB-EONs) and space division multiplexed elastic optical networks (SDM-EONs)—can significantly increase network capacity beyond traditional EONs. A one-time greenfield deployment of these flexible-grid technologies may not be practical, as existing investments in flexible-grid EONs need to be preserved and ongoing services must face minimal disruption. Therefore, we envision the coexistence of flexible-grid, multiband, and multicore technologies during the brownfield migration. Each technology represents a tradeoff between higher capacity and greater deployment overhead, directly impacting network performance. Moreover, as traffic demands continue rising, capacity exhaustion becomes inevitable. Considering the different characteristics of these technologies, we propose a robust network planning solution called Progressive Optics Deployment and Integration for Growing Yields (PRODIGY+) to gradually migrate current C-band EONs. PRODIGY+ employs proactive measures inspired by the Swiss Cheese Model, making the network robust to traffic peaks while meeting service level agreements. The upgrade strategy enables a gradual transition to minimize migration costs while continuously supporting increasing traffic demands. We provide a detailed comparison of our proposed PRODIGY+ strategy against baseline strategies, demonstrating its superior performance.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"E48-E60"},"PeriodicalIF":4.0,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141829895","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}
With progressive network recovery, operators restore network connectivity after massive failures along multiple stages, by identifying the optimal sequence of repair actions to maximize carried live traffic. Motivated by the initial deployments of quantum-key-distribution (QKD) over optical networks appearing in several locations worldwide, in this work we model and solve the progressive QKD network recovery (PQNR) problem in QKD networks to accelerate the recovery after failures. We formulate an integer linear programming (ILP) model to optimize the achievable accumulative key rates during recovery for four different QKD network architectures, considering different capabilities of using trusted relay and optical bypass. Due to the computational limitations of the ILP model, we propose a deep reinforcement learning (DRL) algorithm based on a twin delayed deep deterministic policy gradients (TD3) framework to solve the PQNR problem for large-scale topologies. Simulation results show that our proposed algorithm approaches well compared to the optimal solution and outperforms several baseline algorithms. Moreover, using optical bypass jointly with trusted relay can improve the performance in terms of the key rate by 14% and 18% compared to the cases where only optical bypass and only trusted relay are applied, respectively.
{"title":"DRL-based progressive recovery for quantum-key-distribution networks","authors":"Mengyao Li;Qiaolun Zhang;Alberto Gatto;Stefano Bregni;Giacomo Verticale;Massimo Tornatore","doi":"10.1364/JOCN.526014","DOIUrl":"10.1364/JOCN.526014","url":null,"abstract":"With progressive network recovery, operators restore network connectivity after massive failures along multiple stages, by identifying the optimal sequence of repair actions to maximize carried live traffic. Motivated by the initial deployments of quantum-key-distribution (QKD) over optical networks appearing in several locations worldwide, in this work we model and solve the progressive QKD network recovery (PQNR) problem in QKD networks to accelerate the recovery after failures. We formulate an integer linear programming (ILP) model to optimize the achievable accumulative key rates during recovery for four different QKD network architectures, considering different capabilities of using trusted relay and optical bypass. Due to the computational limitations of the ILP model, we propose a deep reinforcement learning (DRL) algorithm based on a twin delayed deep deterministic policy gradients (TD3) framework to solve the PQNR problem for large-scale topologies. Simulation results show that our proposed algorithm approaches well compared to the optimal solution and outperforms several baseline algorithms. Moreover, using optical bypass jointly with trusted relay can improve the performance in terms of the key rate by 14% and 18% compared to the cases where only optical bypass and only trusted relay are applied, respectively.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"E36-E47"},"PeriodicalIF":4.0,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141641668","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}
There is a strong demand for creating primary/backup optical path pairs between a source and a destination node in order to continue a service when the primary path has some disorder. We also have to consider SRLG (shared risk link group)-disjoint primary/backup path settings for achieving robust path protection against possible network problems on primary paths. To deal with these issues, in this study, we use the $k$ -SPF (shortest path first) algorithm to determine primary/backup path routes between a specified source/destination node pair. We demonstrate that the proposed algorithm can find $k$ SRLG-disjoint primary/backup route pairs with much higher probability and with faster speed compared with other algorithms. In addition, the proposed algorithm can find primary/backup routes with nearly minimum route costs.
{"title":"Extension of the k-SPF algorithm for finding SRLG-disjoint primary and backup route pairs in optical networks","authors":"Hiroshi Matsuura;Kohjun Koshiji;Hanami Yokoi;Tatsuya Matsukawa;Takayuki Fujii","doi":"10.1364/JOCN.525178","DOIUrl":"10.1364/JOCN.525178","url":null,"abstract":"There is a strong demand for creating primary/backup optical path pairs between a source and a destination node in order to continue a service when the primary path has some disorder. We also have to consider SRLG (shared risk link group)-disjoint primary/backup path settings for achieving robust path protection against possible network problems on primary paths. To deal with these issues, in this study, we use the \u0000<tex>$k$</tex>\u0000-SPF (shortest path first) algorithm to determine primary/backup path routes between a specified source/destination node pair. We demonstrate that the proposed algorithm can find \u0000<tex>$k$</tex>\u0000 SRLG-disjoint primary/backup route pairs with much higher probability and with faster speed compared with other algorithms. In addition, the proposed algorithm can find primary/backup routes with nearly minimum route costs.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"E23-E35"},"PeriodicalIF":4.0,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141664995","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}
Optical communication networks are operated with great care to avoid outages. In particular, significant outages having a devastating impact on society must be avoided, and several countries specify “significance standards” for network outages. Although the impact of possible outages strongly depends on routing methods for requested connections, there has been no research specifically on these standards. This paper for the first time, to the best of our knowledge, introduces a routing problem to minimize the impact of outages on a given significance standard. We have shown this problem to be non-deterministic polynomial-time hardness, and an efficient heuristic method is proposed. This method searches for a good solution by reducing the problem to a shortest-path search, where the significance of a link failure is regarded as the link weight, and suppresses outage impact compared with other routing methods. In addition, the analysis of the system dependence among a network model, mean time to repair (MTTR) of failure elements, and significance standards suggests that the total system design considering the MTTR, significance standards, and routing method could dramatically reduce the impact of significant outages on optical networks.
{"title":"Routing problem for reducing significant outages in optical networks and its system analysis","authors":"Katsuaki Higashimori;Takafumi Tanaka;Takeru Inoue","doi":"10.1364/JOCN.520509","DOIUrl":"10.1364/JOCN.520509","url":null,"abstract":"Optical communication networks are operated with great care to avoid outages. In particular, significant outages having a devastating impact on society must be avoided, and several countries specify “significance standards” for network outages. Although the impact of possible outages strongly depends on routing methods for requested connections, there has been no research specifically on these standards. This paper for the first time, to the best of our knowledge, introduces a routing problem to minimize the impact of outages on a given significance standard. We have shown this problem to be non-deterministic polynomial-time hardness, and an efficient heuristic method is proposed. This method searches for a good solution by reducing the problem to a shortest-path search, where the significance of a link failure is regarded as the link weight, and suppresses outage impact compared with other routing methods. In addition, the analysis of the system dependence among a network model, mean time to repair (MTTR) of failure elements, and significance standards suggests that the total system design considering the MTTR, significance standards, and routing method could dramatically reduce the impact of significant outages on optical networks.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"E1-E10"},"PeriodicalIF":4.0,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10634843","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141663860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
First-fit (FF) is a well-known and widely deployed algorithm for spectrum assignment (SA), but until our recent study [J. Opt. Commun. Netw.14, 165 (2022)], investigations of the algorithm had been experimental in nature and no formal properties of the algorithm with respect to SA were known. In this work, we make two contributions. First, we show that FF is a universal algorithm for the SA problem in the sense that, for any variant, 1) it can be used to construct solutions equivalent to, or better than, any solution obtained by any other algorithm, and 2) it can construct an optimal solution. This universality property applies to both the min-max and min-frag objectives and to variants of the SA problem with or without guard band constraints. Consequently, the spectrum symmetry-free model of our recent study [J. Opt. Commun. Netw.14, 165 (2022)] extends to all known SA variants, which therefore reduce to permutation problems. Second, we extend the spectrum symmetry-free model to the routing and spectrum assignment (RSA) problem in general topologies. This model allows for the design of more efficient algorithms as it eliminates from consideration an exponential number of equivalent symmetric solutions. By sidestepping symmetry, the RSA solution space is naturally and optimally decomposed into a routing space and a connection permutation space. Building upon this property, we introduce a two-parameter, symmetry-free universal algorithm that can be used to tackle any RSA variant in a uniform manner. The algorithm is amenable to multi-threaded execution to speed up the search process, and the value of the parameters can be adjusted to strike a balance between running time and solution quality. Our evaluation provides insight into the relative benefits of path diversity (which determines the size of the routing space) and connection diversity (which determines the size of the permutation space).
First-fit (FF) 是一种众所周知并被广泛应用的频谱分配（SA）算法，但在我们最近的研究[J. Opt. Commun. Netw.14, 165 (2022)]之前，对该算法的研究一直是实验性质的，而且不知道该算法在频谱分配方面的正式特性。在这项工作中，我们有两个贡献。首先，我们证明了 FF 是 SA 问题的通用算法，即对于任何变体，1）它都可以用来构建等同于或优于任何其他算法得到的解，2）它可以构建最优解。这一普遍性既适用于最小最大目标和最小碎片目标，也适用于有或无保护带约束的 SA 问题变体。因此，我们最近研究的无频谱对称模型[J. Opt. Commun. Netw.14, 165 (2022)]可扩展到所有已知的 SA 变体，从而简化为置换问题。其次，我们将无频谱对称模型扩展到一般拓扑结构中的路由和频谱分配（RSA）问题。这一模型可以设计出更高效的算法，因为它消除了指数级数量的等效对称解。通过避开对称性，RSA 解决方案空间被自然、优化地分解为路由空间和连接置换空间。基于这一特性，我们引入了一种双参数、无对称的通用算法，可用于以统一的方式处理任何 RSA 变体。该算法适合多线程执行，以加快搜索过程，而且可以调整参数值，在运行时间和解决方案质量之间取得平衡。我们的评估深入分析了路径多样性（决定路由空间的大小）和连接多样性（决定排列空间的大小）的相对优势。
{"title":"Symmetry-free routing and spectrum assignment: a universal algorithm based on first-fit","authors":"George N. Rouskas","doi":"10.1364/JOCN.521978","DOIUrl":"10.1364/JOCN.521978","url":null,"abstract":"First-fit (FF) is a well-known and widely deployed algorithm for spectrum assignment (SA), but until our recent study [J. Opt. Commun. Netw.14, 165 (2022)], investigations of the algorithm had been experimental in nature and no formal properties of the algorithm with respect to SA were known. In this work, we make two contributions. First, we show that FF is a universal algorithm for the SA problem in the sense that, for any variant, 1) it can be used to construct solutions equivalent to, or better than, any solution obtained by any other algorithm, and 2) it can construct an optimal solution. This universality property applies to both the min-max and min-frag objectives and to variants of the SA problem with or without guard band constraints. Consequently, the spectrum symmetry-free model of our recent study [J. Opt. Commun. Netw.14, 165 (2022)] extends to all known SA variants, which therefore reduce to permutation problems. Second, we extend the spectrum symmetry-free model to the routing and spectrum assignment (RSA) problem in general topologies. This model allows for the design of more efficient algorithms as it eliminates from consideration an exponential number of equivalent symmetric solutions. By sidestepping symmetry, the RSA solution space is naturally and optimally decomposed into a routing space and a connection permutation space. Building upon this property, we introduce a two-parameter, symmetry-free universal algorithm that can be used to tackle any RSA variant in a uniform manner. The algorithm is amenable to multi-threaded execution to speed up the search process, and the value of the parameters can be adjusted to strike a balance between running time and solution quality. Our evaluation provides insight into the relative benefits of path diversity (which determines the size of the routing space) and connection diversity (which determines the size of the permutation space).","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 9","pages":"E11-E22"},"PeriodicalIF":4.0,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141663277","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}
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