Celso Henrique de Souza Lopes;Tomas Powell Villena Andrade;Luiz Augusto Melo Pereira;Evandro Conforti;Arismar Cerqueira Sodre Junior
This paper presents two distinct network architectures designed to address the demands of 5G/6G applications. The first architecture is an analog radio-over-fiber (RoF) optical fronthaul operating in the V-band at 60 GHz, integrated within a wavelength-division multiplexing passive optical network (WDM-PON). This setup employs photonic techniques for RF signal generation, specifically using carrier-suppressed double sideband (CS-DSB) modulation via Mach–Zehnder modulators (MZMs), enabling efficient frequency multiplication and signal transport. Experimental results demonstrate its ability to achieve a data rate of approximately 11.8 Gbit/s, meeting the requirements for 5G/6G cell densification. The second architecture is a heterogeneous network (HetNet) that combines fiber-wireless (FiWi), free space optics (FSO), and visible light communication (VLC) technologies in a unified network configuration designed for indoor 6G solutions. This HetNet architecture was tested at 39 GHz and features a 20 km optical fiber midhaul, an FSO fronthaul, and a dual VLC/RF access network. The setup was evaluated based on the root mean square error vector magnitude ( ${{rm EVM}_{{rm RMS}}}$ ) requirements, with results indicating satisfactory coexistence of the employed technologies, achieving a total data throughput of 1.5 Gbit/s.
{"title":"Implementation of HetNet architectures based on FSO, VLC, RoF, and photonics-based RF generation toward 6G applications","authors":"Celso Henrique de Souza Lopes;Tomas Powell Villena Andrade;Luiz Augusto Melo Pereira;Evandro Conforti;Arismar Cerqueira Sodre Junior","doi":"10.1364/JOCN.530373","DOIUrl":"https://doi.org/10.1364/JOCN.530373","url":null,"abstract":"This paper presents two distinct network architectures designed to address the demands of 5G/6G applications. The first architecture is an analog radio-over-fiber (RoF) optical fronthaul operating in the V-band at 60 GHz, integrated within a wavelength-division multiplexing passive optical network (WDM-PON). This setup employs photonic techniques for RF signal generation, specifically using carrier-suppressed double sideband (CS-DSB) modulation via Mach–Zehnder modulators (MZMs), enabling efficient frequency multiplication and signal transport. Experimental results demonstrate its ability to achieve a data rate of approximately 11.8 Gbit/s, meeting the requirements for 5G/6G cell densification. The second architecture is a heterogeneous network (HetNet) that combines fiber-wireless (FiWi), free space optics (FSO), and visible light communication (VLC) technologies in a unified network configuration designed for indoor 6G solutions. This HetNet architecture was tested at 39 GHz and features a 20 km optical fiber midhaul, an FSO fronthaul, and a dual VLC/RF access network. The setup was evaluated based on the root mean square error vector magnitude (\u0000<tex>${{rm EVM}_{{rm RMS}}}$</tex>\u0000) requirements, with results indicating satisfactory coexistence of the employed technologies, achieving a total data throughput of 1.5 Gbit/s.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"1070-1081"},"PeriodicalIF":4.0,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359740","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}
Accurate quality-of-transmission (QoT) estimation tools are crucial to building digital twins (DTs) for optical networks. However, the input-parameter inaccuracy deteriorates the estimation accuracy of the physical models. To address this problem, an input-parameter refinement (IR) paradigm aiming at finding the mappings from uncertain parameters to their corresponding true values is proposed. The primary advantage of the IR paradigm, as demonstrated in this study for Raman amplifiers (RAs), lies in its applicability to dynamic optical networks, where system parameters such as loading conditions and optical device configurations are subject to frequent variations. The use of the proposed paradigm to refine the model of RAs is discussed in detail, while its applicability to other types of devices requires further investigation. The inaccuracy of fiber parameters, signal power, and pump power are taken into account. The particle swarm optimization (PSO) algorithm is utilized to address the problem of the coupling of these parameter inaccuracies. Experiments over a C + L band are conducted. In a single-span scenario, results show the proposed IR scheme can lower the physics-based RA model’s mean prediction error from ${sim}{0.92};{rm dB}$ to ${sim}{0.20};{rm dB}$ and lower the maximum absolute error (MAE) from ${sim}{3.09};{rm dB}$ to ${sim}{1.12};{rm dB}$ . The proposed IR scheme also exhibits high precision when applied in a two-span scenario, indicating its scalability to multi-span optical multiplexing section (OMS) scenarios. Furthermore, we demonstrate that the proposed IR scheme can also effectively enhance the accuracy of machine learning (ML) models. An IR-aided ML-based model training scheme is proposed. It offers significant advantages in scenarios where data collection from real systems is limited. With the proposed IR paradigm, the practical application of both physics-based models and ML-based models can be facilitated in future dynamic multiband optical networks.
精确的传输质量（QoT）估算工具对于构建光网络数字孪生（DT）至关重要。然而，输入参数不准确会降低物理模型的估计精度。为解决这一问题，我们提出了一种输入参数细化（IR）范例，旨在找到不确定参数与其相应真实值之间的映射关系。正如本研究针对拉曼放大器（RA）所展示的那样，IR 范式的主要优势在于它适用于动态光网络，在动态光网络中，加载条件和光学器件配置等系统参数会频繁变化。本文详细讨论了如何利用所提出的范例来完善拉曼放大器模型，同时还需要进一步研究该范例对其他类型设备的适用性。光纤参数、信号功率和泵浦功率的不准确性已被考虑在内。粒子群优化（PSO）算法用于解决这些参数不准确性的耦合问题。在 C + L 波段上进行了实验。在单跨场景中，结果表明所提出的 IR 方案可以将基于物理的 RA 模型的平均预测误差从 ${sim}{0.92};{rm dB}$ 降低到 ${sim}{0.20};{rm dB}$ 并将最大绝对误差（MAE）从 ${sim}{3.09};{rm dB}$ 降低到 ${sim}{1.12};{rm dB}$ 。当应用于双跨场景时，所提出的 IR 方案也表现出很高的精度，这表明它可以扩展到多跨光复用段 (OMS) 场景。此外，我们还证明了所提出的红外方案还能有效提高机器学习（ML）模型的精度。我们提出了一种基于红外辅助 ML 的模型训练方案。该方案在真实系统数据收集有限的情况下具有显著优势。有了所提出的红外范例，基于物理的模型和基于 ML 的模型都能在未来的动态多频带光网络中得到实际应用。
{"title":"Mapping-finding input-parameter refinement paradigm for a dynamic multiband optical network digital twin: the Raman amplifier modeling case","authors":"Yihao Zhang;Xiaomin Liu;Qizhi Qiu;Yichen Liu;Lilin Yi;Weisheng Hu;Qunbi Zhuge","doi":"10.1364/JOCN.539231","DOIUrl":"https://doi.org/10.1364/JOCN.539231","url":null,"abstract":"Accurate quality-of-transmission (QoT) estimation tools are crucial to building digital twins (DTs) for optical networks. However, the input-parameter inaccuracy deteriorates the estimation accuracy of the physical models. To address this problem, an input-parameter refinement (IR) paradigm aiming at finding the mappings from uncertain parameters to their corresponding true values is proposed. The primary advantage of the IR paradigm, as demonstrated in this study for Raman amplifiers (RAs), lies in its applicability to dynamic optical networks, where system parameters such as loading conditions and optical device configurations are subject to frequent variations. The use of the proposed paradigm to refine the model of RAs is discussed in detail, while its applicability to other types of devices requires further investigation. The inaccuracy of fiber parameters, signal power, and pump power are taken into account. The particle swarm optimization (PSO) algorithm is utilized to address the problem of the coupling of these parameter inaccuracies. Experiments over a C + L band are conducted. In a single-span scenario, results show the proposed IR scheme can lower the physics-based RA model’s mean prediction error from \u0000<tex>${sim}{0.92};{rm dB}$</tex>\u0000 to \u0000<tex>${sim}{0.20};{rm dB}$</tex>\u0000 and lower the maximum absolute error (MAE) from \u0000<tex>${sim}{3.09};{rm dB}$</tex>\u0000 to \u0000<tex>${sim}{1.12};{rm dB}$</tex>\u0000. The proposed IR scheme also exhibits high precision when applied in a two-span scenario, indicating its scalability to multi-span optical multiplexing section (OMS) scenarios. Furthermore, we demonstrate that the proposed IR scheme can also effectively enhance the accuracy of machine learning (ML) models. An IR-aided ML-based model training scheme is proposed. It offers significant advantages in scenarios where data collection from real systems is limited. With the proposed IR paradigm, the practical application of both physics-based models and ML-based models can be facilitated in future dynamic multiband optical networks.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"1059-1069"},"PeriodicalIF":4.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328392","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}
Kenji Miyamoto;Hirotaka Ujikawa;Tatsuya Shimada;Tomoaki Yoshida
We propose a user-dedicated optical path switching technique for low-latency and seamless handover in the radio access network (RAN) with the all-photonic network (APN). The APN is a network that connects end points directly with optical paths of dedicated wavelengths assigned to each user and provides large-capacity and low-latency connections. As mobile systems beyond 5th generation (5G) and 6th generation (6G) will require extremely low latency, applying the APN to the RAN is promising to achieve this. However, the RAN with the APN has a challenge in optical path switching during the handover procedure of mobile systems because optical switches that compose the APN do not have an Internet protocol (IP) layer function that enables routing control for handover in the conventional router network. Our proposed optical path switching technique to solve this challenge utilizes optical-wireless cooperative control and switches an optical path dedicated to user equipment (UE) executing handover in conjunction with its handover procedure. The key point of the proposed technique is that a next generation node B (gNB) transmits an optimal-timing optical path switching trigger to the optical switch. We experimentally demonstrated the generation of a dedicated optical path for UE in the RAN with the APN as a premise to enable the proposed optical path switching technique. To evaluate the feasibility and effectiveness of the proposed optical path switching technique, we experimentally compared the optical switch and router in terms of latency performance, packet loss, and packet misdirection in the path switching during handover. The results indicated successful optical path switching during handover without packet loss and packet misdirection while reducing the latency per single network equipment by 99%, from 4 µs for the router to 45 ns for the optical switch.
我们提出了一种用户专用光路切换技术，可在全光子网络（APN）的无线接入网（RAN）中实现低延迟和无缝切换。APN 是一种通过为每个用户分配专用波长的光路直接连接端点的网络，可提供大容量和低延迟连接。由于第五代（5G）和第六代（6G）之后的移动系统将要求极低的延迟，因此将 APN 应用于 RAN 有望实现这一目标。然而，由于组成 APN 的光交换机不具备互联网协议 (IP) 层功能，无法在传统路由器网络中实现路由控制以进行切换，因此，采用 APN 的 RAN 在移动系统切换过程中面临光路径切换的挑战。为解决这一难题，我们提出了光路径切换技术，利用光-无线协同控制，结合用户设备（UE）的切换程序，切换专用于执行切换的光路径。该技术的关键在于下一代节点 B（gNB）向光交换机发送最佳时间光路径切换触发器。我们在实验中演示了以 APN 为前提，在 RAN 中为 UE 生成专用光路，从而实现所提出的光路切换技术。为了评估所提出的光路径切换技术的可行性和有效性，我们在实验中比较了光交换机和路由器在切换过程中路径切换的延迟性能、数据包丢失和数据包误导。结果表明，路由器在切换过程中成功地进行了光路径切换，没有出现数据包丢失和数据包误导，同时单个网络设备的延迟时间减少了 99%，从路由器的 4 µs 减少到光交换机的 45 ns。
{"title":"User-dedicated optical path switching with optical-wireless cooperative control for low-latency and seamless handover","authors":"Kenji Miyamoto;Hirotaka Ujikawa;Tatsuya Shimada;Tomoaki Yoshida","doi":"10.1364/JOCN.522722","DOIUrl":"https://doi.org/10.1364/JOCN.522722","url":null,"abstract":"We propose a user-dedicated optical path switching technique for low-latency and seamless handover in the radio access network (RAN) with the all-photonic network (APN). The APN is a network that connects end points directly with optical paths of dedicated wavelengths assigned to each user and provides large-capacity and low-latency connections. As mobile systems beyond 5th generation (5G) and 6th generation (6G) will require extremely low latency, applying the APN to the RAN is promising to achieve this. However, the RAN with the APN has a challenge in optical path switching during the handover procedure of mobile systems because optical switches that compose the APN do not have an Internet protocol (IP) layer function that enables routing control for handover in the conventional router network. Our proposed optical path switching technique to solve this challenge utilizes optical-wireless cooperative control and switches an optical path dedicated to user equipment (UE) executing handover in conjunction with its handover procedure. The key point of the proposed technique is that a next generation node B (gNB) transmits an optimal-timing optical path switching trigger to the optical switch. We experimentally demonstrated the generation of a dedicated optical path for UE in the RAN with the APN as a premise to enable the proposed optical path switching technique. To evaluate the feasibility and effectiveness of the proposed optical path switching technique, we experimentally compared the optical switch and router in terms of latency performance, packet loss, and packet misdirection in the path switching during handover. The results indicated successful optical path switching during handover without packet loss and packet misdirection while reducing the latency per single network equipment by 99%, from 4 µs for the router to 45 ns for the optical switch.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"1050-1058"},"PeriodicalIF":4.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142324250","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}
Submarine cable is a crucial infrastructure for international communications, and its cost and survivability are two key factors that must be considered at its design phase. In this paper, we propose a machine-learning-assisted submarine cable route planning algorithm for minimizing its accumulated cost and risk. The cost and risk distribution and the direction of the submarine cable route’s starting point and endpoint are used as prior data to initialize the state-action of reinforcement learning (RL). We also propose a multi-agent cross reinforcement learning (MA-XRL) framework composed of Q-learning and SARSA to improve the global optimization capability of RL in the case of multi-objective optimization. The results show that, compared to ant colony optimization (ACO), MA-XRL can reduce the accumulated cost by 26.87% under the same accumulated risk. The maximum accumulated cost of the Pareto solutions obtained by MA-XRL is lower than the minimum accumulated cost of that obtained by ACO. Meanwhile, the running time of MA-XRL is only 1.3‰ of that of ACO. Without prior data of cost and risk initialization, the accumulated cost and risk of the best submarine cable route obtained by MA-XRL is 1.84 times and 7.08 times those with cost and risk distribution initialization, respectively. The direction initialization can accelerate the agent to find the endpoint of the submarine cable route and double the search stability of MA-XRL. Compared to using Q-learning or SARSA alone, MA-XRL can respectively reduce the accumulated risk by 71.81% and 39.51% under the same accumulated cost and can reduce the accumulated cost by 16.65% and 11.99% under the same accumulated risk, respectively.
{"title":"Multi-objective optimization for submarine optical cable route planning based on cross reinforcement learning","authors":"Zanshan Zhao;Guanjun Gao;Weiming Gan;Jialiang Zhang;Zengfu Wang;Haoyu Wang;Yonggang Guo","doi":"10.1364/JOCN.529175","DOIUrl":"https://doi.org/10.1364/JOCN.529175","url":null,"abstract":"Submarine cable is a crucial infrastructure for international communications, and its cost and survivability are two key factors that must be considered at its design phase. In this paper, we propose a machine-learning-assisted submarine cable route planning algorithm for minimizing its accumulated cost and risk. The cost and risk distribution and the direction of the submarine cable route’s starting point and endpoint are used as prior data to initialize the state-action of reinforcement learning (RL). We also propose a multi-agent cross reinforcement learning (MA-XRL) framework composed of Q-learning and SARSA to improve the global optimization capability of RL in the case of multi-objective optimization. The results show that, compared to ant colony optimization (ACO), MA-XRL can reduce the accumulated cost by 26.87% under the same accumulated risk. The maximum accumulated cost of the Pareto solutions obtained by MA-XRL is lower than the minimum accumulated cost of that obtained by ACO. Meanwhile, the running time of MA-XRL is only 1.3‰ of that of ACO. Without prior data of cost and risk initialization, the accumulated cost and risk of the best submarine cable route obtained by MA-XRL is 1.84 times and 7.08 times those with cost and risk distribution initialization, respectively. The direction initialization can accelerate the agent to find the endpoint of the submarine cable route and double the search stability of MA-XRL. Compared to using Q-learning or SARSA alone, MA-XRL can respectively reduce the accumulated risk by 71.81% and 39.51% under the same accumulated cost and can reduce the accumulated cost by 16.65% and 11.99% under the same accumulated risk, respectively.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"1018-1033"},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320452","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}
Noemi Merayo;David de Pintos;Juan Carlos Aguado;Ignacio de Miguel;Ramon J. Duran Barroso;Ruben M. Lorenzo
Software-defined networking (SDN) provides an efficient framework for managing passive optical networks (PONs) with equipment from different manufacturers, technologies, and standards. Thus, we recently proposed a robust and flexible SDN-OpenFlow agent to configure and manage 10 gigabit symmetric passive optical networks (XGS-PONs) to support Internet (data) services. That SDN agent communicates with the SDN controller via the OpenFlow protocol and with the optical line terminal (OLT) of the PON via the manufacturer’s chipset-specific API (application programming interface). In this paper, we significantly extend that SDN agent by incorporating the capability to support two essential services for network operators and Internet service providers, specifically voice over IP (VoIP) and video services. The required extensions and configuration procedures on the different layers that compose the SDN agent are described, and an experimental validation of the extended SDN agent in an XGS-PON is conducted, demonstrating its effectiveness in the integration of those two services. The source code of the SDN agent has been made open and available on GitHub.
软件定义网络（SDN）为管理采用不同制造商、技术和标准的设备的无源光网络（PON）提供了一个高效的框架。因此，我们最近提出了一种强大而灵活的 SDN-OpenFlow 代理，用于配置和管理万兆位对称无源光网络（XGS-PON），以支持互联网（数据）服务。该 SDN 代理通过 OpenFlow 协议与 SDN 控制器通信，并通过制造商芯片组特定的 API（应用编程接口）与 PON 的光线路终端 (OLT) 通信。在本文中，我们大幅扩展了 SDN 代理，为网络运营商和互联网服务提供商提供了支持两种基本服务的功能，特别是 IP 语音（VoIP）和视频服务。本文描述了组成 SDN 代理的不同层所需的扩展和配置程序，并在 XGS-PON 中对扩展 SDN 代理进行了实验验证，证明了它在集成这两种服务方面的有效性。SDN 代理的源代码已在 GitHub 上开放和提供。
{"title":"Software-defined networking agent for integrating voice, data, and video services into XGS-PON architectures","authors":"Noemi Merayo;David de Pintos;Juan Carlos Aguado;Ignacio de Miguel;Ramon J. Duran Barroso;Ruben M. Lorenzo","doi":"10.1364/JOCN.531051","DOIUrl":"https://doi.org/10.1364/JOCN.531051","url":null,"abstract":"Software-defined networking (SDN) provides an efficient framework for managing passive optical networks (PONs) with equipment from different manufacturers, technologies, and standards. Thus, we recently proposed a robust and flexible SDN-OpenFlow agent to configure and manage 10 gigabit symmetric passive optical networks (XGS-PONs) to support Internet (data) services. That SDN agent communicates with the SDN controller via the OpenFlow protocol and with the optical line terminal (OLT) of the PON via the manufacturer’s chipset-specific API (application programming interface). In this paper, we significantly extend that SDN agent by incorporating the capability to support two essential services for network operators and Internet service providers, specifically voice over IP (VoIP) and video services. The required extensions and configuration procedures on the different layers that compose the SDN agent are described, and an experimental validation of the extended SDN agent in an XGS-PON is conducted, demonstrating its effectiveness in the integration of those two services. The source code of the SDN agent has been made open and available on GitHub.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"1034-1049"},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320444","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}
Considering the scattering feature in the ultraviolet (UV) spectrum that can support communication for mobile unmanned aerial vehicles (UAVs), we deploy UAVs equipped with UV communication. Specifically, we focus on ground-to-air UV networks where the UAV collects data from the ground nodes. Assuming that the ground nodes are distributed in two dimensions, we analyze the air-ground connectivity probability. The influence of the transmitter divergence angle on the connectivity probability is investigated. Then, we analyze the probability that there exists interference from multiple nodes. To guarantee reliable communication under such interference, we further propose a handshaking-based UAV access protocol. By solving the coloring problem, we determine the time slot allocation for handshaking and propose a greedy channel allocation method to maximize the average system throughput. Numerical results show the performance gain of the proposed protocol over existing works.
{"title":"Connectivity analysis and user access design of ground-to-air ultraviolet communication networks","authors":"Lei Sun;Chen Gong;Zhengyuan Xu","doi":"10.1364/JOCN.527611","DOIUrl":"https://doi.org/10.1364/JOCN.527611","url":null,"abstract":"Considering the scattering feature in the ultraviolet (UV) spectrum that can support communication for mobile unmanned aerial vehicles (UAVs), we deploy UAVs equipped with UV communication. Specifically, we focus on ground-to-air UV networks where the UAV collects data from the ground nodes. Assuming that the ground nodes are distributed in two dimensions, we analyze the air-ground connectivity probability. The influence of the transmitter divergence angle on the connectivity probability is investigated. Then, we analyze the probability that there exists interference from multiple nodes. To guarantee reliable communication under such interference, we further propose a handshaking-based UAV access protocol. By solving the coloring problem, we determine the time slot allocation for handshaking and propose a greedy channel allocation method to maximize the average system throughput. Numerical results show the performance gain of the proposed protocol over existing works.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"1006-1017"},"PeriodicalIF":4.0,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316347","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 datacenters, bursty and unevenly distributed traffic may lead to serious network performance degradation. Various methods, including reconfigurable optical circuit switching (OCS), traffic control techniques, valiant load balancing (VLB), and so on, have been proposed to solve this problem. Based on these solutions, our method makes a trade-off between cost and performance. In this paper, we propose to use multi-wavelength tunable transmitters in our previously proposed modular arrayed waveguide grating (AWG)-based interconnection network. We discuss how the multiple wavelengths can be shared in the network and then propose a computational model to study its blocking probability. Closed-form equations for low network load cases are also derived to provide the analytical expression for the blocking probability. We verify the accuracy of our computational model through simulations. Comparing the blocking probability of networks with and without multi-wavelength integrated transmitters, we show that network performance can be considerably improved after replacement. When traffic burstiness is 1.25 and traffic skewness is 0.08, the blocking probability is reduced from 0.14 to $3.60 times {10^{- 3}}$ after replacing in each sending module one fixed laser with multi-wavelength tunable transmitters with four wavelengths. Furthermore, we also discuss how different factors influence the blocking probability and the maximum load with the given network performance requirement.
{"title":"Dynamic capacity sharing with multi-wavelength integrated transmitters in hybrid datacenter networks","authors":"Jiawen Zhu;Weiqiang Sun;Tong Ye;Weisheng Hu","doi":"10.1364/JOCN.528443","DOIUrl":"https://doi.org/10.1364/JOCN.528443","url":null,"abstract":"In datacenters, bursty and unevenly distributed traffic may lead to serious network performance degradation. Various methods, including reconfigurable optical circuit switching (OCS), traffic control techniques, valiant load balancing (VLB), and so on, have been proposed to solve this problem. Based on these solutions, our method makes a trade-off between cost and performance. In this paper, we propose to use multi-wavelength tunable transmitters in our previously proposed modular arrayed waveguide grating (AWG)-based interconnection network. We discuss how the multiple wavelengths can be shared in the network and then propose a computational model to study its blocking probability. Closed-form equations for low network load cases are also derived to provide the analytical expression for the blocking probability. We verify the accuracy of our computational model through simulations. Comparing the blocking probability of networks with and without multi-wavelength integrated transmitters, we show that network performance can be considerably improved after replacement. When traffic burstiness is 1.25 and traffic skewness is 0.08, the blocking probability is reduced from 0.14 to \u0000<tex>$3.60 times {10^{- 3}}$</tex>\u0000 after replacing in each sending module one fixed laser with multi-wavelength tunable transmitters with four wavelengths. Furthermore, we also discuss how different factors influence the blocking probability and the maximum load with the given network performance requirement.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"990-1005"},"PeriodicalIF":4.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142274969","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}
Hirotaka Ujikawa;Yuka Okamoto;Takumi Harada;Tatsuya Shimada;Tomoaki Yoshida
This paper proposes an optical-wireless cooperative control method to guarantee end-to-end delays in the case of radio quality degradation in wireless networks by switching optical paths. The method leverages the control information from mobile systems to dynamically switch the optical path between the distributed unit (DU) and the far aggregated central unit (CU) to another path forward to the nearest virtualized central unit (vCU) at the edge sight, on the basis of the radio quality. This enables demanding applications that require a combination of high bandwidth and low latency, such as remote operation using drones. Preliminary simulations were conducted to investigate the effect of quality degradation in the wireless domain and the potential effectiveness of the proposed delay compensation method. In the experiments conducted to verify the feasibility of the proposed method, the results demonstrated that the optical path switching was successfully performed without packet loss and within 4 ms from the transmission of the control frame. The proposed method was also able to correctly switch back when the processing rate of mobile edge computing (MEC) was exceeded after the radio quality recovered. This study demonstrates the effectiveness of further coordination between wired and wireless control for a wider range of real-time applications using video.
{"title":"Real-time optical-wireless cooperative switching on wireless quality degradation for end-to-end video delay guarantee","authors":"Hirotaka Ujikawa;Yuka Okamoto;Takumi Harada;Tatsuya Shimada;Tomoaki Yoshida","doi":"10.1364/JOCN.522729","DOIUrl":"https://doi.org/10.1364/JOCN.522729","url":null,"abstract":"This paper proposes an optical-wireless cooperative control method to guarantee end-to-end delays in the case of radio quality degradation in wireless networks by switching optical paths. The method leverages the control information from mobile systems to dynamically switch the optical path between the distributed unit (DU) and the far aggregated central unit (CU) to another path forward to the nearest virtualized central unit (vCU) at the edge sight, on the basis of the radio quality. This enables demanding applications that require a combination of high bandwidth and low latency, such as remote operation using drones. Preliminary simulations were conducted to investigate the effect of quality degradation in the wireless domain and the potential effectiveness of the proposed delay compensation method. In the experiments conducted to verify the feasibility of the proposed method, the results demonstrated that the optical path switching was successfully performed without packet loss and within 4 ms from the transmission of the control frame. The proposed method was also able to correctly switch back when the processing rate of mobile edge computing (MEC) was exceeded after the radio quality recovered. This study demonstrates the effectiveness of further coordination between wired and wireless control for a wider range of real-time applications using video.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"981-989"},"PeriodicalIF":4.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142246370","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}
Mohammad M. Hosseini;Joao Pedro;Nelson Costa;Carlos Castro;Antonio Napoli
Cutting-edge network architectures and solutions are needed to empower operators to address capacity demands in metro and access networks efficiently. The horseshoe topology, along with similar topologies, is commonly employed in metro-aggregation segments due to its compatibility with the hub-and-spoke traffic pattern present in these networks and the survivability that they can provide. A filterless architecture can enhance cost-effectiveness by replacing active elements with passive components. Moreover, supporting coherent-based point-to-multipoint transceivers—enabled by digital subcarrier multiplexing (DSCM)—can yield additional cost savings. It is noteworthy that telecommunication network topologies often evolve to accommodate more end (leaf) nodes, extending the original horseshoe with spurs or small and short trees. This paper targets these types of networks and proposes combining the utilization of coherent pluggable transceivers leveraging DSCM to guarantee transparent communication between the hub and leaf nodes while adopting different filterless node architectures with selective amplifier deployment. Moreover, it discusses the potential advantages of the architecture using an exact optimization framework tailored to various network sizes and scenarios, which accounts for the amplifiers’ placement and the available types of power splitters/combiners/couplers. The results demonstrate that strategically deploying add/drop and express amplifiers, along with optimizing coupler ratios, can effectively meet design requirements while minimizing the number of optical amplifiers required.
{"title":"Optimized design of horseshoe-and-spur filterless networks leveraging point-to-multipoint coherent pluggable transceivers","authors":"Mohammad M. Hosseini;Joao Pedro;Nelson Costa;Carlos Castro;Antonio Napoli","doi":"10.1364/JOCN.529546","DOIUrl":"https://doi.org/10.1364/JOCN.529546","url":null,"abstract":"Cutting-edge network architectures and solutions are needed to empower operators to address capacity demands in metro and access networks efficiently. The horseshoe topology, along with similar topologies, is commonly employed in metro-aggregation segments due to its compatibility with the hub-and-spoke traffic pattern present in these networks and the survivability that they can provide. A filterless architecture can enhance cost-effectiveness by replacing active elements with passive components. Moreover, supporting coherent-based point-to-multipoint transceivers—enabled by digital subcarrier multiplexing (DSCM)—can yield additional cost savings. It is noteworthy that telecommunication network topologies often evolve to accommodate more end (leaf) nodes, extending the original horseshoe with spurs or small and short trees. This paper targets these types of networks and proposes combining the utilization of coherent pluggable transceivers leveraging DSCM to guarantee transparent communication between the hub and leaf nodes while adopting different filterless node architectures with selective amplifier deployment. Moreover, it discusses the potential advantages of the architecture using an exact optimization framework tailored to various network sizes and scenarios, which accounts for the amplifiers’ placement and the available types of power splitters/combiners/couplers. The results demonstrate that strategically deploying add/drop and express amplifiers, along with optimizing coupler ratios, can effectively meet design requirements while minimizing the number of optical amplifiers required.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"969-980"},"PeriodicalIF":4.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142246417","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}
Quantum key distribution (QKD) networks are expected to enable information-theoretical secure (ITS) communication over a large-scale network. Most research on relay-based QKD networks assumes all relays or nodes are completely trustworthy. However, this assumption is unreasonable because the malicious behavior of even a single node can undermine the security of the entire network. Currently, there is no method to directly distinguish between honest nodes and malicious nodes. Moreover, the status of nodes as honest or malicious can be dynamic. Therefore, a solution is needed that can withstand a certain proportion of malicious nodes in QKD networks. We propose a novel paradigm, inspired by distributed systems, to address the active and passive attacks by collaborating with malicious nodes in QKD networks. First, regarding security, we propose the ITS distributed authentication scheme, which additionally ensures two crucial security properties to QKD networks: identity unforgeability and non-repudiation. Second, concerning correctness, we propose an ITS fault-tolerant consensus scheme based on our ITS distributed authentication to ensure global consistency. This enables participating nodes to collaborate correctly and complete end-to-end key distribution within a constant number of communication rounds. Through our simulation, we have shown that our scheme exhibits a significantly lower growth trend in key consumption compared to the original end-to-end pre-shared keys scheme. For instance, in larger networks, such as when the number of nodes is 80, our scheme’s key consumption is only 13.1% of the pre-shared keys scheme.
量子密钥分发（QKD）网络有望在大规模网络上实现信息理论安全（ITS）通信。关于基于中继的 QKD 网络的大多数研究都假设所有中继或节点都是完全可信的。然而，这种假设是不合理的，因为即使是单个节点的恶意行为也会破坏整个网络的安全性。目前，还没有直接区分诚实节点和恶意节点的方法。此外，节点的诚实或恶意状态可能是动态的。因此，我们需要一种能承受 QKD 网络中一定比例恶意节点的解决方案。受分布式系统的启发，我们提出了一种新的范例，通过与 QKD 网络中的恶意节点合作来解决主动和被动攻击问题。首先，在安全性方面，我们提出了 ITS 分布式验证方案，该方案还能确保 QKD 网络的两个关键安全属性：身份不可伪造性和不可抵赖性。其次，在正确性方面，我们提出了基于 ITS 分布式验证的 ITS 容错共识方案，以确保全局一致性。这使得参与节点能够正确协作，并在一定的通信轮数内完成端到端的密钥分发。通过仿真，我们发现与原始的端到端预共享密钥方案相比，我们的方案在密钥消耗方面的增长趋势要低得多。例如，在节点数为 80 个的大型网络中，我们方案的密钥消耗量仅为预共享密钥方案的 13.1%。
{"title":"Distributed information-theoretical secure protocols for quantum key distribution networks against malicious nodes","authors":"Yi Luo;Qiong Li;Hao-Kun Mao","doi":"10.1364/JOCN.530575","DOIUrl":"https://doi.org/10.1364/JOCN.530575","url":null,"abstract":"Quantum key distribution (QKD) networks are expected to enable information-theoretical secure (ITS) communication over a large-scale network. Most research on relay-based QKD networks assumes all relays or nodes are completely trustworthy. However, this assumption is unreasonable because the malicious behavior of even a single node can undermine the security of the entire network. Currently, there is no method to directly distinguish between honest nodes and malicious nodes. Moreover, the status of nodes as honest or malicious can be dynamic. Therefore, a solution is needed that can withstand a certain proportion of malicious nodes in QKD networks. We propose a novel paradigm, inspired by distributed systems, to address the active and passive attacks by collaborating with malicious nodes in QKD networks. First, regarding security, we propose the ITS distributed authentication scheme, which additionally ensures two crucial security properties to QKD networks: identity unforgeability and non-repudiation. Second, concerning correctness, we propose an ITS fault-tolerant consensus scheme based on our ITS distributed authentication to ensure global consistency. This enables participating nodes to collaborate correctly and complete end-to-end key distribution within a constant number of communication rounds. Through our simulation, we have shown that our scheme exhibits a significantly lower growth trend in key consumption compared to the original end-to-end pre-shared keys scheme. For instance, in larger networks, such as when the number of nodes is 80, our scheme’s key consumption is only 13.1% of the pre-shared keys scheme.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"16 10","pages":"956-968"},"PeriodicalIF":4.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142235829","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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