Journal of Optical Communications and Networking最新文献_第8页

Task placement and traffic interleaving for cross-datacenter LLM training over optical networks 光网络上跨数据中心LLM培训的任务布置和流量交错

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-29 DOI: 10.1364/JOCN.579324

Qiaojun Hu;Wei Wang;Chongzhu Huang;Xiaoyu Wang;Yajie Li;Yongli Zhao;Yanlei Zheng;Yanxia Tan;Jie Zhang

{"title":"Task placement and traffic interleaving for cross-datacenter LLM training over optical networks","authors":"Qiaojun Hu;Wei Wang;Chongzhu Huang;Xiaoyu Wang;Yajie Li;Yongli Zhao;Yanlei Zheng;Yanxia Tan;Jie Zhang","doi":"10.1364/JOCN.579324","DOIUrl":"https://doi.org/10.1364/JOCN.579324","url":null,"abstract":"With the continuous growth of large language model (LLM) sizes, individual datacenters are increasingly insufficient to support LLM training. Cross-datacenter training has become a feasible solution, where optical networks play a crucial role in data transmission. However, current optical networks suffer from severe over-provisioning issues, primarily due to the conflict between the bursty nature of LLM traffic and the fixed bandwidth of optical network connections. Therefore, this paper presents CrossOptic, a novel, to our knowledge, framework for optimizing cross-datacenter LLM training over optical networks. The proposed solution addresses the critical challenges of bandwidth under-utilization in optical networks and excessive communication overhead in distributed LLM training. CrossOptic integrates two synergistic components: adaptive GPU resource orchestration (AGRO) for communication-minimizing task placement and traffic-interleaved connectivity provisioning (TICP) for bandwidth-efficient flow aggregation. Through comprehensive simulations using realistic GPT model workloads, CrossOptic outperforms conventional dedicated connection approaches by 38.1% in terms of optical resource utilization. For a GPT model with 529.6B parameters, compared with the training methods using data parallelism and pipeline parallelism between datacenters, CrossOptic reduces the iteration time by 55% and 14%, respectively. The framework achieves significant cost efficiency in the optical infrastructure while supporting the computational demands of LLM training.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"18 2","pages":"137-149"},"PeriodicalIF":4.3,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082191","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}

引用次数: 0

BCSRA: bidirectional-propagation-based crosstalk-avoided spectrum-efficient resource allocation scheme in SDM-EONs 基于双向传播的sdm - eon中避免串扰的频谱高效资源分配方案

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-29 DOI: 10.1364/JOCN.573325

Bowen Bao;Ming Wei;Xiaoliang Li;Yan Ding;Jiajia Zhao;Qiuyan Yao;Hui Yang;Bijoy Chand Chatterjee;Eiji Oki

{"title":"BCSRA: bidirectional-propagation-based crosstalk-avoided spectrum-efficient resource allocation scheme in SDM-EONs","authors":"Bowen Bao;Ming Wei;Xiaoliang Li;Yan Ding;Jiajia Zhao;Qiuyan Yao;Hui Yang;Bijoy Chand Chatterjee;Eiji Oki","doi":"10.1364/JOCN.573325","DOIUrl":"https://doi.org/10.1364/JOCN.573325","url":null,"abstract":"With the development of services such as video streaming and cloud computing, the demand for network capacity and quality of transmission would be gradually increased. Space-division multiplexing elastic optical networks (SDM-EONs) provide a promising approach to support the greater capacities of networks due to their sufficient resources with multi-core transmission existence. Unfortunately, inter-core crosstalk results in significant degradation of spectrum resource utilization and quality of transmission in SDM-EONs. To avoid this dilemma, this paper focuses on the crosstalk mitigation benefit of counter-propagation between the adjacent cores and presents a crosstalk impact fragmentation-aware metric (CIFA) under bidirectional spectrum where the state of spectrum slots is defined as unoccupied (“0”) and occupied (“1” for positive and “−1” for opposite transmissions). In this metric, the crosstalk impact on adjacent cores reflects the utilization of counter-propagation, and the fragmentation is considered to estimate spectrum utilization. Furthermore, benefiting from the presented metric, this paper proposes a bidirectional-propagation-based crosstalk-avoided spectrum-efficient resource allocation (BCSRA) scheme in SDM-EONs, which aims to avoid the crosstalk and fully utilize the spectrum resources in networks. In this scheme, the algorithm assigns the lightpath with the minimum CIFA to the incoming request, which minimizes the impact on future requests. Simulation results show that the proposed BCSRA scheme can effectively reduce the blocking probability and enhance resource utilization while avoiding inter-core crosstalk in SDM-EONs.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"18 2","pages":"114-125"},"PeriodicalIF":4.3,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082267","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}

引用次数: 0

Nanosecond-level optical switching for flexible and resilient fronthaul networks 柔性和弹性前传网络的纳秒级光交换

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-29 DOI: 10.1364/JOCN.578768

Vaigai Nayaki Yokar;Ali Mehrpooya;Sen Shen;Yiran Teng;Wanxin Zhao;Shuangyi Yan;Dimitra Simeonidou

{"title":"Nanosecond-level optical switching for flexible and resilient fronthaul networks","authors":"Vaigai Nayaki Yokar;Ali Mehrpooya;Sen Shen;Yiran Teng;Wanxin Zhao;Shuangyi Yan;Dimitra Simeonidou","doi":"10.1364/JOCN.578768","DOIUrl":"https://doi.org/10.1364/JOCN.578768","url":null,"abstract":"This paper presents a novel, to the best of our knowledge, ultra-low latency fronthaul networking approach based on nanosecond (ns)-precision optical switching with advanced synchronization. We propose and demonstrate a comprehensive control architecture that integrates precision time protocol (PTP)-based time alignment with semiconductor optical amplifier (SOA)-based optical switches, enabling coordinated, jitter-minimized switching with accuracy as fine as 100 ns. Two primary synchronization methods are explored: a distributed hardware approach employing dedicated timing devices for simultaneous switch configuration, and “SyncNet,” a software-defined networking (SDN) controller utilizing time information inspired by reverse PTP. Experimental validation on a commercial Open RAN 5G system shows that our fronthaul switching framework achieves exceptional reliability, evidenced by only 0.00024% packet loss during link recovery while maintaining steady throughput (uplink: 1.03 Mbps and downlink: 1.01 Mbps) over repeated switching events. The proposed architecture supports dynamic reconfiguration for rapid link recovery and energy-efficient, traffic-adaptive resource allocation. Our results establish a robust foundation for next-generation fronthaul networks, delivering deterministic performance and flexibility aligned with 6G requirements. This work directly addresses the escalating needs for ultra-low latency, high reliability, and energy efficiency in emerging mobile and AI-driven applications.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"18 2","pages":"126-136"},"PeriodicalIF":4.3,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082268","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}

引用次数: 0

Field trial and spectral allocation analysis of transparent heterogeneous digital coherent and analog radio over fiber mmWave/sub-THz signals over a live production network 现场试验和频谱分配分析透明异构数字相干和模拟无线电在光纤毫米波/亚太赫兹信号在现场生产网络

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-28 DOI: 10.1364/JOCN.575391

Devika Dass;Colm Browning;Dan Kilper;Amol Delmade;Agastya Raj;Eoin Kenny;Liam Barry;Marco Ruffini

引用次数: 0

Design of a key management system for efficient key supply in quantum key distribution networks 量子密钥分配网络中有效密钥供应的密钥管理系统设计

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-28 DOI: 10.1364/JOCN.577670

Emir Dervisevic;Amina Tankovic;Enio Kaljic;Miroslav Voznak;Miralem Mehic

引用次数: 0

Proposal and feasibility study of a converged all-optical intra-/inter-data-center network with external laser sources to distribute optical carriers to coherent transceivers 采用外部激光源将光载波分配到相干收发器的融合全光数据中心内/间网络的提出与可行性研究

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-23 DOI: 10.1364/JOCN.571907

Ritsuki Hamagami;Masamichi Fujiwara;Shin Kaneko;Jun-ichi Kani;Tomoaki Yoshida;Tatsuya Shimada

{"title":"Proposal and feasibility study of a converged all-optical intra-/inter-data-center network with external laser sources to distribute optical carriers to coherent transceivers","authors":"Ritsuki Hamagami;Masamichi Fujiwara;Shin Kaneko;Jun-ichi Kani;Tomoaki Yoshida;Tatsuya Shimada","doi":"10.1364/JOCN.571907","DOIUrl":"https://doi.org/10.1364/JOCN.571907","url":null,"abstract":"We propose a DCN architecture that directly connects server racks distributed among DCs connected to metro-access nodes consisting of ROADMs. ELSs are introduced to coherent TRXs to prevent laser diodes being operated under high-temperature conditions on ToR electrical packet switches. A single-wavelength ELS for intra-DCIs is distributed to several hundred TRXs by splitting its optical power. A full C-band WDM ELS for inter-DCIs supplies each wavelength to a TRX. Both intra- and inter-DCIs are executed using an identical colorless coherent TRX, and the wavelength assignment and optical-path switching are carried out using OCSs. We experimentally evaluated the feasibility of the proposed architecture through BER measurements in a four-node ring network with four DCs per node and about 300 racks per DC, where ToR pairs communicated using 112 Gb/s DP-QPSK signals. The intra-DCI results indicate a sufficient received power margin of 11.6 dB despite a 2.4 dB penalty induced by in-band XT occurring in the OCSs. We conducted 42 channel dense WDM transmission experiments involving flat bandwidth loading with ASE noise for inter-DCIs, where in-band XT in each node and DC was ignored since our analytical estimations showed that its impact was negligible. The inter-DCI results indicate a sufficient OSNR margin of 10.9 dB despite the OSNR penalties induced by the linear/nonlinear impairments of 100 km transmission and spectrum narrowing by eight wavelength-selective switches.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"18 2","pages":"83-97"},"PeriodicalIF":4.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026455","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}

引用次数: 0

Demonstration of a 100 Gb/s complex-valued double-sideband direct-detection PON with a 42/49 dB optical power budget over a 20 km SSMF/AR-HCF 在20 km的SSMF/AR-HCF上演示了一个具有42/49 dB光功率预算的100gb /s复值双面带直接检测PON

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-23 DOI: 10.1364/JOCN.575553

Xingfeng Li;Xu Zhang;Hui Chen;Yao Lu;Honglin Ji;Zhaopeng Xu;Peng Sun;Siyue Jin;Tonghui Ji;Shuchao Mi;Bo Wu;Chao Li;Qibing Wang;Zichen Liu;Jie Luo;Lei Zhang;Lei Wang;Zhixue He;Shaohua Yu

{"title":"Demonstration of a 100 Gb/s complex-valued double-sideband direct-detection PON with a 42/49 dB optical power budget over a 20 km SSMF/AR-HCF","authors":"Xingfeng Li;Xu Zhang;Hui Chen;Yao Lu;Honglin Ji;Zhaopeng Xu;Peng Sun;Siyue Jin;Tonghui Ji;Shuchao Mi;Bo Wu;Chao Li;Qibing Wang;Zichen Liu;Jie Luo;Lei Zhang;Lei Wang;Zhixue He;Shaohua Yu","doi":"10.1364/JOCN.575553","DOIUrl":"https://doi.org/10.1364/JOCN.575553","url":null,"abstract":"In passive optical networks (PONs), the optical power budget serves as a key determinant of system scalability. A higher power budget allows for larger split ratios over a given transmission medium, thereby enabling more end users to share the same infrastructure and reducing the cost per subscriber. In this paper, we introduce a carrier-assisted complex-valued double-sideband direct detection PON architecture that eliminates the need for a local oscillator laser at the optical network unit of coherent PON while maintaining a high optical power budget. The system leverages a deep-learning-enabled optimal direct-detection receiver to achieve high launch power and receiver sensitivity without the complexity of coherent detection. Using the proposed architecture, we experimentally demonstrate an optical power budget of 42 dB for 100 Gb/s downstream transmission over 20 km standard single-mode fiber (SSMF), meeting the 15% soft-decision forward error correction (SD-FEC) threshold of <tex>${2} times {{10}^{- 2}}$</tex>. To the best of our knowledge, this represents the highest optical power budget for a 100 Gb/s direct-detection PON using SSMF. Furthermore, by employing our self-developed 20 km anti-resonant hollow-core fiber, we demonstrate an optical power budget of 49 dB under the 15% SD-FEC threshold, marking a record-high optical power budget achieved to date for 100 Gb/s PON.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"18 1","pages":"35-41"},"PeriodicalIF":4.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026435","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}

引用次数: 0

From data to decision: a multi-stage framework for class imbalance mitigation in optical network failure analysis 从数据到决策：光网络故障分析中类失衡缓解的多阶段框架

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-23 DOI: 10.1364/JOCN.576774

Yousuf Moiz Ali;Jaroslaw E. Prilepsky;Nicola Sambo;Joao Pedro;Mohammad M. Hosseini;Antonio Napoli;Sergei K. Turitsyn;Pedro Freire

{"title":"From data to decision: a multi-stage framework for class imbalance mitigation in optical network failure analysis","authors":"Yousuf Moiz Ali;Jaroslaw E. Prilepsky;Nicola Sambo;Joao Pedro;Mohammad M. Hosseini;Antonio Napoli;Sergei K. Turitsyn;Pedro Freire","doi":"10.1364/JOCN.576774","DOIUrl":"https://doi.org/10.1364/JOCN.576774","url":null,"abstract":"Machine learning-based failure management in optical networks has gained significant attention in recent years, but severe class imbalance, where normal instances far outnumber failure cases, remains a considerable challenge. While pre- and in-processing techniques have been widely studied, post-processing methods are largely unexplored. We present a direct comparison of pre-, in-, and post-processing approaches for class imbalance mitigation in failure detection and identification using an experimental dataset. For failure detection, post-processing, particularly threshold adjustment, yields the highest F1 score improvement of up to 15.3%, while random under-sampling offers the fastest inference. In failure identification, generative AI methods deliver the most significant performance gains up to 24.2%, whereas post-processing has a limited impact in multi-class settings. When class overlap exists and latency is critical, over-sampling methods like synthetic minority over-sampling technique (SMOTE) are most effective; without latency constraints, meta-learning excels. In low-overlap scenarios, generative AI approaches provide the best performance with minimal inference time.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"18 1","pages":"42-58"},"PeriodicalIF":4.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11363018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026434","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}

引用次数: 0

Deterministic optical time-slot scheduling and performance evaluation via time-aware resource allocation in metro all-optical spine-leaf networks 城域全光脊叶网络中基于时间感知资源分配的确定性光时隙调度与性能评估

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-23 DOI: 10.1364/JOCN.577375

Huitao Zhou;Lizhu Liu;Chen Su;Bojun Zhang;Zhiqun Gu;Jiawei Zhang;Yuefeng Ji

{"title":"Deterministic optical time-slot scheduling and performance evaluation via time-aware resource allocation in metro all-optical spine-leaf networks","authors":"Huitao Zhou;Lizhu Liu;Chen Su;Bojun Zhang;Zhiqun Gu;Jiawei Zhang;Yuefeng Ji","doi":"10.1364/JOCN.577375","DOIUrl":"https://doi.org/10.1364/JOCN.577375","url":null,"abstract":"The rise of time-sensitive applications has intensified the need for deterministic transmission across networks. As computing and service functions are shifted toward the edge, metro networks have become the key interconnection layer between access and core domains. However, conventional optoelectronic-switched network architectures, which rely on statistical multiplexing and slow reconfiguration, fail to meet stringent latency and jitter constraints. To overcome these challenges, this paper focuses on a scalable all-optical spine-leaf network architecture by introducing an optical time-slot switching (OTS) framework. OTS offers fine-grained switching and low-latency transmission; however, achieving deterministic transmission over shared optical resources remains challenging due to slot contention and insufficient coordination in existing scheduling schemes. Therefore, we propose a time-aware wavelength and slot allocation (TA-SA) scheme that allocates transmission windows (TWs) according to individual flow parameters, including arrival time, period, and jitter tolerance. We formulate an integer linear programming model and a heuristic algorithm to jointly optimize TW placement and wavelength-slot mapping under strict QoS constraints. To analyze worst-case network performance, deterministic network calculus is adopted to model delay and backlog bounds for different scheduling schemes. Simulation results show that TA-SA not only guarantees end-to-end latency and jitter constraints but also improves average resource utilization by over 34.9% compared to the existing scheduling schemes. Moreover, the proposed scheme significantly reduces buffer occupancy under increasing traffic loads, demonstrating its scalability and effectiveness for deterministic transmission in metro all-optical networks.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"18 1","pages":"59-73"},"PeriodicalIF":4.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026439","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}

引用次数: 0

High-speed PON solutions: recent evolutions and expected trends [Invited Tutorial] 高速PON解决方案：最新发展和预期趋势[特邀教程]

IF 4.3 2区计算机科学

Journal of Optical Communications and Networking Pub Date : 2026-01-23 DOI: 10.1364/JOCN.575601

Giuseppe Rizzelli;Roberto Gaudino

{"title":"High-speed PON solutions: recent evolutions and expected trends [Invited Tutorial]","authors":"Giuseppe Rizzelli;Roberto Gaudino","doi":"10.1364/JOCN.575601","DOIUrl":"https://doi.org/10.1364/JOCN.575601","url":null,"abstract":"This tutorial paper presents a survey on several current ongoing research activities about the expected evolution of passive optical networks, focusing on the physical layer (i.e., on the physical media dependent or PMD layer). After the recent public release of the ITU-T G.9804.3 50G-PON standard, there is today ongoing extensive scientific brainstorming on what can be the best optical transmission solutions for the PON “next step,” which will likely be targeting 100G or 200G per wavelength per direction. Elaborating on our OFC2025 tutorial on these topics, we start with a brief overview of the possible IM-DD solutions and their actual limitations for 200G-PON, while the core of the paper discusses the pros and cons of the introduction of advanced modulation formats and coherent detection also in PON, including some hybrid solutions that are currently under investigation in the ITU-T Very High Speed PON initiative. We show that coherent PON can actually reach the 200G per wavelength target, including some spare link budget margin, which can potentially be used for new access architectures. As an example, we present a summary of our recent results on hybrid solutions and on the all-optical convergence between the metro and access segments.","PeriodicalId":50103,"journal":{"name":"Journal of Optical Communications and Networking","volume":"18 2","pages":"A134-A149"},"PeriodicalIF":4.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146026451","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}

引用次数: 0