Optical Packet Switching Research Articles

Two‐mode multiplexed Fourier‐based labels

AbstractA two‐mode optical packet switching architecture using an optical multiport mode‐division multiplexing label generator and processor is proposed. By combining optical labels on two modes, the number of labels is increased exponentially. Beat noise significantly affects the label error rate, when multimode crosstalk is maximum. This impairment can be mitigated by time shifting the optical labels of the two modes by half of the label duration.

An efficient and improved algorithm for generating an equivalent planar architecture of the data vortex switch

The data vortex (DV) switch was originally designed as an all optical interconnection network for high performance computing (HPC) applications. It was highly scalable with low latency and high throughput, compared to traditional switches used for optical packet switching (OPS) and HPC applications. The equivalent planar (chained MIN) model of the DV, proposed in previous literature, is a planar diagrammatic conversion of a 3-D model of the DV network. In this paper, we will focus on exploring a new, efficient and improved generalized algorithm that enables the arrangement of routing pathways to be implemented as an equivalent planar architecture (EPA, chained MIN) of a DV to find all possible routes between each source and target node pair. The original 3-D architecture of any size can be converted to a planar structure more simply by using the new generalized equivalent planar architecture (EPA) algorithm. To verify the proposed EPA algorithm, it was tested with different input traffic loads and network sizes while keeping the active angle ‘A’ constant. Network performance parameters, including injection rate (throughput) and latency (mean hops), obtained from simulation results are also provided to confirm the validity of the proposed EPA algorithm. This new algorithm is versatile, simple and can be applied to networks of various sizes.

Next Generation Exabit/s Data Center Network Supporting All Optical Circuit and Packet Switching

Next Generation Exabit/s Data Center Network Supporting All Optical Circuit and Packet Switching

Congestion control analysis of optical packet switch for optical data center applications

Abstract Optical data centers serve as the backbone of modern networking, facilitating seamless connectivity for users across the globe. The connection between users and the optical data centers is established through various network topologies, which play a critical role in determining the traffic characteristics. The design and implementation of these network topologies, along with the assortment of applications hosted on optical data centers, significantly influence the flow of data within the network. The advent of cloud computing has further revolutionized optical data center operations, leading to the coexistence of a wide range of applications on different optical data center switches. As a result, the traffic characteristics observed on each optical data center switch vary significantly. This diversity in traffic patterns necessitates a comprehensive understanding of how data arrival is managed and handled by the networking infrastructure. In this paper, we explore the concept of a random traffic model for data arrival on Top of Rack (ToR) switches, which represent a crucial component of optical data center networking. In the modeling, small world model is considered. The effect of buffering and packet priorities is observed on traffic shaping. Finally, to evaluate the effectiveness of the traffic shaping techniques, we measure the packet loss performance of ToR switches and found to be as low as 10−4 even at the higher loads. Blocking performance provides valuable insights into how effectively the optical data center network manages incoming data and avoids congestion or bottlenecks.

Comparative analysis of optical data center switches

Abstract In the recent past, there has been an explosive growth in data traffic within data center systems. This rapid increase in data volume has put significant constraints on the speed of current data communication networks, which are predominantly based on electronic controllers and memory. The speed limitations of electronic devices hinder their ability to process data at higher rates efficiently. To address this issue and enable faster data processing, the use of optical communication emerges as the most promising solution. Optical communication leverages the capabilities of light signals and optical components, which can handle data at much higher rates compared to their electronic counterparts. One key element in optical communication systems is the utilization of fiber delay lines (FDLs) as optical storage for packets. FDLs offer the ability to temporarily store and delay optical signals, providing buffering capabilities within optical networks. These FDLs can be configured in various setups, including feed forward, feed backward, and recirculating configurations, each with its own set of advantages and disadvantages. In this context, this article explores several state-of-the-art arrayed waveguide grating (AWG)-based optical packet switch (OPSW) architectures. These switches are designed to efficiently route and manage optical packets within data center networks. Each architecture is summarized, highlighting its unique features and capabilities. To compare the different AWG-based OPSW architectures, various key parameters are considered, such as the cost, physical losses, bit error rate (BER), and the number of tunable components required. These parameters are critical in determining the performance, efficiency, and cost-effectiveness of the switches.

Operating Characteristic Curves of Optical Packet-Switching Using Optical Code-Division Multiplexing for Label Switching

In this paper, the operating characteristic curves (OCCs) of optical code-division multiplexing (OCDM) technology for label switching of an optical packet-switching (OPS) network was evaluated. A node structure for processing the packets, with spectral-amplitude-coding (SAC) labels, considering a balanced detector and an optical switch, was developed and modeled. The effects of decoding noises on the performance of both M-sequence and stuffed quadratic congruence (SQC) labeling systems were addressed. Hypothesis testing was applied to the decoder to investigate the results of label recognition. The null and alternative hypotheses were, respectively, defined as a decoder receiving the matching and mismatching labels. Due to the noise effects, the decoder output may not reflect the label status correctly. Type I error occurs when the null hypothesis is true while accepting the alternative one. Type II error occurs when the alternative hypothesis is true while accepting the null one. Analytic equations of both errors were given, considering a desired packet that was missed and an undesired packet shown in a switched path. The trade-off between these two errors, regarding the decoder threshold, was demonstrated in operating characteristic curves (OCCs). A better OCC could be found when a packet had more labeled payload bits, or when the utilized label code had a lower auto-to-cross-correlation ratio.

Photonic integrated multicast switch-based optical wireless data center network

Optical wireless data center networks (OW-DCNs), which employ optical wireless technology and optical wired switching technology, are gaining interest as they promise to eliminate cable complexity, as well as to create high bandwidth interconnections and a low-cost and power-efficient system. In particular, the incorporation of optical tunable transmitters (T-TXs) and passive optical beam steering technologies is a promising way to build an OW-DCN benefitting from the potential of fast optical switching speed, low switch control complexity, and easy reconfiguration. However, the practical deployment of such an OW-DCN remains a challenge as fast (nanosecond) T-TX is required for fast optical switching operation. Implementation of fast T-TX can be realized by an array of lasers and optical gates, which are combined with photonic integration technology to achieve a compact, stable, and efficient nanosecond T-TX. In this paper, we propose an OW-DCN based on arrayed waveguide grating routers and fast T-TXs that exploit photonic integrated circuit multicast switches (PIC-MCSs). This PIC-MCS chip not only offers nanosecond-scale fast optical switching but also plays an essential role in enabling multicast operation, T-TX sharing, and dynamic bandwidth allocation between the intra- and inter-cluster networks. A 4×2 PIC-MCS has been designed, fabricated, and characterized in this proposed OW-DCN system. Experimental results validate that the proposed OW-DCN supports lossless, nanosecond, and multicast switching operation. Moreover, the dynamic bandwidth allocation and optical packet switching capability have been experimentally demonstrated. Finally, system performance with this fabricated PIC-MCS chip in a 4×4 rack OW-DCN is experimentally validated for different transmission scenarios and modulation formats. Wavelength division multiplexing multicast transmission with 50 Gb/s non-return-to-zero on–off-keying signals has been verified with less than 1.5 dB power penalty. 58 Gb/s four-level pulse-amplitude modulation transmission has also shown operation below the forward error correction threshold of 3.84×10−3 for all the different transmission scenarios.

Hybrid Optical-Electrical Data Center Networking: Challenges and Solutions for Bandwidth Resource Optimization

Fast optical switching (FOS) is the most promising technology for data center networks (DCNs) to meet data rate requirements beyond 800 Gb/s, considering its transparent modulation format, low power consumption and dense port integration. However, FOS, leveraging optical packet switching (OPS) technology, is hardly compatible with the electrical switches that are widely used in the current hybrid optical/electrical switching data center networks (Hoe-DCNs). The diversity of topologies and multi-switching granularity increases the risk of service disruption and reduces bandwidth efficiency. Based on the IP-over-OPS system, we propose bandwidth resource optimization techniques with the aid of hybrid polling contention resolution and microsecond-level load balancing in Hoe-DCNs. We first present an optical switching architecture to show its performance characteristics in the context of nanosecond-level FOSs in terms of resource management and setup optimization. Based on the fabricated FOS structure, we discuss the emerging problem of packet contention and introduce a bufferless scheduling solution. The characteristics of load balancing for Hoe-DCN are then investigated and evaluated by simulating Hoe-DCNs. Finally, the numerical results are given and analyzed based on a large-scale DCN testbed.

160 Gbps capacity and sub-us latency of polarization-independent optical packet switch architecture for free-space optical network using PLZT optical switch

In this paper, we discuss the challenges and limitations of current free-space optical (FSO) networks toward scaling beyond the 100 Gbps switch capacity era while achieving low-latency and high-reliability. Owing to the slowdown of Moore’s law, to avoid electronically-induced bottlenecks, we construct an FSO switch network and experimentally evaluate the feasibility of ultrafast optical packet switch architecture based on polarization-independent plomb lanthanum zirconate titanate (PLZT) switch without buffering. The bit error ratio of 160 Gbps ([Formula: see text]) data was validated based on measurements while still preserving the sub-us latency metrics ([Formula: see text] ns). The experimental results may offer a significant reference for FSO communication and network.

Implicit Label Number for Optical Packets in Label Switching Networks Based on Spectral Amplitude Coding and OCDM Path

This paper presents an implicit labeling scheme where stacked spectral-amplitude-coding (SAC) labels are inscribed in multiple payload bits in the packet front. Reliable label recognition in optical packet switching (OPS) is achieved by analyzing the overall decoding results of all labeled bits instead of considering each labeled signal individually. The concept of hypothesis testing is employed to determine the optimal labeled bit number. A decision rule of correct switching is designed based on the photocurrent mean of the decoded label stacks. Considering the noise factors shown in the decoding process, the desired label number has been analyzed under different conditions of code types, label power, and the level of significance. Simulation results provide good suggestions for the tradeoff between the system insensitivity to noise effects and the transmission redundancy of carrying repetitive label information in an optical packet.

RGAIA: a reconfigurable AWGR based optical data center network.

Benefitting from the cost-effective and flexible interconnection between computing nodes and storing infrastructures, various applications and services are deployed in data centers (DCs). These traffic-boosting applications put tremendous pressures on current electrically switched DC networks (DCNs) which suffer the bandwidth bottleneck. Benefitting from the data-rate and format transparency, the optically switched DCN with intrinsic high-bandwidth characteristics is a promising solution to update the hierarchical electrical DCNs with bandwidth limitations. Moreover, the applications deployed in DCNs with mixed traffic characteristics require dynamic quality of service (QoS) provisioning. Optical DCNs thus need to be designed in a flexible topology with the capability of bandwidth reconfigurability to adapt the variety of the traffic. In this paper, we propose and experimentally investigate a reconfigurable optical packet switching DCN named RGAIA, based on flexible top of racks (ToRs) and fast optical switch, where the optical switch is implemented by tunable transceiver combing with arrayed waveguide grating router (AWGR). Under the management of the designed software defined network (SDN) control plane, RGAIA can dynamically distribute the wavelength resource and then reconfigure the bandwidth in real-time based on the monitored traffic characteristics. Experimental assessments validate RGAIA improving performance of 37% and 66% in latency and packet loss, respectively, compared with the network with rigid interconnections at the traffic load of 0.8.

Preface

Due to recent pandemic, 2022 8th International Symposium on Sensors, Mechatronics and Automation System (ISSMAS 2022) was held virtually online on January 14-16, 2022. The decision to hold the virtual conference was made in compliance with many restrictions and regulations that were imposed by countries around the globe. Such restrictions were made to minimize the risk of people contracting or spreading the COVID-19 through physical contact. There were 150 individuals who attended this on-line conference, represented many countries.The idea of the conference is for the scientists, scholars, engineers and students from the Universities all around the world and the industry to present ongoing research activities, and hence to foster research relations between the universities and the industry. The conference will be held every year to make it an ideal platform for people to share views and experiences in Sensors, Mechatronics and Automation System and related areas. It will bring you an unexpected harvest.During the conference, the conference model was divided into three sessions, including oral presentations, keynote speeches, and online Q&A discussion. In the first part, some scholars, whose submissions were selected as the excellent papers, were given about 5-10 minutes to perform their oral presentations one by one. Then in the second part, keynote speakers were each allocated 30-45 minutes to hold their speeches.In the second part, we invited five professors as our keynote speakers. Dr. Xiaohui Liang, our first keynote speaker, from Institute of Chemical Materials (ICM), China Academy of Engineering Physics (CAEP), China. His research interest includes structure healthy monitor and destroy diagnose of military-industrial material and structure, fault diagnose of major equipment, Advanced signal and information process, modern control technology, control technology application of electromechanical and hydraulic equipment. The second keynote speakers, Assoc.Prof. Kai-Sheng Chen, School of Electrical and Computer Engineering, Nanfang College of Sun Yat-Sen University, China. His research interests cover optical CDMA, radio-over-fiber, optical packet switching, and visible light communications. Assoc.Prof. K.VINOTH KUMAR, Karpagam University, Coimbatore. His research interests included Electronics & Communication Engineering, Applied Electronics, Wireless Sensor Networks Survey, Investigations on Location based Multipath Secured Energy Efficient Routing Approach. Assoc.Prof. Ruhui Ma, Shanghai Jiaotong University, Department of Computer Science and Engineering. His main research directions are artificial intelligence, computer vision, intelligent manufacturing, medical-industrial intersection, cloud computing system, cloud security, intelligent system, etc. Lastly, we were glad to invite Prof. Shahid Hussain, Jiangsu University, China. His Research interests: MOS-MOF-MXene Nanomaterials, Gas-Sensors, Electrochemical Supercapacitors, Li-S batteries. Their insightful speeches had triggered heated discussion in the third session of the conference. Every participant praised this conference for disseminating useful and insightful knowledge.The proceedings are a compilation of the accepted papers and represent an interesting outcome of the conference. Topics include but are not limited to the following areas: Sensing and measurement in electromechanical systems, Intelligent sensing and control, Computational Fluid Dynamics, Fault Detection and Diagnostics, Control of Distributed Generation Systems and other related topics. All the papers have been through rigorous review and process to meet the requirements of international publication standard.We would like to acknowledge all of those who supported ISSMAS 2022. The help and contribution of each individual and institution was instrumental in the success of the conference. In particular, we would like to thank the organizing committee for its valuable inputs in shaping the conference program and reviewing the submitted papers.We sincerely hope that the ISSMAS 2022 turned out to be a forum for excellent discussions that enabled new ideas to come about, promoting collaborative research. We are sure that the proceedings will serve as an important research source of references and knowledge, which will lead to not only scientific and engineering findings but also new products and technologies.The Committee of ISSMAS 2022List of titles Committee member, Conference General Chair, Technical Program Committee Chair, Publication Chair, Organizing Committees Member, Technical Program Committee Member are available in this Pdf.

An AWG based optical packet switch with add-drop of data

An AWG based optical packet switch with add-drop of data

Why Optical Packet Switching failed and can Elastic Optical Networks take its place?

In this special issue devoted to the memory of Prof. Fabio Neri we would like to look back at the time of the international research projects where some of us collaborated with him. On the basis of our personal experience of the time and the current viewpoint, we will discuss why Optical Packet Switching (OPS) is a technology that never came to market in spite of the great amount of research that was devoted to it. Then we will explore how Elastic Optical Network came to the stage more recently, somewhat overcoming the OPS technical proposal both in the interest of the researchers as well as of the industry.

Architecture and Performance Evaluation of a Novel Optical Packet Switch with Input Concentrators

In this paper, we propose a novel optical packet switch (OPS) architecture with input concentrators, which employ multi-input single-output optical buffers to aggregate all the incoming traffic into a small size switching fabric. Accordingly, the physical size, the number of the needed wavelength converters, and the economic cost of the total OPS node are decreased dramatically. However, the deployment of input concentrators introduces additional packet loss and delay, except from the contention at the switch output. A Markov model is presented to study the packet loss ratio (PLR) and average packet delay given by the input concentrators. The corresponding closed form expressions are given. The model also demonstrates that the system performance can be greatly improved by increasing the buffer size when the traffic load is not larger than 0.69315. The analytical values are compared with the simulation results. All the obtained results show that the proposed model provides satisfactory approximations under different network scenarios. Moreover, the economic cost savings of the proposed OPS node at the present time and its evolution as a function of time are also discussed in detail. The proposed architecture can also be applied in a packet enhanced optical transport network (OTN).

Design of optical packet switch in presence of dispersion compensation and amplifier noise

Abstract Optical communication gained popularity in past few years. Optical communication has many distinct advantages over copper cable based electronic communication. Optical switches are integral part of optical networks which are used for rerouting of packets and also plays important role in contention resolution of the packets. These switch uses fiber delay lines (FDLs) act as optical memory. In past analysis of the switch is done by considering loss, power and noise and finally bit error rate (BER); however dispersion was neglected which is an important parameter in high speed communication. In this paper, design analysis is done by considering dispersion compensation along with optical amplifier noise.

Solitons based optical packet switch analysis

Abstract Due to the evolution of data centric applications demand for high speed data transfer and more bandwidth is increasing continuously. The unavailability of components like tunable wavelength converters (TWCs) restrict the transfer of parallel information using wavelength division multiplexing (WDM), therefore in the present scenario optical orthogonal frequency division multiplexing can be used. Moreover in optical communication narrow Gaussian pulses are transmitted, which spread with distance and leads to the broadening of the pulse and pulse peak power goes down and thus limits the system. In this paper a Soliton based optical communication system is proposed and its comparison with Gaussian pulse is presented and it has been found that soliton pulse has lesser bit error rate in comparison to Gaussian pulses.

Hybrid buffer and AWG based add-drop optical packet switch

Abstract Optical packet switching (OPS) exhibits the ability to be utilized as a data transmission technique for next-generation. The core router/switch plays a significant role in packet routing and buffering in OPS. Arrayed waveguide grating (AWG) is realized as a promising core element for fast optical switching, with its intrinsic capacity to achieve wavelength routing of different wavelengths in parallel. This paper proposes an AWG-based add-drop optical packet switch, including a hybrid buffer, to resolve contention among packets. In a hybrid buffer, both optical and electronic buffers are used for the buffering of contending packets. AWGs are affected by crosstalk that can significantly impair system operation. The physical layer analysis is discussed in the presence of crosstalk, and the performance of the switch is evaluated in terms of bit error rate. The desired minimum input power is calculated for the switch’s correct operation for both optical buffer and electronic buffer. Finally, the packet loss probability (PLP) of the hybrid buffer is examined under various buffering conditions. Results reveal that with the increase in the optical power of the input signal, crosstalk power increases linearly for optical and electronic buffers. The increased crosstalk power is higher for electronic buffers than the optical buffer. The use of electronic memory in the hybrid buffer allows the hybrid buffer to increase its buffer size thus, reducing the PLP.

End-to-End 1024-Port Optical Packet Switching With 25 Gb/s Burst-Mode Reception for Data Centers

Despite the fact that Optical Packet Switching (OPS) emerges as a promising solution for future Data Center (DC) networks, towards increasing capacity and radix, while retaining sub-μs latency performance, the requirement for ultra-fast burst-mode reception has been a serious restraining factor. We attempt to overcome this limitation and demonstrate, for the first time to our knowledge, an end-to-end optical packet switch link through the 1024-port 25.6 Tb/s Hipoλaos OPS, featuring burst-mode reception with <; 50 ns locking time. The switch performance for unicast traffic is evaluated via Bit-Error-Rate measurements and error-free performance at 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> is reported for all validated port-combinations, with a mean power penalty of 2.88 dB. Moreover, multicast flows from two different ports of the switch were successfully received validating the architecture's credentials for efficient multicast packet delivery. Taking one step further towards a realistic evaluation of an OPS-enabled DC, a simulation analysis was conducted, proving that low-latency performance, including the burst-mode reception time-overhead, can be successfully realized in a Hipoλaos-switched DC with up-to 100% throughput for a variety of traffic profiles.

Performance analysis of a 1024-port Hipoλaos OPS in DCN, HPC, and 5G fronthauling Ethernet applications

The explosive traffic growth of emerging cloud, augmented/virtual reality, artificial intelligence, and 5G applications along with the inherent need for high-bandwidth transport of big data has fueled the expansion of the Ethernet switch market for data centers (DCs), high-performance computers (HPCs), and 5G fronthaul networks. As such, next-generation switches have to be capable of conforming to the requirements of a versatile traffic environment, expanding along DC, HPC, and 5G fronthauling infrastructures while meeting the performance needs of these different application sectors. Within this frame, we experimentally validate for the first time, to the best of our knowledge, the performance of the recently reported Hipoλaos optical packet switch (OPS) within Ethernet-based traffic exchange in DC and 5G fronthaul testbeds, highlighting the credentials of the 1024-port and 10.24 Tb/s capacity OPS to successfully support real-world DC and 5G applications. Error-free unicast and dual-output multicast Ethernet packet transmission at 10 Gb/s are successfully validated for different output ports of the switch, followed by successful server-to-server high-definition video transmission, both when the OPS was employed in the DC as well as in the 5G fronthauling testbed. Network performance and stability over time were confirmed through several measurements carried out through the iperf application suite, revealing submicrosecond end-to-end (Layer 7) latency performance. Finally, an OMNeT++ simulation analysis for an Ethernet-switched Hipoλaos network utilizing real-world application traces collected from the MareNostrum HPC system revealed up to 89% lower latency performance compared to the actual system.