Browsing by Author "Lee, Steven S. W."

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A 10G QoS-enabled optical packet-switching system: Technology and experimentation
(2006-01-01)
Lee, Steven S. W.
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Yuang, Maria C.
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Tien, Po-Lung
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Lin, Yu-Min
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Shih, Julin
The paper presents the architecture and experimentation of a 10-Gb/s QoS-enabled almost-all-optical packet switching system (QOPS) for metro WDM networks. By applying cluster-based wavelength sharing and downsized single-staged optical buffers, QOPS is featured by its highly scalable and cost-effective design. In this paper, we first introduce the switch architecture, system operation, and the key techniques. We describe the in-band header/payload modulation and optical label swapping that is suitable for high-speed optical packet switching. We also present the design of the highly efficient Four-Wave Mixing wavelength converters for packet preemption. We then present an adaptive bifurcated routing (ABR) that directs same-connection packets to different switch clusters according to optimal bifurcation probabilities. Experimental and simulation results demonstrate that QOPS can achieve superior packet-loss performance, QoS differentiation, and minimize traffic blocking probability.
A 40-Gb/s OFDM PON System Based on 10-GHz EAM and 10-GHz Direct-Detection PIN
(2012-01-01)
Chen, Hsing-Yu
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Wei, Chia Chien
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Hsu, Dar-Zu
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Yuang, Maria C.
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Chen, Jyehong
This letter demonstrates a 40-Gb/s optical double-sideband (ODSB) orthogonal frequency-division multiplexing passive optical network (OFDM-PON) system using a cost-effective 10-GHz-bandwidth electroabsorption modulator (EAM). By employing a subcarrier-adaptive modulation format and pre-emphasis, we successfully achieve 20-km EAM-based single-mode-fiber (SMF) transmission.
A High-Performance Optical Access and Control System for Packet-Switched WDM Metro Ring Networks
(2008)
Yuang, Maria C.
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Chao, I-Fen
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Lin, Yu-Min
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Lo, Bird C.
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Tien, Po-Lung
In this paper, we present the access and control design of a High-Performance Optical Packet-Switched WDM Metro ring Network (HOPSMAN). HOPSMAN has been designed for networks and nodes to be unconstrained by the number of wavelengths. It includes a handful of nodes that are equipped with fast optical slot erasers making bandwidth reusable and achieving greater bandwidth efficiency. In essence, HOPSMAN incorporates a versatile Medium Access Control (MAC) scheme, which embodies efficient and fair bandwidth allocation in accordance with a quota being exerted probabilistically. The quota is analytically derived with the number of slot-eraser-nodes taken into account. The scheme also employs a new notion of credit to regulate flexible access of remaining bandwidth that is suitable for the metro environment with bursty traffic. With the MAC scheme, HOPSMAN is shown to achieve exceptional throughput, delay, and fairness performance under a wide range of traffic settings via simulation results.
A Lagrangean relaxation based near-optimal algorithm for advance lightpath reservation in WDM networks
(2010-02-01)
Lee, Steven S. W.
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Chen, Alice
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Yuang, Maria C.
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資訊工程學系
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Department of Computer Science
Advance lightpath reservation is a new research topic for connecting high-speed computer servers in lambda grid applications and for dynamic lightpath provisioning in the future optical internet. In such networks, users make call requests in advance to reserve network resources for communications. The challenge of the problem comes from how to jointly determine call admission control, lightpath routing, and wavelength assignment. In this paper, we propose an efficient Lagrangean relaxation (LGR) approach to resolve advance lightpath reservation for multi-wavelength optical networks. The task is first formulated as a combinatorial optimization problem in which the revenue from accepting call requests is to be maximized. The LGR approach performs constraint relaxation and derives an upper-bound solution index according to a set of Lagrangean multipliers generated through subgradient-based iterations. In parallel, using the generated Lagrangean multipliers, the LGR approach employs a new heuristic algorithm to arrive at a near-optimal solution. By upper bounds, we assess the performance of LGR with respect to solution accuracy. We further draw comparisons between LGR and three heuristic algorithms-Greedy, First Come First Serve, and Deadline First, via experiments over the widely-used NSFNET network. Numerical results demonstrate that LGR outperforms the other three heuristic approaches in gaining more revenue by receiving more call requests.
A Near-Optimal Heuristic Algorithm for Advance Lightpath Reservation in WDM Networks
(2008)
Chen, Alice
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Lee, Steven S. W.
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資訊工程學系
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Department of Computer Science
We proposes a Lagrangean Relaxation based algorithm that derives profoundly tight lower and upper bounds with low computational complexity, yielding a near-optimal solution to the advance lightpath reservation problem.
A Novel Passive Optical Network Architecture Supporting Seamless Integration of RoF and OFDMA Signals
(2010-03-15)
Lin, Yu-Min
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Tien, Po-Lung
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Yuang, Maria C.
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Lee, Steven S. W.
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Chen, Jason (Jyehong)
In this letter, we propose a novel passive optical network (PON) architecture supporting radio-over-fiber signals and orthogonal frequency-division multiple access (OFDMA) PON signals. The architecture transports upstream multiple remote antenna's wireless signals using only one upstream wavelength. In addition, the windowed-orthogonal frequency-division-multiplexing technique is employed to mitigate interference during the integration process. Experimental results shows that 10-Gb/s OFDMA and three radio-frequency signals at 2.1 GHz are successfully transmitted over 20-km single-mode fiber in a 32-optical-network-unit PON.
A QoS Optical Packet Switching System: Architectural Design and Experimental Demonstration
(2010-05-01)
Yuang, Maria C.
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Lin, Yu-Min
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Shih, Ju-Lin
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Tien, Po-Lung
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Chen, Jason J.
Optical packet switching has been considered a prominent paradigm for future WDM networks to efficiently support a multitude of applications with diverse quality of service requirements. In this article we present the architectural design and experimental demonstration of a 10 Gb/s QoS optical packet switching system (QOPSS) for WDM networks. It embodies a set of many-to-one space switches, each of which handles the switching solely for a cluster of wavelengths. With the cluster-based optical switch design, QOPSS trades off limited statistical multiplexing gains for higher system scalability. By many-to-one, multiple packets that are carried by different internal wavelengths are scheduled to switch to the same output port but receive different delays afterward. QOPSS adopts downsized feed-forward optical buffers, yielding drastic reduction in packet loss probability in an economical manner. Significantly, through using four-wave-mixing wavelength converters at the output section, QOPSS permits optical packet preemption, thus achieving effectual QoS differentiation. The article presents both simulation and experimental testbed results to demonstrate the feasibility and superior packet loss/QoS performance of the system.
Demonstration of a Novel PON System with Distributed Real-Time Bandwidth Allocation
(2009)
Yuang, Maria C.
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Lin, Shih-Hsuan
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Lee, Steven S. W.
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Shih, Julin
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Lin, Yu-Min
This paper demonstrates a novel distributed control PON system (DCPON). Equipped with a distributed adaptable DBA algorithm that enables real-time precise bandwidth allocation, DCPON achieves high utilization, fairness, low request/response time, and superior service differentiation. (C)2009 Optical Society of America
HOPSMAN: An experimental testbed system for a 10-Gb/s optical packet-switched WDM metro ring network
(2008-07-01)
Yuang, Maria C.
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Chao, I-Fen
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Lo, Bird C.
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Tien, Po-Lung
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Chen, Jason J.
For future WDM MANs, optical packet-switching has been considered to be a promising paradigm that efficiently supports a wide range of Internet-based applications having time-varying and high bandwidth demands and stringent delay requirements. This article presents the design of an experimental testbed system for a high-performance optical packet-switched WDM metro ring network, HOPSMAN. HOPSMAN boasts three crucial features. First, it has a scalable architecture in which the number of nodes is unconstrained by the number of wavelengths. Second, HOPSMAN nodes are equipped with high-speed photonic hardware components, including fast tunable receivers and optical slot erasers, capable of performing speedy optical packet-switching operations. Third, HOPSMAN incorporates a MAC scheme that embodies efficient and dynamic bandwidth allocation, resulting in exceptional delay-throughput performance. The article presents the key hardware components by highlighting the challenging issues we faced and the solutions we proposed for the testbed implementation. Finally, to demonstrate the feasibility of HOPSMAN, the article describes the experimental setup and presents the results obtained from running a commercially available remote media player application on the system.
Multi-Path Provisioning for NG-SONET Networks with Quality-of-Survivability Constraints
(2008)
Chen, Alice
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Lee, Steven S. W.
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資訊工程學系
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Department of Computer Science
We propose a multi-path provisioning scheme for NG-SONET networks. Users can specify their bandwidth requirements for different network states. Numerical results reveal that the proposed scheme outperforms legacy SONET protection in all experimental cases.
Optical coarse packet-switched IP-over-WDM network (OPSINET): Technologies and experiments
(2006-08-01)
Yuang, Maria C.
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Lee, Steven S. W.
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Tien, Po-Lung
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Lin, Yu-Min
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Shih, Julin
Optical Packet Switching (OPS) has been envisioned as a prominent future optical networking technology for data-centric IP over Wavelength Division Multiplexing (WDM) networks, or optical Internet. Such OPS technology however raises significant transport and Quality of Service QoS) challenges due to technological limitations. To circumvent OPS limitations, we have proposed a new Optical Coarse Packet Switching (OCPS) paradigm, which uses in-band-controlled per-burst switching and advocates traffic control enforcement to achieve high packet-loss performance and differentiated services. Based on OCPS, we have constructed an experimental IP-over-WDM network, referred to as OPSINET. OPSINET consists of two major types of nodes- edge routers, and Optical Label Switched Routers (OLSRs), and is facilitated with an out-of-band Generalized Multi-protocol Label Switching (GMPLS) control network. In this paper, we first introduce the OCPS paradigm. We then present the architecture of OPSINET, describe the in-band header/payload modulation technique, and detail the operations of the edge routers, OLSRs, and GMPLS control.