Browsing by Author "Yuang, Maria C."

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2.1-Tb/s.km OFDM Long-Reach PON Transmission using a Cost-Effective Electro-Absorption Modulator
(2011-01-01)
Hsu, Dar-Zu
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Wei, Chia-Chien
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Chen, Hsing-Yu
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Chen, Jyehong
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Yuang, Maria C.
We experimentally demonstrate a superior performance of 2.1-Tb/s.km OFDM-signal transmission over 100-km long-reach PONs, which is achieved by using an EAM and direct-detection, and adopting the 128-QAM format and adaptive subcarrier power weighting.
21 Gb/s after 100 km OFDM long-reach PON transmission using a cost-effective electro-absorption modulator
(2010-12-20)
Hsu, Dar-Zu
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Wei, Chia-Chien
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Chen, Hsing-Yu
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Chen, Jyehong
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Yuang, Maria C.
We experimentally demonstrate a superior performance of 2.1-Tb/s.km OFDM signal transmission over 100-km long-reach PONs. While the bandwidth of a 100-km SMF transmission system is limited to 4.3 GHz due to positive chirp, we successfully achieve spectrally-efficient 21-Gb/s signaling by using a cost-effective and low-chirp EAM, and adopting the 128-QAM format and adaptive subcarrier pre-emphasis. (C)2010 Optical Society of America
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 OFDMA PON System Architecture and Medium Access Control
(2012-06-01)
Yuang, Maria C.
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Tien, Po-Lung
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Hsu, Dar-Zu
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Chen, Shing-Yu
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Wei, Chia-Chien
Orthogonal frequency-division multiplexing (OFDM) passive optical network (PON) has been considered to be a promising next-generation broadband wired access solution. However, based on the current tree-based architecture, existing OFDM PON systems face severe challenges when increasing the scalability and data-rate performance. In this paper, we propose a high-performance virtual-tree orthogonal frequency-division multiple access PON system (VTOPS). With the virtual-tree architecture and coupled with the use of inexpensive direct modulation, VTOPS features high reliability, scalability, spectrum efficiency, and cost effectiveness all at once. For governing the flexible/fair access and dynamic allocation of bandwidth, VTOPS incorporates a rate-based medium access control (MAC) scheme. The MAC scheme performs dynamic rate adjustment using a neural-fuzzy system. By adjusting the system parameters, the MAC scheme can achieve a wide range of delay and fairness performance under a variety of traffic patterns. Finally, we show both theoretical and experimental results to demonstrate that, by applying the power pre-emphasis algorithm and adaptive subchannel modulation, VTOPS achieves 40 Gb/s downlink and 40 Gb/s uplink transmissions, using low-cost 10 GHz directly modulated lasers.
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 novel medium access control and processing system for a packet-switched WDM metro ring network
(2008)
Yuang, Maria C.
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Wang, Ya-Shian
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Lin, Yu-Min
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資訊工程學系
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Department of Computer Science
We present the design/experimentation of a medium-access control and processing system (MACOPS) for an optical packet-switched WDM network. MACOPS enables optical parallel headers to be efficiently received/modified via wavelength-time conversion, and achieves exceptional throughput/delay/fairness performance. (C) 2008 Optical Society of America.
A Novel Optical-Header Processing and Access Control System for a Packet-Switched WDM Metro Ring Network
(2009-11-01)
Yuang, Maria C.
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Lin, Yu-Min
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Wang, Ya-Shian
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資訊工程學系
;
Department of Computer Science
Optical packet switching (OPS) has been considered to be a promising paradigm to support a wide range of applications with different time-varying and high bandwidth demands for future optical metropolitan area networks (MANs). In this paper, we present the design of an experimental optical-header processing and access control system (OPACS) for an OPS wavelength-division multiplexing metro slotted-ring network. On the slotted ring, each control header is in-band time-division-multiplexed with its corresponding payload within a slot. OPACS enables the optical headers across all parallel wavelengths to be efficiently received, modified, and retransmitted by means of a wavelength-time conversion technique. Moreover, OPACS embodies a versatile medium access control (MAC) scheme, referred to as the distributed multigranularity and multiwindow reservation (DMGWR) mechanism, which is particularly advantageous for traffic of high and varying loads and burstiness. Basically, DMGWR requires each node to make reservation requests prior to transmissions while maintaining a distributed queue for ensuring fair access of bandwidth. By "multigranularity," each node can make a reservation of multiple slots at a time. By "multiwindow," each node is allowed to have multiple outstanding reservations within the window size. From simulation results that pit the OPACS network against two other existing networks, we show that the OPACS network outperforms these networks with respect to throughput, access delay, and fairness under various traffic patterns. Experimental results demonstrate that all optical headers are removed and combined with the data in a fully synchronous manner, justifying the viability of the system.
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.
An Energy and Cost Efficient WDM/OFDMA PON System: Design and Demonstration
(2013-08-15)
Yuang, Maria C.
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Hsu, Dar-Zu
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Tien, Po-Lung
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Chen, Hsing-Yu
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Wei, Chia-Chien
In this paper, we propose an energy and cost efficient WDM/OFDMA PON system, referred to as NEWOPS. Based on a new two-tiered semi-tree architecture, NEWOPS allows a large number of ONUs to be connected to OLT using only a handful of colorless transceivers. Due to the architecture, NEWOPS not only facilitates high spectral efficiency and flexible sub-channel bandwidth allocation, but also reduces the Rayleigh backscattering (RB) problem and achieves high energy and cost efficiency. Experimental results demonstrate that, taking only 5-GHz bandwidth for each wavelength, NEWOPS successfully achieves 20-Gb/s downstream and 10-Gb/s upstream OFDM-xQAM transmissions via the same fiber trunk. We depict that, to support 40 ONUs for example, NEWOPS achieves energy efficiency that is three to six times higher than that of a typical 10-Gb/s WDM/OFDM PON.
Circuit Emulation in Optical Packet-Switched WDM Ring Network for Wireless Backhaul
(2013)
Chao, I-Fen
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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
In this paper, we propose an integrated traffic control scheme (ITCS), which facilitates circuit emulation service (CES) for wireless backhaul over a previously proposed experimental optical packet-switched WDM ring network, HOPSMAN. To ensure efficient setup of CES connections, ITCS employs a simple mean-rate-based distributed admission control followed by a novel slot-marking reservation. The total connection setup delay is comprised of the setup queueing delay and slot-marking delay. While the slot-marking delay is nearly a ring time, the mean setup queueing delay is formally computed through an accurate approximation based on an M/G/m queueing analysis. Simulation results show that ITCS accommodates remarkably high CES traffic loads while satisfying a wide range of delay and jitter requirements for wireless backhaul.
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
Design and Experimentation of an Optical-Header Processing and Access Control System for a Packet-Switched WDM Metro Ring Network
(2009)
Yuang, Maria C.
;
Wang, Ya-Shian
;
Lin, Yu-Min
;
資訊工程學系
;
Department of Computer Science
In this paper, we present the design of an experimental optical-header processing and access control system (OPACS) for an optical packet switched (OPS) WDM metro slotted-ring network. Each control header is in-band time-division-multiplexed with its payload. OPACS enables the optical headers across all parallel wavelengths to be efficiently received, modified, and re-transmitted based on a wavelength-time conversion technique. Bandwidth access in OPACS is governed by a versatile access control scheme, called the distributed multi-granularity and multi-window reservation (DMGWR) mechanism. With DMGWR, the OPACS network is shown to outperform two existing networks with respect to throughput, access delay, and fairness under various traffic patterns. Experimental results demonstrate that all optical headers are removed and combined with the data in a fully synchronous manner, justifying the viability of the system.
Fault-Tolerance Enhanced Design and Analyses for Optical Pyramid Data Center Network (OPMDC)
(2016)
Yuang, Maria C.
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Yang, Jing-Chun
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Chen, Hsing-Yu
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Tien, Po-Lung
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資訊工程學系
This paper presents a fault-tolerance enhanced design and analyses for OPMDC[1]. Capacity-based analysis shows OPMDC accommodates 0.91-capacity under the worst-case single WSS-failure. Emulation analysis justifies that a 26dB-OSNR is retained under the worst-case three-WSS-failure scenario.
gamma-TBSC: Time-Bound Signaling Control with gamma-Percent Soft Guarantee in IEEE 802.11 Wireless LANs
(2010)
Shih, Ju-Lin
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Yuang, Maria C.
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Lin, Shih-Hsuan
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資訊工程學系
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Department of Computer Science
Signaling control schemes for wireless multimedia services are expected to maximize the number of newly-accepted mobile terminals (MTs), i.e., system throughput, while maintaining the quality of service (QoS) requirements for the existing MTs in the system. In this paper, we propose a gamma-percent time-bound signaling control (gamma-TBSC) scheme that resolves a maximum number of MTs mostly within a given bounded time, subject to assuring gamma-percent soft guarantee for existing MTs. The gamma-TBSC scheme performs signaling control in two phases: the call-invitation phase, and the contention-resolution phase. In the first phase, an access point invites a number of so-called potential MTs to make reservations during a call invitation interval (CII). If any collision occurs, gamma-TBSC performs contention resolution in the second phase until all potential MTs are resolved successfully. Most importantly, prior to the two-phase operation, gamma-TBSC analytically and statistically determines the potential MT number and the CII length such that the system throughput is maximized and the QoS is soft guaranteed. From simulation results that pit gamma-TBSC against several variants of carrier sense multiple access with collision avoidance (CSMA/CA) schemes, we delineate that gamma-TBSC outperforms these schemes with respect to throughput and delay performance.
HOPSMAN: An Experimental Optical Packet-Switched Metro WDM Ring Network With High-Performance Medium Access Control
(2010-02-01)
Yuang, Maria C.
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Chao, I-Fen
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Lo, Bird C.
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資訊工程學系
;
Department of Computer Science
Future optical metropolitan area networks (MANs) have been expected to exploit advanced optical packet switching (OPS) technologies to cost-effectively satisfy a wide range of applications having time-varying and high bandwidth demands and stringent delay requirements. In this paper, we present the architecture and access control of our experimental high-performance OPS metro WDM slotted-ring network (HOPSMAN). HOPSMAN has a scalable architecture in which the node number is unconstrained by the wavelength number. It encompasses a handful of nodes (called server nodes) that are additionally equipped with optical slot erasers capable of erasing optical slots resulting in an increase in bandwidth efficiency. In essence, HOPSMAN is governed by a novel medium access control (MAC) scheme, called probabilistic quota plus credit (PQOC). PQOC embodies a highly efficient and fair bandwidth allocation in accordance with a quota being exerted probabilistically. The probabilistic quota is then analytically derived taking the server-node number and destination-traffic distribution into account. Besides, PQOC introduces a time-controlled credit for regulating a fair use of the remaining bandwidth, particularly in the metro environment with traffic of high burstiness. Extensive simulation results show that HOPSMAN with PQOC achieves exceptional delay-throughput performance under a wide range of traffic loads and burstiness.
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.
Next-Generation Broadband Optical Access Network Technologies
(2010-08-01)
Yuang, Maria C.
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Lam, Cedric
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Kuwahara, Hideo
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Willner, Alan
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資訊工程學系