Browsing by Author "Shih, Ju-Lin"

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A 40-Gb/s OFDM PON System Based on 10-GHz EAM and 10-GHz Direct-Detection PIN
(2012-01-01)
Chen, Hsing-Yu
;
Wei, Chia Chien
;
Hsu, Dar-Zu
;
Yuang, Maria C.
;
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.
;
Tien, Po-Lung
;
Hsu, Dar-Zu
;
Chen, Shing-Yu
;
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 Novel Passive Optical Network Architecture Supporting Seamless Integration of RoF and OFDMA Signals
(2010-03-15)
Lin, Yu-Min
;
Tien, Po-Lung
;
Yuang, Maria C.
;
Lee, Steven S. W.
;
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.
;
Lin, Yu-Min
;
Shih, Ju-Lin
;
Tien, Po-Lung
;
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.
A Virtual-Tree OFDMA PON System Architecture
(2012)
Yuang, Maria
;
Tien, Po-Lung
;
Chen, Jyehong
;
Shih, Ju-Lin
;
Hsu, Dar-Zu
OFDM PON has been considered to be one of the most prominent next-generation broadband wired access solutions. However, based on the current tree-architecture, existing OFDM PON systems face severe challenges when increasing the scalability and data-rate performance. In this paper, we propose a novel virtual-tree architecture of an OFDMA PON system (VTOPS). Coupled with the use of inexpensive direct modulation, VTOPS simultaneously achieves high reliability, scalability, and spectrum efficiency (i.e., high data rate) in a cost-effective manner. Theoretical and experimental results demonstrate that, by applying the pre-emphasis algorithm and subchannel adaptive modulation, VTOPS achieves 40-Gb/s downlink and uplink transmissions using low-cost 10-GHz directly modulated lasers.
gamma-TBSC: Time-Bound Signaling Control with gamma-Percent Soft Guarantee in IEEE 802.11 Wireless LANs
(2010)
Shih, Ju-Lin
;
Yuang, Maria C.
;
Lin, Shih-Hsuan
;
資訊工程學系
;
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.