Browsing by Author "Chen, Alice"

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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.
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.
The Design of Big Data Analytics for Testing & Measurement and Traffic Flow on an Experimental 4G/LTE Network
(2015)
Lin, Bao-Shuh
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Tung, Li-Ping
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Hsieh, I-Ching
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Liu, Tsai-Hua
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Chou, Shu-Yuan
BML(Broadband Mobile Lab.) at NCTU has been utilized to support the testing & measurement for communication and networking products. It also has proven to be able to develop applications and services in a campus scale experimental networking environment. In the meantime, ITRI in Taiwan is conducting a greater metropolitan (Hsinchu) scale experimental networking environment, called ITRINET under the MOEA national program to improve and speed up the 4G/LTE applications and services. The BML at NCTU will be integrated with ITRINET and merged to become its subnet. With the cloud-enabled 4G/LTE-based ITRINET, we have designed the system to conduct the big data analytics for testing&measurement data and for network traffic and management data through a real-time streaming computing software package, InfoSphere, run on a cloud server platform, Inventec Zion. The testing&measurement data is generated and collected through the industry-academia R&D services while the network traffic and management data is created and collected by engaged a variety of APP\'s on smart devices (SD). This paper addresses the system design methodology and issues related to the data analytics for an experimental network environment.