Ching-Fong Su

University of California, Davis, Davis, CA, United States

Are you Ching-Fong Su?

Claim your profile

Publications (21)10.25 Total impact

  • S. Rai, Ching-Fong Su, B. Mukherjee
    [Show abstract] [Hide abstract]
    ABSTRACT: We investigate connection provisioning in an all-optical wavelength-division multiplexing (WDM) network in the presence of physical-layer impairments. As the channel bit rate increases, impairments pose a more serious problem, and lightpaths need to be routed intelligently, so that the destination node receives the signal with adequate quality. We study the models of major physical impairments that affect optical signals. With reasonable assumptions, we model the major impairments as link-based metrics and we formulate schemes for routing, which consider the impairment constraints imposed by the underlying physical infrastructure. Prior work in this area has focused on enumerating a set of paths based on criteria such as minimum hops/distances, and then selecting a path from this set based on complex calculations of signal quality. Our approach integrates verification of impairment constraints while searching for paths. Routing with multiple additive constraints being NP-hard, we give an optimal heuristic algorithm with fast execution time for practical networks, as well as a dynamic programming pseudo-polynomial-time algorithm for the case when one impairment constraint dominates. We also examine the case of a practical ??all-optical?? network with signal regeneration facility at some nodes. We explore routing in such a translucent network and discover that finding a simple feasible path passing through a regenerator is NP-complete.
    IEEE/ACM Transactions on Networking 01/2010; · 2.01 Impact Factor
  • S. Rai, Ching-Fong Su, T. Hamada, B. Mukherjee
    [Show abstract] [Hide abstract]
    ABSTRACT: SONET/SDH is historically the dominant telecom transport infrastructure for backbone networks, and it is optimized for reliable delivery of voice and private-line services. Efficient utilization of the existing infrastructure through novel methods and algorithms can lead to higher revenue, which is attractive for network operators. In this study, we examine a network of inter-connected SONET/SDH rings that use dual-node interconnection employing the drop-and-continue facility, which is the de-facto standard for interworking SONET/SDH protection architectures. We develop an efficient algorithm for provisioning in such a network while keeping fragmentation of capacity low and taking into account the various constraints imposed by the underlying physical layer. We examine the case of dual-node-interconnected ring networks employing both contiguous and virtual concatenation (a next-generation SONET/SDH architecture), and as expected, we discover that provisioning higher-bandwidth connections with virtual concatenation offers significant improvement. The stringent time-slot alignment and contiguity constraints imposed by contiguous concatenation are further compounded by the constraints imposed by the ring interworking architecture, and virtual concatenation allows capacity to be used more efficiently.
    IEEE Journal on Selected Areas in Communications 05/2008; · 3.12 Impact Factor
  • IEEE Journal on Selected Areas in Communications. 01/2008; 26:36-46.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Optical burst transport networks employ burst transmission in WDM ring architectures and are promising candidates for MANs. We investigate QoS differentiation in OBT, and compare its performance to IEEE 802.17 resilient packet ring (RPR) standard.
    Optical Fiber Communication and the National Fiber Optic Engineers Conference, 2007. OFC/NFOEC 2007. Conference on; 04/2007
  • [Show abstract] [Hide abstract]
    ABSTRACT: We present a new approach to provision connections in ultra-long-haul optical networks with physical impairments. Our cross-layer approach finds paths satisfying impairment constraints while taking into account regenerators (3R) present in the network.
    03/2007;
  • [Show abstract] [Hide abstract]
    ABSTRACT: The optical burst transport network is a novel WDM ring network architecture and protocol. In this paper, we investigate network protection of OBT network. The result shows fast link restoration at the OBT ring network.
    03/2007;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We propose a sublambda traffic-grooming scheme on wavelength-division-multiplexing ring networks, named optical burst transport. The network protocol and architecture are designed to support dynamic bandwidth allocation, which is more reasonable for bursty data traffic. To verify our network protocol and architecture, we build a testbed which supports burst-mode transmission. Also, we transmit streaming video over Ethernet as an application
    Journal of Lightwave Technology 02/2007; · 2.56 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Optical Burst Transport network is a novel WDM ring architecture for Metropolitan Area Networks (MAN). It leverages the advantages of optical burst switching and WDM rings, while using a token-based medium access scheme. In this paper, we investigate protection together with spatial reuse property. Specifically we show how protection in OBT can be different from conventional protection and propose three algorithms for implementing a fast and low implementation cost, unidirectional 1:1 protection scheme. We analyzed the performance of these schemes via simulation and found an optimum algorithm for minimizing data loss and maximizing data delivery during the fault.
    Broadband Communications, Networks and Systems, 2006. BROADNETS 2006. 3rd International Conference on; 11/2006
  • [Show abstract] [Hide abstract]
    ABSTRACT: Optical burst transport (OBT), a novel WDM ring network, is a promising contender for the new metropolitan area network. In this paper, we investigate the spatial reuse property of the OBT, which is able to significantly improve the network performance.
    Optical Fiber Communication Conference, 2006 and the 2006 National Fiber Optic Engineers Conference. OFC 2006; 04/2006
  • [Show abstract] [Hide abstract]
    ABSTRACT: We present a new approach to provision connections in a network of dual-node interconnected rings. Our approach satisfies the unique constraints imposed by SONET/SDH standards and is very useful for reducing link capacity fragmentation.
    Optical Fiber Communication Conference, 2006 and the 2006 National Fiber Optic Engineers Conference. OFC 2006; 04/2006
  • [Show abstract] [Hide abstract]
    ABSTRACT: A sublambda traffic-grooming scheme on wavelength-division-multiplexed (WDM) rings, which is called optical burst transport (OBT), is proposed. The network protocol and architecture allow increased flexibility to tailor the transport network behavior for efficient delivery of bursty data traffic. Using different network parameters, its performance is analyzed via simulation, and the implementation issues including the media-access-control (MAC) protocol, tunable-filter controller, and burst-mode receiver are addressed. Finally, the feasibility of the OBT with an experimental testbed built by the authors is demonstrated and a streaming-video application is used to present its overall functionality.
    Journal of Lightwave Technology 02/2006; 24(1):44- 53. · 2.56 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Applications that require periodic optical connectivity may be serviced by scheduled lightpaths. Many applications are flexible about when exactly the scheduled lightpaths should occur. Lightpath service providers can exploit this flexibility to schedule connections for better utilization of resources, and presumably lower prices for clients. To find the relationship between network resources and time flexibility, a simple WDM link and a leaky bucket traffic model are considered. The network resources, and in particular the required number of wavelengths W, are shown to be a function of the traffic parameters and the time flexibility. For random traffic, simulations are used to measure the sensitivity of W with time flexibility.
    Optical Switching and Networking. 01/2006;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a 2.5 Gbps OBS network testbed named Optical Burst Transport (OBT). OBT combines a reliable control channel with a tightly controlled high speed burst mode transmission. The result is verified by burst mode BER test.
    01/2006;
  • [Show abstract] [Hide abstract]
    ABSTRACT: For WDM rings, we propose a sub-lambda traffic grooming scheme, which we term optical burst transport (OBT). To demonstrate its scalability and performance, we investigate the operational issues, and discuss an OBT prototype implementation.
    Optical Fiber Communication Conference, 2005. Technical Digest. OFC/NFOEC; 04/2005
  • Richard Rabbat, Ching-Fong Su
    [Show abstract] [Hide abstract]
    ABSTRACT: © 2005 Optical Society of America
    03/2005;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Radio Frequency Identification (RFID) and sensor networks are both wireless technologies that provide limitless future potentials. While the industry has witnessed rapid growth in developing and applying RFID technology, and the network research community has devoted tremendous efforts in sensor networks, these two communities would benefit greatly by learning from each other. In pursuing this effect, a project utilizing and integrating both technologies is described. The goal is to build an in-home elder healthcare system that monitors patients' medication in take. This would help addressing the challenge of a growing aging population.
    01/2005;
  • [Show abstract] [Hide abstract]
    ABSTRACT: One major challenge in sensor networks is to maximize network life under the constraint of extremely limited power supply. Thus, an important design issue of routing and data-gathering protocols is minimizing energy. This paper investigates the energy efficiency of two data gathering protocols, based on distributed versions of Shortest Path Tree (SPT) and Maximum Leaf Tree (MLT) algorithms [1]. The two have been extended to be dynamic by applying localized tree-reconstruction mechanism [2] to handle joining and leaving (death) of sensor nodes. Accurate energy consumption has been carefully modeled for both leaf-nodes and intermediate nodes, when sending and receiving data. Performance is evaluated through detailed simulation, including exchange of control messages among sensor nodes. Simulation results have shown that SPT, due to its simplicity and smaller number of control messages, achieves better energy efficiency and less delay in tree constructions, data transmissions, and dynamic tree reconstructions.
    Proceedings of the Twenty-Fourth Annual ACM Symposium on Principles of Distributed Computing, PODC 2005, Las Vegas, NV, USA, July 17-20, 2005; 01/2005
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper investigates the effectiveness of data gathering protocols for in-body biomedical sensor networks. We studied the performance of representatives from each of three major protocol categories: (1) low energy adaptive clustering hierarchy (LEACH), a cluster-based protocol, (2) power efficient gathering for sensory information systems (PEGASIS), a chain-based protocol, and (3) hybrid indirect transmissions (HIT), a hybrid of chains and clusters. First, the ability of each protocol to perform in-network source separation was judged. We consider a human-machine interaction application in which implanted bio-sensors communicate motor unit actions of human muscles to a remote computer. Motor unit action potentials (MUAPs) were modeled, and source separation and recovery at each sensor was simulated. We compare the performance of HIT and LEACH in terms of signal distortion ratios and the energy costs of fusion and communication. Second, we report on the efficiency of each protocol for in-body data collection, using Gupta et al's propagation loss model for biomedical applications (PMBA) - an accurate model of power loss due to signal absorption by the human body. We investigate the effectiveness of HIT, LEACH, and PEGASIS under this model, and compare their performance in terms of energy efficiency and network lifetime
    Global Telecommunications Conference, 2005. GLOBECOM '05. IEEE; 01/2005
  • Source
    Galen H. Sasaki, Ching-fong Su, David Blight
    [Show abstract] [Hide abstract]
    ABSTRACT: A problem of survivable layout of an IP network topology on a wavelength division multiplexed network is considered. Simple layout algorithms are given that have low time complexities. The algorithms are variations of a basic algorithm, that lays out IP links as lightpaths sequentially according to some order and with respect to link costs. Simulations show that the ordering and link costs can significantly affect the performance of the algorithm. 1.
    07/2001;
  • Source
    Galen H Sasaki, Ching-Fong Su
    [Show abstract] [Hide abstract]
    ABSTRACT: The design of a survivable IP network is considered where the IP links are realized by subscribing to lightpath services from a WDM network. Lightpath services can be protected or unprotected. The survivability requirement for the IP network is that it remains connected after any fault in the WDM network. The dual-homed lightpath service is another protection grade that is also considered. It is shown that this service can reduce costs significantly.

Publication Stats

223 Citations
10.25 Total Impact Points

Institutions

  • 2006
    • University of California, Davis
      • Department of Computer Science
      Davis, CA, United States
  • 2005
    • Stanford University
      • Photonics and Networking Research Laboratory
      Palo Alto, CA, United States
    • San Jose State University
      • Department of Computer Science
      San Jose, CA, United States