Institute for Systems Research

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Subject: search.filters.subject.ATM networks

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    A Methodology for Modeling, Performance Analysis, and Control of ATM Networks with Multi-Media Traffic
    (1997) Chou, Chih-Hsien; Chan, Wai-Chung; Geraniotis, Evaggelos A.; ISR; CSHCN
    In this paper we review recent advances in developing a methodology for traffic modeling, performance evaluation, and control of ATM networks that can be used to support several aspects of Task 4.3 of the ATIRP project. Our methodology includes model matching and validation for multi-media traffic, analytical approximation techniques for time-efficient and accurate evaluation of end-to-end as well as intermediate node performance measures of multi-hop networks, and optimization of control (resource allocation) schemes.
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    Hybrid Network Management
    (1996) Baras, John S.; Ball, Michael O.; Karne, Ramesh K.; Whitefield, David; Kelley, Stephen; Jang, Kap D.; Plaisant, Catherine; Roussopoulos, Nick; Stathatos, Kostas; Vakhutinsky, Andrrew; Valluri, Jaibharat; ISR; CSHCN
    We describe our collaborative efforts towards the design and implementation of a next generation integrated network management system for hybrid network (INMS/HN). We describe the overall software architecture of the system at its current stage of development. This network management system if specifically designed to address issues relevant for complex heterogeneous networks consisting of seamlessly interoperable terrestrial and satellite networks. Network management systems are a key element for interoperability in such networks. We describe the integration of configuration management and performance management. The next step in this integration is fault management. In particular we describe the object model, issues of the Graphical User Interface (GUI), browsing tools and performance data graphical widget displays, management, information database (MIB) organization issues. Several components of the system are being commercialized by Hughes Networks Systems.
      A revised version of this technical report has been published in
      Proceedings of the AIAA: 16th International Communications Satellite Systems Conference and Exhibit, Part 1, pp. 490-500, Washington, D.C., February 25- 29, 1996.
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    Call Rerouting in an ATM Environment
    (1995) Ball, Michael O.; Vakhutinsky, A.; ISR; CSHCN
    ATM networks must handle multiclass traffic with diverse quality of service requirements. We consider a multiclass routing model in which routes are calculated in a distributed fashion by the call origination nodes. Within this general context, we address the problem of rerouting a set of previously routed calls to avoid a failed link. Under the approach we propose, a single node executes an aggregate global rerouting of all affected calls and then converts the set of aggregate routes into an allocation of bandwidth on each link to call origination nodes for the purpose of rerouting. The bandwidth allocation is distributed to each origination node, which in turn then calculates routes for the individual calls. The problem faced by each call origination node is a variant of the so-called bandwidth packing problem. We develop and analyze an approximate algorithm for solving the problem in the specific context that arises in our setting.
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    Dynamic Routing of Voice/Data-Integrated and ATM-based Hybrid Networks
    (1994) Chen, Shihwei; Baras, John S.; ISR; CSHCN
    A hybrid network consisting of a satellite network and a terrestrial network will increase the overall network efficiency considerably by using all available resources and media. This dissertation considers dynamic routing in both voice/data- integrated and ATM-based hybrid networks.

    Optimal dynamic routing in such mixed-media (voice/data-integrated) networks under Markov Queueing Modeling has been developed and solved. Routing problems in such a domain usually lead to a weighted-sum minimization or a minimax problem. A new approach to obtain the trade-off curve of multiple-objective optimization is outlined. With a numerical optimization package, we can plot the trade-off curve exactly.

    Both a centralized and a distributed implementation of this problem with Kalman filter techniques and Equilibrium Programming are presented. These techniques allow the control of a large and stochastic network by communicating with a group of communication managers in a parallel manner.

    For ATM- based hybrid networks, an economic model with the objective of maximizing the ﲳocial welfare has been adapted. This model can be developed into a form of a two-player game. With a little modification and adaptation, we will be able to solve the joint problem of access control and routing in both the weighted-sum formulation and the economic formulation.

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    Hierarchical Coding of High Data Rate Video for Asynchronous Transfer Mode Networks
    (1994) Sivarajan, R.; Narayan, P.; ISR; CSHCN
    High data rate video is an integral part of high-quality multimedia for broadband networks. Owing to the high rate, compression of video information is required for an efficient use of network bandwidth. A hierarchical DCT-based video codec is examined that prioritizes and compresses high data rate video for transmission over ATM networks.

    The video codec utilizes intraframe coding by independently processing each frame of the video sequence. The lossless compression part consists of run length coding to exploit zero values in the high frequency DCT coefficients and variable length coding (VLC) to further reduce the bit rate. Three compression schemes are examined: adaptive Huffman, arithmetic coding, and Lempel-Ziv-Welch coding. For the model-based compression algorithms, we study several models to characterize the input bit stream to the VLC: memoryless, and Markov with either fixed orders or orders determined by an order estimator. For the three VLCs in the codec, the best performance was obtained from a combination of a memoryless Huffman codec and two first-order Huffman codecs. Many of the models incorporating memory, performed poorly due to the small size of the input files.

    Due to the VLC, the output rate of the system is variable; however, since intraframe coding is utilized, rate variations are small. In order to fully utilize available bandwidth, we examine the rate control problem of converting the codec from a variable rate system to a fixed rate system. The rate control problem is formulated as one of constrained minimization, and analyzed for optimal solutions. Algorithms are presented for optimal rate control.