Traffic engineering for hybrid optical and electronic switching networks

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2001.Includes bibliographical references (leaves 115-118).Quality of Service (QoS) over the Internet is receiving increasing attention with growing need to support upcoming multimedia applications. Many of these applications including real-time video and audio traffic require a more robust architecture that can deliver faster response times to the service requested. The Internet infrastructure currently supports a best effort service paradigm that does not differentiate between different flows. To support future applications, this thesis proposes an approach to solve the QoS needs of the traffic the network carries, by reserving bandwidth, reducing delay and increasing availability. The issues addressed in this dissertation are two-fold, leading to a better network switching architecture to support the differing needs of high-priority and low-priority voice and data traffic. Link failure is a problem that seriously affects QoS-enabled routing. The thesis addresses this challenge by designing a mechanism to restore network connectivity and reach optimality in the event of failures, while using a variant of link-state routing protocols. The thesis applies insights from the first problem to design an improved switching/routing architecture that services the needs of both low-priority and highpriority traffic. It achieves this architecture by making intelligent traffic admission and transport and assigning that traffic to packet switching or circuit switching hardware, in this case, an IP router and an all-optical cross-connect combined in a single hybrid switch design.by Richard Rizkallah Rabbat.Ph.D

Models for planning the evolution of local telecommunication networks

Includes bibliographical references.Research initiated through a grant from GTE Laboratories, Inc. Supported in part by an AT&T research award. Supported in part by the Systems Theory and Operations Research Program of the National Science Foundation. ECS-8316224 Supported in part by ONR. N0000-14-86-0689A. Balakrishnan ... [et al.]

Models for planning the evolution of local telecommunication networks

Includes bibliographical references.Research initiated through a grant from GTE Laboratories, Inc. Supported in part by an AT&T research award. Supported in part by the Systems Theory and Operations Research Program of the National Science Foundation. ECS-8316224 Supported in part by ONR. N0000-14-86-0689A. Balakrishnan ... [et al.]

Routing and wavelength assignment in WDM optical networks

In this thesis, we focus on the routing and wavelength assignment problems in WDM all-optical networks. Since the general problem is difficult (NP-complete), we classify the problem into several models with different formulations. Our objectives are to analyze some subclasses of routing and wavelength assignment problems; to understand their special properties; to estimate algorithm bounds and performance; and, to design efficient heuristic algorithms. These goals are important because results that follow can help engineers design efficient network topologies and protocols, and eventually provide end-users with cost-effective high bandwidth.;We first study the off-line wavelength assignment problem in single fiber ring and tree networks: an optimal algorithm and an exact characterization of the optimal solution is given for binary and ternary tree topologies; an open problem based on path length restriction on trees, mentioned in the literature, is solved; and bounds are given for path-length and covering restrictions of the problem on ring networks. Then we consider multifiber optical networks, in which each link has several parallel fibers. We extend a stochastic model from the single-fiber case to the multifiber case and show that multifiber links can improve performance significantly. For some specific networks, such as ring and tree networks, we obtain some performance bounds. The bounds support our multifiber stochastic model conclusion. For practical importance, we also consider a WDM optical ring network architecture configuration problem as well as cost-effectiveness. We propose several WDM ring networks with limited fiber switching and limited wavelength conversion and these networks achieve almost optimal wavelength utilization. Attacking resource allocation within an WDM optical ring network to reduce overall equipment cost, we design a new algorithm and our simulation results indicate improvement of about 25%. This thesis also includes a new coloring problem partition-coloring and its applications.;In summary, the contributions in this thesis include several heuristic algorithms and theoretical tight upper bounds for both single fiber and multifiber all-optical networks. In particular, for ring networks we have proposed several network architectures to improve wavelength utilization and devised a new algorithm that combines routing and wavelength assignment to reduce hardware costs

Performance analysis of a proposed hybrid optical network

This dissertation discusses a novel Hybrid Optical Network (HON) that can provide service differentiation based on traffic characteristics (i.e., packet, burst, and long-lived flow) with QoS guarantee not only in network layer, but also in physical layer. The DHON consists of sophisticated edge-nodes, which can classify, monitor, and dynamically adjust optical channels in the core layer as traffic variation. The edge nodes aggregate traffic, identifying end-to-end delay by ingress queuing delay or burst timeout. The network can estimate number of channels by arriving traffic intensity and distribution with estimated upper-bound delay. The core layer employs two parallel optical switches (OCS, OBS) in the same platform. Thanks to the overflow system, the proposed network enhances utilization with fewer long distance premium channels. The premium channel can quickly handle burst traffic without new channel assignment. With less overprovisioning capacity design, the premium channel enhances utilization and decrease number of costly premium channels. This research also proposes mathematic models to represent particular DHON channels (i.e., circuit, packet, and burst). We employ method of moments based on overflow theory to forecast irregular traffic pattern from circuit-based channel (i.e., M/M/c/c) to overflow channel, in which G/G/1 model based on Ph/Ph/1 matrix can represent the overflow channel. Moreover, secondary channel supports packet-based traffic over wavelength channel with two service classes: Class I based on delay sensitive traffic (i.e., long flow) and Class II for non-delay sensitive traffic (e.g., best effort). In addition, mixture of traffic in the wavelength channels is investigated based on M/G/1 and M/G/2 with specific service time distribution for particular class. Finally, we show our DHON based on (O-O-O) switching paradigm has improved the performance over typical (O-E-O) switching network architecture based on NSF topology

Annual General Assembly of the International Association of Maritime Universities

978-84-947311-7-

Bodily sensation in contemporary extreme horror film

Bodily Sensation in Contemporary Extreme Horror Film provides a theory of horror film spectatorship rooted in the physiology of the viewer. In a novel contribution to the field of film studies research, it seeks to integrate contemporary scientific theories of mind with psychological paradigms of film interpretation. Proceeding from a connectionist model of brain function that proposes psychological processes are underpinned by neurology, this thesis contends that whilst conscious engagement with film often appears to be driven by psychosocial conditions – including cultural influence, gender dynamics and social situation – it is physiology and bodily sensation that provide the infrastructure upon which this superstructure rests. Drawing upon the philosophical works of George Lakoff, Mark Johnson and Alain Berthoz, the argument concentrates upon explicating the specific bodily sensations and experiences that contribute to the creation of implicit structures of understanding, or embodied schemata, that we apply to the world round us. Integrating philosophy with contemporary neurological research in the spheres of cognition and neurocinematics, a number of correspondences are drawn between physiological states and the concomitant psychological states often perceived to arise simultaneously alongside them. The thesis offers detailed analysis of a selection of extreme horror films that, it is contended, conscientiously incorporate the body of the viewer in the process of spectatorship through manipulation of visual, auditory, vestibular, gustatory and nociceptive sensory stimulations, simulations and the embodied schemata that arise from everyday physiological experience. The phenomenological film criticism of Vivian Sobchack and Laura U. Marks is adopted and expanded upon in order to suggest that the organicity of the human body guides and structures the psychosocial engagement with, and interpretation of, contemporary extreme horror film. This project thus exposes the body as the architectural foundation upon which conscious interaction with film texts occurs