Multi-MetaRing fairness control in a WDM folded-bus architecture

The paper deals with fairness issues in a slotted, single-hop, WDM (Wavelength Division Multiplexing) optical architecture, based on a folded bus topology, previously proposed as a broadband access system or as a metro network. The peculiar fairness problem arising in this folded bus based architecture is addressed and an extension of the MetaRing protocol to the WDM scenario, named Multi-MetaRing, is proposed. Feasible Multi-MetaRing strategies are defined and analyzed. Both fair access and high aggregate network throughput can be achieved with a low complexity distributed access protocol by properly handling node access through all WDM channel

Queueing and Stability Analysis of Buffered CSMA/CD Local Networks.

This dissertation develops a joint probability generating function for the message quene lengths in a slotted p-persistent CSMA/CD (Carrier-Sense Multiple-Access with Collision Detection) system with a finite population of buffered users. Each user is assumed to have an independent and identical process of packet generation and an infinite buffer for storing outstanding packets. A closed form formula is obtained for the generating function in case of a two user system. Analytic formulas for the stability condition of a p-persistent CSMA/CD system are derived using the generating function. The range of the transmission probability p that leads to stability is examined through numerical analysis over a wide variety of the user\u27s communication demand, the packet length distribution, the number of users on the network, and the time to detect and abort collided packets

Simulation and analytical performance studies of generic atm switch fabrics.

As technology improves exciting new services such as video phone become possible and economically viable but their deployment is hampered by the inability of the present networks to carry them. The long term vision is to have a single network able to carry all present and future services. Asynchronous Transfer Mode, ATM, is the versatile new packet -based switching and multiplexing technique proposed for the single network. Interest in ATM is currently high as both industrial and academic institutions strive to understand more about the technique. Using both simulation and analysis, this research has investigated how the performance of ATM switches is affected by architectural variations in the switch fabric design and how the stochastic nature of ATM affects the timing of constant bit rate services. As a result the research has contributed new ATM switch performance data, a general purpose ATM switch simulator and analytic models that further research may utilise and has uncovered a significant timing problem of the ATM technique. The thesis will also be of interest and assistance to anyone planning on using simulation as a research tool to model an ATM switch

Exact analysis of single-wavelength optical buffers with feedback markov fluid queues

Optical buffering via fiber delay lines is used for contention resolution in optical packet and optical burst switching nodes. This article addresses the problem of exactly finding the blocking probabilities in an asynchronous single-wavelength optical buffer. Packet lengths are assumed to be variable and modeled by phase-type distributions, whereas the packet arrival process is modeled by a Markovian arrival process that can capture autocorrelations in interarrival times. The exact solution is based on the theory of feedback fluid queues for which we propose numerically efficient and stable algorithms. We not only find the packet blocking probabilities but also the entire distribution of the unfinished work in this system from which all performance measures of interest can be derived. © 2009 Optical Society of America

On-board B-ISDN fast packet switching architectures. Phase 1: Study

The broadband integrate services digital network (B-ISDN) is an emerging telecommunications technology that will meet most of the telecommunications networking needs in the mid-1990's to early next century. The satellite-based system is well positioned for providing B-ISDN service with its inherent capabilities of point-to-multipoint and broadcast transmission, virtually unlimited connectivity between any two points within a beam coverage, short deployment time of communications facility, flexible and dynamic reallocation of space segment capacity, and distance insensitive cost. On-board processing satellites, particularly in a multiple spot beam environment, will provide enhanced connectivity, better performance, optimized access and transmission link design, and lower user service cost. The following are described: the user and network aspects of broadband services; the current development status in broadband services; various satellite network architectures including system design issues; and various fast packet switch architectures and their detail designs

Aeronautical Engineering: A continuing bibliography, supplement 120

This bibliography contains abstracts for 297 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1980