Exploring a new Markov chain model for multiqueue systems.

Traditionally, Markov models have been used to study multiserver systems using exhaustive or gated service. In addition, exhaustive-limited and gate-limited models have also been used in communication systems to reduce overall latency. Recently the authors have proposed a new Markov Chain approach to study gate-limited service. Multiqueue systems such as polling systems, in which the server serves various queues have also been extensively studied but as a separate branch of queueing theory. This paper proposes to describe multiqueue systems in terms of a new Markov Chain called the Zero-Server Markov Chain (ZSMC). The model is used to derive a formula for the waiting times in an exhaustive polling system. An intuitive result is obtained and this is used to develop an appoximate method which works well over normal operational ranges

Spacelab system analysis: The modified free access protocol: An access protocol for communication systems with periodic and Poisson traffic

The protocol definition and terminal hardware for the modified free access protocol, a communications protocol similar to Ethernet, are developed. A MFA protocol simulator and a CSMA/CD math model are also developed. The protocol is tailored to communication systems where the total traffic may be divided into scheduled traffic and Poisson traffic. The scheduled traffic should occur on a periodic basis but may occur after a given event such as a request for data from a large number of stations. The Poisson traffic will include alarms and other random traffic. The purpose of the protocol is to guarantee that scheduled packets will be delivered without collision. This is required in many control and data collection systems. The protocol uses standard Ethernet hardware and software requiring minimum modifications to an existing system. The modification to the protocol only affects the Ethernet transmission privileges and does not effect the Ethernet receiver

Performance investigation of a document retrieval system on a voice-data integrated token ring local area network

Lately, the interest in integration of voice and data on local computer networks has been on the rise. Subsequently, much research has been devoted to exploring various techniques that are implementable using the existing standards. This research has focused on the design issues in implementing a document retrieval system on a token ring network. The presence of voice and data traffic on the network complicates the protocol design further. The performance requirements of these traffic types are different. Voice creates stream traffic on a network, where as data traffic is bursty. Voice packets need to be delivered within a limited time interval, whereas the data emphasizes on error-free delivery. The necessity and the technological feasibility with off-the-shelf components has prompted this study. A possible solution is discussed in this dissertation;During the course of this research, due to the time consuming nature of simulation experiments, a need for efficient simulation techniques was felt. Thus, as a byproduct of the initial goal of protocol design, an approximate version of the regenerative simulation was developed and is discussed here in detail;Lastly, modeling difficulties encountered in forming an analytical model are listed and a performance analysis of the subsystems of interest is given

Evaluación de los protocolos de acceso al medio CSMA/CD (acceso multiple con escuha de canal y detección de colisión) y paso de testigo, en redes locales con topologia bus

El objetivo de la tesis es crear una herramienta de evaluación de prestaciones de redes de área local a nivel MAC para los mecanismos de acceso múltiple aleatorio y con control mediante paso de testigo. La metodología de evaluación se basa en la obtención de modelos analíticos y de simulación y su contratación con resultados experimentales. En acceso aleatorio se aportan modelos analíticos de características caudal-retardo explicitas para los protocolos CSMA/CD en función del concepto de persistencia del acceso.Del mecanismo de paso de testigo se estudia la dependencia estadística introducida por el mecanismo de acceso para los casos de estación sin almacenamiento y almacenamiento infinito

Some aspects of a code division multiple access local area network

Not Availabl

Congestion control in interconnected computer networks

Ankara : The Department of Computer Engineering and Information Sciences and the Institute of Engineering and Sciences of Bilkent Univ. , 1988.Thesis (Master's) -- Bilkent University, 1988.Includes bibliographical references leaves 62-65.A computer network has a collection of resources shared by multiple users. The capacity of the resources is limited, and if the user demands exceed the capacity, the network becomes ’congested’. The congestion causes a degradation in system performance. In interconnected networks there are two classes of traffic within a network. One class is the local traffic that is generated and transmitted within the network. The other class is the internetwork traffic transmitted to or from other networks. In this thesis, the effect of internetwork traffic on the performance of a network is investigated. Computer simulation of an interconnected network model is provided in order to evaluate the effectiveness of a window-based congestion control mechanism on preventing congestion in gateways and in attached networks caused by the overload of internetwork traffic. Also two dynamic window congestion control algorithms are provided and studied. These algorithms provide further control to window mechanism by adjusting the window size in accordance with the availability of the network resources at the destination. Dynamic algorithms are evaluated comparing them with static window control.Ulusoy, ÖzgürM.S