Abstract: : Analysis of network reliability is important in computer, communication, power and various other networks. Components of a particular network may be subject to random failure and the network may or may not continue to function after some of its components have failed. We wish, as efficiently as possible, to determine the probability that the network is functional. The purpose of this thesis is to develop new reduction techniques for computing network reliability and to show how computational complexity can be decreased by using these techniques. The network model which is used to this work may be thought of as a communication network with duplex communication links connecting various transceiving stations. Communication can pass in both directions along a link if the link is working; no communication in either direction is possible if the link has failed. The network is considered functional if a specified set of the transceiving stations is able to communicate. (Author)

Abstract: The Packet-Switched Computer Communication Networks have now been well-established regarding their use for data communication, computer-hardware and software resource sharing, database access facility, interactive computing and many other uses. Recently, the study of cost-effective structure of computer networks is in great progress. The success has been very well achieved in the design of terrestrial networks in which a data or message can be transmitted with minimum possible delay. In this paper, authors survey some of the network design algorithms and procedures. Flow Deviation and Cut-Saturation algorithms have been extended for the design of a mixed-media network which contains both the terrestrial and satellite links. The study shows that the incorporation of a high capacity satellite channel increases the network throughout and reduces the average packet delay at minimum cost and thereby improves the performance of the network.

Abstract: Wyle Data Services is a California-based company which operates a computer communications network for several clients. Using transaction count and message size data provided by Wyle, a cost-effectiveness exercise is performed to investigate alternative network architectures and capabilities. The foundation of the network analysis uses the steady slate queueing delay formulas for a single-server queue. A cost/delay analysis shows that considerable savings may be accrued with minimal damage to delay times from changing network processing speeds across the communications links.

Abstract: The apparatus, networks, systems and method of the present invention are predicated upon the following concept. A multiprocessor system intercouples the processors (14, 16, 18-23) with an active logic network (50a) having a plurality of priority determining nodes. Messages applied concurrently to the network (50a) in groups are sorted, using the data content of the messages. to a single or common priority message which is distributed to all the processors (14, 16, 18-23) with a predetermined total network delay time. Losing messages are again retired concurrently in groups at a later time. Message routing is determined by local acceptance or rejection of messages at the processors (14, 16. 18-23), based upon destination data in the messages. All messages occupy places in a coherent priority scheme and are transferred in contending groups with prioritisation on the network (50a). Using data. status, control and response messages. and different multiprocessor modes, the system is particularly suited for configuration in a relational data base machine having capability for maintaining an extended data base and handling complex quenes.

Abstract: Results from a digital computer simulation of a network of approximately 50 nodes, typifying a spread spectrum time division multiple access (TDMA) system such as the Joint Tactical Information Distribution System (JTIDS), in a ground environment, are presented, and discussed. The results apply to initialization performance of network synchronization. The results provide an insight into network management tradeoffs which may be made with respect to: a) method of network synchronization, b) system capacity needed for network synchronization, and c) degree of network connectivity. The results provide qualitative as well as quantitative assessment of the impact of changing any of the above network management variables when the others remain fixed at various operating points. Since a wide range of time delays, typically from, few to many minutes may be incurred, it is concluded that network management techniques may be optimized to meet the initialization performance requirements of a given network. Such optimizations, however, depend upon specific implementations of the network synchronization process, the dynamics of the network nodes and the environment (electromagnetic, terrain, and weather) affecting their connectivity.

Abstract: Diverse network application requirements bring about local networks of various size, degree of complexity and architecture. The purpose of this paper is to present a network protocol layer which is used to provide a homogeneous operating environment and to ensure the availability of network resources. The network layer process probes the underlying local network to discover its properties and then adapts to changing network conditions. The principle contribution of this paper is to generalize properties of diverse local networks which can be measured. This is important when considering maintenance and service of various communication links. Three type of links are point-to-point links, multi-drop, loop or switched links and multi-access contention data buses. A prototype network is used to show a complexity improvement in the number of measurement probes required using a multi-access contention bus. Examples of measurement techniques and network adaption are presented.