The 800-Mb HIPPI data channel has been defined by ANSI X3T9.3 for the purpose of connecting supercomputers, large-scale peripheral systems, high-performance workstations, and network layer routers. In addition to being a capable point-to-point medium, the HIPPI standard permits traffic to be routed through a series of intermediate crossbar switches, similar to telephone switching technology. The presence of crossbar switches requires a technique to control the selection of intermediate trunks between systems. An implementation of link state routing algorithms that can be practically used in this environment is described. The algorithms used take advantage of the fact that paths cannot be reentered as data progress from source to destination and are not directly applicable to many upcoming switching technologies such as ATM. However, they are applicable to such items as automated video and PBX switching systems, where peer-to-peer connectivity between switching systems is preferred over a highly administered hierarchy of switches.>

Standards compliant FDDI interfaces have been available for between one and two years. As measured by the installed base, the authors believe that the technology is being accepted and deployed, with the number of nodes per network growing rapidly. In this paper, based on their experiences as a vendor of FDDI equipment, they first briefly recount certain features of FDDI. Next, they examine the reality of FDDI based upon their experiences with over 100 installations, including the fiber types used, ring sizes (diameters and number of nodes), use of concentrators, bridging and routing uses, costs, and interoperability in multi-vendor situations. Next, they examine measured performance gathered from several installations with supercomputer, mainframe, workstation, and bridge/router nodes, and examine the factors affecting performance. They examine FDDI futures, including FDDI-II and follow-on FDDI options.>

An examination is made of the rationale behind the need for ever higher networking speeds, the technological developments that are making them possible on a commercial basis, the directions being taken in their development, and the issues surrounding their construction and use. Roadblocks to providing high-speed networks are discussed. The impact of standardization efforts on development efforts is considered, focusing on the HSC channels, the fiber distributed data interface (FDDI), and metropolitan- and wide-area networks (MANs and WANs). Possibilities for future technologies and architectures are described.>

We introduce a method for broadcasting control information (such as the information essential for correct operation of SOSAM and other scheduling-function-based access protocols) in stationary networks with "hidden" nodes (multihop networks). Control information is transmitted as short bit- parallel control messages on a separate control channel whose capacity is shared among the bits of a control message using code division multiplexing (CDM). The CDM method takes advantage of spread-spectrum signal properties that allow, in particular, high accuracy of time-of-arrival measurement and relatively easy separation of multipath copies of a control message.

We describe an adaptive multiaccess channel protocol for use in radio networks with an arbitrary distribution of stationary hidden nodes, which provides the nodes with controlled, collision-free access to the channel. The protocol can be considered to belong to the BRAM [5] protocol family, but differs in significant ways from BRAM. In this paper we describe the tenets of the protocol, then develop the protocol, and finally develop analytic expressions for its expected throughput and delay performance. Given these delay-throughput expressions, we show how protocol "delay" optimization can be achieved by dynamic adjustment of a protocol parameter as the network traffic load changes.

In this paper we consider HYPERchannel adapter local networks, the most oft used approach to realizing very high speed (50 Mbit/s transmission rates) local networks. We first describe the channel selection, channel access, and virtual circuit protocols used in HYPERchannel networks. Next, to characterize adapter network performance we present and interpret a series of measurements obtained from an adapter testbed network. From these measurements we are able to characterize the effects of various adapter protocol parameter settings, and hence recommend settings to avoid certain possible anomalous performance behavior and achieve desired effects.

We present a theoretical description and analysis of a collision-free channel-access protocol for a shared channel with "mobile" nodes that are all within range and in line-of-sight of each other, in arbitrarily changing spatial (one-, two-or three-dimensional) configurations.

Abstract We present a language for specifying and documenting discrete event simulation models, designed to facilitate communication during model design, implementation and maintenance. The systems from which models are developed are viewed as collections of communicating elements. Each element is specified separately in a module consisting of attributes, axioms and a scenario. The model's specification consists of each model element's specification and some systemwide attributes and axioms. Synchronization among model elements (model dynamics) is specified within the model elements rather than globally. Each language control structure has a monitor associated with it. Appropriate changes are made in the model's state in response to a monitor's sensing an attribute change. The language contains a library of specifications for common simulation model entities such as the priority queue. The syntax and semantics of the language are presented through examples. Examples of a library specification and a model specification are included.

In this paper, we first present the broadcast recognizing access method (BRAM), an access protocol suitable for regulating internode communication in either a radio or (coaxial or fiber) cable based communication system. The method avoids collisions, imposes negligible computational requirements on the nodes attempting to transmit, and is fair in the sense that no node will be indefinitely prevented from transmitting. Next we introduce parametric BRAM which attempts to balance the length of inserted channel idle periods, resulting from scheduling effects, against the probability of allowed message collisions. We show that parametric BRAM can be used to realize a method which balances inserted channel idle time against the probability of message collision to yield enhanced performance. For high message loads, parametric BRAM converges to BRAM, while for low and medium loadings it yields throughputs in excess of BRAM, and other methods. Both BRAM and parametric BRAM are discussed under the assumption of homogeneous message arrival rates at the nodes. We conclude by showing how the parametric BRAM can be applied when the nodes operate with heterogeneous or mixed message arrival rates.

This paper discusses the issues involved in building a real-time control system using a message-directed distributed architecture. We begin with a discussion of the nature of real-time soft ware, including the viability of using hierarchical models to organize the software. Next we discuss some realistic design objectives for a distributed real-time system including fault isolation, independent module verification, context independence, decentralized control and partitioned system state. We conclude with some observations concerning the general nature of distributed system software.

This paper describes the kernel of an Executive being implemented for the Honeywell Experimental Distributed Processor (HXDP) -- a vehicle for research in distributed computers for real-time control. The kernel provides message transmission primitives for use by application programs or higher level executive functions. In the paper we describe the message transmission primitives provided by the kernel and the rationale for their selection based upon the objectives and constraints described in a companion paper.

article Free Access Share on An Efficient Algorithm for the Kolmogorov-Smirnov and Lilliefors Tests Authors: Teofilo Gonzalez Department of Computer, Information and Control Sciences, 114 Main Engineering Building, Minneapolis, MN Department of Computer, Information and Control Sciences, 114 Main Engineering Building, Minneapolis, MNView Profile , Sartaj Sahni Department of Computer, Information and Control Sciences, 114 Main Engineering Building, Minneapolis, MN Department of Computer, Information and Control Sciences, 114 Main Engineering Building, Minneapolis, MNView Profile , W. R. Franta Department of Computer, Information and Control Sciences, 114 Main Engineering Building, Minneapolis, MN Department of Computer, Information and Control Sciences, 114 Main Engineering Building, Minneapolis, MNView Profile Authors Info & Claims ACM Transactions on Mathematical SoftwareVolume 3Issue 1March 1977 pp 60–64https://doi.org/10.1145/355719.355724Published:01 March 1977Publication History 23citation2,096DownloadsMetricsTotal Citations23Total Downloads2,096Last 12 Months621Last 6 weeks49 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

As a result of the development of microcomputers, the term distributed computing has taken on new meaning. In this paper, we intend it to mean a general purpose computing system whose basic elements are microprocessors, and we are primarily concerned with the development of algorithms and the subsequent specification of software for the systems. We establish first a model for such a parallel asynchronous computing system giving particular attention to communications between microprocessors. Next, we propose a language for programs to execute on this system. Its syntax closely follows Simula, but its semantics are geared to the underlying hardware. The semantics we propose are such that we can use the programs both to investigate performance by simulation and to expound general techniques for algorithm construction for distributed systems.

In this paper attention is focused on closed multiprogrammed computer type systems. In particular, two-stage closed queueing systems are considered. The first stage can be associated with the CPU (Central Processing Unit) and the other with the I/O (Input-Output) operations. For all the models discussed.

Abstract This paper describes a system, known as LINK, which provides inter‐machine communication between like machines operating under significantly different operating systems. The methodology employed by LINK was selected from among several alternatives on the basis of effectiveness, complexity and cost.