waashk/acm huggingface dataset:
a control and management network for wireless atm systems  this paper describes the design of a control and management network (orderwire) for a mobile wireless asynchronous transfer mode (atm) network. this mobile wireless atm network is part of the rapidly deployable radio network (rdrn). the orderwire system consists of a packet radio network which overlays the mobile wireless atm network. each network element in this network uses global positioning system (gps) information to control a beamforming antenna subsystem which provides for spatial reuse. this paper also proposes a novel virtual network configuration (vnc) algorithm for predictive network configuration. a mobile atm private network--network interface (pnni) based on vnc is also discussed. finally, as a prelude to the system implementation, results of a maisie simulation of the orderwire system are discussed.  stephen f. bush sunil jagannath ricardo sanchez joseph b. evans gary j. minden k. sam shanmugan victor s. frost
performance of a joint cdma/prma protocol with heavy-tailed on/off source  the performance of a joint cdma/prma protocol with heavy-tailed on/off source has been studied. compared with the random access scheme, the prma protocol improves the system performance (such as packet loss, throughput) whether the traffic is srd or lrd. the less bursty traffic is, the greater the improvement. the buffer design should take into account knowledge about the network traffic such as the presence or absence of the noah effect in a typical source, especially of \alpha_{\mathrm{on}, the intensity of the noah effect of on-period. the smaller \alpha_{\mathrm{on} is, the smaller the buffering gain, and the more packets will be lost. lrd has impacts on the overall system performance. the noah effect, especially \alpha_{\mathrm{off}, the intensity of the noah effect of off-period, has significant impact on the overall system performance such as capacity, time delay, etc. as \alpha_{\mathrm{off} gets closer to 1, the traffic becomes more bursty, the system capacity is decreased and time delay is increased.  m. wang z. s. wang wei lu j. l. lin d. r. chen
performance analysis of a fault detection scheme in multiprocessor systems  a technique is described for detecting and diagnosing faults at the processor level in a multiprocessor system. in this method, a process is assigned whenever possible to two processors: the processor that it would normally be assigned to (primary) and an additional processor which would otherwise be idle (secondary). two strategies will be described and analyzed: one which is preemptive and another which is non-preemptive. it is shown that for moderately loaded systems, a sufficient percentage of processes can be performed redundantly using the system's spare capacity to provide a basis for fault detection and diagnosis with virtually no degradation of response time.  anton t. dahbura krishan k. sabnani william j. hery
receiver-driven layered multicast state of the art, real-time, rate-adaptive, multimedia applications adjust their transmission rate to match the available network capacity. unfortunately, this source-based rate-adaptation performs poorly in a heterogeneous multicast environment because there is no single target rate --- the conflicting bandwidth requirements of all receivers cannot be simultaneously satisfied with one transmission rate. if the burden of rate- adaption is moved from the source to the receivers, heterogeneity is accommodated. one approach to receiver-driven adaptation is to combine a layered source coding algorithm with a layered transmission system. by selectively forwarding subsets of layers at constrained network links, each user receives the best quality signal that the network can deliver. we and others have proposed that selective-forwarding be carried out using multiple ip-multicast groups where each receiver specifies its level of subscription by joining a subset of the groups. in this paper, we extend the multiple group framework with a rate-adaptation protocol called receiver-driven layered multicast, or rlm. under rlm, multicast receivers adapt to both the static heterogeneity of link bandwidths as well as dynamic variations in network capacity (i.e., congestion). we describe the rlm protocol and evaluate its performance with a preliminary simulation study that characterizes user- perceived quality by assessing loss rates over multiple time scales. for the configurations we simulated, rlm results in good throughput with transient short-term loss rates on the order of a few percent and long-term loss rates on the order of one percent. finally, we discuss our implementation of a software-based internet video codec and its integration with rlm. steven mccanne van jacobson martin vetterli
parallel processing architecture for the hitachi s-3800 shared-memory vector multiprocessor  this paper discusses the architecture of the new hitachi supercomputer series, which is capable of achieving 8 gflops in each of up to four processors. this architecture provides high-performance processing for fine-grain parallelism, and it allows efficient parallel processing even in an undedicated environment. it also features the newly- developed time-limited spin-loop synchronization, which combines spin-loop synchronization with operating system primitives, and a communication buffer (cb) which caches shared variables for synchronization, thus allowing them to be accessed faster. three new instructions take advantage of the cb in order to reduce the parallel overhead. the results of performance measurements confirm the effectiveness of the cb and the new instructions.  katsuyoshi kitai tadaaki isobe yoshikazu tanaka yoshiko tamaki masakazu fukagawa teruo tanaka yasuhiro inagami
performance evaluation of isolated and interconnected token bus local area networks  the token bus based local area network, redpuc, designed and implemented at the pontificia universidade catolica do rio de janeiro is briefly described. analytic models are presented, which allow one to obtain an approximation for the average packet delay, as well as exact upper and lower bounds for the same performance measure. a performance evaluation of interconnected local networks is also given.  daniel a. menasce leonardo lellis p. leite
connection admission control for capacity-varying networks with stochastic capacity change times  many connection-oriented networks, such as low earth orbit satellite (leos) systems and networks providing multipriority service using advance reservations, have capacities which vary over time. connection admission control (cac) policies which only use current capacity information may lead to intolerable dropping of admitted connections whenever network capacity decreases. we present the admission limit curve (alc) for capacity-varying networks with random capacity change times. we prove the alc is a constraint limiting the conditions under which any connection-stateless cac policy may admit connections and still meet dropping guarantees on an individual connection basis. the alc also leads to a lower bound on the blocking performance achievable by any connection-stateless cac policy which provides dropping guarantees to individual connections. in addition, we describe a cac policy for stochastic capacity change times which uses knowledge about future capacity changes to provide dropping guarantees on an individual connection basis and which achieves blocking performance close to the lower bound.  j. siwko i. rubin
mixing traffic in a buffered banyan network  a model of banyan networks is developed to account for their operational as well as topological characteristics. the model incorporates a description of the states of individual switching nodes and explicitly captures the interconnection patterns between stages. accordingly, the performance of a network can be evaluated via an iterative procedure. using the model, we analyzed one class of nonuniform traffic pattern referred to as "point-to- point" traffic that has particular significance to mixed voice, data, and video applications. the results obtained indicate that even a single dedicated channel (with point-to-point traffic) can significantly limit the throughput of the background uniform traffic. the paper concludes with several switch design strategies for switching point-to-point traffic using a self- routing switching network.  l. t. wu
a new model for scheduling packet radio networks  packet radio networks are modeled as arbitrary graphs by most researchers. in this paper we show that an arbitrary graph is an inaccurate model of the radio networks. this is true because there exists a large class of graphs which will not model the radio networks. radio networks can be modeled accurately by a restricted class of graphs called the planar point graphs. since the radio networks can accurately be modeled only by a restricted class of graphs, the np- completeness results for scheduling using an arbitrary graph as the model, do not correctly reflect the complexity of the problem. in this paper we study the broadcast scheduling problem using the restricted class as the model. we show that the problem remains np-complete even in this restricted domain. we give an o(n log n) algorithm when all the transceivers are located on a line.  arunabha sen mark l. huson
a vector and array multiprocessor extension of the sylvan architecture  the main intent of this paper will be the description of a multiprocessor system that uses microprogrammed hardware to support operating system primitives that contribute to its high performance vector processing capability. the system consists of nodes that communicate over a system interconnect. each node is a tripartite subsystem that consists of a host processor complex running application code, a vector co-processor and a kernel support processor that handles both operating system functions and control of the vector co-processor. the microcoded kernel processor is used to support a message based operating system that allows concurrent processes to communicate while residing in the same node or in different nodes. since the kernel processor controls the functioning of the vector co-processor as well as the management of processes (for example, context switching), the node can utilize the resources of the co-processor very effectively.  f. j. burkowski
wireless atm: an enabling technology for multimedia personal communication  an atm-based wireless network capable of supporting integrated voice, video and data services with quality-of-service (qos) control is proposed as a key element of the future distributed multimedia computing scenario. a specific architecture for "wireless atm" is described, and design issues are briefly discussed for each major functional layer of the network. the system approach is based on the incorporation of wireless channel specific medium access, data link and wireless control layers into a mobility- enhanced atm protocol stack. selected software emulation results are given for applicable medium access control (mac) and data link control (dlc) protocols. the paper concludes with a brief view of related ongoing prototyping activities aimed at demonstrating a seamless wired plus wireless multimedia networking environment.  d. raychaudhuri
delivery of time-critical messages using a multiple copy approach  reliable and timely delivery of messages between processing nodes is essential in distributed real-time systems. failure to deliver a message within its deadline usually forces the system to undertake a recovery action, which introduces some cost (or overhead) to the system. this recovery cost can be very high, especially when the recovery action fails due to lack of time or resources.  proposed in this paper is a scheme to minimize the expected cost incurred as a result of messages failing to meet their deadlines. the scheme is intended for distributed real-time systems, especially with a point-to-point interconnection topology. the goal of minimizing the expected cost is achieved by sending multiple copies of a message through disjoint routes and thus increasing the probability of successful message delivery within the deadline. however, as the number of copies increases, the message traffic on the network increases, thereby increasing the delivery time for each of the copies. there is therefore a tradeoff between the number of copies of each message and the expected cost incurred as a result of messages missing their deadlines. the number of copies of each message to be sent is determined by optimizing this tradeoff. simulation results for a hexagonal mesh and a hypercube topology indicate that the expected cost can be lowered substantially by the proposed scheme.  parameswaran ramanathan kang g. shin
netman: the design of a collaborative wearable computer system  this paper presents a wearable groupware system designed to enhance the communication and cooperation of highly mobile network technicians. it provides technicians in the field with the capabilities for real-time audio- conferencing, transmission of video images back to the office, and context- sensitive access to a shared notebook. an infrared location-tracking device allows for the automatic retrieval of notebook entries depending on the user's current location.  gerd kortuem martin bauer zary segall
pushing dependent data in clients-providers-servers systems  in a satellite and wireless networks and in advanced traffic information systems in which the up-link bandwidth is very limited, a server broadcasts data files in a round-robin manner. the data files are provided by different providers and are accessed by many clients. the providers are independent and therefore files may share information. the clients who access these files may have different patterns of access. some clients may wish to access more than one file at a time in any order, some clients may access one file out of of several files, and some clients may wish to access a second file only after accessing another file. the goal of the server is to order the files in a way that minimizes the access time of the clients given some a-priori knowledge of their access patterns. this paper introduces a clients- providers-servers model that represents certain environments better than the traditional clients-servers model. then, we show that a random order of the data files performs well independent of the specific access pattern. our main technical contribution is showing how to de-randomize the randomized algorithm that is based on selecting a random order. the resulting algorithm is a polynomial time deterministic algorithm that finds an order that achieves the bounds of the random order.  amotz bar-noy joseph naor baruch schieber
the impact of delayed acknowledgments on tcp performance over satellite links the performance of the transmission control protocol (tcp) overnetwork paths that include a wireless or a satellite link is a veryactive area of research. a number of papers have been publishedproposing different ways to improve tcp over these kinds of links,either by new tcp functionality, or by link level enhancements.very few of these papers consider the delayed acknowledgmentstrategy that is implemented by many tcp receivers, when presentingtheir results. in this paper we will show that this acknowledgmentstrategy can have a significant impact on the performance of tcpand should not be neglected when evaluating new solutions forwireless environments. tanja lang daniel floreani
a mesh/token ring hybrid-architecture lan  this paper presents a hybrid architecture for local area networks (lans) which combines the advantages of token ring and mesh networks while remaining relatively simple. each node may have two communication channels. the first is a token ring and is used for short or prioritized message data transmissions. the other consists of an arbitrary collection of data links, which are used for relatively high volume and low priority data messages. with this architecture, a lan can be installed in the form of token ring and can be upgraded and "tuned" to its application environment by the insertion of node- to-node data links.  simulation results indicate that even with rather simple network control and routing algorithms, performance is improved over token ring due to data transmission concurrency greater than one.  c. kang j. herzog
design choices in the shrimp system: an empirical study the shrimp cluster- computing system has progressed to a point of relative maturity; a variety of applications are running on a 16-node system. we have enough experience to understand what we did right and wrong in designing and building the system. in this paper we discuss some of the lessons we learned about computer architecture, and about the challenges involved in building a significant working system in an academic research environment. we evaluate significant design choices by modifying the network interface firmware and the system software in order to empirically compare our design to other approaches. matthias a. blumrich richard d. alpert yuqun chen douglas w. clark stefanos n. damianakis cezary dubnicki edward w. felten liviu iftode kai li margaret martonosi robert a. shillner
a real-time expert system for computer network monitor and control  semacs, is a continuous, real-time expert monitor and control system that actively and passively monitors a computer network. it detects and diagnoses hardware and software problems with the network and provides advice and solutions to an operator in his domain of influence. it was developed jointly by sperry and one of its customers during an expert systems apprenticeship with the sperry knowledge systems center. the prototype system, which includes all major components of the final, operational system, was developed over a period of six weeks, and an operational system was put on- line within 3 months of starting the project.  barton b dunning john switlik
construction of internet for japanese academic communities  wide (widely integrated distributed environment) is a research project aimed at achieving a transparent distributed environment over heterogeneous distributed computing elements with the consideration of various types of connections for internetworking. the target environment of the research is computing environment in the academic and research communities especially in japan.  the wide project started its research activities at the end of 1986. the initial purpose of the group was to design the future junet environment. in japan junet has been the only network that provides connectivities among academic and research institutes in both private and public organizations. in order to provide better computer communication with the network, interconnection of networks based on open architecture is strongly required. as the result of various studies, the project started its actual design in late 1987 and has been establishing working environments by connecting several universities with various types of links.  together with the actual state and the future plan of the wide project, this paper discusses the overview of technologies being employed for the achievement of project goals such as networking technologies, operating system architecture and name space. as the background status of the wide projects, this paper also reports an overview of existing academic and research computer networks in japan, especially focusing on university environments where the sharing of the large scale computing resources are provided.  j. murai h. kusumoto s. yamaguchi a. kato
an algorithm for distributed computation of a spanningtree in an extended lan  a protocol and algorithm are given in which bridges in an extended local area network of arbitrary topology compute, in a distributed fashion, an acyclic spanning subset of the network.  the algorithm converges in time proportional to the diameter of the extended lan, and requires a very small amount of memory per bridge, and communications bandwidth per lan, independent of the total number of bridges or the total number of links in the network.  algorhyme  i think that i shall never see a graph more lovely than a tree.  a tree whose crucial property is loop-free connectivity.  a tree which must be sure to span so packets can reach every lan.  first the root must be selected by id it is elected.  least cost paths from root are traced. in the tree these paths are placed.  a mesh is made by folks like me then bridges find a spanning tree.  radia perlman
the effectiveness of multiple hardware contexts  multithreaded processors are used to tolerate long memory latencies. by executing threads loaded in multiple hardware contexts, an otherwise idle processor can keep busy, thus increasing its utilization. however, the larger size of a multi- thread working set can have a negative effect on cache conflict misses. in this paper we evaluate the two phenomena together, examining their combined effect on execution time.  the usefulness of multiple hardware contexts depends on: program data locality, cache organization and degree of multiprocessing. multiple hardware contexts are most effective on programs that have been optimized for data locality. for these programs, execution time dropped with increasing contexts, over widely varying architectures. with unoptimized applications, multiple contexts had limited value. the best performance was seen with only two contexts, and only on uniprocessors and small multiprocessors. the behavior of the unoptimized applications changed more noticeably with variations in cache associativity and cache hierarchy, unlike the optimized programs.  as a mechanism for exploiting program parallelism, an additional processor is clearly better than another context. however, there were many configurations for which the addition of a few hardware contexts brought as much or greater performance than a larger multiprocessor with fewer than the optimal number of contexts.  radhika thekkath susan j. eggers
a model of the contention resolution time for binary tree protocols  in a binary tree type local area network (lan) protocol, the number of probe slots (k) needed for contention resolution, when m out of n terminals are contending for the bus access depends not only on the value of m but also on the pattern of the active terminals, i.e., where the physical addresses of the active terminals are located in the logical binary tree structure. the value of m depends on the traffic intensity and increases with the packet arrival rate.  in this paper, we develop simple mathematical models for the upper and lower bounds on k as a function of m, with n as a parameter taking into account the above active terminal patterns. the models developed are useful in determining the maximum and minimum transmission frame durations for the performance evaluation of binary type lan protocols and other reservation type lan protocols which employ binary tree type probing algorithm. in the case of integrated traffic, when frame duration is to be fixed, the model will enable to optimize bandwidth allocation to different types of traffic.  jagan p. agrawal mary l. gerken