waashk/acm huggingface dataset:
the aloha system the aloha system is composed of a related series of contracts and grants from a variety of funding agencies with principal support from arpa, which deal with two main themes: computer communications (task 1), and computer structures (task 2).under computer-communications there is work in (a) studies on computer communications using radio and satellites, (b) the development of a prototype radio-linked time-sharing network, (c) system studies and planning for a pacific area computer communications network linking major universities in the u.s., japan, australia and other pacific countries.under computer structures, we are engaged in research/development in multiprocessor computing structures, computer networks, and geographically distributed computing systems. this work is being undertaken in two phases: 1) the establishment of a research facility and 2) the research work itself. the research facility is centered around the bcc 500 computing system. f. f. kuo
toward a parametric approach for modeling local area network performance  the task of modeling the performance of a single computer (host) with associated peripheral devices is now well understood [computer 80]. in fact, highly usable tools based on analytical modeling techniques are commercially available and in widespread use throughout the industry. [buzen 78] [buzen 81] [won 81] these tools provide a mechanism for describing computerized environments and the workloads to be placed on them in a highly parameterized manner. this is important because it allows users to describe their computer environments in a structured way that avoids unnecessary complexity. it also is helpful in facilitating intuitive interpretations of modeling results and applying them to capacity planning decisions.  a first step toward building a modeling tool and associated network specification language that allows straightforward, inexpensive, and interpretable modeling of multi- computer network performance is to identify the set of characteristics (parameters) that most heavily influence that performance. the result of such a study for the communication aspects of local area networks is the subject of this paper.  peter s. mager
local and global handovers based on in-band signaling in wireless atm networks this paper presents a handover protocol for wireless atm networks, which makes use of in-band signaling, i.e., of atm resource management cells, to process network handovers and guarantee the in-sequence and loss-free delivery of the atmcells containing user data. the goal of the proposed approach is to minimize the modifications of the atm signaling standard required to overlay user mobility onto the fixed network infrastructure, and provide for a gradual upgrade of the fixed network to handle mobility. the proposed protocol handles both local handovers, in which the connection access point needs not migrate to a new atm local exchange, and global handovers, in which the connection access point must migrate to a new local exchange. the handover scheme is devised so as to grant in-sequence delivery of cells. the performance of the network during handover is analyzed in case of connections requiring loss-free operation. the considered performance figures are the cell transmission delay introduced by the handover and the cell buffering requirements posed to the network. the behavior of the proposed protocol in presence of multiple handovers is studied via simulation, while a simple analytical method is derived for the performance evaluation of a single handover in isolation. m. ajmone marsan a. fumagalli r. lo cigno c. f. chiasserini m. munafó
on the minimal synchronism needed for distributed consensus  reaching agreement is a primitive of distributed computing. whereas this poses no problem in an ideal, failure-free environment, it imposes certain constraints on the capabilities of an actual system: a system is viable only if it permits the existence of consensus protocols tolerant to some number of failures. fischer et al. have shown that in a completely asynchronous model, even one failure cannot be tolerated. in this paper their work is extended: several critical system parameters, including various synchrony conditions, are identified and how varying these affects the number of faults that can be tolerated is examined. the proofs expose general heuristic principles that explain why consensus is possible in certain models but not possible in others.  danny dolev cynthia dwork larry stockmeyer
performance analysis of multipath multistage interconnection networks  this paper closely examines the performance analysis for unbuffered multipath multistage interconnection networks. a critical discussion of commonly used analysis is provided to identify a basic flaw in the model. a new analysis based on the grouping of alternate links is proposed as an alternative to rectify the error. the results based on the new analysis and extensive simulation are presented for three representative networks. the simulation study strongly supports the results of the new analysis.  s. c. kothari a. jhunjhunwala a. mukherjee
evaluation of the lock mechanism in a snooping cache  this paper discusses the design concepts of a lock mechanism for a parallel inference machine (the pim/c prototype) and investigates the performance of the mechanism in detail.  lock operations are extremely frequent on the pim; however, lock contention rarely occurs during normal memory usage. for this reason, the lock mechanism is designed so as to minimize the lock overhead time in the case of no contention. this is done by using an invalidation lock mechanism, which utilizes the exclusive state of the snooping cache and in which the locked address is not broadcast.  experimental results demonstrate the benefits of the lock mechanism in regions of few lock contentions. they also confirm that, in most cases, the lock mechanism works well on the pim. however, the mechanism is also found to cause performance degradation when a locked address is accessed by multiple processing elements (pes) in a tightly-coupled multi- processor (tcmp). this is because shared data such as the flags for inter-pe communication, which are shared by all the pes, may be accessed by multiple pes at the same time, thus generating heavy contention. this paper also shows that combining a register- based broadcasting facility with the proposed lock mechanism can solve the above problem.  toshiaki tarui takayuki nakagawa noriyasu ido machiko asaie mamoru sugie
description of a planned federal information processing standard for transport protocol  the national bureau of standards has developed service and design specifications for transport and session protocols for use in computer system and network procurements. these protocols reside in layers four and five of the international organization for standardization's (iso) reference model for open systems interconnection. this paper describes the services, interfaces, and internal behavior of the transport protocol. the transport (and session) protocol specifications were derived from the most recent developments within iso on these protocols. specific features were selected based on the needs of the agencies of the federal government within the united states, but they are consistent with the needs of any large organization engaged in the procurement or development of networks of heterogeneous computer systems.  john f. heafner robert p. blanc
a fair protocol for fast resource assignment in wireless pcs networks  efficient sharing of communication resources is essential to pcs networks since the wireless bandwidth is limited. the resource auction multiple access (rama) protocol was recently proposed for fast resource assignment and handover in wireless pcs networks. the rama protocol assigns available communication resources (e.g., tdma time slots or frequency channels) to subscribers one at a time using a collision resolution protocol based on subscriber id's. however, the rama protocol encounters an unfairness problem; furthermore, performance results also indicate that it is inefficient at transmitting fixed-length subscriber id's. moreover, the emerging services such as teleconferencing have been presenting new challenges to dynamic- priority resource assignment. in this paper, we propose a modification to the rama protocol to improve its performance and resolve the unfairness problem. the proposed protocol also adopts dynamic priority assignment to improve the qos for subscribers in overload environments.  tsan-pin wang chien- chao tseng shu-yuen hwang
on the relevance of long-range dependence in network traffic there is mounting experimental evidence that network traffic processes exhibit ubiquitous properties of self-similarity and long range dependence (lrd), i.e. of correlations over a wide range of time scales. however, there is still considerable debate about how to model such processes and about their impact on network and application performance. in this paper, we argue that much recent modeling work has failed to consider the impact of two important parameters, namely the finite range of time scales of interest in performance evaluation and prediction problems, and the first-order statistics such as the marginal distribution of the process.we introduce and evaluate a model in which these parameters can be easily controlled. specifically, our model is a modulated fluid traffic model in which the correlation function of the fluid rate is asymptotically second-order self-similar with given hurst parameter, then drops to zero at a cutoff time lag. we develop a very efficient numerical procedure to evaluate the performance of the single server queue fed with the above fluid input process. we use this procedure to examine the fluid loss rate for a wide range of marginal distributions, hurst parameters, cutoff lags, and buffer sizes.our main results are as follows. first, we find that the amount of correlation that needs to be taken into account for performance evaluation depends not only on the correlation structure of the source traffic, but also on time scales specific to the system under study. for example, the time scale associated to a queueing system is a function of the maximum buffer size. thus for finite buffer queues, we find that the impact on loss of the correlation in the arrival process becomes nil beyond a time scale we refer to as the correlation horizon. second, we find that loss depends in a crucial way on the marginal distribution of the fluid rate process. third, our results suggest that reducing loss by buffering is hard. we advocate the use of source traffic control and statistical multiplexing instead. m. grossglauser j.-c. bolot
analysis of a variant hypercube topology  each node of a hypercube system, when fabricated, comes with a fixed number of links designed for a maximum sized construction. very often, there are links left unused at each node in a real system. in this article, we study the hypercube in which extra connections are added between pairs of nodes through otherwise unused links. those extra connections are made in order to maximize the improvement of the performance measure of interest under various traffic distributions. the resulting hypercube, called the variant hypercube, requires a simple routing algorithm and is guaranteed not to create any traffic- congested point or link. the variant hypercube is found to achieve considerable reduction in diameter, and noticeable improvement in mean internode distance and traffic density. in addition, a variant hypercube is more cost-effective than a regular hypercube and does not suffer from practical implementation difficulty. as a result, it also appears advantageous for hypercube systems with no available unused links to augment each node so as to accommodate an extra link, provided that the building block is not pin limited and is allowed to do so.  nian-feng tzeng
distributed admission control for power-controlled cellular wireless systems it is well known that power control can help to improve spectrum utilization in cellular wireless systems. however, many existing distributed power control algorithms do not work well without an effective connection admission control (cac) mechanism, because they could diverge and result in dropping existing calls when an infeasible call is admitted. in this work, based on a system parameter defined as the discriminant, we propose two distributed cac algorithms for a power-controlled system. under these cac schemes, an infeasible call is rejected early, and incurs only a small disturbance to existing calls, while a feasible call is admitted and the system converges to the pareto optimal power assignment. simulation results demonstrate the performance of our algorithms. mingbo xiao ness b. shroff edwin k. p. chong
new call blocking versus handoff blocking in cellular networks  in cellular networks, blocking occurs when a base station has no free channel to allocate to a mobile user. one distinguishes between two kinds of blocking, the first is called new call blocking and refers to blocking of new calls, the second is called handoff blocking and refers to blocking of ongoing calls due to the mobility of the users. in this paper, we first provide explicit analytic expressions for the two kinds of blocking probabilities in two asymptotic regimes, i.e., for very slow mobile users and for very fast mobile users, and show the fundamental differences between these blocking probabilities. next, an approximation is introduced in order to capture the system behavior for moderate mobility. the approximation is based on the idea of isolating a set of cells and having a simplifying assumption regarding the handoff traffic into this set of cells, while keeping the exact behavior of the traffic between cells in the set. it is shown that a group of 3 cells is enough to capture the difference between the blocking probabilities of handoff call attempts and new call attempts.  moshe sidi david starobinski
isdn architecture: a basis for new services  isdn is an acronym for integrated services digital network. isdn embodies world-wide standards that will engender the technology necessary to weave the fabric of a global communications network and provide the foundation for information age services. siemens has a cost effective isdn introduction strategy that will allow isdn to interwork with existing switching systems, current transmission networks, and nonproprietary customer premises equipment (cpe), as well as to interface with operational and administration systems. this strategy also entails the development of isdn terminals, terminal adapters and service capabilities so that the end user can quickly realize the benefits of isdn. siemens is forming partnerships with bell operating telephone companies, like wisconsin bell telephone co., to perform market research of the end users to better determine their isdn needs and applications. isdn architecture is briefly discussed to provide a basis for some examples on how isdn and network components can be combined to meet customer needs.  daryl j. eigen
cost reduction in location management using semi-realtime movement information  this paper introduces a dynamic paging scheme based on the semi- realtime movement information of an individual user, which allows a more accurate predication of the user location at the time of paging. in general, a realtime location tracking scheme may require complex control schemes and incur unacceptably high computation and messaging cost. our proposed approach, namely the velocity paging scheme, relaxes the realtime constraints to semi- realtime to provide a good combination of cost reduction and ease of implementation. the proposed velocity paging scheme utilizes semi-realtime velocity information, namely velocity classes, of individual mobile terminals and dynamically calculates a paging zone (a list of cells to be paged) for an incoming call. therefore, the total paging cost can be reduced due to the paging area reduction. much consideration also has been given to reduce the complexity of the proposed scheme. as a result, it only requires minimal extra overhead and is feasible to implement in current cellular/pcs networks. the velocity paging can be combined with the movement-based registration or other registration schemes. analytical and simulation results of the velocity paging and movement-based registration combination are provided to demonstrate the cost effectiveness of the scheme under various parameters in comparison with the location area scheme.  guang wan eric lin
multicast support for mobile hosts using mobile ip: design issues and proposed architecture  in this paper, we consider the problem of providing multicast to mobile hosts using mobile ip for network routing support. providing multicast in an internetwork with mobile hosts is made difficult because many multicast protocols are inefficient when faced with frequent membership or location changes. this basic difficulty can be handled in a number of ways, but three main problems emerge with most solutions. the tunnel convergence problem, the duplication problem, and the scoping problem are identified in this paper and a set of solutions are proposed. the paper describes an architecture to support ip multicast for mobile hosts using mobile ip. the basic unicast routing capability of mobile ip is used to serve as the foundation for the design of a multicast service facility for mobile hosts. we believe that our scheme is transparent to higher layers, simple, flexible, robust, scalable, and, to the extent possible, independent of the underlying multicast routing facility. for example, our scheme could interoperate with dvmrp, mospf, cbt, or pim in the current internet. where differences exist between the current version of ip (ipv4) and the next generation protocol (ipv6), these differences and any further optimizations are discussed.  vineet chikarmane carey l. williamson richard b. bunt wayne l. mackrell
a petri net reduction algorithm for protocol analysis  petri net is a powerful model for analyzing communication protocols because they share many common properties. currently, protocol analysis suffers the state explosion problem especially for error-recoverable protocols and multi- party protocols. protocol synthesis relieves this problem by generating new and complicated protocols from simple subsets of the protocol models. reduction analysis provides theoretical ground for correct synthesis or expansion. thus, reduction is a very important research area. in this paper, we present a general petri net reduction algorithm that reduces the number of states while preserving all desirable and undesirable properties. to the best of our knowledge, this is the first general petri net reduction algorithm for protocol analysis. we first present and extend dong's [don 83] definition of wbms to include more subnets as wbms. to render the reductions automated, a new concept of simple well-behaved modules (swbms) is introduced. recursively performing reductions of swbms, complicated wbms can be reduced. a main program is written to implement this recursive procedure. the problem is then reduced to finding conditions for swbms. we do this by progressing from simpler swbms to more complicated ones, i.e., from single-arc ones to multi- arcs ones. finally, we demonstrate the usefulness of this algorithm by applying it to the state exploration in protocol synthesis. other applications such as error detection, performance evaluation, and software engineering will be discussed in future.  c v ramamoorthy y yaw
contingency planning and disaster recovery  the ability to provide uninterruptable access to automated informational resources will be profoundly different in the fifth generation. the types of changes that we can expect are already being reflected in the emerging building blocks for the fifth generation.  as our dependency on the computerized environment, as well as our need for easy access to informational resources increases, there is a corresponding increase in tools and mechanisms designed to allow us to quickly and easily recover from many types of natural and man- made disasters.  today, we are just beginning to address the need for uninterruptable access. by the fifth generation, we will have solved problems which today appear to be so complex as to be impossible to solve.  ken fong
performance modeling of asynchronous data transfer methods of ieee 802.11 mac protocol  to satisfy the needs of wireless data networking, study group 802.11 was formed under ieee project 802 to recommend an international standard for wireless local area networks (wlans). a key part of standard are the medium access control (mac) protocol needed to support asynchronous and time bounded delivery of data frames. it has been proposed that unslotted carrier sense multiple access with collision avoidance (csma/ca) be the basis for the ieee 802.11 wlan mac protocols. we conduct performance evaluation of the asynchronous data transfer protocols that are a part of the proposed ieee 802.11 standard taking into account the decentralized nature of communication between stations, the possibility of "capture", and presence of "hidden" stations. we compute system throughput and evaluate fairness properties of the proposed mac protocols. further, the impact of spatial characteristics on the performance of the system and that observed by individual stations is determined. a comprehensive comparison of the access methods provided by the 802.11 mac protocol is done and observations are made as to when each should be employed. extensive numerical and simulation results are presented to help understand the issues involved.  harshal s. chhaya sanjay gupta
editorial  the generation and propagation of radio frequency (rf) electromagnetic waves was first demonstrated by heinrich hertz in 1888. a few years later, guglielmo marconi succeeded in transmitting, wirelessly, a radio signal over a long terrestrial distance in 1896 and then across the atlantic ocean in 1901. the number of devices and systems that emit rf radiation has been increasing at an accelerating rate ever since. some have estimated that there were over 80 million users of mobile telephones by the end of 1996. indeed, wireless communication service is sweeping the world and has brought instant, two-way radio communication to many people constantly on the move.  the concept of personal communication systems (pcs) aims at providing two-way communication services, speech and data to individual users, indoors or out. its goal is to establish a mass network for mobile communications and to provide a competitive alternative to the conventional wired public switched telecommunication network. the wide-spread impact of this new technology has raised concerns about the safety of human exposure to rf energy emitted by these telecommunication devices. clearly, we need a better understanding of the biological effects of rf electro-magnetic field so that we can safeguard against possible harm to the general population and enhance its beneficial uses.  within the last few years there has been a resurgence of research effort to achieve better and more quantitative understanding of the relationships between the biological effects of rf radiation and the physical variables that may cause them. some results are beginning to appear in the literature. this special issue is intended to provide an overview of the current status of our scientific understanding and to present recent advances coming from various research laboratories.  paolo bernardi james c. lin
lossless handover for wireless atm  handover is one of the key research topics for the emerging wireless atmnetworks. this paper describes a handover mechanism for intra-switch handovers for wireless atm. the handover procedure is simple enough to be implementable as a limited enhancement to atm switch platforms for fixed network, yet provides lowdelay and lossless handover when used together with a suitable radio interface. the paper also reports on initial simulation result.  håkan mitts harri hansen jukka immonen simo veikkolainen