waashk/acm huggingface dataset:
a performance evaluation model for a digital group with multislot traffic streams  we present a unified model to compute various performance measures when a mixture of multi-slot traffic streams is offered on a trunk group of an integrated digital network under various bandwidth control schemes. when we considered a bandwidth reservation scheme based on traditional trunk reservation and a variation called partial bandwidth reservation, we have observed that the performance criteria themselves has significant impact in deciding which reservation scheme to use and at what level to use.  d. medhi a. van de liefvoort c. s. reece
retransmission control and fairness issue in mobile slotted aloha networks with fading and near-far effect  the effects of different retransmission control policies on the performance of a mobile data system employing the slotted aloha protocol are investigated, with the emphasis on the unfairness between close-in and distant users due to the near-far effect. an analytical multi-group model is developed to evaluate both the user and the network performance of the mobile slotted aloha network under two classes of retransmission control policies, namely the uniform policy and the nonuniform policy. the uniform policy requires that all users adopt the same retransmission probability, whereas the nonuniform policy allows more distant users to have larger retransmission probability in order to compensate for the unfairness caused by the near-far effect. the performance of a slotted aloha network with a linear topology in a rician fading channel under the two policies is compared by the multi-group model and simulation. the nonuniform policy is found to be more effective in alleviating the unfairness of user throughput over a wider range of the data traffic load than the uniform policy, which is effective only when the data traffic load is very light. thus, a mobile data network can enjoy the network performance improvement derived from the near-far effect while the unfairness between close-in and distant users can be greatly mitigated without resorting to power control.  te-kai liu john a. silvester andreas polydoros
monitoring quality improvement on a pc  report processor for supplier rating and reporting  on-line reporting to further analyze the raw and summarized data, including on-line graphics  backup and recovery to backup from the fixed disk to floppy diskettes and vice versa.  a general schematic showing the overall structure of the pc system is shown in figure 1.  even though this system has a particular application in mind, the statistical methods and all capabilities of the system could be used to monitor the quality improvement of any set of products, processes, or services. examples of such applications include: monitoring the quality of products produced at manufacturing, monitoring the quality of the entire manufacturing process, monitoring the quality of service provided through questionnaires on customer satisfaction, or monitoring the processes needed to smoothly run a warehousing operation.  jan p. gipe deborah a. guyton
a case study of decnet applications and protocol performance  this paper is a study based on measurements of network activities of a major site of digital's world-wide corporate network. the study yields two kinds of results: (1) decnet protocol performance information and (2) decnet session statistics. protocol performance is measured in terms of the various network overhead (non-data) packets in routing, transport and session layers. from these protocol performance data, we are able to review how effective various network protocol optimizations are; for example the on/off flow control scheme and the delayed acknowledgement scheme in the transport protocol. decnet session statistics characterizes the workload in such a large network. the attributes of a session include the user who started it, the application invoked, the distance between the user and the application, the time span, the number of packets and bytes in each direction, and the various reasons if a session is not successfully established. based on a large sample of such sessions, we generate distributions based on various attributes of sessions; for example the application mix, the visit count distribution and various packet number and size distributions.  d.-m. chiu r. sudama
a new 'building block' for performance evaluation of queueing networks with finite buffers  we propose a new 'building block', for analyzing queueing networks. this is a model of a server with a variable buffer-size. such a model enables efficient analysis of certain queueing networks with blocking due to limited buffer spaces, since it uses only product-form submodels. the technique is extensively tested, and found to be reasonably accurate over a wide range of parameters. several examples are given, illustrating practical situations for which our model would prove to be a useful performance analysis tool, specially since it is simple to understand, and easy to implement using standard software for closed queueing networks.  rajan suri gregory w. diehl
error correction and error detection techniques for wireless atm systems  error correction and error detection techniques are often used in wireless transmission systems. the asynchronous transfer mode (atm) employs header error control (hec). since atm specifications have been developed for high- quality optical fiber transmission systems, hec has single-bit error correction and multiple-bit error detection capabilities. when hec detects multiple-bit error, the cell is discarded. however, wireless atm requires a more powerful forward error correction (fec) scheme to improve the bit error rate (ber) performance resulting in a reduction in the transmission power and antenna size. this concatenation of wireless fec and hec of the atm may effect cell loss performance. this paper proposes error correction and error detection techniques suitable for wireless atm and analyzes the performance of the proposed schemes.  satoru aikawa yasushi motoyama masahiro umehira
a unified approach to scan time analysis of token rings and polling networks.  token rings and multipoint polled lines are two widely used network interconnection techniques. the general concept of cyclic allocation processes is defined and used to characterize token passing and polling in these networks. scan time, the time to poll all nodes at least once, is an important quantity in the response time analysis of such networks. we derive expressions for the mean and variance of scan times using a direct, operational approach. resulting expressions are general and are applicable to both exhaustive and non-exhaustive service. the effect of higher level protocols is easily incorporated in the analysis via calculations of constituent quantities. the expression for mean scan time is exact and depends only on the means of message transmission times and arrival rates. the approximate analysis of variance takes into account the correlation between message transmissions at different nodes. expected level of accuracy is indicated by an example.  subhash c. agrawal jeffrey p. buzen ashok k. thareja
processing location-dependent queries in a multi-cell wireless enviroment  we develop several methods for scheduling location-dependent queries clients cross cell bounderies in a multi-cell wireless environment. our study is based on a common scenario where data objects are stationary while clients, which issue the queries, are mobile. for query processing, we use voronoi diagrams to construct an index and a semantic cache for improving data reusability. for handoff clients, we propose three scheduling methods, namely, the priority method, the intelligent method, and the hybrid method to improve performance. a simulation is conducted to study the performance of the methods.  baihua zheng dik lun lee
reuse partitioning in cellular networks in dynamic channel allocation  great interest in recent years has been devoted to mobile communications. the research effort has been directed to increasing the capacity of radio systems by applying space reuse techniques. higher efficiency in the usage of the available frequency spectrum can be obtained either by reducing the cell size, thus requiring the provision of new base stations, or by reusing the available spectrum more efficiently without cell size reduction. in this paper we present a dynamic frequency allocation algorithm for cellular networks that exploits a given reuse pattern. the performance of the proposed scheme, in terms of blocking probability, is evaluated by means of computer simulations both when the position of the mobiles remains unchanged and when mobility is taken into account, under both uniform and hot-spot traffic. the numerical results show that the capacity of the proposed scheme is sensibly higher than that of a dynamic channel allocation without reuse partitioning. the effects of both user mobility and reuse partitioning on the signalling load are also considered.  a. pattavina s. quadri v. trecordi
near-optimality of distributed load-adaptive dynamic channel allocation strategies for cellular mobile networks  in this paper we focus on the so-called load-adaptive dynamic channel allocation (dca) strategies for cellular mobile networks. such strategies envisage the dynamic assignment of radio resources with the constraint that the outage probability (i.e. the probability that the carrier-to-interference power ratio be less than a given threshold) be less than a specified value, even in the worst foreseen propagation scenario. we identify a set of constraints to be satisfied in order that a dca strategy belongs to the load- adaptive class. this provides a tight lower bound on traffic blocking and dropping performance such that: (i) it implies a dramatically lower computational effort than the known optimum strategy (based on the maximum packing algorithm); (ii) it is much tighter than the bound provided by the simple erlang-b formula. a performance evaluation is carried out to compare the call blocking and dropping probabilities resulting from the tight bound above with those relevant to the fixed channel allocation and to some recently proposed dca strategies, including the geometric dca. the simulations exploit a mobility model that provides different degrees of offered traffic peakedness. it emerges that the geometric dca yields a practical way to attain near optimal performance in the load-adaptive class, leading a viable pathway to enhance the capacity of nowadays 2nd generation cellular networks in the short-medium term.  andrea baiocchi fabrizio sestini
a performance-driven standard-cell placer based on a modified force-directed algorithm  we propose a performance-driven cell placement method based on a modified force-directed approach. a pseudo net is added to link the source and sink flip-flops of every critical path to enforce their closeness. given user- specified i/o pad locations at the chip boundaries and starting with all core cells in the chip center, we iteratively move a cell to its force-balanced location assuming all other cells are fixed. the process stops when no cell can be moved farther than a threshold distance. next, cell rows are adjusted one at a time starting from the top and bottom. after forming these two rows (top/bottom), all movable core cells force-balanced locations are updated. the row-formation-and-update process continues until all rows are adjusted and, hence, a legal placement is obtained.  we have integrated the proposed approach into an industrial apr flow. experimental results on benchmark circuits up to 191k-cell (500k-gate) show that the critical path delay can be improved by as much as 11.5%. we also study the effect on both layout quality and cpu time consumption due to the amount of pseudo net added. we found that the introduction of pseudo net indeed significantly improves the layout quality. yih-chih chou youn-long lin
dynamic selection of a performance-effective transmission sequence for token- passing networks with mobile nodes  we describe a distributed method for keeping down "token-passing" overhead in a mobile multi-access network, by performing local corrections in the token- passing sequence as they become necessary due to changes in node spatial configuration. these corrections involve only a subset of the nodes in the network, thus reducing the required computational effort. the method consists of three distributed protocols. the first is for detecting deterioration and identifying a subset of nodes that constitutes a "problem area", the second is to provide each node with the distances (propagation delays) to all other nodes, and the third is to use this topological information to construct a minimal spanning tree, from which a good "token passing" sequence can be derived. the second and third protocols may also have applications other than the one described here, such as position location, routing and broadcasting.  yaron i. gold shlomo moran
an open approach for deploying programming nodes into communication networks nowadays, we are facing in the computer network reserach communication new challenges related to the concepts of programmable and active networks. great efforts have been spent to make current data communication networks more flexible and dynamic. unfortunately, such efforts are followed by complexity and, therefore, the process of deploying the mechanisms has been committed. in order to make this process simpler, this work presents an open approach for having programmable nodes that make computer networks more dynamic in terms of adding new services without increasing complexity. this approach presents snpi (simple network programmable interface), which is group of skeletons and data structures resources that make possible to the programmers and developers a fast deployment of new services into the network. the mechanism presented allows that access to internal mechanisms of data flow processing in the network nodes. cris amon c. rocha aecio paiva braga jose neuman de souza
connection principles for multipath, packet switching networks  packet switched multistage interconnection networks (mins) have been mostly proposed to use unique connection path between any source and destination. we propose to add a few extra stages in an min to create multiple paths between any source and destination. connection principles of multipath mins (mmins) for packet switching are presented in this paper. performance of such network is analyzed for possible use in multiprocessor systems and dataflow computers. for an mmin with n nodes, the number of required stages is confined in the range [log2n+1, 2log2n-1]. each stage consists of n/2 buffered 2-by-2 switching cells. in practice, one or two extra stages is sufficient beyond log2n stages required in a unique-path min. the delays of mmins are shown much shorter than that of using unique-path mins for packet switching. the improvement lies in significantly reduced packet wait delays in buffers, especially under heavy traffic conditions. the tradeoffs between reduced network delays and increased hardware cost are studied. optimal design criteria and procedures are provided for developing mmins with a fixed network size and stages.  chi-yuan chin kai hwang
probabilistic language analysis of weighted voting algorithms  we present a method of analyzing the performance of weighted voting algorithms in a fault-tolerant distributed system. in many distributed systems, some processors send messages more frequently than others and all processors share a common communication medium, such as an ethernet. typical fault-tolerant voting algorithms require that a certain minimum number of votes be collected from different processors. system performance is significantly affected by the time required to collect those votes. we formulate the problem of weighted voting in terms of probabilistic languages and then use the calculus of generating functions to compute the expected delay to collect that number of votes. an application of the method to a particular voting algorithm, the total protocol, is given.  louise e. moser vikas kapur p. m. melliar- smith
time and message-efficient s-based consensus (brief announcement)  the class of strong failure detectors (denoted s) includes all failure detectors that suspect all crashed processes and that do not suspect some (a priori unknown) process that never crashes. so, a failure detector that belongs to s is intrinsically unreliable as it can arbitrarily suspect correct processes.  several s-based consensus protocols have been designed. they proceed in consecutive asynchronous rounds. some of them systematically require n rounds (n being the number of processes), each round involving n2 or n messages. others allow early decision (i.e., when there are no erroneous suspicions, the number of rounds depends only on the maximal number of crashes) but require each round to involve n2 messages.  this brief annoucement introduces an early deciding (s-based consensus protocol each round of which involves 3(n \\- 1) messages. so, the proposed protocol is particularly time and message-efficient. it is based on the rotating coordinator paradigm. due to space limitation the reader is referred to [2] for an in-depth presentation of the protocol (underlying principles, proof, cost analysis and generalization). here, the limited space allows us to only compare it with the other s-based consensus protocols we are aware of.  this comparison is provided in table 1. "nb", "msg" and "c_s" are shortcuts for "number", "messages" and "communication steps" respectively; ghmr denotes the proposed protocol; denotes the maximum number of processes that are allowed to crash; |v| is the maximal size (in bits) of a value a process can initially propose to the consensus.  all the protocols work provided that < n. hence, they are optimal with respect to the number of process crashes that can be tolerated. the protocols of the first two lines systematically require n rounds ([4] and [5] each proposes a particular generalization of s; we consider here their protocols used with s). the behavior of the protocols of the last two lines depends on failure occurrences and false failure suspicions (that is why they allow early decision in "good" scenarios, i.e., when the failure detector does not make mistake). for those lines, the table considers that (1) the failure detector does not make mistake, (2) there are failures, and (3) there is a failure per round (the "simultaneity" of failure occurrences can actually reduce the number of rounds). for the generic protocol described in [3], the table considers its instantiation with s.  hence, it appears that the proposed protocol owns several noteworthy features. the most important of them are its ability to allow early decision and its linear cost for the number of messages per round.  fabíola greve michel hurfin raimundo macêdo michel raynal
network security considerations in bln  in a heterogeneous computer network, resources on each node are protected by the local security mechanism. network services allow local resources to be accessed remotely from other nodes. without appropriate network security measures, each node is vulnerable to attack from the network. this paper analyzes the heterogeneous bell labs network (bln) environment and lists the potential network security risks. by assessing the risks, counter-measures are proposed for minimizing potential exposure. these counter-measures are part of a global network security mechanism being implemented for bln.  j. yao
a performance study of a highly-parallel architecture to provide registration and translation services in an intelligent network  this paper presents the initial investigation of a highly parallel architecture that can be used as an intelligent network translation and registration platform (intarp). the intarp architecture is deterministic and uses a hyper-switch as well as bus connections to pass messages. threads through the multiprocessing pipelines are maintained by service definitions of the call procedures on "anchor processors". the processes call procedures distributed over "sequencing processors". intarp is being prototyped using the inmos, family of transputers. unlike other architectures designed for the intelligent network, intarp is designed specifically to minimize the post dial delay (pdd) the architecture contributes to circuit switch call processing. unmanaged pdd in the intelligent network can lead to higher call abandonments. pdd also increase trunk and port capitalization due to the greater call holding time in peripheral processors prior to information transfer. the intarp architecture is evaluated using a simulation model. translation, pcn registration and calling card services have been implemented on the simulation model and the performance of the architecture is inferred from the performance of the simulation studies.  jerry stach jerry place
analyzing communication latency using the nectar communication processor  for multicomputer applications, the most important performance parameters of a network is the latency for short messages. in this paper we present an analysis of communication latency using measurement of the nectar system. nectar is a high-performance multicomputer built around a high- bandwidth crosspoint network. nodes are connected to the nectar network using network coprocessors that are primarily responsible the protocol processing, but that can also execute application code. this architecture allows us to analyze message latency both between workstations with an outboard protocol engine and between lightweight nodes with a minimal runtime system and a fast, simple network interface (the coprocessors). we study how much context switching, buffer management and protocol processing contribute to the communication latency and we discuss how the latency is influenced by the protocol implementation.  peter steenkiste
heat dissipation in wearable computers aided by thermal coupling with the user  wearable computers and pda's are physically close to, or are in contact with, the user during most of the day. this proximity would seemingly limit the amount of heat such a device may generate, conflicting with user demands for increasing processor speeds and wireless capabilities. however, this paper explores significantly increasing the heat dissipation capability per unit surface area of a mobile computer by thermally coupling it to the user. in particular, a heat dissipation model of a forearm-mounted wearable computer is developed, and the model is verified experimentally. in the process, this paper also provides tools and novel suggestions for heat dissipation that may influence the design of a wearable computer.  thad starner yael maguire
security protocol for ieee 802.11 wireless local area network  as wireless local area networks (wlans) are rapidly deployed to expand the field of wireless products, the provision of authentication and privacy of the information transfer will be mandatory. these functions need to take into account the inherent limitations of the wlan medium such as limited bandwidth, noisy wireless channel and limited computational power. moreover, some of the ieee 802.11 wlan characteristics such as the use of a point coordinator and the polling based point coordination function (pcf) have also to be considered in this design. in this paper, we introduce a security protocol for the ieee 802.11 pcf that provides privacy and authentication, and is designed to reduce security overheads while taking into account the wlan characteristics. we prove this protocol using the original and modified ban logic.  se hyun park aura ganz zvi ganz