waashk/acm huggingface dataset:
switching strategies in a class of packet switching networks  this paper investigates some methods for improving the performance of single stage shuffle exchange networks (sens) and multistage interconnection networks (mins). the three new switching strategies proposed use extra buffers to enhance performance. approximate analysis and simulation results indicate significant improvement in performance for both sens and mins. an intuitive method for determining the applicability of the approximate analysis is discussed and some performance measures, which should be useful in evaluating the performance of networks are defined.  manoj kumar daniel m. dias j. r. jump
a multiple stream microprocessor prototype system: amp-1  a general- purpose multiple-stream processor with shared memory and a single time- multiplexed synchronous bus has been implemented. the amp-1 system uses eight standard microprocessors and 64k bytes of memory. the design is highly efficient in the use of processor, bus, and memory resources. preliminary performance measurements agree closely with an analytic memory access conflict model and show extremely low conflict-based performance degradation. heavy interleaving of the memory and effective multitasking of a job can yield significant performance speedups. considerations for future implementations are presented.  edward s. davidson
multi-terminal nets do change conventional wire length distribution models  conventional models for estimating wire lengths in computer chips use rent's rule to estimate the number of terminals between sets of gates. the number of interconnections then follows by taking into account that most nets are point- to-point connections. in this paper, we introduce a model for multi- terminal nets and we show that such nets have a fundamentally different influence on the wire length estimations than point-to-point nets. the multi- terminal net model is then used to estimate the wire length distribution in two cases: (i)m the distribution of source-sink pairs for applications of delay estimation and (ii) the distribution of steiner tree lengths for applications related to routing resource estimation. the effects of including multi-terminal nets in the estimations are highlighted. experiments show that the new estimated wire length distributions are close to the measured ones.  dirk stoobandt
the totem multiple-ring ordering and topology maintenance protocol  the totem multiple-ring protocol provides reliable totally ordereddelivery of messages across multiple local-area networks interconnectedby gateways. this consistent message order is maintained in the presenceof network partitioning and remerging, and of processor failure andrecovery. the protocol provides accurate topology change information aspart of the global total order of messages. it addresses the issue ofscalability and achieves a latency that increases logarithmically withsystem size by exploiting process group locality and selectiveforwarding of messages through the gateways. pseudocode for the protocoland an evaluation of its performance are given.  \\---authors' abstract d. a. agarwal l. e. moser p. m. melliar-smith r. k. budhia
performance evaluation of reduced bandwidth multistage interconnection networks  this paper presents and evaluates a class of buffered interconnection networks which provide performance and cost levels intermediate to a bus and a delta network. these networks, referred to as hybrid networks, are formed by beginning with a delta network and substituting buses for the final stages of the network. the choice of the number of stages replaced determines the bandwidth of the network. the reduction of network bandwidth is accompanied by a corresponding reduction in network cost. hybrid networks provide the system architect with a cost-effective solution to design problems in which the required interconnection bandwidth is greater than that of a bus but less than that of a full delta network.  the performance of hybrid networks is investigated by developing a numerical model and by using simulation. two features of the model, buffers of arbitrary length at network switches and resource service times greater than interstage transfer delays, have not been included in previous analytical models of delta networks. results show that in some cases, the expense of a multistage network is not required in order to maintain the maximum level of system performance.  d. t. harper j. r. jump
an efficient multicast protocol for pcs networks  in a personal communication services (pcs) network, mobile hosts communicate with other mobile hosts through base stations on a wired (static) network. the mobile hosts connect to different base stations through wireless links and the base stations to which mobile hosts are connected change depending on the current location of the mobile hosts. in this environment, the problem of efficiently delivering a multicast message from one mobile host to a group of other mobile hosts becomes challenging. in this paper, we present a multicast protocol that delivers multicast messages from a mobile host to a group of other mobile hosts without flooding the wired network. the multicast protocol is built on top of a user location strategy that should follow one of the three models of user location described in the paper. the basic multicast protocol proposed guarantees exactly-once message delivery to all mobile hosts in the multicast group and also ensures that multicast messages are delivered in fifo order from the point of view of the base station that originates the multicast message (referred to as bs-fifo). more importantly, an extension of the basic protocol is provided that, unlike earlier work, delivers multicast messages in fifo order from the point of view of the mobile host that initiates the multicast message (referred to as mh-fifo). the modifications to be made to the multicast protocol to accommodate each of the three models of user location is also described.  vanitha aravamudhan karunaharan ratnam sampath rangarajan
configurable flow control mechanisms for fault-tolerant routing fault-tolerant routing protocols in modern interconnection networks rely heavily on the network flow control mechanisms used. optimistic flow control mechanisms such as wormhole routing (wr) realize very good performance, but are prone to deadlock in the presence of faults. conservative flow control mechanisms such as pipelined circuit switching (pcs) insures existence of a path to the destination prior to message transmission, but incurs increased overhead. existing fault-tolerant routing protocols are designed with one or the other, and must accommodate their associated constraints. this paper proposes the use of configurable flow control mechanisms. routing protocols can then be designed such that in the vicinity of faults, protocols use a more conservative flow control mechanism, while the majority of messages that traverse fault-free portions of the network utilize a wr like flow control to maximize performance. such protocols are referred to as two-phase protocols, where routing decisions are provided some control over the operation of the virtual channels. this ability provides new avenues for optimizing message passing performance in the presence of faults. a fully adaptive two-phase protocol is proposed and compared via simulation to those based on wr and pcs. the architecture of a network router supporting configurable flow control is described, and the paper concludes with avenues for future research. binh vien dao jose duato sudhakar yalamanchili
adapting to network and client variability via on-demand dynamic distillation the explosive growth of the internet and the proliferation of smart cellular phones and handheld wireless devices is widening an already large gap between internet clients. clients vary in their hardware resources, software sophistication, and quality of connectivity, yet server support for client variation ranges from relatively poor to none at all. in this paper we introduce some design principles that we believe are fundamental to providing "meaningful" internet access for the entire range of clients. in particular, we show how to perform on-demand datatype-specific lossy compression on semantically typed data, tailoring content to the specific constraints of the client. we instantiate our design principles in a proxy architecture that further exploits typed data to enable application-level management of scarce network resources. our proxy architecture generalizes previous work addressing all three aspects of client variation by applying well-understood techniques in a novel way, resulting in quantitatively better end-to-end performance, higher quality display output, and new capabilities for low-end clients. armando fox steven d. gribble eric a. brewer elan amir
achieving the best performance on superscalar processors in this paper the operation of a superscalar processor is studied. an analytical model is developed for computing the throughput and the speedup of the superscalar processors. the throughput is computed as a function of the reoccurrence period of the instructions in the program. it is shown that, when the number of the instructions is sufficiently large, the probability of referring to the different pipes and the number of pipes are more important than the length of the pipes.also the results show that maximum throughput of a p-issues superscalar processor is equal to p instructions per cycle. this upper bound is reachable if and only if some conditions for reoccurrence period of the instructions in the program are fulfilled. at the end of the paper some remarks related to the structural designing and the number of pipes are offered. h. s. shahhoseini m. naderi s. nemati
the slide mechanism with applications in dynamic networks  this paper presents a simple and efficient building block, called slide, for constructing communication protocols in dynamic networks whose topology frequently changes. we employ slide to derive (1) an end-to-end communication protocol with optimal amortized message complexity, and (2) a general method to efficiently and systematically combine dynamic and static algorithms. (dynamic algorithms are designed for dynamic networks, and static algorithms work in networks with stable topology.)  the new end-to-end communication protocol has amortized message communication complexity o(n) (assuming that the sender is allowed to gather enough data items before transmitting them to the receiver), where n is the total number of nodes in the network (the previous best bound was (o(m), where m is the total number of links in the network). this protocol also has bit communication complexity o(nd), where d is the data item size in bits (assuming data items are large enough; i.e., for d = Ω(nm log n)). in addition we give, as a byproduct, an end-to-end communication protocol using o(n2m) messages per data item, which is considerably simpler than other protocols known to us (the best known end-to-end protocol has message complexity o(nm)[ag91]). the protocols above combine in an interesting way several ideas: the information dispersal algorithm of rabin [rab89], the majority insight of [afwz88, aaf+], and the slide protocol.  .  the second application of slide develops a systematic mechanism to combine a dynamic algorithm with a static algorithm for the same problem, such that the combined algorithm automatically adjusts its communication complexity to the network conditions. that is the combined algorithm solves the problem in a dynamic network, and if the network stabilizes for a long enough period of time then the algorithm's communication complexity matches that of the static algorithm. this approach has been first introduced in [am88] in the context of topology update algorithms.  yehuda afek eli gafni adi rosen
laboratory for emulation and study of integrated and coordinated media communication  in future telecommunications networks, understanding the issues of user- network control, customer premise equipment (cpe) technologies, services and user applications is as important as the classical network problems of channel structure, switching, and transmission. this paper discusses a bell communications research facility, the integrated media architecture laboratory (imal), designed to flexibly emulate a wide range of current and future network and cpe environments with a focus on multiple media communications. imal combines off-the-shelf technologies to create an easily clonable emulation environment for studying, planning, demonstrating, and checking the feasibility of integrated media communications.  the imal project has assembled workstations which feature speech- synthesis/sampled-audio/telephony capabilities, local 1 mip computation capacity, and a high-resolution color display integrating text/graphics/image/video under an expanded x window display management system. (x windows is an emerging windowing standard to provide high performance device-independent graphics.) the workstations may be augmented as needed by local image digitizers, video cameras, and color image printers producing paper and viewgraph hardcopies. also, the workstations are interconnected with switches permitting access to one another as well as shared databases, temporary storage, intelligence, and information processing/conversion resources. communications services are implemented under a distributed, real-time service primitive control scheme. this multiple-media service primitives scheme employs a threaded/dataflow-type architecture to support user-defined, network-defined, and vendor-defined services while including a wealth of flexible features for the study of network architecture, protocol, network management, and billing functions.  l. f. ludwig d. f. dunn
forward acknowledgement: refining tcp congestion control we have developed a forward acknowledgment (fack) congestion control algorithm which addresses many of the performance problems recently observed in the internet. the fack algorithm is based on first principles of congestion control and is designed to be used with the proposed tcp sack option. by decoupling congestion control from other algorithms such as data recovery, it attains more precise control over the data flow in the network. we introduce two additional algorithms to improve the behavior in specific situations. through simulations we compare fack to both reno and reno with sack. finally, we consider the potential performance and impact of fack in the internet. matthew mathis jamshid mahdavi
internet mobility 4 4 mobile ip protocols allow mobile hosts to send and receive packets addressed with their home network ip address, regardless of the ip address of their current point of attachment in the internet.while some recent work in mobile ip focuses on a couple of specific routing optimizations for sending packets to and from mobile hosts [joh96] [mon96], we show that a variety of different optimizations are appropriate in different circumstances. the best choice, which may vary on a connection-by-connection or even a packet-by-packet basis, depends on three factors: the characteristics the protocol should optimize, the permissiveness of the networks over which the packets travel and the level of mobile-awareness of the hosts with which the mobile host corresponds.of the sixteen possible routing choices that we identify, we describe the seven that are most useful and discuss their benefits and limitations. these optimizations range from the most costly, which provides completely transparent mobility in all networks, to the most economical, which does not attempt to conceal location information. in particular, hosts should retain the option to communicate conventionally without using mobile ip whenever appropriate.further, we show that all optimizations can be described using a 4 4 grid of packet characteristics. this makes it easier for a mobile host, through a series of tests, to determine which of the currently available optimizations is the best to use for any given correspondent host. stuart cheshire mary baker
delay analysis for forward signaling channels in wireless cellular network  we consider connection-oriented wireless cellular networks. such second generation systems are circuit-switched digital networks which employ dedicated radio channels for the transmission of signaling information. a forward signaling channel is a common signaling channel assigned to carry the multiplexed stream of paging and channel-allocation packets from a base station to the mobile stations. similarly, for atm wireless networks, paging and virtual-circuit-allocation packets are multiplexed across the forward signaling channels as part of the virtual-circuit set-up phase. the delay levels experienced by paging and channel-allocation packets are critical factors in determining the efficient utilization of the limited radio channel capacity. a multiplexing scheme operating in a "slotted mode" can lead to reduced power consumption at the handsets, but may in turn induce an increase in packet delays. in this paper, focusing on forward signaling channels, we present schemes for multiplexing paging and channel-allocation packets across these channels, based on channelization plans, access priority assignments and paging group arrangements. for such multiplexing schemes, we develop analytical methods for the calculation of the delay characteristics exhibited by paging and channel-allocation packets. the resulting models and formulas provide for the design and analysis of forward signaling channels for wireless network systems.  izhak rubin cheon won choi
using prediction to accelerate coherence protocols most large shared-memory multiprocessors use directory protocols to keep per-processor caches coherent. some memory references in such systems, however, suffer long latencies for misses to remotely-cached blocks. to ameliorate this latency, researchers have augmented standard coherence protocols with optimizations for specific sharing patterns, such as read-modify-write, producer-consumer, and migratory sharing. this paper seeks to replace these directed solutions with general prediction logic that monitors coherence activity and triggers appropriate coherence actions.this paper takes the first step toward using general prediction to accelerate coherence protocols by developing and evaluating the cosmos coherence message predictor. cosmos predicts the source and type of the next coherence message for a cache block using logic that is an extension of yeh and patt's two-level pap branch predictor. for five scientific applications running on 16 processors, cosmos has prediction accuracies of 62% to 93%. cosmos' high prediction accuracy is a result of predictable coherence message signatures that arise from stable sharing patterns of cache blocks. shubhendu s. mukherjee mark d. hill
analytical comparison of local and end-to-end error recovery in reactive routing protocols for mobile ad hoc networks  in this paper we investigate the effect of local error recovery vs. end-to-end error recovery in reactive protocols. for this purpose, we analyze and compare the performance of two protocols: the dynamic source routing protocol (dsr[2]), which does end-to-end error recovery when a route fails and the witness aided routing protocol (war[1]), which uses local correction mechanisms to recover from route failures. we show that the performance of dsr degrades extremely fast as the route length increases (that is, dsr is not scalable), while war maintains both low latency and low resource consumption regardless of the route length.  ionut d. aron sandeep k. s. gupta
a codesign experiment in acoustic echo cancellation: gmdf  continuous advances in processor and asic technologies enable the integration of more and more complex embedded systems. embedded systems have become commonplace in recent years. since their implementations generally require the use of heterogeneous resources (e.g., processor cores, asics) in one system with hard design constraints, the importance of hardware/software codesign methodologies increases steadily. hw/sw codesign approaches consist generally of hw/sw partitioning and scheduling, constrained code generation, and hardware and interface synthesis. this article presents the codesign of an industrial experiment in acoustic echo cancellation (gmdfα algorithm); and emphasizes the partitioning and communication synthesis steps. this experiment brings to light interesting problems such as data and program distribution between system memories and the modeling of communications in the partitioning process  l. freund m. israel f. rousseau j. m. berge m. auguin c. belleudy g. gogniat
modeling mobile ip in mobile unity  with recent advances in wireless communication technology, mobile computing is an increasingly important area of research. a mobile system is one where independently executing components may migrate through some space during the course of the computation, and where the pattern of connectivity among the components changes as they move in and out of proximity. mobile unity is a notation and proof logic for specifying and reasoning about mobile systems. in this article it is argued that mobile unity contributes to the modular development of system specifications because of the declarative fashion in which coordination among components is specified. the packet-fowarding mechanism at the core of the mobile ip protocol for routing to mobile hosts is taken as an example. a mobile unity model of packet forwarding and the mobile system in which it must operate is developed. proofs of correctness properties, including important real-time properties, are outlined, and the role of formal verification in the development of protocols such as mobile ip is discussed.  peter j. mccann gruia-catalin roman
hierarchically-organized, multihop mobile wireless networks for quality-of- service support  mmwn is a modular system of adaptive link- and network-layer algorithms that provides a foundation on which to build mechanisms for quality-of-service provision in large, multihop mobile wireless networks. such networks are a practical means for creating a communications infrastructure where none yet exists or where the previously existing infrastructure has been severely damaged. these networks provide communications for such diverse purposes as tactical maneuvering and strategic planning on the battlefield, emergency relief in an area afflicted by a natural disaster, and field studies conducted by a team of scientists in a remote location. in this paper, we describe three key components of the mmwn system: the clustering procedures for defining a virtual, hierarchical control structure superimposed on a large network of mobile switches and endpoints; the location management procedures for determining the current locations of mobile endpoints relative to the hierarchical control structure; and the virtual circuit management procedures for setting up and repairing virtual circuits as switches and endpoints move. we also provide simulation results that illustrate the robustness of each of these components with respect to a broad spectrum of transmission ranges and relative mobility of switches and endpoints.  ram ramanathan martha steenstrup