waashk/acm huggingface dataset:
a novel feedback scheme to increase throughput in multiple access radio systems  to enhance the throughput of a slotted aloha control channel in a radio communication system, we present and analyze a method for estimating the number of remote stations that are attempting to transmit to a central base station. each of the contending remote stations randomly chooses to transmit with probability p. our novel contribution is the use of information concerning the number of successful packet transmissions that arrive without retransmission i.e., that are successfully received on their first transmission attempt , as a metric for accurately and robustly estimating the number of contending remote stations. this estimate is determined at the base station and then used to compute the optimal transmission probability p that is used as feedback to the remote stations for their use. the proposed estimation method is analyzed and shown to provide good steady - state performance for a variety of system models, including situations with noise and idling remote stations. the scheme is also shown to provide good tracking capabilities.  richard o. lamaire arvind krishna
bounds on the speedup and efficiency of partial synchronization in parallel processing systems  in this paper, we derive bounds on the speedup and efficiency of applications that schedule tasks on a set of parallel processors. we assume that the application runs an algorithm that consists of n iterations and before starting its i+1st iteration, a processor must wait for data (i.e., synchronize) calculated in the ith iteration by a subset of the other processors of the system. processing times and interconnections between iterations are modeled by random variables with possibly deterministic distributions. scientific applications consisting of iterations of recursive equations are examples of such applications that can be modeled within this formulation. we consider the efficiency of applications and show that, although efficiency decreases with an increase in the number of processors, it has a nonzero limit when the number of processors increases to infinity. we obtain a lower bound for the efficiency by solving an equation that depends on the distribution of task service times and the expected number of tasks needed to be synchronized. we also show that the lower bound is approached if the topology of the processor graph is ldquo;spread- out," a notion we define in the paper.  c. s. chang r. nelson
a model for naming, addressing and routing  naming and addressing are areas in which there is still a need for clarification. many definitions for names, addresses, and routes have been proposed, but the exact relations among these concepts are obscure. a taxonomy of names, addresses, and routes is presented. first, we identify names and routes as the essential concepts of communication. then, addresses are introduced as an intermediate form that eases the process of mapping between names and routes; an original definition of an address is thus proposed. relations among names, addresses, and routes are explained with the concept of mapping. on this basis, a general model relating names, addresses, and routes is built and then applied recursively throughout a layered architecture, leading to a layered naming and addressing model which may play the same role for naming and addressing features that the os1 reference model plays for the definition of services and protocols. finally, the model is particularized to a typical network architecture. the model may also be applied to non-osi layered systems; naming, addressing, and routing issues in any network architecture could be a particular instance of this layered model.  bernard m. hauzeur
performance of integrated services (voice/data) csma/cd networks  we consider a voice/data integrated local area communication system. due to the high suitability of csma/cd protocols for data communication and the existence of real time voice delay constraints we consider a hybrid tdm/csma/cd protocol. this model fundamentally differs from the very well documented voice/data integrated systems in point to point networks in which both voice and data users are assigned fixed duration time slots for transmission. the tdm/csma/cd integrated system performance is analysed and basic performance tradeoffs in the system design are manifested.  i. chlamtac m. eisinger
crossover switch discovery for wireless atm lans  the emergence of wireless local area networks (wlans) has brought about the possibility of mobile computing. in order to maintain connectivity to mobile hosts (mhs), a handover mechanism is needed as mhs migrate from one base station's (bs) wireless cell to another. current handover schemes are mainly catered for connectionless wlans (example mobile ip) which do not have the ability to support quality of service (qos) for continuous media traffic. hence, mobility for connection-oriented wlans (example wireless atm) should be considered. the problem faced in a connection-oriented wlan is the ability to provide a fast, efficient and continuous handover mechanism. mechanisms that can meet most of these requirements are the incremental and multicast based re-establishment handover schemes. in particular, the incremental re- establishment scheme relies on the presence of a "crossover switch" (cx) to establish the new partial circuits to the new bs. in this paper, five cx discovery schemes are proposed to compute and select the optimised new partial path such that both the set-up latency and network resource consumption associated with the handover are small. the proposed cx discovery schemes (loose select, prior path knowledge, prior path optimal, distributed hunt and backward tracking) are suitable for wireless atmlans employing either the centralised or distributed connection management approach with either distance-vector or link-state-like minimum-hop routing schemes. simulation results obtained from a trace-driven mobile network simulator on four different network topologies (random, star, tree and hierarchical redundancy) reveal that the prior path knowledge and distributed hunt discoveries outperform the other schemes in various aspects. finally, using the ibm paris gigabit network as an example, we show how cx discovery is incorporated with routing, connection management and qos.  chai-keong toh
an internodal protocol for packet switched data networks  this paper describes a proprietary data transmission protocol developed for internodal trunks on the northern telecom sl-10 packet switched data network. the protocol has been implemented and tested in the new universal trunk processor. two separate market forces dictated the protocol requirements. the first was a demand for high speed trunks in the t1 (1.54 mb/s) and above range to cost effectively serve future networks. the second market force was the emergence of satellite data technology with its attendant high bandwidth and lower cost. a protocol with a large sequence number range and the ability to selectively retransmit more than one packet in error without impacting the flow of correctly received packets was required. none of the standard data protocols met these requirements.  d. drynan d. baker
design of a lisp machine - flats  design of a 10 mips lisp machine used for symbolic algebra is presented. besides incorporating the hardware mechanisms which greatly speed up primitive lisp operations, the machine is equipped with parallel hashing hardware for content addressed associative tabulation and a very fast multiplier for speeding up both arithmetic operations and fast hash address generation.  e. goto t. soma n. inada t. ida m. idesawa k. hiraki m. suzuki k. shimizu b. philipov
an architectural approach for integrated network and systems management today's enterprises are accepting networked systems as a fundamental part of their information technology strategy. the constant growth in quantity and quality of networked systems and the thereby arising problems concerning complexity, heterogeneity and diversity of components in a multi-vendor environment require a sophisticated management of resources. increasingly the automation of such management is being demanded.in this paper we introduce an architecture for the integrated management of all resources in a networked system, i.e. application, system and network resources. the architecture uses domains as flexible and pragmatic means of grouping resources and of specifying management responsibility and authority boundaries. it maintains a clear distinction between management objectives and the resources being managed in order to provide an integrated view of the various tasks of management as well as an integrated and uniform view of the distributed and heterogeneous managed environment. the uniform management model on which the architecture is based is expressive enough to capture the full richness of management structures and policies both within enterprises and between them. it allows for recursive and generic structuring, we consider as the basis for management activity automation.as an example, we apply our architectural concepts to structure the management of a high speed multi-network (atm, dqdb, fddi). emphasis lies on an automated quality of service management in the fddi management domain. raouf boutaba simon znaty
dynamics of large scale distributed networks  this talk addresses the question of robustness for large scale, distributed communications networks from a dynamical standpoint. in particular, we are interested in maximizing call throughput (carried load) subject to varying levels of localized congestion and network node and link outages. the networks considered use alternate routing and crankback control to route calls. a set of approximately one hundred public switched network (psn) switching systems, together with a subset of psn facility and trunk interconnectivity, are used to generate several network designs. trunk to facility assignments are included in the design process, so that the effect of correlated trunk failures is properly taken into account.  two networks having different types of connectivity are discussed. the first network possesses "nearest neighbor" connectivity in which each node is connected by trunk groups to its nearest neighbors only ("nearest" referring to the physical proximity of nodes). the second network incorporates a "route- around" capability in which node pairs are interconnected by facility paths around interveining nodes. the route-around connectivity is extracted from psn trunk groups, and hence is not considered to be costly augmentation. route- around allows an alternate routing plan, perhaps used in conjunction with an adaptive routing algorithm, to route calls around trouble spots in the network.  using a network model to evaluate network performance, it is shown that these two networks (i.e., the nodes together with their trunk group connectivity) have very different performance characteristics when subjected to congestion and node and link outages. furthermore, it is seen that the network with bypass connectivity not only maintains a higher call-carrying capacity than the nearest neighbor network, under local congestion and node outage, but also has a lower average call set-up time. the data and algorithms used for network design and performance evaluation will be discussed. through the use of simulation it is shown that the "nearest neighbor" topology exhibits natural high usage routes with the attendant robustness concerns. the question of how to increase trunk connectivity so as to improve robustness without significantly affecting network cost is investigated.  clayton m. lockhart mario r. garzia douglas l. mikula
perspectives on atm switch architecture and the influence of traffic pattern assumptions on switch design  switch designs and the uniform distribution traffic pattern that has been the basis of much switch design analysis are discussed. in particular it is shown that head of line blocking is not the major cause of switch and link underutilization. switch fabric and buffer system input bandwidth tradeoffs are described. for client server applications it is shown that having the majority of switch buffers on the input side of a switch reduces overall switch buffering.  robert j. simcoe tong-bi pei
traffic placement policies for multi-band network  recently protocols have been introduced that enable the integration of synchronous traffic (voice or video) and asynchronous traffic (data) and extend the size of local area networks without loss in speed or capacity. one of these is drama, a multiband protocol based on broadband technology. it provides dynamic allocation of bandwidth among clusters of nodes in the total network. in this paper, we propose and evaluate a number of traffic placement policies for such networks. metrics used for performance evaluation include average network access delay, degree of fairness of access among the nodes, and network throughput. the feasibility of the drama protocol is established through simulation studies. drama provides effective integration of synchronous and asynchronous traffic due to its ability to separate traffic types. under the suggested traffic placement policies, the drama protocol is shown to handle diverse loads, mixes of traffic types, and numbers of nodes, as well as modifications to the network structure and momentary traffic overloads.  k. j. maly e. c. foudriat d. game r. mukkamala c. m. overstreet
distributing resources in hypercube computers  given a type of resource such as disk units, extra memory modules, connections to the host processor, or software modules, we consider the problem of distributing the resource units to processors in a hypercube computer so that certain performance requirements are met at minimal cost. typical requirements include the condition that every processor is within a given distance of a resource unit, that every processor is within a given distance of each of several resources, and that every m-dimensional subcube contains a resource unit. the latter is particularly important in a multiuser system in which different users are given their own subcubes. in this setting, we also consider the problem of meeting the performance requirements at minimal cost when the subcube allocation system cannot allocate all possible subcubes and the requirements apply only to allocable subcubes. we also analyze the problem of partitioning processors with resources into different classes, requiring that every processor is within a given distance of, or in a subcube of given dimension with, a member of each class. efficient constructive techniques for distributing or partitioning a resource are given for several performance requirements, along with upper and lower bounds on the total number of resource units required.  m. livingston q. f. stout
network support for mobile multimedia using a self-adaptive distributed proxy  recent advancements in video and audio codec technologies~(e.g., realv ideo [18] make multimedia streaming possible across a wide range of network conditions. with an increasing trend of ubiquitous connectivity, more and more areas have overlapping coverage of multiple wired and wireless networks. because the best network service changes as the user moves, to provide good multimedia application performance, the service needs to adapt to user movement as well as network and computational resource variations. for wireless multimedia applications, one must ensure smooth transitions when network connectivity changes. we argue that network adaptations for multimedia applications should be provided at the application layer with help from proxies in the network. the reasons are ease of programming, ease of deployment, better fault-tolerance, and greater scalability.  we propose aself-adaptive distributed proxy systemthat provides streaming multimedia service to mobile wireless clients. our system intelligently adapts to the real-time network variations and hides handoff artifacts using application protocol specific knowledge whenever possible. it also uses application- independent techniques such as dynamic relocation of transcoders and automatic insertion of forward error correction and compression into the data transcoding path. we advocate a composable, relocatable transcoding data path consisting of a directed acyclic graph ofstrongly- typedoperators to bridge any data format mismatch between the client and the data source. in this paper, we present the design, implementation, and evaluation of our system in the context of streaming video playback involving a series of transcoding proxies and a mobile client.  zhuoqing morley mao hoi-sheung wilson so byunghoon kang
performance of a decnet based disk block server  this report describes an experimental disk block server implemented for the rsx-11m operating system using decnet. the block server allows user programs on one system to access files on a disk physically located on a different system. the actual interface is at the level of physical blocks and io transfers. results of basic performance measurements are given, and explained in terms of major components. performance predictions are made for servers of this type supporting more complex workloads.  rollins turner jeffrey schriesheim indrajit mitra
a model for evaluating demand assignment protocols with arbitrary workloads  demand assignment protocols have been implemented in a large number of operational lans. however, the analytic models for protocol evaluation currently capture only a limited range of lan operational circumstances. in this paper we present an analytic tool for evaluating fair and prioritized demand assignment protocols with a relatively general workload model. we consider arbitrary and station dependent message size distributions and arrival rates. this allows the modeling of lans with heterogeneous workloads, thus permitting a larger correspondence between the modeled system and the real life network.  z koren i chlamtac a ganz
mac-cube, the macintosh-based hypercube  the mac-cube is a macintosh- based hypercube. it uses appletalk hardware and software as the medium for the nodal connections. at the physical level appletalk has a bus topology. hypercube connectivity is emulated on the appletalk local area network while the hypercube communication protocol is integrated in the appletalk software. available for mac-cube is the crystalline operating system iii (cros iii.) mac-cube provides a programming environment similar to any other hypercube systems running cros iii. it allows inexpensive hands-on experience with a concurrent machine. data can be displayed on graphics monitor and/or stored locally at each node. in addition to the low cost, these capabilities of the mac-cube makes it an indispensable instructional and development tool for parallel processing. some application programs which are taken from the book solving problems on concurrent processors [fox 88] have been implemented with graphics enhancement on mac- cube. the applications are solving the mandelbrot set in the complex plane, and solving a 2-dimensional laplace equation using finite difference.  a. ho g. c. fox d. w. walker m. breaden s. chen a. knutson s. kuwamoto t. cole
duplication of packets and their detection in x.25 communication protocols  in the context of x.25 communication protocols, this paper is concerned with the process of duplication of packets at the frame level, and with their detection at the packet level. with suitable constraints involving  (i) the window sizes used at both the frame and packet levels to flow control, and  (ii) the numbering scheme used to number user data packets,  it is possible to detect and discard all duplicate copies thereof. further, it is argued that duplication of 'messages' by a particular layer be detected at the level where these messages are generated and interpreted. deferring this detection to higher levels is unnecessary and more difficult.  bijendra n. jain
mobile router technology development  cisco system and nasa have been performing joint research on mobile routing technology under a nasa space act agreement. cisco developed mobile router technology and provided that technology to nasa for applications to aeronautic and space-based missions. nasa has performed stringent performance testing of the mobile router, including of the interaction of routing and transport level protocols. this paper describes mobile routing, the mobile router, and some key configuration parameters. in addition, the paper describes the mobile routing test network and test results documenting the performance of transport protocols in dynamic routing environments.  william d. ivancic david h. stewart terry l. bell brian a. kachmar dan shell kent leung
a hybrid handover protocol for local area wireless atm networks  while handovers of voice calls in a wide area mobile environment are well understood, handovers of multi-media traffic in a local area mobile environment is still in its early stage of investigation. unlike the public wireless networks, handovers for multi-media wireless lans (wlans) have special requirements. in this paper, the problems and challenges faced in a multi-media wlan environment are outlined and a multi-tier wireless cell clustering architecture is introduced. design issues for multi-media handovers are specified and a fast, continuous and efficient hybrid handover protocol is proposed. the protocol is scalable and supports source and destination mobile handovers in a mutually exclusive manner. crossover switch (cx) discovery is also introduced to support fast inter-cluster handovers with consideration given to mobile quality of service (m-qos). the resulting wireless atm lan exhibits a distributed mobile location management, call admission control and handover management architecture. a prototype of the proposed handover protocol is implemented into a cambridge fairisle atm switch and the results of handovers for a single mobile host (mh) with a single on-going connection are evaluated. it was found that implementing transport mobility for a wireless atm environment is not practical as the cell re-routing function changes the traffic characteristics and is not scalable to increasing cell rate and to the number of mobile connections. the data-link layer mobility implementation however, is found to work well. the protocol provides symmetric data disruption to traffic flows in both directions and up to seventy-five intra-cluster handovers can be supported in a second. throughout the experiment, cells arrive in sequence with no cell loss observed during the handover, up to the capacity limit of the atm switch. finally, `zig-zag' handovers and handovers for a single mh with multiple ongoing unicast connections are performed in order to evaluate the robustness and performance of the protocol under different mhs' migration and communication environment.  chai-keong toh