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Showing papers on "Network topology published in 1994"


Proceedings Article
01 Jan 1994
TL;DR: An incremental network model is introduced which is able to learn the important topological relations in a given set of input vectors by means of a simple Hebb-like learning rule.
Abstract: An incremental network model is introduced which is able to learn the important topological relations in a given set of input vectors by means of a simple Hebb-like learning rule. In contrast to previous approaches like the "neural gas" method of Martinetz and Schulten (1991, 1994), this model has no parameters which change over time and is able to continue learning, adding units and connections, until a performance criterion has been met. Applications of the model include vector quantization, clustering, and interpolation.

1,806 citations


Journal ArticleDOI
TL;DR: An architecture is presented for a high-speed cellular radio access network based on ATM transport technology which avoids the need to involve the network call processor for every cell handoff attempt and which can readily support a very high rate of handoffs.
Abstract: An architecture is presented for a high-speed cellular radio access network based on ATM transport technology. Central to this approach is a new concept known as the virtual connection tree which avoids the need to involve the network call processor for every cell handoff attempt. Such an approach can readily support a very high rate of handoffs, thereby enabling use of physically small radio cells to provide very high system capacity, but may occasionally cause the volume of traffic to be handled by one cell site to exceed that cell site's capacity. A simple analytical methodology is developed which can be used for admission control, the purpose of which is to limit the number of in-progress calls such that two new quality of service metrics (overload probability and average time in overload) can be kept suitably low. Finally, a general framework is presented for overall system organization and signaling. >

488 citations


Journal ArticleDOI
TL;DR: This paper proposes a system based on a parallel genetic algorithm with enhanced encoding and operational abilities that has been applied to two widely different problem areas: Boolean function learning and robot control.
Abstract: This paper proposes a system based on a parallel genetic algorithm with enhanced encoding and operational abilities. The system, used to evolve feedforward artificial neural networks, has been applied to two widely different problem areas: Boolean function learning and robot control. It is shown that the good results obtained in both cases are due to two factors: first, the enhanced exploration abilities provided by the search-space reducing evolution of both coding granularity and network topology, and, second, the enhanced exploitational abilities due to a recently proposed cooperative local optimizing genetic operator. >

473 citations


Proceedings ArticleDOI
08 May 1994
TL;DR: This paper presents a new approach to path planning for robots with many degrees of freedom (DOF) operating in known static environments that is particularly attractive for many-DOF robots which have to perform many successive point-to-point motions in the same environment.
Abstract: This paper presents a new approach to path planning for robots with many degrees of freedom (DOF) operating in known static environments. The approach consists of a preprocessing and a planning stage. Preprocessing, which is done only once for a given environment, generates a network of randomly, but properly selected, collision-free configurations (nodes). Planning then connects any given initial and final configurations of the robot to two nodes of the network and computes a path through the network between these two nodes. Experiments show that after paying the preprocessing cost (on the order of hundreds of seconds), planning is extremely fast (on the order of a fraction of a second for many difficult examples involving a 10-DOF robot). The approach is particularly attractive for many-DOF robots which have to perform many successive point-to-point motions in the same environment. >

441 citations


Journal ArticleDOI
TL;DR: A robust scheduling protocol is proposed which is unique in providing a topology transparent solution to scheduled access in multi-hop mobile radio networks and is robust in the presence of mobile nodes.
Abstract: Transmissions scheduling is a key design problem in packet radio networks, relevant to TDMA and CDMA systems. A large number of topology-dependent scheduling algorithms are available, in which changes of topology inevitably require recomputation of transmission schedules. The need for constant adaptation of schedules to mobile topologies entails significant, sometime insurmountable, problems. These are the protocol overhead due to schedule recomputation, performance penalty due to suspension of transmissions during schedule reorganization, exchange of control message and new schedule broadcast. Furthermore, if topology changes faster than the rate at which new schedules can be recomputed and distributed, the network can suffer a catastrophic failure. The authors propose a robust scheduling protocol which is unique in providing a topology transparent solution to scheduled access in multi-hop mobile radio networks. The proposed solution adds the main advantages of random access protocols to scheduled access. Similarly to random access it is robust in the presence of mobile nodes. Unlike random access, however, it does not suffer from inherent instability, and performance deterioration due to packet collisions. Unlike current scheduled access protocols, the transmission schedules of the proposed solution are independent of topology changes, and channel access is inherently fair and traffic adaptive. >

385 citations


Journal ArticleDOI
TL;DR: This paper presents a model for designing wormhole routing algorithms based on analyzing the directions in which packets can turn in a network and the cycles that the turns can form, which produces routing algorithms that are deadlock free, livelockfree, minimal or nonminimal, and highly adaptive.
Abstract: This paper presents a model for designing wormhole routing algorithms. A unique feature of the model is that it is not based on adding physical or virtual channels to direct networks (although it can be applied to networks with extra channels). Instead, the model is based on analyzing the directions in which packets can turn in a network and the cycles that the turns can form. Prohibiting just enough turns to break all of the cycles produces routing algorithms that are deadlock free, livelock free, minimal or nonminimal, and highly adaptive. This paper focuses on the two most common network topologies for wormhole routing, n-dimensional meshes and k-ary n-cubes without extra channels

385 citations


Journal ArticleDOI
TL;DR: The results show that the decentralized data fusion system described in this paper offers many advantages in terms of robustness, scalability and flexibility over a centralized system.

362 citations


Proceedings ArticleDOI
01 Aug 1994
TL;DR: This paper presents an APL system for forecasting univariate time series with artificial neural networks that delivered a better forecasting performance than results obtained by the well known ARIMA technique.
Abstract: Artificial neural networks are suitable for many tasks in pattern recognition and machine learning. In this paper we present an APL system for forecasting univariate time series with artificial neural networks. Unlike conventional techniques for time series analysis, an artificial neural network needs little information about the time series data and can be applied to a broad range of problems. However, the problem of network “tuning” remains: parameters of the backpropagation algorithm as well as the network topology need to be adjusted for optimal performances. For our application, we conducted experiments to find the right parameters for a forecasting network. The artificial neural networks that were found delivered a better forecasting performance than results obtained by the well known ARIMA technique.

290 citations


Journal ArticleDOI
TL;DR: The authors determine necessary and sufficient conditions for shortest path routing and characterize maximum-sized families of parallel paths between any two nodes of the star graph, and parallel paths are proven of minimum length within a small additive constant.
Abstract: Undertakes a comparative study of two important interconnection network topologies: the star graph and the hypercube, from the graph theory point of view. Topological properties are derived for the star graph and are compared with the corresponding properties of the hypercube. Among other results, the authors determine necessary and sufficient conditions for shortest path routing and characterize maximum-sized families of parallel paths between any two nodes of the star graph. These parallel paths are proven of minimum length within a small additive constant. They also define greedy and asymptotically balanced spanning trees to support broadcasting and personalized communication on the star graph. These results confirm the already claimed topological superiority of the star graph over the hypercube. >

239 citations


Journal ArticleDOI
Reza Raji1
TL;DR: The author discusses the control net architecture, network topology and the fast response of the network.
Abstract: Control networks move small packets of data to a large set of nodes, so as to integrate and automate everything from home appliances to entire factories. This is due to the use of embedded microprocessors. The author discusses the control net architecture, network topology and the fast response of the network. >

209 citations


Journal ArticleDOI
TL;DR: A comparative study of the effectiveness of KSP versus Max Flow as an alternative rerouting criteria in the context of transport network span restoration, and the hypothesis is made that a generalized "trap" topology is responsible for all KSP-Max Flow capacity differences.
Abstract: In the development of technologies for span failure restoration, a question arises about the restoration rerouting characteristics to be specified. In theory, maximal rerouting capacity is obtained with a maximum flow (Max Flow) criterion. However, rerouting that realizes the k-successively shortest link disjoint paths (KSP) may be faster, easier, and, in distributed implementation, more robust than a distributed counterpart for Max Flow. The issue is, therefore, what the restoration capacity penalty is if KSP is used instead of Max Flow. To explore this tradeoff, the authors present a comparative study of the effectiveness of KSP versus Max Flow as an alternative rerouting criteria in the context of transport network span restoration. The comparison applies to both centrally controlled and distributed restoration systems. Study methods include exhaustive span failure experiments on a range of network models, and parametric and analytical investigations for insight into the factors resulting in KSP versus Max Flow differences. The main finding is that KSP restoration capacity is more than 99.9% of that from Max Flow in typical network models. The hypothesis is made that a generalized "trap" topology is responsible for all KSP-Max Flow capacity differences. The hypothesis is tested experimentally and used to develop analytical bounds which agree well with observed results. These findings and data are relevant to standards makers and equipment developers in specifying and engineering future restorable networks. >

Journal ArticleDOI
Kumar N. Sivarajan1, Rajiv Ramaswami1
TL;DR: De Bruijn graphs are proposed as logical topologies for multihop lightwave networks consisting of all-optical routing nodes interconnected by point-to-point fiber links and a physical topology based on a de Bruijn graph can support a large number of stations using a relatively small number of wavelengths.
Abstract: Proposes de Bruijn graphs as logical topologies for multihop lightwave networks. After deriving bounds on the throughput and delay performance of any logical topology, the authors compute the throughput and delay performance of de Bruijn graphs for two different routing schemes and compare it with their bounds and the performance of shufflenets. For a given maximum nodal in- and out-degree and average number of hops between stations, a logical topology based on a de Bruijn graph can support a larger number of stations than a shufflenet and this number is close to the maximum that can be supported by any topology. The authors also propose de Bruijn graphs as good physical topologies for wavelength routing lightwave networks consisting of all-optical routing nodes interconnected by point-to-point fiber links. The worst-case loss experienced by a transmission is proportional to the maximum number of hops (diameter). For a given maximum nodal in- and out-degree and diameter, a physical topology based on a de Bruijn graph can support a large number of stations using a relatively small number of wavelengths. >

Proceedings ArticleDOI
12 Jun 1994
TL;DR: The authors found that without any wavelength converters, the wavelength conflict possesses an inherent blocking to alternate route traffic and that the use of wavelength converter to resolve wavelength conflicts does not give any significant reduction of blocking probability.
Abstract: Analyzes an adaptive routing rule in a WDM lightwave network. Each switching node in the network may have a number of wavelength converters which can be used to resolve wavelength conflicts in multi-hop paths. The authors found that without any wavelength converters, the wavelength conflict possesses an inherent blocking to alternate route traffic and that the use of wavelength converter to resolve wavelength conflicts does not give any significant reduction of blocking probability. >

Proceedings ArticleDOI
12 Jun 1994
TL;DR: Algorithms are developed so that the WDM-based network architecture will provide a high aggregate system capacity due to spatial reuse of wavelengths, and support a large and scalable number of users, given a limited number of wavelengths.
Abstract: Explores design principles for next generation optical wide-area networks, employing wavelength-division multiplexing (WDM), and targeted to nationwide coverage. This almost-all-optical network will exploit wavelength multiplexers and optical switches in routing nodes, so that arbitrary virtual topologies may be imbedded on a given physical network. The virtual topology, which is packet switched and which consists of a set of all-optical lightpaths, is set up to exploit the relative strengths of both optics and electronics viz. packets of information are carried by the virtual topology "as far as possible" in the optical domain, but packet forwarding from lightpath to lightpath is performed via electronic switching, whenever required. Algorithms are developed so that the WDM-based network architecture will (a) provide a high aggregate system capacity due to spatial reuse of wavelengths, and (b) support a large and scalable number of users, given a limited number of wavelengths. The authors illustrate their approaches by employing experimental traffic statistics collected from NSFNET. >

Patent
12 May 1994
TL;DR: In this article, the authors proposed to split the network in backbone and local nodes to speed up the path selection, which can take advantage of the particular network topology to drastically reduce the complexity of paths computation.
Abstract: Currently, the routing algorithms compute all the available paths in the network, from the source node to the destination node before to select the optimal route. No assumption is made on the network topology and the route computation is often time and resource consuming. Some paths which are calculated are not acceptable due to the particular geographical configuration of the network. In the real world, large transport networks are not fully meshed. The present invention is based on the observation that networks are usually built around a hierarchical structure. A set of nodes, interconnected by high throughput lines, are used to build a 'Backbone' (401) with a high degree of meshing to allow the redundancy and reliability required by the user. The other nodes or 'local' nodes (404) are attached to one or several backbone nodes. It is the network designer responsibility, at the configuration time to define for each node what is its attribution: backbone (402) or local node (404). The list of the node attributions appears in the topology table (306) and is updated each time a node is added to or dropped from the network. The routing algorithm can take advantage of the particular network topology to drastically reduce the complexity of paths computation. For a given connection, only a limited number of nodes are eligible and are taken in account by the algorithm in the optimal route search. The object of the invention is to split the network in backbone and local nodes to speed up the path selection.

Book ChapterDOI
16 May 1994
TL;DR: The Reliable Router is a network switching element targeted to two-dimensional mesh interconnection network topologies that uses adaptive routing coupled with link-level retransmission and a unique-token protocol to increase both performance and reliability.
Abstract: The Reliable Router (RR) is a network switching element targeted to two-dimensional mesh interconnection network topologies. It is designed to run at 100 MHz and reach a useful link bandwidth of 3.2 Gbit/sec. The Reliable Router uses adaptive routing coupled with link-level retransmission and a unique-token protocol to increase both performance and reliability. The RR can handle a single node or link failure anywhere in the network without interruption of service. Other unique features include a queueless low-latency plesiochronous channel interface, and simultaneous bidirectional signalling.

Journal ArticleDOI
TL;DR: This paper discusses the reconfiguration phase which is the transition between the current logical connection diagram and a target diagram, and considers here an approach where the network reaches some target connectivity graph through a sequence of intermediate connection diagrams, so that two successive diagrams differ by a single branch-exchange operation.
Abstract: Some of today's telecommunications networks have the ability to superimpose some form of logical connectivity, or virtual topology, on top of the underlying physical infrastructure. According to the degree of independence between the logical connectivity and the physical topology, the network can dynamically adapt its virtual topology to track changing traffic conditions, and cope with failure of network equipment. This is particularly true for lightwave networks, where a logical connection diagram is achieved by assignment of transmitting and receiving wavelengths to the network stations that tap into, and communicate over, an infrastructure of fiber glass. Use of tunable transmitters and/or receivers allow the logical connectivity to be optimized to prevailing traffic conditions. With rearrangeability having thus emerged as a powerful network attribute, this paper discusses the reconfiguration phase which is the transition between the current logical connection diagram and a target diagram. We consider here an approach where the network reaches some target connectivity graph through a sequence of intermediate connection diagrams, so that two successive diagrams differ by a single branch-exchange operation. This is an attempt at logically reconfiguring the network in a way that is minimally disruptive to the traffic. We propose and compare three polynomial-time algorithms that search for "short" sequences of branch-exchange operations, so as to minimize the overall reconfiguration time. For networks made of up to 40 stations, theoretical and simulation results show that, when a randomly selected diagram is to be changed to another randomly chosen diagram, the average number of branch-exchange operations required grows linearly with the size of the network. >

Journal ArticleDOI
D.F. Bantz1, F.J. Bauchot
TL;DR: The authors argue that there is a design point that provides the best fit with present and future wireless LAN user needs and slow frequency-hopping at 2.4 GHz and TDMA-based medium access control provide the best mix of cost, range, interference, and performance.
Abstract: The authors have discussed several alternatives in wireless LAN design: media choice, operating frequency, operating mode, network topology, and access method. Although each technical choice presents both advantages and disadvantages, they argue that there is a design point that provides the best fit with present and future wireless LAN user needs. Considering all factors/spl mdash/including robustness, regulatory considerations, and interference avoidance/spl mdash/using a product based on the slow frequency-hopping spread spectrum, in the 2.4 GHz ISM band, relying on a base station remote station network topology and using a TDMA-based access method is the best way to meet the needs of radio-frequency wireless LAN users. The choices are many, but slow frequency-hopping at 2.4 GHz and TDMA-based medium access control provide the best mix of cost, range, interference, and performance. >

Patent
27 Sep 1994
TL;DR: In this article, a method for determining the maximum transfer speed for data packets transmitted over a high performance acyclic serial bus is proposed, based on the IEEE 1394 standard.
Abstract: In a tree topology network, a method for determining the maximum transfer speed for data packets transmitted over a high performance acyclic serial bus is disclosed The acyclic serial bus, patterned along the lines of the IEEE 1394 standard, is capable of operating at multiple transmission rates, depending upon the transmission rate of any particular node Once the transfer speeds have been determined by finding transmission rates to and from an ancestor node, an efficient storage technique for representing the transfer speeds is also disclosed The method supports packet speed selection for all types of data packets allowed by the IEEE standard, such as, for example, asynchronous, isochronous and broadcast packets

Proceedings ArticleDOI
01 Apr 1994
TL;DR: The advantages of CR and FCR not only simplify hardware support for adaptive routing and fault-tolerance, they also can simplify communication software layers.
Abstract: Compressionless Routing (GR) is a new adaptive routing framework which provides a unified framework for efficient deadlock-free adaptive routing and fault-tolerance. CR exploits the tight-coupling between wormhole routers for flow control to detect potential deadlock situations and recover from them. Fault-tolerant Compressionless Routing (FCR) extends Compressionless Routing to support end-to-end fault-tolerant delivery. Detailed routing algorithms, implementation complexity and performance simulation results for CR and FCR are presented.CR has the following advantages: deadlock-free adaptive routing in torus networks with no virtual channels, simple router designs, order-preserving message transmission, applicability to a wide variety of network topologies, and elimination of the need for buffer allocation messages. FCR has the following advantages: tolerates transient faults while maintaining data integrity (nonstop fault-tolerance), tolerates permanent faults, can be applied to a wide variety of network topologies, and eliminates the need for software buffering and retry for reliability. These advantages of CR and FCR not only simplify hardware support for adaptive routing and fault-tolerance, they also can simplify communication software layers.

Patent
Claude Galand1, Paolo Scotton1
12 May 1994
TL;DR: In this paper, the authors propose an automatic decomposition of a packet switching network in backbone nodes and sub-areas nodes to speed up the routing path search without degrading the optimization criterion of the routing algorithm and without generating additional control messages on the network.
Abstract: The object of the invention is to perform an automatic decomposition of a packet switching network in backbone nodes and subareas nodes to speed up the routing path search without degrading the optimization criterion of the routing algorithm and without generating additional control messages on the network. Currently, routing algorithms compute all the available paths in the network, from the source node to the destination node before to select an optimal route. However, networks are rarely fully meshed. They are usually built around a hierarchical structure: a set of nodes, interconnected by high throughput lines,are used to build a backbone with a high degree of meshing and then, local nodes are grouped in geographical subareas themselves attached to the backbone. Routing algorithms can take advantage of this particular network topology to drastically reduce the complexity of paths computation. For a given connection, only a limited number of nodes are defined as usable and are taken in account by the algorithm in its path calculation.

Journal ArticleDOI
TL;DR: In this article, the authors proposed an IP-based routing protocol that does not require any changes to stationary hosts and routers, and achieves optimal routing by coordinating a collection of mobile hosts (MHs) as a new IP network.
Abstract: Users of portable computers would like to carry their laptops with them whenever they move from one place to another and yet maintain transparent network access through the wireless link. The existing set of network protocols do not meet this requirement since they were designed under the assumption of a stationary network topology in which hosts do not change their location over time. The authors' approach, which is based on the use of a natural model and an existing IP option, does not introduce any new protocol and achieves optimal routing. The solution is transparent to transport and higher layers, and does not require any changes to stationary hosts and routers. The model is natural, because the authors coordinate a collection of mobile hosts (MHs) as a new IP network. They route packets to the MHs by using a router. The router is special because once it receives a packet, it does special things to ensure its safe delivery to its destination (the MH). This special operation is invisible to existing hosts and routers, so all the routing difference due to movement of the hosts can be hidden and effected by mechanisms under the control of the special entities. The other part of the model, which is a very natural part of a physical wireless data communications system, is the transceiver (access point), which collects wireless packets from a MH for delivery to existing hosts along existing wired networks. This transceiver provides the reference point by which the location of the MH is known.

Journal ArticleDOI
TL;DR: The cascade correlation algorithm is modified to generate networks with restricted fan-in and small depth by controlling the connectivity and the results reveal that there is a tradeoff between connectivity and other performance attributes like depth, total number of independent parameters, and learning time.
Abstract: The cascade correlation is a very flexible, efficient and fast algorithm for supervised learning. It incrementally builds the network by adding hidden units one at a time, until the desired input/output mapping is achieved. It connects all the previously installed units to the new unit being added. Consequently, each new unit in effect adds a new layer and the fan-in of the hidden and output units keeps on increasing as more units get added. The resulting structure could be hard to implement in VLSI, because the connections are irregular and the fan-in is unbounded. Moreover, the depth or the propagation delay through the resulting network is directly proportional to the number of units and can be excessive. We have modified the algorithm to generate networks with restricted fan-in and small depth (propagation delay) by controlling the connectivity. Our results reveal that there is a tradeoff between connectivity and other performance attributes like depth, total number of independent parameters, and learning time. >

Proceedings ArticleDOI
20 Nov 1994
TL;DR: This version sacrifices some diversity of tasks and efficiency for simplicity and clarity of details, and gives more efficient procedures in less detail.
Abstract: We consider asynchronous general topology dynamic networks of identical nameless nodes with worst-case transient faults. Starting from any faulty configuration, our protocols self-stabilize any computation in time polynomial in the (unknown) network diameter. This version sacrifices some diversity of tasks and efficiency for simplicity and clarity of details. Appendix gives more efficient procedures in less detail. >

Journal ArticleDOI
TL;DR: This paper presents the OMMH topology, analyzes its architectural properties and potentials for massively parallel computing, and compares it to the hypercube, and presents a three-dimensional optical design methodology based on free-space optics.
Abstract: A new interconnection network for massively parallel computing is introduced. This network is called an optical multi-mesh hypercube (OMMH) network. The OMMH integrates positive features of both hypercube (small diameter, high connectivity, symmetry, simple control and routing, fault tolerance, etc.) and mesh (constant node degree and scalability) topologies and at the same time circumvents their limitations (e.g., the lack of scalability of hypercubes, and the large diameter of meshes). The OMMH can maintain a constant node degree regardless of the increase in the network size. In addition, the flexibility of the OMMH network makes it well suited for optical implementations. This paper presents the OMMH topology, analyzes its architectural properties and potentials for massively parallel computing, and compares it to the hypercube. Moreover, it also presents a three-dimensional optical design methodology based on free-space optics. The proposed optical implementation has totally space-invariant connection patterns at every node, which enables the OMMH to be highly amenable to optical implementation using simple and efficient large space-bandwidth product space-invariant optical elements. >

Journal ArticleDOI
TL;DR: The authors propose a method for properly initializing the parameters (weights) of a two-layer perceptron, and for identifying the most suitable network size and topology for solving the problem under investigation.
Abstract: Multilayer perceptrons are now widely used for pattern recognition, although the training remains a time consuming procedure often converging toward a local optimum. Moreover, as the optimum network size and topology are usually unknown, the search of this optimum requires a lot of networks to be trained. In this paper the authors propose a method for properly initializing the parameters (weights) of a two-layer perceptron, and for identifying (without the need for any error-backpropagation training) the most suitable network size and topology for solving the problem under investigation. The initialized network can then be optimized by means of the standard error-backpropagation (EBP) algorithm. The authors' method is applicable to any two-layer perceptron comprising concentric as well as squashing units on its hidden layer. The output units are restricted to squashing units, but direct connections from the input to the output layer are also accommodated. To illustrate the power of the method, results obtained for different classification tasks are compared to similar results obtained using a traditional error-backpropagation training starting from a random initial state. >

Proceedings ArticleDOI
11 Aug 1994
TL;DR: A network switching element targeted to two-dimensional mesh interconnection network topologies that can handle a single node or link failure anywhere in the network without in terruption of service.
Abstract: The Reliable Router (RR) is a network switching element targeted to two-dimensional mesh interconnection network topologies. It is designed to run at 100 MHz and reach a useful link bandwidth of 3.2 Gbitlsec. The Reliable Router uses adaptive routing coupled with link-level retransmission and a unique-token protocol to increase both performance and reliability. The RR can handle a single node or link failure anywhere in the network without in terruption of service. Other unique features include a queueless low-latency plesiochronous channel inter face and simultaneous bidirectional signalling.

Proceedings ArticleDOI
12 Jun 1994
TL;DR: The results show that even when the buffer overflow probability at switches and receivers is low, the cumulative loss probability seen by a source may be quite high, and the average throughput increases significantly if the transport protocol delivers packets to the application layer out-of-sequence.
Abstract: The authors examine the performance implications of providing reliability in conjunction with multicast transport over a high speed wide area network. They use a block based acknowledgement and selective retransmission protocol to evaluate the impact of the loss rate and the multicast tree topology on the achievable throughput. Their results show that even when the buffer overflow probability at switches and receivers is low, the cumulative loss probability seen by a source may be quite high. They also demonstrate that the average throughput increases significantly if the transport protocol delivers packets to the application layer out-of-sequence. They investigate the scaling properties of the error control mechanism and show that the multicast tree topology that results in minimum transfer time is not necessarily the same as the one constructed using minimal bandwidth or shortest path algorithms. >

Journal ArticleDOI
TL;DR: In this article, the authors presented time-wavelength scheduling algorithms for WDM star-based networks, which incorporate the unique aspects of WDM communication such as a number of tunable transmitters and receivers at each node, the tuning time, and a limited number of wavelengths.
Abstract: Presents time-wavelength scheduling algorithms for WDM star based networks. The algorithms incorporate the unique aspects of WDM communication such as a number of tunable transmitters and receivers at each node, the tuning time, and a limited number of wavelengths. The transmission duration is composed of two elements: 1) the packet transmission time and 2) the tuning time of the system's transmitters and receivers. Based on the ratio between these two elements, the authors designed two scheduling algorithms. The first algorithm provides a minimal packet transmission duration, while trying to minimise the tuning time. The second algorithm obtains a schedule with a minimal tuning duration, while minimising the packet transmission time of the schedule. >

Patent
23 Nov 1994
TL;DR: In this paper, the authors propose a multi-segment agent topology mechanism for use by multiuser network devices in an Ethernet network, where a device's topology agent maintains and updates topology information in topology tables which identifies interconnected network devices, such as concentrators and bridges, by IP address and segment identifier information.
Abstract: A multi-segment agent topology mechanism for use by multi-segment network devices in an Ethernet network. Topology information packets exchanged between topology agents in a network include segment identifier information as well as IP address of the sending agent. A device's topology agent maintains and updates topology information in topology tables which identifies interconnected network devices, such as concentrators and bridges, by IP address and segment identifier information as well as incoming slot and port information for eventual use by a network management system in evaluating a networks topology map, and in automatically determining changes in the network's topology.