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Showing papers on "Geographic routing published in 1984"


Journal ArticleDOI
TL;DR: The algorithms are based on Gallager's method and provide methods for iteratively updating the routing table entries of each node in a manner that guarantees convergence to a minimum delay routing and utilize second derivatives of the objective function.
Abstract: We propose a class of algorithms for finding an optimal quasi-static routing in a communication network. The algorithms are based on Gallager's method [1] and provide methods for iteratively updating the routing table entries of each node in a manner that guarantees convergence to a minimum delay routing. Their main feature is that they utilize second derivatives of the objective function and may be viewed as approximations to a constrained version of Newton's method. The use of second derivatives results in improved speed of convergence and automatic stepsize scaling with respect to level of traffic input. These advantages are of crucial importance for the practical implementation of the algorithm using distributed computation in an environment where input traffic statistics gradually change.

162 citations


Patent
Alan Huang1, Scott C Knauer1
08 Mar 1984
TL;DR: In this article, a self-routing switching network consisting of a conventional self routing sorting network (20) followed by a self routing expander (40) is described. But the authors do not specify the destination address of the input signal.
Abstract: A full access, non-blocking, wide band switching network that is self routing. Responsive to input signals having embedded destination addresses, the self routing switching network comprises a conventional self routing sorting network (20) followed by a self routing expander (40). Incoming signals are ordered, and simultaneously appear at the output of the sorting network (20) in ascending order of destination addresses. The signals incoming to the expander network (40) are also processed simultaneously. The processing consists of relating the intermediate address of the expander network input line (1300) at which each signal appears with the destination address of the signal, and steering the signal to the appropriate output line (1400).

74 citations


Journal ArticleDOI
J. Hahn1, D. Stolle

68 citations


Patent
Kho Sy Kian-Bon1
04 Jun 1984
TL;DR: In this paper, the authors propose a frame format and procedure for routing messages through a single ring or multi-ring communication system, which includes a plurality of control bits positioned within a Routing Information (RI) field, a frame control field and a frame status field.
Abstract: The architecture provides a frame format and procedure for routing messages through a single ring or multi-ring communication system. Stations associated with the exchange of messages are located on the single ring or on different rings of the multi-ring communication system. The rings are connected by bridges to form a local area network. The frame format includes a plurality of control bits positioned within a Routing Information (RI) field, a frame control field and a frame status field. Messages are generated and structured in accordance with the frame format. A group of the control bits, in each message, is set with initial values according to the message type. Thus, different messages are characterized by a different sequence of control bit settings. A routing algorithm analyzes the message and depending on the status of the control bits, the message is processed and ultimately switched to its proper destination.

49 citations


Journal ArticleDOI
TL;DR: The usefulness of nonhierarchical alternate routing in reducing the blocking probability in already existing networks, and in decreasing the number of trunks required to maintain a prespecified grade of service, both in real and artificially generated networks is given.
Abstract: Nonhierarchical alternate routing is the simplest extension to the hierarchical routing currently used in telephone networks. In order to evaluate the merits of such a technique, it is necessary to be able to optimize some performance measure over the routing variables. In a first step, a short discussion is presented of the evaluation algorithms used for computing the end-to-end blocking probabilities in networks operating under nonhierarchicai alternate routings. Then the results of a statistical sampling of the routing space for a small network are presented, to illustrate important characteristics of the routing problem. Next, two heuristic optimization techniques are discussed, one based on classical steepest descent and the other inspired from classical routing optimization of traffic flows in transportation and communication networks. Acceleration techniques are discussed in both cases, and the convergences rates of the alorgithms are presented for a number of networks. A brief discussion is finally given of the usefulness of nonhierarchical alternate routing in reducing the blocking probability in already existing networks, and in decreasing the number of trunks required to maintain a prespecified grade of service, both in real and artificially generated networks.

12 citations


Proceedings ArticleDOI
01 Dec 1984
TL;DR: This work proves convergence of a distributed gradient projection method for optimal routing in a data communication network and takes into account the possibility of transients caused by updates in the routing strategy being used.
Abstract: We prove convergence of a distributed gradient projection method for optimal routing in a data communication network. The analysis is carried out without any synchronization assumptions and takes into account the possibility of transients caused by updates in the routing strategy being used.

5 citations



01 Aug 1984
TL;DR: This thesis examines the design of geographically centralized high performance packet switched networks called routing networks intended to be used to interconnect the modules of a highly parallel computer system.
Abstract: This thesis examines the design of geographically centralized high performance packet switched networks called routing networks. Each of these networks is intended to be used to interconnect the modules of a highly parallel computer system. The design of such networks is considered in present (1984) technology where only a small number of network nodes can be placed on a single chip and in VLSI technology where a large number of nodes can be placed on a chip. In both technologies, the design of routing networks for uniform patterns of communication is considered. In each technology, it is shown that the characteristics of these patterns imply a minimum cost for networks capable of supporting them. In present technology, the performance of a particular network that is well suited for uniform communication, the indirect n-cube network that is found still allows the throughput of the network for uniform patterns of communication to grow linearly with the size of the network. In VLSI, the use of networks such as the crossbar and the indirect n-cube to support uniform patterns of communication is considered. The design of routing networks for a few localized patterns of communication is briefly considered in both technologies. In each technology, networks that are well suited for these localized communication patterns are discussed.

1 citations


Proceedings ArticleDOI
01 Jan 1984
TL;DR: A new topology for a network with connectivity of four is described that has a regular structure and can accommodate any number of nodes and the proposed routing and protocol for data transfer between any two nodes of the network is described.
Abstract: connectivity of four. This paper describes a new topology for a network with connectivity of four. The topology has a regular structure and can accommodate any number (>8) of nodes. The paper also describes the proposed routing and protocol for data transfer between any two nodes of the network. Beforetransferring data the sending node must establish connection to the destination node. This is done by use of a special packet called 'Interconnection Packet'. The performance of the network has been evaluated by simulations done ona Honeywell DPS8 computer using Pascal compiler. Results of the simulations are presented.