Showing papers on "Zone Routing Protocol published in 1983"
TL;DR: Extensions to the basic route first--cluster second method both to improve its effectiveness and to enable it to cope with practical constraints are described.
Abstract: In this paper we consider route first—cluster second methods for the vehicle routing problem. Extensions to the basic method both to improve its effectiveness and to enable it to cope with practical constraints are described. Computational results are given for the method applied to standard vehicle routing problems drawn from the literature.
377 citations
TL;DR: It is found that dynamic routing algorithms improve network performance by increasing the number of paths available for call connection over what would otherwise be available to a corresponding static routing.
Abstract: The performance of three dynamic routing techniques for small circuit-switched networks is compared by simulation with three static routing techniques and with a repacking technique for calls in progress. It is found that dynamic routing algorithms improve network performance by increasing the number of paths available for call connection over what would otherwise be available to a corresponding static routing. It is also shown that call repacking increases the amount of carried traffic significantly, and that this improvement is obtained by a different mechanism than for dynamic routing. The possibility of combining the two techniques is also investigated, and general characteristics of good dynamic routing techniques are presented.
43 citations
01 Oct 1983
TL;DR: Protocols and algorithms for efficiently dealing with the characteristics of various types of multiaccess links, when they are included as links in a general topology net are presented.
Abstract: Conventional routing protocols and algorithms work most efficiently on sparsely connected networks. Network topologies today include multiaccess links which include hundreds of nodes, all of which are capable of direct communication with each other. Some of these multiaccess links have broadcasting ability. This paper presents protocols and algorithms for efficiently dealing with the characteristics of various types of multiaccess links, when they are included as links in a general topology net.
8 citations
01 Dec 1983
TL;DR: The problem of dynamic routing in data communication networks is considered in a team-theory framework and the structure of the optimal strategies is derived.
Abstract: The problem of dynamic routing in data communication networks is considered. A model is introduced which takes into proper account the decentralization of the information about the network status. The problem is thus considered in a team-theory framework and the structure of the optimal strategies is derived.
5 citations
01 Oct 1983
TL;DR: Adaptive routing algorithms for communication networks that are subject to damage route calls through the network when the network configuration is not fully known, and adaptively reorder the routing tables as they gather more information about the network configured.
Abstract: This paper proposes and examines adaptive routing algorithms for communication networks that are subject to damage. These algorithms route calls through the network when the network configuration is not fully known, and adaptively reorder the routing tables as they gather more information about the network configuration. (The path that a call follows in the network is determined by routing tables. When a call reaches a node, a routing table is consulted to find the next node to attempt.) We concentrate on learning mechanisms that reorder the routing tables in real-time. For example, the success-to-top mechanism moves the table entry that led to a successful connection of a call to the top of the routing table. Success-to-top leaves the relative order of the other entries in the routing table unchanged. Other possible schemes include failure-to-bottom (entries that lead to unsuccessful connection attempts are placed on the bottom of the list), and success-up-one (in which the successful entry is moved up by one in the routing table). Markov chain models are described for success-to-top and failure-to-bottom schemes. Analytical expressions for the steady-state probabilities are used to form measures for these two strategies. We compare these measures for a wide selection of blocking probabilities. Further, a simulation model is used to evaluate the merits of all three (and more) schemes. The simulation provides network measurements not available from the analytical model. The simulation also examines information sharing mechanisms in which a single call is used to change the routing tables at many nodes.
4 citations
01 Dec 1983
TL;DR: Two distributed routing procedures based upon the Yen shortest path algorithm are developed for application in a packet-switched communications network and exhibit robust operating characteristics which are almost optimal in simple situations.
Abstract: : Two distributed routing procedures based upon the Yen shortest path algorithm are developed for application in a packet-switched communications network. The algorithm uses a unique method in calculating shortest paths based upon the time of arrival of update messages. The first routing procedures uses a proposed 'combination' link weight function having parameters involving both current link queue size and recent history of link utilization. Performance of this procedure is analyzed under a variety of network conditions using computer simulation. A comparison study is done with both a least hop routing protocol and a multiple path static routing protocol. The second routing procedure has a hierarchical structure which offers substantial reductions in routing traffic and memory requirements over the first version when implemented in large networks. The major conclusion is that these routing procedures exhibit robust operating characteristics which are almost optimal in simple situations. (Author)
1 citations