Network topology

About: Network topology is a research topic. Over the lifetime, 52259 publications have been published within this topic receiving 1006627 citations.

Optimizing cost and performance for multihoming

Abstract: Multihoming is often used by large enterprises and stub ISPs to connect to the Internet. In this paper, we design a series of novel smart routing algorithms to optimize cost and performance for multihomed users. We evaluate our algorithms through both analysis and extensive simulations based on realistic charging models, traffic demands, performance data, and network topologies. Our results suggest that these algorithms are very effective in minimizing cost and at the same time improving performance. We further examine the equilibrium performance of smart routing in a global setting and show that a smart routing user can improve its performance without adversely affecting other users.

Fault-Tolerant Consensus Tracking Control for Linear Multiagent Systems Under Switching Directed Network

Abstract: In this paper, for linear leader–follower networks with multiple heterogeneous actuator faults, including partial loss of effectiveness fault and actuator bias fault, a cooperative fault-tolerant control (CFTC) approach is developed. Assume that the interaction network topology among all nodes is a switching directed graph. To address the difficulty of designing the distributed compensation control laws under the time-varying asymmetrical network structure, a novel distributed-reference-observer-based fault-tolerant tracking control approach is established, under which the global tracking errors are proved to be asymptotically convergent in the presence of actuator failures. First, by constructing a group of distributed reference observers based on neighborhood state information, all followers can estimate the leader’s state trajectories directly. Second, a decentralized adaptive fault-tolerant tracking controller via local estimation is designed to achieve the global synchronization. Furthermore, the reliable coordination problem under switching directed topology with intermittent communications is solved by utilizing the presented CFTC approach. Finally, the effectiveness of the proposed coordination control protocol is illustrated by its applications to a networked aircraft system.

Method and apparatus for optimizing computer networks

Abstract: An optimization method collects data regarding network topology and traffic flow and creates a network model. The model is analyzed using optimization rules and network performance objectives to determine the optimal configuration of the network according to the network performance objectives. An optimization rule for positioning a shared central resource on the network identifies the communication paths between all clients of the resource and assigns a cost value to the traffic flowing between the clients and the resource. This is repeated for each potential resource position in the network. The position having the lowest traffic cost is the optimal position for the resource. An optimization rule for partitioning network segments determines all possible partitions at the hubs of a segment and scores the performance of each possible partition, according to network performance goals. The hub partition having the lowest score is the optimal hub for partitioning the network segment.

Network layer support for service discovery in mobile ad hoc networks

Abstract: Service discovery is an integral part of the ad hoc networking to achieve stand-alone and self-configurable communication networks. In this paper, we discuss possible service discovery architectures along with the required network support for their implementation, and we propose a distributed service discovery architecture which relies on a virtual backbone for locating and registering available services within a dynamic network topology. Our proposal consists of two independent components: (i) formation of a virtual backbone and (ii) distribution of service registrations, requests, and replies. The first component creates a mesh structure from a subset of a given network graph that includes the nodes acting as service brokers and a subset of paths (which we refer as virtual links) connecting them. Service broker nodes (SBNs) constitute a dominating set, i.e. all the nodes in the network are either in this set or only one-hop away from at least one member of the set. The second component establishes subtrees rooted at service requesting nodes and registering servers for efficient dissemination of the service discovery probing messages. Extensive simulation results are provided for comparison of performance measures. i.e. latency, success rate, and control message overhead, when different architectures and network support mechanisms are utilized in service discovery.

On-demand routing in large ad hoc wireless networks with passive clustering

Abstract: This paper presents on-demand routing scalability improvements achieved using a "passive" clustering. Any on-demand routing typically requires some form of flooding. Clustering can dramatically reduce transmission overhead during flooding. In fact, by using clustering, we restrict the set of forwarding nodes during flood search and thus reduce the energy cost and traffic overhead of routing in dynamic traffic and topology environments. However existing "active" clustering mechanisms require periodic refresh of neighborhood information and tend to introduce quite a large amount of communication maintenance overhead. We introduce a passive clustering protocol scheme which is mostly supported/maintained by user data packets instead of explicit control packets. The passive scheme is consistent with the on-demand routing philosophy. Simulation results show significant performance improvements when passive clustering is used.