7 research outputs found

    Implementation and evaluation of a simulation system based on particle swarm optimisation for node placement problem in wireless mesh networks

    Get PDF
    With the fast development of wireless technologies, wireless mesh networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless internet connectivity. This paper implements a simulation system based on particle swarm optimisation (PSO) in order to solve the problem of mesh router placement in WMNs. Four replacement methods of mesh routers are considered: constriction method (CM), random inertia weight method (RIWM), linearly decreasing Vmax method (LDVM) and linearly decreasing inertia weight method (LDIWM). Simulation results are provided, showing that the CM converges very fast, but has the worst performance among the methods. The considered performance metrics are the size of giant component (SGC) and the number of covered mesh clients (NCMC). The RIWM converges fast and the performance is good. The LDIWM is a combination of RIWM and LDVM. The LDVM converges after 170 number of phases but has a good performance.Peer ReviewedPostprint (author's final draft

    Node placement in Wireless Mesh Networks: a comparison study of WMN-SA and WMN-PSO simulation systems

    Get PDF
    (c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our previous work, we implemented a simulation system based on Simulated Annealing (SA) for solving node placement problem in wireless mesh networks, called WMN-SA. Also, we implemented a Particle Swarm Optimization (PSO) based simulation system, called WMN-PSO. In this paper, we compare two systems considering calculation time. From the simulation results, when the area size is 32 × 32 and 64 × 64, WMN-SA is better than WMN-PSO. When the area size is 128 × 128, WMN-SA performs better than WMN-PSO. However, WMN-SA needs more calculation time than WMN-PSO.Peer ReviewedPostprint (author's final draft

    Implementation of a new replacement method in WMN-PSO simulation system and its performance evaluation

    Get PDF
    (c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our previous work, we implemented the Linearly Decreasing Vmax Method (LDVM) for our WMN-PSO simulation system. In this paper, we implement a new replacement method for mesh routers called Rational Decrement of Vmax Method (RDVM). We use Size of Giant Component (SGC) and Number of Covered Mesh Clients (NCMC) as metrics for optimization. From the simulation results, we found that RDVM converges faster to best solution than LDVM.Peer ReviewedPostprint (author's final draft

    Design tools for wireless broadcast networks

    Get PDF
    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 89-92).In this thesis, we address the combination of three technologies in wireless broadcast networks: network coding, multi-packet reception (MPR) and feedback. We will primarily discuss the performance of a single-hop network, both with and without these technologies. A single-hop network can be used as a building block for larger and more topologically diverse networks and provides a basis for analyzing the interaction of these mechanisms. Because many applications are interested in speedy transmission of data, we have focused our attention on answering the question of how to optimally use these technologies in order to reduce the overall transmission time. Initially, we consider a fully connected network and show that MPR capability of m can reduce the total time for a file transfer by as much as a factor of m/2 without network coding. We emphasize that a two-fold MPR capability will not reduce the total dissemination time without network coding and is thus ineffective. We also show that no gain can be obtained, if network coding is used without MPR. However the combination of network coding and MPR can reduce the total transfer time by as much as a factor of m. We then consider transmission of a file over a broadcast erasure channel with a potentially large number of receivers. Noting that traditional reliable multicast protocols suffer from the inevitable feedback implosion associated with servicing a large number of receivers, we present a novel feedback protocol dubbed SMART, Speeding Multicast by Acknowledgment Reduction Technique. The protocol involves an asymptotically optimal predictive model which determines a suitable feedback time that assures most receivers have completed the download. We also introduce a new single slot feedback mechanism, which enables any number of receivers to give their feedback simultaneously. We show that scheduling the feedback according to this predictive model and enhancing the protocol by the single slot mechanism reduces the feedback traffic as well as transmission of extraneous coded packets, and will provide a good completion time characteristic for all users. We show that counter to conventional wisdom, Quality of Experience (QoE) of multicast sessions is not sensitive to the number of users, however it is very sensitive to imbalanced effective rate and heterogeneity among users. Furthermore, we show that SMART performs nearly as well as an omniscient transmitter that requires no feedback.by Arman Rezaee.S.M

    Quality of service-aware routing and admission control for mobile ad hoc networks

    Get PDF
    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Exploring the Unknown: Selected Documents in the History of the US Civilian Space Program

    Get PDF
    One of the most important developments of the twentieth century has been the movement of humanity into space with machines and people. The underpinnings of that movement -why it took the shape it did; which individuals and organizations were involved; what factors drove a particular choice of scientific objectives and technologies to be used; and the political, economic, managerial, and international contexts in which the events of the space age unfolded- are all important ingredients of this epoch transition from an earthbound to spacefaring people. This desire to understand the development of spaceflight in the United States sparked this documentary history series. 'Exploring the Unknown' is a multi-volume series containing a selection of key documents in history of the U.S. civil space program. This current volume, Volume III, focusing on the use of space for practical applications, prints 112 key documents on the history of satellite communications, remote sensing of earth, and space as an investment in economic growth, edited for ease of use. Each is introduced by a headnote providing context, bibliographical information, and background information necessary to understanding the document
    corecore