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Networks, 2009. ICN '09. Eighth International Conference on

Date 1-6 March 2009

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Displaying Results 1 - 25 of 85
  • [Front cover]

    Page(s): C1
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  • [Title page i]

    Page(s): i
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  • [Title page iii]

    Page(s): iii
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  • [Copyright notice]

    Page(s): iv
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  • Table of contents

    Page(s): v - xi
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  • Program Committee

    Page(s): xiii - xv
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  • list-reviewer

    Page(s): xvi - xviii
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  • Simulation Based Performance Analysis of Ethernet MPI Cluster

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (140 KB) |  | HTML iconHTML  

    This paper shows the influence of network aspects and MPI implementation on the performance of an Ethernet based computer cluster. Following factors are considered: message size, number of nodes, node heterogeneity, network speed, switching technology and MPI implementation. The basic index of performance is throughput measured with Intel MPI Benchmark. This paper shows that there is a specific message size that is optimal for each cluster configuration. Most important factor is the network speed, the second is MPI implementation. One can also find that using a faster master node can give a speed bonus. View full abstract»

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  • A Program Suite for Distributed Simulation of Networks in Multi-core Environments

    Page(s): 6 - 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (221 KB) |  | HTML iconHTML  

    The ns-2 simulator is one of the most popular and widely used discrete event network simulators. Its usage of the general purpose Tcl scripting language accompanied with a wide range of networking technologies allows users to easily create complex and differentiated simulation scenarios. The main limitation of ns-2 is its lack of support for multiprocessing, especially considering that the multi-core environments have recently become tools of everyday use. In this paper we (a) propose a programming approach that allows running single-model simulations simultaneously on a multi-core systems using ns-2 and (b) present a set of software tools developed following the proposed convention. In addition, we describe a lightweight software scheduler extending the use of ns-2 on ad-hoc grid systems. View full abstract»

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  • The Impact of AP Placement in WLAN-Based Indoor Positioning System

    Page(s): 12 - 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB) |  | HTML iconHTML  

    In recent years, the indoor positioning systems using the existing wireless local area network and location fingerprinting schemes are the most popular systems. The accuracy of the system is the most important indicator. In this paper we present some experimental results to explore different environment parameters that impact localization error. View full abstract»

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  • Designing and Implementing an Embedded Linux for Limited Resource Devices

    Page(s): 18 - 23
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (682 KB) |  | HTML iconHTML  

    In this paper, the implementation details of an embedded Linux for limited resource devices are provided. Due to lack of an actual hardware to test the implemented embedded Linux, a simulator for development work had to be built. Thus, the implementation details of the simulator as well as an analysis of simulation results are described. Moreover, some new ideas that will be used in our future research work are proposed. View full abstract»

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  • Measuring Route Diversity in the Internet from Remote Vantage Points

    Page(s): 24 - 29
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (270 KB) |  | HTML iconHTML  

    Recent works on modeling the Internet topology have highlighted how the complexity of relationships between Autonomous Systems (ASes) can not be oversimplified without sacrificing accuracy in capturing route selection. Such a shortcoming can mislead the understanding, hence the prediction, of the BGP (Border Gateway Protocol) behavior. In particular, models that assume an AS to be an atomic entity fail to account for route diversity, informally defined as the selection within a single AS of multiple routes to the same destination prefix. Internet topology models are usually built out of BGP data collected by remote vantage points. Thus, in this paper we aim at extracting and characterizing the route diversity that can be measured using such dataset. Towards this goal, we devise a methodology to compute route diversity from a continuous stream of collected BGP messages. The analysis of our results shows that (i) accounting for the BGP dynamics allows to extract much more diversity than from a static snapshot of the Internet routing configuration; (ii) route diversity observed for an AS is strongly related to its location in the customer-provider hierarchy; (in) the distribution of route diversity over ASes is unlikely to be biased by the specific choice of the collection system, while the number of prefixes exhibiting route diversity can depend on both number and location of the vantage points. View full abstract»

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  • Does the Internet Still Demonstrate Fractal Nature?

    Page(s): 30 - 34
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (310 KB) |  | HTML iconHTML  

    The self-similar nature of bursty Internet traffic has been investigated for the last decade. A first generation of papers, approximately from 1994 to 2004, argued that the traditionally used Poisson models oversimplified the characteristics of network traffic and were not appropriate for modeling bursty, local-area, and wide-area network traffic. Since 2004, a second generation of papers has challenged the suitability of these results in networks of the new century and has claimed that the traditional Poisson-based and other models are still more appropriate for characterizing todaypsilas Internet traffic. A possible explanation was that as the speed and amount of Internet traffic grow spectacularly, any irregularity of the network traffic, such as self-similarity, might cancel out as a consequence of high-speed optical connections, new communications protocols, and the vast number of multiplexed flows. These papers analyzed traffic traces of Internet backbone collected in 2003. In one of our previous papers we applied the theory of smoothly truncated Levy flights and the linear fractal model in examining the variability of Internet traffic from self-similar to Poisson. We demonstrated that the series of interarrival times was still close to a self-similar process, but the burstiness of the packet lengths decreased significantly compared to earlier traces. Since then, new traffic traces have been made public, including ones captured from the Internet backbone in 2008. In this paper we analyze these traffic traces and apply our new analytical methods to illustrate the tendency of Internet traffic burstiness. Ultimately, we attempt to answer the question: Does the Internet still demonstrate fractal nature? View full abstract»

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  • Capacity Theorem for Finite Duration Symbols

    Page(s): 35 - 39
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (237 KB) |  | HTML iconHTML  

    The proof of capacity theorem assumed that the symbols are of infinite time duration. Since the infinite time symbols are not meaningful and is not used in the existing technology, in this paper we decided to prove it over finite time interval. The result shows that the new capacity of a band limited channel explicitly depends on the sample rate. This new approach helps us to show that all shift keying methods do not meet the Shannonpsilas model and therefore cannot achieve the basic capacity limits. We also show that the function modulation method can be engineered to achieve the new extended limits. To establish our theory we use the well known mathematical concept of infinite dimensionality of function space. The new capacity result is stated in a theorem. View full abstract»

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  • Filter Design for Image Preprocessing in Image Communication

    Page(s): 40 - 45
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (324 KB) |  | HTML iconHTML  

    An effective approach in the design of two-dimensional notch FIR filters for image preprocessing useful in image communication is presented. The completely analytical design method is based on Zolotarev polynomials. Closed form formulas for the filter design are presented. One example demonstrates the design procedure. An application of the 2-D notch FIR filter for image preprocessing is presented. View full abstract»

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  • Application of Game Theory in Ad-Hoc Opportunistic Radios

    Page(s): 46 - 51
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (399 KB) |  | HTML iconHTML  

    The application of mathematical analysis to the study of wireless ad hoc networks has met with limited success due to the complexity of mobility, traffic models and the dynamic topology. A scenario based UMTS TDD opportunistic cellular system with an ad hoc behavior that operates over UMTS FDD licensed cellular network is considered. In this paper, we describe how ad hoc opportunistic radio can be modeled as a game and how we apply game theory based power control in ad-hoc opportunistic radio. View full abstract»

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  • A Node's Number of Neighbors in Wireless Mobile Ad Hoc Networks: A Statistical View

    Page(s): 52 - 60
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3528 KB) |  | HTML iconHTML  

    In the last decade, since the advent of advanced wireless technology, wireless mobile ad hoc networks have grown in both size and complexity, and their applications are also expanding at a great rate due to their many advantages, principally mobility and the fact that they do not require a fixed supporting structure. Security, routing protocols, and connectivity are major issues with mobile ad hoc networks, and seeking a solution to these and other problems is of great interest within the research community.All of these problems are affected by the number of neighbors that a given node has at a given time. In this paper, we examine the number of neighbors that a node has at an arbitrary moment during simulation time. We find that the interested number is not stuck with the node distribution or speed stable state but rather it fluctuates until converging after a period of time. Based on the results obtained from simulations, we have built a statistical model to grab a view of the number of neighbors each node has. Additionally, we have addressed some problems that are closely related to the average number of neighbors. View full abstract»

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  • Simulation Platform for Wireless Sensor Networks Based on Impulse Radio Ultra Wide Band

    Page(s): 61 - 66
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (319 KB) |  | HTML iconHTML  

    Impulse radio ultra wide band (IR-UWB) is a promising technology to address wireless sensor network (WSN) constraints. However, existing network simulation tools do not provide a complete WSN simulation architecture, with the IR-UWB specificities at the physical (PHY) and the medium access control(MAC) layers. In this paper, we propose a WSN simulation architecture based on the IR-UWB technique. At the PHY layer, we take into account the pulse collision by dealing with the pulse propagation delay. We also modelled MAC protocols specific to IRUWB,for WSN applications. To completely fit the WSN simulation requirements, we propose a generic and reusable sensor and sensing channel model. Most of the WSN application performances can be evaluated thanks to the proposed simulation architecture. The proposed models are implemented on a scalable and well known network simulator: Global Mobile Information System Simulator (GloMoSim). However,they can be reused for all other packet based simulation platforms. View full abstract»

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  • Self-Configuration Channel in the Wireless Networks

    Page(s): 67 - 70
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (175 KB) |  | HTML iconHTML  

    This paper describes the importance of choosing channels in the wireless local networks (WLAN) performance. The massive use of channel 6, the default channel in most 802.11 networks, usually impacts at least, 100% in the throughput of the network. In some cases, considering the number of 802.11 networks around and the time, the impact can be as high as 1200%. The protocols implemented in the 802.11b/g/n networks use carrier sense multiple access with collision avoidance (CSMA/CA), a multiplexing structure between users. This paper proposes a new structure of multiplexing between users and access points to improve the performance of these networks. View full abstract»

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  • A TDMA-Based MAC Protocol for Mobile Sensor Networks

    Page(s): 71 - 75
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (337 KB) |  | HTML iconHTML  

    Although many medium access control (MAC) protocols have been specifically designed for WSNs where energy awareness is an essential consideration, only a few of them have considered the presence of mobile nodes or dynamic network topology in their protocols. However, they have usually considered occasional mobility, in which a few number of nodes may start moving at very low speeds and then remained immobile for a long period of time. In this paper, we propose a modified version of LMAC as mobile-LMAC (M-LMAC) to improve its performance in the scenarios include continuous mobility. The protocol is compared to SMAC and LMAC by simulation. The results show that the proposed M-LMAC protocol has much better performance in terms of packet delivery ratio, network life time and end-to-end delay in presence of mobile nodes. View full abstract»

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  • A Hybrid Approach to Actor-Actor Connectivity Restoration in Wireless Sensor and Actor Networks

    Page(s): 76 - 81
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB) |  | HTML iconHTML  

    Wireless sensor and actor networks (WSANs) consist of powerful actors and resource constraint sensors, which are linked together in wireless networks. In some applications, actors must communicate with each other to make appropriate decisions and perform coordinated actions. Actor-actor network connectivity is vital to networks in such applications. Since WSAN applications are mostly deployed in harsh environments, actor nodes may fail and partition their network. This paper proposes a comparatively more efficient distributed approach to restore actor-actor connectivity upon the failure of any actor by identifying critical actors as well as the connectivity dominating set of the network. This hybrid method helps in detecting critical nodes and candidate replacement actors more precisely while minimizing the total number of required messages for network restoration. Handling the failure of the actors is done in a proactive manner. The proposed approach minimizes both the total actors' movements and restoration time of network. When a failed actor is a critical node, actors in its neighborhood are relocated in a coordinated way to reconnect the actor network. The superiority of the proposed approach is validated through simulative experiments. View full abstract»

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  • Proposal of Data Intensive Sensor Networks with Forwarder Nodes

    Page(s): 82 - 87
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (269 KB) |  | HTML iconHTML  

    Reducing power consumption and increasing battery life of sensor nodes are important challenges for sensor networks. In this paper, we propose a simple routing protocol that constructs routes depending on a remaining battery capacity. Then, we explore a new type of sensor network with forwarder nodes and a data aggregation scheme. The forwarder node is a special node that has a large size of battery and supports the route construction to the sink node from sensor nodes. Finally, we evaluate the advantage of the data aggregation scheme for this sensor network. In numerical results, we show that our protocol can extend the lifetime of the sensor networks and improve the event delivery ratio at the sink node. View full abstract»

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  • QoS in IEEE 802.16e for VoIP and Video with Mechanism of Soft Handover – FBSS in Highway

    Page(s): 88 - 93
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (442 KB) |  | HTML iconHTML  

    This evaluation is intended to show through simulations, the performance of FBSS Handover mechanism in the case of high speed mobility with mobile WIMAX for multimedia. The model we propose for the evaluation, is close to a real case in life, where it is made up of a highway between two cities far from 145 km and responsible of vehicles traveling in both directions with relatively high speeds and variable between 70 and 130 km/h. The passengers in vehicles are equipped with terminals adapted to the IEEE 802.16e better known as the "mobile WiMAX". As a result we will suppose that the terminals exchange traffics such as VoIP and video with base stations for a real time of 100 minutes. The highway is covered by 6 base stations, whose range is a 14 km (radius) and every two base stations belong to the same ASN. So, we will evaluate the QoS of this mobility model, which uses the mechanism of Handover: Fast Base Station Switching (FBSS) during the passage of vehicles between WIMAX cells, through the measures that we will obtain by simulations. The simulations were conducted under the mobility module NIST of the simulator NS2.29. View full abstract»

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  • On the Path Processing under Energy Constraints

    Page(s): 94 - 98
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (186 KB) |  | HTML iconHTML  

    In wireless sensor networks and pervasive environments situations occur where only one path between a source of raw data and a target requiring processed data is available by topology and/or by the network layer. All nodes - source, target, and relay nodes between them - underly energy constraints. The depletion of the energy of any involved node would disable the network. In consequence, a scheme for the distribution of data processing that minimizes local peaks in energy consumption is needed. This paper introduces solutions for the given problem, where no information about the battery status is available. Furthermore, model modifications to meet more practical situations and the problem of total energy consumption are discussed. View full abstract»

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