197 research outputs found

    Comparative Performance Simulation of DSDV AODV and DSR MANET Protocols in NS2

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    Mobile Ad hoc Networks (MANET) are self-configured and infrastructure less networks with autonomous mobile nodes. Due to the high flexibility, these kind of networks are heavily used in rescue operations, military missions etc. Many routing protocols for this kind of networks exist. This article presents a comparative and quantitative performance study of DSDV, AODV and DSR routing protocols using different simulation models in NS2. Performance metrics like PDR, E2E Delay and Throughput are analyzed under varying network, traffic and mobility parameters like number of nodes, traffic flows, mobility speed and pause time. Results show that AODV outperforms DSDV and DSR in all the performance metrics. DSDV performs better than DSR in terms of PDR and E2E delay. DSR gives 20-30 higher Throughput than DSDV. Performance metrics are highly influenced by network topology parameters like number of nodes and number of traffic flow connections. Mobility parameters like speed and pause time have slight impact on performance

    Comparative Performance Simulation of DSDV AODV and DSR MANET Protocols in NS2

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    Mobile Ad hoc Networks (MANET) are self-configured and infrastructure less networks with autonomous mobile nodes. Due to the high flexibility, these kind of networks are heavily used in rescue operations, military missions etc. Many routing protocols for this kind of networks exist. This article presents a comparative and quantitative performance study of DSDV, AODV and DSR routing protocols using different simulation models in NS2. Performance metrics like PDR, E2E Delay and Throughput are analyzed under varying network, traffic and mobility parameters like number of nodes, traffic flows, mobility speed and pause time. Results show that AODV outperforms DSDV and DSR in all the performance metrics. DSDV performs better than DSR in terms of PDR and E2E delay. DSR gives 20-30 higher Throughput than DSDV. Performance metrics are highly influenced by network topology parameters like number of nodes and number of traffic flow connections. Mobility parameters like speed and pause time have slight impact on performance

    Comparative Performance Simulation of DSDV, AODV and DSR MANET Protocols in NS2

    Get PDF
    Mobile Ad hoc Networks (MANET) are self-configured and infrastructure less networks with autonomous mobile nodes. Due to the high flexibility, these kind of networks are heavily used in rescue operations, military missions etc. Many routing protocols for this kind of networks exist. This article presents a comparative and quantitative performance study of DSDV, AODV and DSR routing protocols using different simulation models in NS2. Performance metrics like PDR, E2E Delay and Throughput are analyzed under varying network, traffic and mobility parameters like number of nodes, traffic flows, mobility speed and pause time. Results show that AODV outperforms DSDV and DSR in all the performance metrics. DSDV performs better than DSR in terms of PDR and E2E delay. DSR gives 20-30 higher Throughput than DSDV. Performance metrics are highly influenced by network topology parameters like number of nodes and number of traffic flow connections. Mobility parameters like speed and pause time have slight impact on performance

    The effects of network factors on the performance of 3G UMTS applications

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    Includes bibliographical references (leaves 139-148).3G is the wireless network technology expected to allow wireless applications to perform on par with wired applications. However 3G has factors which limit its performance. These factors include both device factors such as small screens, limited battery power and life, as well as network factors such as high delay networks and low bandwidths. This thesis investigates the following: how network factors affect the performance of 3G UMTS applications; which network factors have the most significant impact on a specific application; whether there are any minimum requirements needed for an application. Eight popular 3G applications were investigated: FTP, email, MMS, SMS, HTTP web browsing, broadcast media, video calling and streaming media

    A novel multimedia adaptation architecture and congestion control mechanism designed for real-time interactive applications

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    PhDThe increasing use of interactive multimedia applications over the Internet has created a problem of congestion. This is because a majority of these applications do not respond to congestion indicators. This leads to resource starvation for responsive flows, and ultimately excessive delay and losses for all flows therefore loss of quality. This results in unfair sharing of network resources and increasing the risk of network ‘congestion collapse’. Current Congestion Control Mechanisms such as ‘TCP-Friendly Rate Control’ (TFRC) have been able to achieve ‘fair-share’ of network resource when competing with responsive flows such as TCP, but TFRC’s method of congestion response (i.e. to reduce Packet Rate) is not ideally matched for interactive multimedia applications which maintain a fixed Frame Rate. This mismatch of the two rates (Packet Rate and Frame Rate) leads to buffering of frames at the Sender Buffer resulting in delay and loss, and an unacceptable reduction of quality or complete loss of service for the end-user. To address this issue, this thesis proposes a novel Congestion Control Mechanism which is referred to as ‘TCP-friendly rate control – Fine Grain Scalable’ (TFGS) for interactive multimedia applications. This new approach allows multimedia frames (data) to be sent as soon as they are generated, so that the multimedia frames can reach the destination as quickly as possible, in order to provide an isochronous interactive service. This is done by maintaining the Packet Rate of the Congestion Control Mechanism (CCM) at a level equivalent to the Frame Rate of the Multimedia Encoder.The response to congestion is to truncate the Packet Size, hence reducing the overall bitrate of the multimedia stream. This functionality of the Congestion Control Mechanism is referred to as Packet Size Truncation (PST), and takes advantage of adaptive multimedia encoding, such as Fine Grain Scalable (FGS), where the multimedia frame is encoded in order of significance, Most to Least Significant Bits. The Multimedia Adaptation Manager (MAM) truncates the multimedia frame to the size indicated by the Packet Size Truncation function of the CCM, accurately mapping user demand to available network resource. Additionally Fine Grain Scalable encoding can offer scalability at byte level granularity, providing a true match to available network resources. This approach has the benefits of achieving a ‘fair-share’ of network resource when competing with responsive flows (as similar to TFRC CCM), but it also provides an isochronous service which is of crucial benefit to real-time interactive services. Furthermore, results illustrate that an increased number of interactive multimedia flows (such as voice) can be carried over congested networks whilst maintaining a quality level equivalent to that of a standard landline telephone. This is because the loss and delay arising from the buffering of frames at the Sender Buffer is completely removed. Packets sent maintain a fixed inter-packet-gap-spacing (IPGS). This results in a majority of packets arriving at the receiving end at tight time intervals. Hence, this avoids the need of using large Playout (de-jitter) Buffer sizes and adaptive Playout Buffer configurations. As a result this reduces delay, improves interactivity and Quality of Experience (QoE) of the multimedia application

    Performance Evaluation of AODV Protocol Using NS2 Simulator

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    Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes which can dynamically self-organize into arbitrary and temporary, ïżœad-hocïżœ network topologies. This allows people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure. One interesting research area in MANET is routing. Routing in the MANETs is a challenging task and has received a tremendous amount of attention from researchers. This has led to development of many different routing protocols for MANETs. A mobile node is a collection point in the network which uses a particular protocol to forward data from source to destination. The nodes are free to move about and organize themselves into a network. The requirement of routing protocol is to send and receive information among the nodes with best suited path with the minimum delay. Correct and efficient route establishment between a pair of nodes is the primary goal of routing protocol. This paper is a simulation based analysis of Ad hoc on demand Distance Vector (AODV). The mobility models used in this work is Random Waypoint using network simulation tool NS2. The results presented in this work illustrate the performance of AODV routing protocols in an ad hoc environment

    Performance comparison of SCTP and UDP over mobile ad hoc networks

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    Countless researchers have put efforts to conduct researchs about the performance of the traditional transport control protocols (TCP) and user datagram protocol (UDP).Recently new transport protocol had been designed calledStream Control Transmission Protocol (SCTP).In this research, we will focus to study the effect of Mobile Ad Hoc Networks (MANET) on these two transport protocols SCTP and UDP and find out which one performs better over MANET.The transport protocol SCTP has more services and features compare to the traditional transport protocol.We also present some literatures on SCTP and UDP performance over MANET.The simulation parameters and the results of the simulation will also be discussed

    A comparative study of routing protocols in MANETs

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    Mobile Ad Hoc networks are emerging area of mobile computing. A mobile ad hoc network (MANET) is composed of mobile routers and associated hosts connected by wireless links. The routers are free to move randomly and organize themselves arbitrarily, thus, the network\u27s wireless topology may change rapidly and unpredictably. In fact, it is considered that each node would have some capacity to relay the information thus constrained by computational power, battery life and increasingly complex routing with added functionality of a router. Nodes may keep joining and leaving an ad hoc network. Such a network may operate in a stand alone fashion, or may be connected to the larger Internet. Lack of infrastructure in ad hoc networks sets new challenges for routing algorithms where the network is formed by a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. A number of routing protocols like Dynamic Source Routing (DSR), Ad Hoc On-Demand Distance Vector Routing (AODV), Destination-Sequenced Distance-Vector (DSDV), Zone Routing Protocol (ZRP) and Temporally Ordered Routing Algorithm (TORA) have been implemented. In this thesis an attempt has been made to compare the performance of prominent on-demand reactive routing protocols for mobile ad hoc networks (AODV and TORA), along with the traditional proactive DSDV protocol. Although AODV and TORA share similar on-demand behavior, the differences in the protocol mechanics can lead to significant performance differentials. The performance differentials are analyzed using varying network loads, mobilities, and network sizes. These simulations are carried out using network simulator (ns-2.1b9a) to run mobile ad hoc network simulations

    Measuring and Predicting Total Energy Expenditure Among Highly Active Humans in Natural Environments

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    The current model for predicting human total energy expenditure (TEE), the Factorial Method, significantly underestimates actual TEE, particularly among highly active populations. In this study, the Allocation Model is presented for predicting TEE. Unlike the Factorial Method, the Allocation Model includes metabolic cost terms for both thermoregulation and the thermic effect of food, as well as using more accurate basal metabolic rate and activity cost estimations. The Allocation Model was tested using doubly labeled water and flex-heart rate measured TEEs of healthy, highly active adults (N=56) participating in National Outdoor Leadership School semester long courses. Two of the semester-long courses took place in both hot and temperate climates and the other two in both temperate and cold climates. The Allocation Model produces TEE predictions that are not significantly different from measured TEE values. Overall, the Allocation Model comes within 12% of measured TEE values. The Allocation Model also comes within 10% of measured TEEs greater than 3500 kCal day-1 compared to a 30.2% underestimation by the factorial method. This analysis demonstrates that the Allocation Model is more accurate at TEE prediction than the Factorial Method across a range of activity levels and in different climates. Furthermore, the Allocation Model succeeds where the Factorial Method has failed - at high levels of energy expenditure. The Allocation Model can also be used to better understand how energy is allocated under different climatic and activity level conditions. From this, it was found that in cold conditions, the heat produced from activity helps to mitigate potentially high costs of thermoregulation. I was also able to analyze the relationship between the surface area/mass ratio and energy expenditure in the different climates. This allowed me to determine whether an energetic advantage of Bergmann\u27s and Allen\u27s rules was present among the NOLS population. In this study it was found that a greater surface area/mass ratio provided an energetic advantage in hot climates. However, there is also evidence that a greater surface area/mass ratio is advantageous for heat dissipation in cold environments in individuals wearing heavily insulated clothing. The results presented here suggest the Allocation Model is a powerful new tool that should be used in place of the Factorial Method for estimating human TEE, and can be used to analyze adaptations, life history strategies and differential energy allocation among highly active humans in natural environments

    Contributions to Vehicular Communications Systems and Schemes

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    La derniĂšre dĂ©cennie a marquĂ© une grande hausse des applications vĂ©hiculaires comme une nouvelle source de revenus et un facteur de distinction dans l'industrie des vĂ©hicules. Ces applications vĂ©hiculaires sont classĂ©es en deux groupes : les applications de sĂ©curitĂ© et les applications d'info divertissement. Le premier groupe inclue le changement intelligent de voie, l'avertissement de dangers de routes et la prĂ©vention coopĂ©rative de collision qui comprend la vidĂ©o sur demande (VoD), la diffusion en direct, la diffusion de mĂ©tĂ©o et de nouvelles et les jeux interactifs. Cependant, Il est Ă  noter que d'une part, les applications vĂ©hiculaires d'info divertissement nĂ©cessitent une bande passante Ă©levĂ©e et une latence relativement faible ; D'autre part, les applications de sĂ©curitĂ© requiĂšrent exigent un dĂ©lai de bout en bout trĂšs bas et un canal de communication fiable pour la livraison des messages d'urgence. Pour satisfaire le besoin en applications efficaces, les fabricants de vĂ©hicules ainsi que la communautĂ© acadĂ©mique ont introduit plusieurs applications Ă  l’intĂ©rieur de vĂ©hicule et entre vĂ©hicule et vĂ©hicule (V2V). Sauf que, l'infrastructure du rĂ©seau sans fil n'a pas Ă©tĂ© conçue pour gĂ©rer les applications de vĂ©hicules, en raison de la haute mobilitĂ© des vĂ©hicules, de l'imprĂ©visibilitĂ© du comportement des conducteurs et des modĂšles de trafic dynamiques. La relĂšve est l'un des principaux dĂ©fis des rĂ©seaux de vĂ©hicules, car la haute mobilitĂ© exige au rĂ©seau sans fil de faire la relĂšve en un trĂšs court temps. De plus, l'imprĂ©visibilitĂ© du comportement du conducteur cause l'Ă©chec des protocoles proactifs traditionnels de relĂšve, car la prĂ©diction du prochain routeur peut changer en fonction de la dĂ©cision du conducteur. Aussi, le rĂ©seau de vĂ©hicules peut subir une mauvaise qualitĂ© de service dans les rĂ©gions de relĂšve en raison d'obstacles naturels, de vĂ©hicules de grande taille ou de mauvaises conditions mĂ©tĂ©orologiques. Cette thĂšse se concentre sur la relĂšve dans l'environnement des vĂ©hicules et son effet sur les applications vĂ©hiculaires. Nous proposons des solutions pratiques pour les rĂ©seaux actuellement dĂ©ployĂ©s, principalement les rĂ©seaux LTE, l'infrastructure vĂ©hicule Ă  vĂ©hicule (V2V) ainsi que les outils efficaces d’émulateurs de relĂšves dans les rĂ©seaux vĂ©hiculaires.----------ABSTRACT: The last decade marked the rise of vehicular applications as a new source of revenue and a key differentiator in the vehicular industry. Vehicular Applications are classified into safety and infotainment applications. The former include smart lane change, road hazard warning, and cooperative collision avoidance; however, the latter include Video on Demand (VoD), live streaming, weather and news broadcast, and interactive games. On one hand, infotainment vehicular applications require high bandwidth and relatively low latency; on the other hand, safety applications requires a very low end to end delay and a reliable communication channel to deliver emergency messages. To satisfy the thirst for practical applications, vehicle manufacturers along with research institutes introduced several in-vehicle and Vehicle to Vehicle (V2V) applications. However, the wireless network infrastructure was not designed to handle vehicular applications, due to the high mobility of vehicles, unpredictability of drivers’ behavior, and dynamic traffic patterns. Handoff is one of the main challenges of vehicular networks since the high mobility puts pressure on the wireless network to finish the handoff within a short period. Moreover, the unpredictability of driver behavior causes the traditional proactive handoff protocols to fail, since the prediction of the next router may change based on the driver’s decision. Moreover, the vehicular network may suffer from bad Quality of Service (QoS) in the regions of handoff due to natural obstacles, large vehicles, or weather conditions. This thesis focuses on the handoff on the vehicular environment and its effect on the vehicular applications. We consider practical solutions for the currently deployed networks mainly Long Term Evolution (LTE) networks, the Vehicle to Vehicle (V2V) infrastructure, and the tools that can be used effectively to emulate handoff on the vehicular networks
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