M Tech Dissertations

Permanent URI for this collectionhttp://drsr.daiict.ac.in/handle/123456789/3

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  • ItemOpen Access
    Traffic profile measurement and traffic driven network reconfiguration
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2011) Monga, Jasneet Kaur; Srivastava, Sanjay
    In multi hop ad hoc network, nodes are constrained by the power or the energy sources that are available. Efficient algorithms for saving the energy are required to manage the network in such a manner that the resources available, get properly utilized and nodes in the network do not drain out. Switching and working over idle and busy periods of a node, one can achieve this dual goal and it comes under the category of sleep scheduling. In this approach, the basic emphasis is on the traffic profiles of the network nodes which is estimated based on the network traffic flows. The traffic estimated becomes the weight of the path between the different source destination pairs available in the network and this value averaged either at the local level or the global level is needed to be reduced, hence saving the overall energy of the network. The traffic weighted paths which consume energy above the average or the threshold value become the prime candidates for the consideration. The aim is to go for shorter and lighter paths in the network which require the sleeping nodes in the proximity of heavy and longer paths to be awaken to be a part of network topology and saving the extra energy wasted on longer paths. This makes the nodes in longer paths go through a sleep state so that they can be utilized when they are required, hence making topology changes by reconfiguring the paths.
  • ItemOpen Access
    Packet forwarding strategies for cooperation enforcement in mobile wireless ad hoc networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2011) Patel, Nidhi; Muthu, Rahul
    In self-organized ad hoc networks, all networking functions rely on the contri- bution of the relay nodes. Nodes have to forward packets for each other in order to enable multi-hop communication. In recent years, researchers have identi ed the problem of stimulating cooperation in ad hoc networks and proposed several solutions to give nodes incentive to contribute to common network services. These solutions are based on incentive mechanisms like reputation based system or virtual currency based system. This paper aims at determining conditions under which, such cooperation without incentives can exist, while taking the network topology into account. We have focused on the most basic networking mechanism, namely, packet forwarding and proposed a game theoretic approach for achieving cooperation. We have de ned a game model where nodes act as players, their actions (forward or drop a packet) de ne strategies and they are given payo s based on the payo functions designed in terms of network parameters. We have considered di erent parameters for simulation like tramsmission range, di erent strategies, initial condition of nodes, energy cost for sending or forwarding packets, tra c rate, noise e ect, mobility, etc. Our simu- lation result shows how cooperation is achieved in network with nodes getting better payo s. Later we have extended our work to cover network with mobile nodes.
  • ItemOpen Access
    Cooperation enforcement mechanisms in wireless adhoc networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Chaturvedi, Manish Shivshankar; Srivastava, Sanjay
    Wireless adhoc networks are autonomous, infrastrutureless networks where there are no dedicated routers or base stations and nodes are expected to cooperate in Wireless performing routing duties to keep network connected. Cooperation can be assumed if all nodes belong to single authority (e.g. military service or disaster management). But in applications where nodes do not belong to single authority and have limited resources (energy of battery driven devices), like pervasive computing or ubiquitous computing environment, one can not deny possibility of node selfishness. Also as there is no central authority to control node behavior, one can not deny possibility of node maliciousness. Many cooperation enforcement schemes are proposed in literature, and every scheme is shown to perform better under its own set of assumptions. These assumptions are different for different schemes. So, we aim at defining common set of assumptions and comparing selected schemes on this common ground with respect to packet delivery ratio, energy consumption, routing and other control overhead. We find that with the traffic scenario where nodes do not need services of one another at the same time, the cooperation schemes are not effective in dealing with node selfish ness. We also find that, while dealing with malicious nodes, all cooperation schemes perform better than Dynamic Source Routing(DSR) protocol in improving packet de- livery ratio(PDR), but this improvement comes at the cost of significant increase in routing control packets overhead and energy consumption of cooperation enforcement schemes is higher than that of DSR. Also they fail in punishing misbehaving nodes and the PDR of malicious nodes is comparable to that of good nodes.
  • ItemOpen Access
    Wireless sensor network based automatic meter reading: WSNAMR
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Sutariya, Mahesh R.; Ranjan, Prabhat
    Automatic Meter Reading is technology evolved from 1995[3] or before, for remote collection of utilities measurement data which involve Electricity, Gas and Water etc. In this process of evolution every time new idea was methodology being used for implementation. In this thesis same task of meter reading will be performed wirelessly by using zigbee standard developed for the low power wireless sensor network. Concentration is on electrical energy. Goal of this work is to have a Remote collection of measured energy value as well as to have an on/off control of this energy supply which will indirectly enable wireless monitoring of energy consumption, prepaid billing etc through web based interface provided. So work will involve development of hardware and firmware and web based software to achieve this functionality. Once energy consumption data is available to us, it can be used for purpose of dynamic tariff management, dynamic load management, power quality monitoring, peak power consumption etc.
  • ItemOpen Access
    Queueing-theoretic framework for perfermance analysis of mobile ad hoc networks with finite buffer nodes
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2008) Shah, Sapan; Lenin, R. B.; Srivastava, Sanjay
    Wireless Ad Hoc network is a decentralized wireless network which allows nodes to join and create networks without any infrastructure. These kinds of networks are advantageous because they can be readily deployed anywhere, anytime. Mobile Ad Hoc Network (MANET) is a special type of ad hoc network where nodes are mobile. Due to mobility of the nodes, network topology may change rapidly and unpredictably. MANETs are expected to plat a vital role in a variety of applications and are therefore studied extensively. It is imperative to analyze these networks, to assess the suitability of their use in different scenarios and to identify the techniques to improve their performance. In last few years, many models have been proposed to analyze MANETs. Many of then have an unrealistic assumption of an infinite buffer in each node. Moreover, in MANETs, as nodes are mobile, a packet may revisit the same node which creates feedback loops of a packet. These loops make modeling and analysis of MANETs difficult as the network becomes cyclic. This work analyzes MANET with finite buffer nodes. Open finite queuing network with gated queue, intermittent links and servers is used. The expansion method technique has been used to study the open finite queuing network with stable links and servers. We modify the method for intermittency. Numerical results are derived and compared with simulation results to show effectiveness of the method.
  • ItemOpen Access
    Study of MPLS traffic engineering with constraint-based routing
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2004) Modi, Bhavesh; Maitra, Anutosh
    Multi-protocol Label Switching (MPLS) is fast becoming popular for future communication networks running applications demanding high speed and Quality of Service. In this work, we have studied the evolution of MPLS, various issues related to MPLS and the architecture ofMPLS. The simplicity and functional capabilities ofMPLS enables various important applications over it such as Virtual Private Networks, Provisioning of Quality of Service and Traffic Engineering. The traffic engineering perspective of MPLS is studied in a greater detail as MPLS protocol has certain advantageous features in traffic engineering applications, the major being that it allows explicit routing, through which separately calculated routes can be specified for different traffic flows. The process of route calculation can be automated with the help of Constraint-based Routing. The thesis also presents a study on Constraint-based routing in MPLS environment. After that, a few classical constraint-based routing algorithms that consider bandwidth as constraint are investigated. The effectiveness of these algorithms is ascertained by means of simulation results. The concept of minimum interference routing and the corresponding algorithm MIRA is studied in greater detail in this work and presented in the thesis. The performance of MIRA was analyzed and factors that affect the performance were identified. Finally, the work suggests two modifications over MIRA based on the observations and analysis mentioned above. The primary philosophy behind the modifications are identifying the criticality of the resources and quantifying the order of the criticality. The performance of the suggested modified algorithms is benchmarked against classical MIRA algorithm and the simulation results are presented.
  • ItemOpen Access
    Selfish routing and network creation games
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2005) Gandhi, Ratnik; Chatterji, Samaresh
    This work studies the two important problems of routing and network creation in the situation of selfish behavior of agents. In routing, agents want to send their data from source to destination. They try to reduce cost incurred in the process of routing. In network creation, agents create agent-to-agent link to form a network on which they can Communicate. Here there are two types of cost incurred: link creation cost and routing cost. Each agent tries to reduce his own cost. To study degradation caused by selfish behavior of agents we primarily use the standard notation of Price of Anarchy, which is ratio of the cost incurred at Nash equilibrium to the optimal cost. We show some results on Price of Anarchy and on different cost functions for above two problems, we propose a new model in network creation and show a polynomial time algorithm to verify Nash equilibrium.
  • Item
    Novel approach for localization in Ad-Hoc sensor networks
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2004) Desai, Vishal; Ranjan, Prabhat
    The ability of a sensor node to move itself or to otherwise influence its location will be critical in sensor networks. Today, the wireless community is putting great effort on the possibility of deploying thousands of tiny sensors all over the place and measuring all kinds of data within. Sensor network is a network of small devices, collaborating with each other to produce a larger sensing task. Most of the current literature on location discovery in wireless and sensor networks assumes the availability of GPS receivers at some nodes or beacon nodes with known position. But as we know having a GPS receiver at sensor nodes may not be feasible due to the limitations of satellite coverage inside the building or due to cost reasons. Further for ad hoc deployment of nodes, it is unreasonable to assume the presence of beacon nodes with prior position information. Hence, the main objective behind this research work is to introduce a localization/positioning method that would be GPS-free and beaconless, and finally we come up with a method called “LRT - Localization using Routing Table” which is also scalable, distributed and able to support the ad hoc deployment of large-scale sensor networks quickly and efficiently.