M Tech Dissertations
Permanent URI for this collectionhttp://drsr.daiict.ac.in/handle/123456789/3
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Item Metadata only Service level agreement parameter matching in cloud computing(Dhirubhai Ambani Institute of Information and Communication Technology, 2011) Chauhan, Tejas; Chaudhary, Sanjay; Bise, MinalCloud is a large pool of easily usable and accessible virtualized resources (such as hardware, development platforms and/or software services). It provides an on-demand, pay-asyo-ugo computing resources and had become an alternative to traditional IT infrastructure. As more and more consumers delegate their task to cloud providers, Service Level Agreement (SLA) between consumer and provider becomes an important aspect. Due to the dynamic nature of cloud the matching of service level agreement need to be dynamic and continuous monitoring of Quality of Service (QoS) is necessary to enforce SLAs. This complex nature of cloud warrants a sophisticated means of managing SLAs. SLA contains many parameters like cloud’s types of services, resources (physical memory, main memory, processor speed, ethernet speed etc.) and properties (availability, response time, server reboot time etc.). At present, actual Cloud SLAs are typically plain-text documents, and sometimes an informative document published online. Consumer needs to manually match application requirements with each and every cloud provider to identify compatible cloud provider. This work addresses the issue of matching SLA parameters to find best suitable cloud provider. Proposed algorithm identifies the compatible cloud provider by matching parameters of application requirements and cloud SLAs. It gives suggestion to a consumer in terms of number of matched parameters.Item Open Access Ant colony optimization in routing algorithms of mobile ad hoc networks(Dhirubhai Ambani Institute of Information and Communication Technology, 2010) Agarwal, Navneet; Srivastava, Sanjay; Sunitha, V.The study on performance of On-demand Ant Routing Algorithm for Mobile Ad Hoc Network is done. An ant routing algorithm based on swarm intelligence and especially on Ant Colony Optimization (ACO). It describes a noval on demand Ant colony algorithm for MANETs. This algorithm tries to minimize complexity at nodes and this is achived at exoences of optimality of routing path. Inextensive set of simulation experiment, We try to set parameter of ant routing algorithms and compare Proposed algorithm with DAR,a pre existing on demand ant routing algorithms and with AODV,a reference algorithm in MANETs. The comparition base on optimal path length with respect to control overhead.Item Open Access Testbed based experimental analysis of transport protocols over wireless ad hoc networks(Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Shah, Harshil Anilkumar; Srivastava, SanjayAd hoc networks are networks with no infrastructure and self-organized in nature. ad hoc networks allow nodes to form network when they come into range of each other provided nodes are configured in ad hoc mode. But these types of network are challenges like high bit error rates, route failures due to mobility, high noise, signal fading and low speed etc. to deal with. Due to this, protocols which are widely used in traditional wired networks may not perform well in MANETs. lower layers like MAC and network layer are either completely changed like 802.11 instead of 802.3 at MAC layer and introducing reactive routing protocols instead of only proactive routing at network layer or significant improvement schemes have been proposed for wireless networks in the existing legacy wired network protocols. But transport layer in MANET is mostly similar to wired networks except some improvements like TCP-ELFN and TCP-Feedback and new transport protocols like Ad hoc-TCP (ATCP), Transport Protocol for Ad hoc networks (TPA) and Ad-hoc Transport Pro- tool (ATP).performance degradation of TCP over wireless links is mainly due to wireless characteristics, TCP features like self-clocking, loss based congestion control, coupling of congestion and reliability, slow start. Several studies have been carried out to evaluate performance of TCP over MANETs but most of them are simulation based studies. But as simulation scenarios can not model exactly the unpredictable nature of wireless environment, we have decided to analyze performance of trans- port protocols over experimental test bed which can be more accurate evaluation of protocols in real-life situation. Performance of 2 transport protocols is analyzed.Item Open Access Cache performance evaluation in DSR protocol through cross-layering for mobile ad hoc networks(Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Sharma, Kapil; Sunitha, V.Wireless mobile ad-hoc networks are being actively studied by many researchers these days. These networks are suitable to be used in various situations because of (i) their infrastructure-less property and (ii) the mobility of the nodes of the network. However, it is these features which give rice to problems in study of such networks. Further, routing is one of the basic issues in any network design. Inclusion of moving capability to the nodes, make the routing problem more complicated. One is always interested in increasing the throughput and reducing overhead while at the same time solving the issues related to routing. DSR is a protocol that is extensively used for routing in such networks. Cache management and route caching play a significant role in using DSR successively to attain the best behavior for these networks. This thesis looks at and suggests some methods for route caching in DSR.Item Open Access Cooperation enforcement mechanisms in wireless adhoc networks(Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Chaturvedi, Manish Shivshankar; Srivastava, SanjayWireless 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.Item Open Access Comparative study between exponential back off and dynamic waiting strategies for medium access in wireless ad hoc networks(Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Shah, Rahul; Srivastava, SanjayIEEE 802.11 DCF (IEEE 802.11 Distributed Coordination Function) is widely used MAC protocol for wireless channel access. Although it is developed for single hop networks where all nodes are in the same radio range, it can be directly used for wireless multiphop hoc networks. But performance of IEEE 802.11 DCF in wireless ad hoc networks suers as it has been developed considering single hop networks only. Many amendments has been proposed to enhance its performance in multihop ad hoc networks. One such scheme is DWMAC (Dynamic Waiting Medium Access Control). In this work, performance of IEEE 802.11 DCF and DWMAC are compared for different network scenarios and traffic patterns. It has been observed that the performance of DWMAC can be further improved if we alter the restricted mode operation of the nodes. We have proposed a new modified protocol DWMAC-Modied and have shown by simulations that DWMAC-Modied offers singnificant improvements.
Item Open Access Energy efficient data gathering protocol for wireless sensor network(Dhirubhai Ambani Institute of Information and Communication Technology, 2008) Rao, Parth A.; Srivastava, SanjayWireless Sensor Network is made up of hundreds and thousands of miniature electronic devices called node, which have sensors built on them. Functionality of a sensor is entirely application dependent. They can perform a large number of functions from measuring the forces of nature like temperature, humidity, geophysical activity, sound vibrations to motion detection and military surveillance. Apart from sensing or measuring, the nodes are responsible for efficiently collecting the sensed data by performing appropriate activities on the collected data and there by weeding out redundant data so as to reduce transmission overload on nodes. Thus the nodes are responsible for gathering data and routing the data to the base station. Data Gathering can be performed in number of ways after nodes are deployed in the sensing field depending on their application. The manner in which nodes are deployed in the sensing field also affects the lifetime of the sensor network. It is not always possible that all nodes after deployment in the sensing field are able to communicate with the base station. Moreover efficient utilization of the energy is a must for sensor nodes, because these sensors are battery powered devices, and after they are deployed in the sensing field it is not feasible to change the battery of the nodes. So energy preservation of nodes in sensor network is a crucial requirement to be taken care of. The other prime matter worth considering is that during the whole life time of the sensor network care should be taken that load distribution on all the nodes in the sensing field is equal. All nodes should either die randomly at random location in the sensing field at random time intervals, or all nodes should start dying at more or less the same time. We have proposed an energy efficient protocol for data gathering in wireless sensor networks, which through hierarchical cluster formation reduce the number of high energy transmissions per round of data gathering and takes care of the load balancing issue by randomized rotation of the cluster heads. Routing of data is done in multi-hop fashion to ensure that the most remotely located node is also able to communicate with the base station through the best available intermediary nodes.Item Open 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, SanjayWireless 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.Item Open Access Mining effective association rules using support-conviction framework(Dhirubhai Ambani Institute of Information and Communication Technology, 2007) Sharma, Adarsh; Jotwani, Naresh D.Discovering association rules is one of the most important tasks in data mining. Most of the research has been done on association rule mining by using the support-confidence framework. In this thesis, we point out some drawbacks of the support-confidence framework for mining association rules. In order to avoid the limitations in the rule selection criterion, we replace confidence by the conviction, which is a more reliable measure of implication rules. We have generated the test data synthetically by the Hierarchical Synthetic Data Generator, which appropriately models the customer behaviour in the retailing environment. Experimental Results show that there is higher correlation between the antecedent and consequent of the rules produced by the supportconviction framework compared with the rules produced by support-confidence framework. Although support-conviction framework mines the effective associations but the association rules generated are large in numbers that are difficult to deal with. To overcome this problem, we propose an association rule pruning algorithm, which produces non-redundant and significant rules. Results obtained with synthetic data show that the proposed approach for mining association rules is quite effective and generates meaningful associations among the sets of data items.