10,150 research outputs found

    Service discovery using Bloom filters

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    A protocol to perform service discovery in adhoc networks is introduced in this paper. Attenuated Bloom filters are used to distribute services to nodes in the neighborhood and thus enable local service discovery. The protocol has been implemented in a discrete event simulator to investigate the behavior in case of a multihop mobile ad-hoc network with nodes that all have services to offer. Methods to optimize the used bandwidth, which is a scarce resource in wireless networks, are investigated. Experiments performed with the simulator suggest that the proposed service discovery system enables users to find local services in a multihop ad-hoc network efficiently. The costs for advertising can be kept low, whereas the additional costs for queries set due to so-called false positives are moderate

    Small-world networks, distributed hash tables and the e-resource discovery problem

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    Resource discovery is one of the most important underpinning problems behind producing a scalable, robust and efficient global infrastructure for e-Science. A number of approaches to the resource discovery and management problem have been made in various computational grid environments and prototypes over the last decade. Computational resources and services in modern grid and cloud environments can be modelled as an overlay network superposed on the physical network structure of the Internet and World Wide Web. We discuss some of the main approaches to resource discovery in the context of the general properties of such an overlay network. We present some performance data and predicted properties based on algorithmic approaches such as distributed hash table resource discovery and management. We describe a prototype system and use its model to explore some of the known key graph aspects of the global resource overlay network - including small-world and scale-free properties

    Proof-of-Concept Implementation of the Ahoy Discovery Protocol for Ad-hoc Networks

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    The context discovery protocol Ahoy has been proposed ear- lier for resource-limited fully-distributed ad-hoc networks. Ahoy has been proven as an efficient context discovery pro- tocol, which generates only little network traffic, in both static and dynamic ad-hoc networks. In this report, we im- plement the prototype of Ahoy and test it on UNIX-like platforms. We show the possibility to implement Ahoy in the real world

    Secure Cloud Communication for Effective Cost Management System through MSBE

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    In Cloud Computing Architecture, Brokers are responsible to provide services to the end users. An Effective Cost Management System (ECMS) which works over Secure Cloud Communication Paradigm (SCCP) helps in finding a communication link with overall minimum cost of links. We propose an improved Broker Cloud Communication Paradigm (BCCP) with integration of security issues. Two algorithms are included, first is Secure Optimized Route Cost Finder (S-ORCF) to find optimum route between broker and cloud on the behalf of cost factor and second is Secure Optimized Route Management (S-ORM) to maintain optimum route. These algorithms proposed with cryptographic integrity of the secure route discovery process in efficient routing approaches between broker and cloud. There is lack in Dynamic Source Routing Approach to verify whether any intermediate node has been deleted, inserted or modified with no valid authentication. We use symmetric cryptographic primitives, which is made possible due to multisource broadcast encryption scheme. This paper outlines the use of secure route discovery protocol (SRDP)that employs such a security paradigm in cloud computing.Comment: 12 pages, 3 figures, International Journal on Cloud Computing: Services and Architecture(IJCCSA),Vol.2, No.3, June 201

    JiTS: Just-in-Time Scheduling for Real-Time Sensor Data Dissemination

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    We consider the problem of real-time data dissemination in wireless sensor networks, in which data are associated with deadlines and it is desired for data to reach the sink(s) by their deadlines. To this end, existing real-time data dissemination work have developed packet scheduling schemes that prioritize packets according to their deadlines. In this paper, we first demonstrate that not only the scheduling discipline but also the routing protocol has a significant impact on the success of real-time sensor data dissemination. We show that the shortest path routing using the minimum number of hops leads to considerably better performance than Geographical Forwarding, which has often been used in existing real-time data dissemination work. We also observe that packet prioritization by itself is not enough for real-time data dissemination, since many high priority packets may simultaneously contend for network resources, deteriorating the network performance. Instead, real-time packets could be judiciously delayed to avoid severe contention as long as their deadlines can be met. Based on this observation, we propose a Just-in-Time Scheduling (JiTS) algorithm for scheduling data transmissions to alleviate the shortcomings of the existing solutions. We explore several policies for non-uniformly delaying data at different intermediate nodes to account for the higher expected contention as the packet gets closer to the sink(s). By an extensive simulation study, we demonstrate that JiTS can significantly improve the deadline miss ratio and packet drop ratio compared to existing approaches in various situations. Notably, JiTS improves the performance requiring neither lower layer support nor synchronization among the sensor nodes
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