30 research outputs found

    Performance Analysis of Distributed Cache Invalidation Method in Mobile Ad hoc Networks using AODV and AOMDV Routing Protocols

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    Mobile Ad hoc Networks (MANETs) is an active wireless network that can be formed without any existing permanent framework networks. Mobile Ad hoc Networks is an independent structure of mobile nodes communicated with wireless channels. Distributed cache invalidation method is performed among intermediate routing mobile nodes. In MANETs routing protocols are provided desirable route establishments of the mobile nodes. Ad hoc On-demand distance vector routing protocol (AODV) was well known single route protocol , Ad hoc On-demand Multipath Distance Vector routing protocol (AOMDV) is extends the AODV protocol with multipath. These results are carried out in network simulator version2 (NS2), the performance is analyzed and compared between AODV and AOMDV routing protocols

    Dynamic Cache Invalidation Scheme in IR-Based Wireless Environments

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    A game theoretic approach to energy efficient cooperative cache maintenance in MANETs

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    There have been an increasingly large number of mobile handsets equipped with dual or multiple network interfaces. The server interface (e.g., GPRS, EDGE, UMTS) is responsible for communicating with the network operator, while the peer interfaces (e.g., Bluetooth, IEEE 802.11) are used to connect with other computing devices. However, they are usually used separately. In this paper, we investigate the use of both network interfaces to support energy efficient data applications among mobile clients. Specifically, we proposed a fully distributed protocol for mobile handsets to form cooperative groups to maintain cache consistency with minimal communication with the network operator. Our proposed protocol takes advantage of the low power consumption and high data rate of the peer interface. The aim is to reduce the use of the server interface, which is typically slower and involves higher power consumption. Furthermore, we also consider the presence of selfish clients. It is shown that groups formed by the proposed protocol constitutes a pure Nash Equilibrium. This suggests that our protocol is robust even in the presence of selfish clients. Simulation results confirm that, given the same energy resource, mobile clients running the proposed protocol complete more queries, experience longer lifetime and achieve smaller query latency. © 2005 IEEE.published_or_final_versio

    Game theoretic power aware wireless data access

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    The paper examines the following wireless data access scenario: a number of clients are interested in a set of data items kept at the server. A client sends a query request to inform the server of its desired data item. The server replies in the common broadcast channel. We first define a utility function that considers the client's power consumption in transmit, receive and idle modes. Specifically, utility is expressed as the number of queries that can be completed given a fixed energy source. Based on the utility function, we formulate our power aware wireless data access scheme as a non-cooperative game, called the WDA game. From our theoretical analysis, we show that clients are not always necessary to send query requests to the server. Instead, each client determines the request probability without any explicit communication with one another. Furthermore, we design and evaluate the server and client algorithms for the WDA game. Simulation results confirm that our proposed scheme, compared with a simple always-request one, increases the utility and lifetime of every client while reducing the number of requests sent, at the cost of a slightly larger average query delay.published_or_final_versio

    Design and analysis of channel adaptive wireless cache invalidation strategies with downlink traffic

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    In this paper, we study the performance of the IR+UIR wireless data cache Invalidation approach under a realistic system model: the quality of the wireless channel Is time-varying; and there are other downlink traffics in the system. Our analysis and simulation results show that query delay significantly increases as a result of broadcast error and the additional downlink traffics experience longer delay due to extended broadcast period. Exploiting link adaptation (i.e., transmission rate is adjusted dynamically according to channel quality), we then propose three schemes to tackle these two problems. Our results Indicate that the proposed schemes outperform IR+UIR under a wide range of system parameters.published_or_final_versio

    An Effective Service Mechanism to Achieve Low Query Latency along with reduced Negative Acknowledgement in iVANET: An Approach to Improve Quality of Service in iVANET

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    The Internet Based vehicular ad hoc network (iVANET) combines a wired Internet and vehicular ad hoc networks (VANETs) for developing a new generation of ubiquitous communicating. The Internet is usually applied in vehicle to infrastructure (V2I) solution whereas ad hoc networks are used in vehicle to vehicle (V2V) communication. Since vehicular networks is characterized by High speed dynamically changing network topology The latency is one of the hot issues in VANET which is proportional to the source-&-remote vehicle distance and the mechanism involved in accessing source memory. If the distance between data source and the remote vehicle is wittily reduced by using redefined caching technique along with certain cache lookup mechanism, the latency is likely to be reduced by a significant factor in iVANET. This paper studies and analyzes various cache invalidation schemes including state of art ones and come with a novel idea of fructifying network performance within the purview of query latency and negative acknowledgement in iVANET. In this paper the roles of the mediatory network component are redefined with associative service mechanism which guarantees reduced query latency as well as minimizes negative acknowledgements in iVANET environment

    Constructing Efficient Cache Invalidation Schemes in Mobile Environments

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    [[abstract]]Cache invalidation is an effective approach to maintaining data consistency between the server and mobile clients in a mobile environment. This paper presents two new cache invalidation schemes which are designed according to the real situations and are therefore able to comply with the more practical needs in a mobile environment. The ABI+HCQU divides data into different groups based on their utilization rates (hot/cold/query/update) and adapts their broadcasting intervals (ABI) accordingly to suit the actual needs. The SWRCC + MUVI (sleep/wakeup/recovery/check/confirm+modified/uncertain/ valid/ invalid) aims to solve the validity problem of cached data after a client is disconnected from the server. The new cache invalidation schemes are shown through experimental evaluation to outperform most existing schemes in terms of data access time, cache miss rates and bandwidth consumption.[[conferencetype]]國際[[conferencedate]]20071216~20071218[[iscallforpapers]]Y[[conferencelocation]]Shanghai, Chin

    On Improving the Robustness of Partitionable Internet-Based Mobile Ad Hoc Networks

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    Recent technological advances in portability, mobility support, and high speed wireless communications and users' insatiable interest in accessing the Internet have fueled to development of mobile wireless networks. Internet-based mobile ad hoc network (IMANET) is emerging as a ubiquitous communication infrastructure that combines a mobile ad hoc network (MANET) and the Internet to provide universal information accessibility. However, communication performance may be seriously degraded by network partitions resulted from frequent changes of the network topology. In this paper, we propose an enhanced least recently used replacement policy as a part of the aggregate cache mechanism to improve the information accessibility and reduce the access latency in the presence of network partitioning. The enhanced aggregate cache is analyzed and also evaluated by simulation. Extensive simulation experiments are conducted under various network topologies by using three different mobility models: random waypoint, Manhattan grid, and mo -di -fied random waypoint. The simulation results indicate that the proposed policy significantly improves communication performance in varying network topologies, and relieves the network partition problem to a great extent

    Data Retrieval for Location-Dependent Queries in a Multi-Cell Wireless Environment

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