iosr-JCE   Volume-1 ~ Issue-4

ABSTRACT : For advanced streaming applications over wired-wireless networks TCP-Friendly Rate Control (TFRC) has been widely adopted nowadays to give smooth sending rate and unceasing quality in streaming applications TFRC applies an equation-based rate control scheme. However, TFRC tends to fail in wireless environment if packet lost event was done by poor channel quality but network congestion. Therefore, TFRC not able to provide high quality-of-service for streaming applications over wired-wireless networks. In this paper, we proposed a delay based uni-directional delay jitter based TFRC with end-to-end semantic over wired-wireless networks. This scheme provide smooth sending rate and TCP friendly characteristics like standard TFRC, even it also increase the throughput by estimating the available bandwidth in wired-wireless networks with bursty nature of background traffic. Simulation results show performance improvement without intrusiveness issue and even if background traffic is bursty over wired-wireless networks.
Keywords – Bursty network Congestion Control Mechanism, Streaming applications, TCP Friendly Rate Control (TFRC), Uni Directional Delay Jitter

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ABSTRACT: Mobile technology presents many inherent problems that lead to poor network connectivity, low bandwidth. To overcome poor connectivity, Mobile clients are forced to operate in disconnected and partially connected modes. This paper review a designed method which led to support data availability using data replication and data caching in mobile environment to improving the availability of data and enhancing the performance of data access for users operates in mobile environments.
Keywords: Data Caching, Data Replication, Disconnect Operation, Mobile Computing

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ABSTRACT:A number of Call Graph construction algorithms have been designed for construction of Call Graphs for object-oriented languages. Each of the Call Graph contraction algorithms were proposed to keep in mind the improvements over previous Call Graphs in terms of precision, cost and accuracy. In object oriented languages the Call Graphs are generally contracted to represent the calling relationship between the program's methods. The Call Graph forms the bases for deducing the information about the classes and the methods that are actually invoked, this information can be used to find call sites were virtual function calls can be replaced by direct calls and inline-expansions can be put into work where ever possible. In this paper we present an empirical comparison of various well known Call Graph construction algorithms. Here we used Scoot bytecode reader as front-end to implement various Call Graph construction algorisms. In the processes Scoot bytecode reader is used to read the bytecode of a specific java program then the reachable methods are found for each invoked method. For storing information about the classes, methods, fields and statements we created our own set of data structures. Finally we tested and evaluated the developed algorithms with a variety of java benchmark programs to gather the information for the comparison of various Call Graph algorithms which is the goal of this work. We have included most of the Call Graph algorithms of popularity in this work. The main aim of the work is to consider all the dimensions of the Call Graph construction algorithms like cost, precision, memory and time requirements for its construction. The previous works has either not included all the algorithms of fame or have left some of their construction constraints untouched. This work will bring an effective empirical comparison to the front and will help to reveal that which Call Graph construction algorithm is best and when. The results in the work are mainly considered valid for java and other statically typed object-oriented languages.

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