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چكيده انگليسي :

82 Network Coding Aware Routing in Wireless Network Samaneh Masoumi Godarzi s masoumi@ec iut ac ir Date of Submission 2012 04 28 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr F Hndessi hendessi@cc iut ac ir Dr P Khadivi khadivi@cc iut ac ir Abstract In recent years wireless networks are of considerable importance and their applications are widely increasing As a result researchers are investigating new methods to modify the performance and increase wireless network s throughput One of these methods is network s coding which has been taken into consideration since 2000 In this work We modify wireless network s throughput First a brief introduction of network s coding and investigation of it which are the main idea of this work are discussed In this study the modification of performance and increase in throughput of COPE protocol are investigated so a new protocol is presented If the COPE channel is assumed to be ideal and without error the network will have a good performance However this channel has so much noise that it causes an error in arriving packets to their destination Therefore we first drive the probability of packet s arrival with the concern of probability of unsuccessful packet s arrival in unicast and multicast sending Not only receiving local packets but also multicast sending and opportunistic listening are include in uncertain sending in the new protocol As a result not receiving packets through them are modeled in the form of separate parameters A description upon two factors of the amount of lost packets and the rate of throughput is done These two factors are calculated in both COPE and presented protocol in addition a comparison is carried out these two factors A protocol is presented in a way that a new back off node which is listening to the internal network s sending is added to the scenario of COPE topology it receivers and saves them so that when an error occurs by delays in the back off and intermediate nodes they are used in coding and sending to the destination For example if two packets are sent to intermediate nodes in the right way two packets in the node will be codded and sent to their destination by the coding opportunity which is provided Although back off node is listening to the channel and receivers packets It has not send any until an error occurs For instance one of the packets does not arrive to the intermediate node and back off node which is always listening understands that intermediate node does not have coding opportunity for packets Then back off node which receives those two packets through listening opportunity codes those packets by coding opportunity and sends them to their destinations It is simulated by NS3 software and compare to the result of COPE protocol Finally it is observed that the throughput of presented protocol is improved Keywords Network Coding Aware Routing Throughput Rate of Throughput Lost Packet

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