8,075 research outputs found

    An energy-aware and QOS assured wireless multi-hop transmission protocol

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    A thesis submitted in fulfillment of the requirements for the degree of Master of Science by researchThe Ad-hoc network is set up with multiple wireless devices without any pre-existing infrastructure. It usually supports best-effort traffic and occasionally some kinds of Quality of Service (QoS). However, there are some applications with real-time traffic requirements where deadlines must be met. To meet deadlines, the communication network has to support the timely delivery of inter-task messages. Furthermore, energy efficiency is a critical issue for battery-powered mobile devices in ad-hoc networks. Thus, A QoS guaranteed and energy-aware transmission scheme is one hot of research topics in the research area. The MSc research work is based on the idea of Real-Time Wireless Multi-hop Protocol (RT-WMP). RT-WMP is a well known protocol originally used in the robots control area. It allows wireless real-time traffic in relatively small mobile ad-hoc networks using the low-cost commercial IEEE 802.11 technology. The proposed scheme is based on a token-passing approach and message exchange is priority based. The idea of energy-aware routing mechanism is based on the AODV protocol. This energy-saving mechanism is analysed and simulated in our study as an extension of the RT-WMP. From the simulation results and analysis, it has been shown that adding energy-aware mechanism to RT-WMP is meaningful to optimise the performance of traffic on the network

    A QoS-aware routing protocol with adaptive feedback scheme for video streaming for mobile networks

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    One of the major challenges for the transmission of time-sensitive data like video over mobile ad-hoc networks (MANETs) is the deployment of an end-to-end QoS support mechanism. Therefore, several approaches and enhancements have been proposed concerning the routing protocols. In this paper we propose a new QoS routing protocol based on AODV (named AQA-AODV), which creates routes according to application QoS requirements. We have introduced link and path available bandwidth estimation mechanisms and an adaptive scheme that can provide feedback to the source node about the current network state, to allow the application to appropriately adjust the transmission rate. In the same way, we propose a route recovery approach into the AQA-AODV protocol, which provides a mechanism to detect the link failures in a route and re-establish the connections taking into account the conditions of QoS that have been established during the previous route discovery phase. The simulation results reveal performance improvements in terms of packet delay, number of link failures and connection setup latency while we make more efficient use of the available bandwidth than other protocols like AODV and QAODV. In terms of video transmission, the obtained results prove that the combined use of AQA-AODV and the scalable video coding provides an efficient platform for supporting rate-adaptive video streaming.Castellanos Hernández, WE.; Guerri Cebollada, JC.; Arce Vila, P. (2016). A QoS-aware routing protocol with adaptive feedback scheme for video streaming for mobile networks. Computer Communications. 77:10-25. doi:10.1016/j.comcom.2015.08.012S10257

    Secure and robust multi-constrained QoS aware routing algorithm for VANETs

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    Secure QoS routing algorithms are a fundamental part of wireless networks that aim to provide services with QoS and security guarantees. In Vehicular Ad hoc Networks (VANETs), vehicles perform routing functions, and at the same time act as end-systems thus routing control messages are transmitted unprotected over wireless channels. The QoS of the entire network could be degraded by an attack on the routing process, and manipulation of the routing control messages. In this paper, we propose a novel secure and reliable multi-constrained QoS aware routing algorithm for VANETs. We employ the Ant Colony Optimisation (ACO) technique to compute feasible routes in VANETs subject to multiple QoS constraints determined by the data traffic type. Moreover, we extend the VANET-oriented Evolving Graph (VoEG) model to perform plausibility checks on the exchanged routing control messages among vehicles. Simulation results show that the QoS can be guaranteed while applying security mechanisms to ensure a reliable and robust routing service

    Mengenal pasti masalah pemahaman dan hubungannya dengan latar belakang matematik, gaya pembelajaran, motivasi dan minat pelajar terhadap bab pengawalan kos makanan di Sekolah Menengah Teknik (ert) Rembau: satu kajian kes.

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    Kajian ini dijalankan untuk mengkaji hubungan korelasi antara latar belakang Matematik, gaya pembelajaran, motivasi dan minat dengan pemahaman pelajar terhadap bab tersebut. Responden adalah seramai 30 orang iaitu terdiri daripada pelajar tingkatan lima kursus Katering, Sekolah Menengah Teknik (ERT) Rembau, Negeri Sembilan. Instrumen kajian adalah soal selidik dan semua data dianalisis menggunakan program SPSS versi 10.0 untuk mendapatkan nilai min dan nilai korelasi bagi memenuhi objektif yang telah ditetapkan. Hasil kajian ini menunjukkan bahawa hubungan korelasi antara gaya pembelajaran pelajar terhadap pemahaman pelajar adalah kuat. Manakala hubungan korelasi antara latar belakang Matematik, motivasi dan minat terhadap pemahaman pelajar adalah sederhana. Nilai tahap min bagi masalah pemahaman pelajar, latar belakang Matematik, gaya pembelajaran, motivasi dan minat terhadap bab Pengawalan Kos Makanan adalah sederhana. Kajian ini mencadangkan penghasilan satu Modul Pembelajaran Kendiri bagi bab Pengawalan Kos Makanan untuk membantu pelajar kursus Katering dalam proses pembelajaran mereka
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