14,838 research outputs found

    Performance of Ad-Hoc on-Demand Distance Vector Discovery Algorithms Based On Packet Lifetime

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    Ad hoc On-Demand Distance Vector (AODV) routing protocol is a reactive protocol in Mobile Ad hoc Network (MANET). AODV uses a distance or hop count for determining the best forwarding path and store the sequence number at table entry to ensure the path information is up-to-date. Although the AODV is a better performance compare to other proactive and reactive routing protocol in MANET, this routing still has a limitation and can to be improved. In this research, two algorithms that enhanced the original AODV are proposed. The first algorithm focuses on the AODV route table update management. The combination metrics of the lifetime and the sequence number in the table entry is used to solve the problem of the discarded active path information when the lifetime is expired. From the performance analysis, the proposed algorithm is successful to enhance the original AODV based on the performance of delay, overhead, packet delivery ratio and packet loss ratio. The second proposed algorithm is focused on the AODV route discovery. On the original AODV, packets will be allowed to rebroadcast the packet with a minimal lifetime. This will cause an unnecessary packets are discarded from the broadcasting. To solve this problem, Lifetime Ratio (LR) is proposed to reduce the unnecessary packets rebroadcast until it reaches the destination nodes. Based on the performance analysis, LR algorithm enhances the performance of the overhead, packet delivery ratio and packet loss ratio. The performance analysis of the proposed algorithms was conducted by using the discrete-event simulator, OMNeT++. The simulator was used to simulate the mobility environment and the Open System Interconnections (OSI) layers utilized in wireless simulation. To compare the performance between the original AODV and the proposed algorithms, the performance metrics are based on delay, overhead, packet delivery ratio, packet loss ratio and throughput. From the extensive simulations based on the performance metrics, the two proposed algorithms have shown distinct improvement and subsequently enhancing the performance of AODV

    Enhanced Cluster Based Routing Protocol for MANETS

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    Mobile ad-hoc networks (MANETs) are a set of self organized wireless mobile nodes that works without any predefined infrastructure. For routing data in MANETs, the routing protocols relay on mobile wireless nodes. In general, any routing protocol performance suffers i) with resource constraints and ii) due to the mobility of the nodes. Due to existing routing challenges in MANETs clustering based protocols suffers frequently with cluster head failure problem, which degrades the cluster stability. This paper proposes, Enhanced CBRP, a schema to improve the cluster stability and in-turn improves the performance of traditional cluster based routing protocol (CBRP), by electing better cluster head using weighted clustering algorithm and considering some crucial routing challenges. Moreover, proposed protocol suggests a secondary cluster head for each cluster, to increase the stability of the cluster and implicitly the network infrastructure in case of sudden failure of cluster head.Comment: 6 page

    Optimisation of Mobile Communication Networks - OMCO NET

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    The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University. The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing

    Katakan tidak pada rasuah

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    Isu atau masalah rasuah menjadi topik utama sama ada di peringkat antarabangsa mahupun di peringkat dalam negara. Pertubuhan Bangsa- bangsa Bersatu menegaskan komitmen komuniti antarabangsa bertegas untuk mencegah dan mengawal rasuah melalui buku bertajuk United Nations Convention against Corruption. Hal yang sama berlaku di Malaysia. Melalui pernyataan visi oleh mantan Perdana Menteri Malaysia, Tun Dr. Mahathir bin Mohamed memberikan indikasi bahawa kerajaan Malaysia komited untuk mencapai aspirasi agar Malaysia dikenali kerana integriti dan bukannya rasuah. Justeru, tujuan penulisan bab ini adalah untuk membincangkan rasuah dari beberapa sudut termasuk perbincangan dari sudut agama Islam, faktor-faktor berlakunya gejala rasuah, dan usaha-usaha yang dijalankan di Malaysia untuk membanteras gejala rasuah. Perkara ini penting bagi mengenalpasti penjawat awam menanamkan keyakinan dalam melaksanakan tanggungjawab dengan menghindari diri daripada rasuah agar mereka sentiasa peka mengutamakan kepentingan awam

    SDDV: scalable data dissemination in vehicular ad hoc networks

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    An important challenge in the domain of vehicular ad hoc networks (VANET) is the scalability of data dissemination. Under dense traffic conditions, the large number of communicating vehicles can easily result in a congested wireless channel. In that situation, delays and packet losses increase to a level where the VANET cannot be applied for road safety applications anymore. This paper introduces scalable data dissemination in vehicular ad hoc networks (SDDV), a holistic solution to this problem. It is composed of several techniques spread across the different layers of the protocol stack. Simulation results are presented that illustrate the severity of the scalability problem when applying common state-of-the-art techniques and parameters. Starting from such a baseline solution, optimization techniques are gradually added to SDDV until the scalability problem is entirely solved. Besides the performance evaluation based on simulations, the paper ends with an evaluation of the final SDDV configuration on real hardware. Experiments including 110 nodes are performed on the iMinds w-iLab.t wireless lab. The results of these experiments confirm the results obtained in the corresponding simulations
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