183 research outputs found

    Local heuristic for the refinement of multi-path routing in wireless mesh networks

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    We consider wireless mesh networks and the problem of routing end-to-end traffic over multiple paths for the same origin-destination pair with minimal interference. We introduce a heuristic for path determination with two distinguishing characteristics. First, it works by refining an extant set of paths, determined previously by a single- or multi-path routing algorithm. Second, it is totally local, in the sense that it can be run by each of the origins on information that is available no farther than the node's immediate neighborhood. We have conducted extensive computational experiments with the new heuristic, using AODV and OLSR, as well as their multi-path variants, as underlying routing methods. For two different CSMA settings (as implemented by 802.11) and one TDMA setting running a path-oriented link scheduling algorithm, we have demonstrated that the new heuristic is capable of improving the average throughput network-wide. When working from the paths generated by the multi-path routing algorithms, the heuristic is also capable to provide a more evenly distributed traffic pattern

    Mobile-IP ad-hoc network MPLS-based with QoS support.

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    The support for Quality of Service (QoS) is the main focus of this thesis. Major issues and challenges for Mobile-IP Ad-Hoc Networks (MANETs) to support QoS in a multi-layer manner are considered discussed and investigated through simulation setups. Different parameters contributing to the subjective measures of QoS have been considered and consequently, appropriate testbeds were formed to measure these parameters and compare them to other schemes to check for superiority. These parameters are: Maximum Round-Trip Delay (MRTD), Minimum Bandwidth Guaranteed (MBG), Bit Error Rate (BER), Packet Loss Ratio (PER), End-To-End Delay (ETED), and Packet Drop Ratio (PDR) to name a few. For network simulations, NS-II (Network Simulator Version II) and OPNET simulation software systems were used.Dept. of Electrical and Computer Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .A355. Source: Masters Abstracts International, Volume: 44-03, page: 1444. Thesis (M.Sc.)--University of Windsor (Canada), 2005

    Exploiting the power of multiplicity: a holistic survey of network-layer multipath

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    The Internet is inherently a multipath network: For an underlying network with only a single path, connecting various nodes would have been debilitatingly fragile. Unfortunately, traditional Internet technologies have been designed around the restrictive assumption of a single working path between a source and a destination. The lack of native multipath support constrains network performance even as the underlying network is richly connected and has redundant multiple paths. Computer networks can exploit the power of multiplicity, through which a diverse collection of paths is resource pooled as a single resource, to unlock the inherent redundancy of the Internet. This opens up a new vista of opportunities, promising increased throughput (through concurrent usage of multiple paths) and increased reliability and fault tolerance (through the use of multiple paths in backup/redundant arrangements). There are many emerging trends in networking that signify that the Internet's future will be multipath, including the use of multipath technology in data center computing; the ready availability of multiple heterogeneous radio interfaces in wireless (such as Wi-Fi and cellular) in wireless devices; ubiquity of mobile devices that are multihomed with heterogeneous access networks; and the development and standardization of multipath transport protocols such as multipath TCP. The aim of this paper is to provide a comprehensive survey of the literature on network-layer multipath solutions. We will present a detailed investigation of two important design issues, namely, the control plane problem of how to compute and select the routes and the data plane problem of how to split the flow on the computed paths. The main contribution of this paper is a systematic articulation of the main design issues in network-layer multipath routing along with a broad-ranging survey of the vast literature on network-layer multipathing. We also highlight open issues and identify directions for future work

    A Survey on Issues and Challenges in Congestion Adaptive Routing in Mobile Ad hoc Network

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    Mobile ad hoc networks is the future wireless communication systems have recently emerged as an important trend. Mobile adhoc network is self-configurable and adaptive. Due to the mobility of nodes, the network congestion occurs and it is difficult to predict load on the network which leads to congestion. Mobile adhoc network suffers from a severe congestion controlling problem due to the nature of shared communication and mobility. Standard TCP controlling mechanism for congestion is not fit to the dynamic changing topology of MANETs. This provides a wide scope of research work in mobile ad hoc network. The purpose of this survey is to study and analyze various issues and challenges in congestion control mechanisms in adaptive routing protocols in Mobile Adhoc Network (MANET)

    Towards video streaming in IoT environments: vehicular communication perspective

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    Multimedia oriented Internet of Things (IoT) enables pervasive and real-time communication of video, audio and image data among devices in an immediate surroundings. Today's vehicles have the capability of supporting real time multimedia acquisition. Vehicles with high illuminating infrared cameras and customized sensors can communicate with other on-road devices using dedicated short-range communication (DSRC) and 5G enabled communication technologies. Real time incidence of both urban and highway vehicular traffic environment can be captured and transmitted using vehicle-to-vehicle and vehicle-to-infrastructure communication modes. Video streaming in vehicular IoT (VSV-IoT) environments is in growing stage with several challenges that need to be addressed ranging from limited resources in IoT devices, intermittent connection in vehicular networks, heterogeneous devices, dynamism and scalability in video encoding, bandwidth underutilization in video delivery, and attaining application-precise quality of service in video streaming. In this context, this paper presents a comprehensive review on video streaming in IoT environments focusing on vehicular communication perspective. Specifically, significance of video streaming in vehicular IoT environments is highlighted focusing on integration of vehicular communication with 5G enabled IoT technologies, and smart city oriented application areas for VSV-IoT. A taxonomy is presented for the classification of related literature on video streaming in vehicular network environments. Following the taxonomy, critical review of literature is performed focusing on major functional model, strengths and weaknesses. Metrics for video streaming in vehicular IoT environments are derived and comparatively analyzed in terms of their usage and evaluation capabilities. Open research challenges in VSV-IoT are identified as future directions of research in the area. The survey would benefit both IoT and vehicle industry practitioners and researchers, in terms of augmenting understanding of vehicular video streaming and its IoT related trends and issues

    InfiniBand-Based Mechanism to Enhance Multipath QoS in MANETs

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    Mobile Ad-hoc Networks (MANETs), the continuous changes in topology and the big amounts of data exchanged across the network makes it difficult for a single routing algorithm to route data efficiently between nodes. MANETs usually suffer from high packet loss rates and high link failure rates, which also makes it difficult to exchange data in effective and reliable fashion. These challenges usually increase congestion on some links while other links are almost free. In this thesis, we propose a novel mechanism to enhance QoS in multipath routing protocols in MANETs based on the InfiniBand (IB) QoS architecture. The basic idea of our approach is to enhance the path balancing to reduce congestion on overloaded links. This mechanism has enabled us to give critical applications higher priority to send them packet when routing their packets across the network, effectively manage frequent connections and disconnections and thus help reduce link failures and packet loss rates, and reduce the overall power consumption as a consequence of the previous gains. We have tested the scheme on the (IBMGTSim) simulator and achieved significant improvements in QoS parameters compared to two well-known routing protocols: AODV and AOMDV.هناك نوع من الشبكات حيث يكون كل المكونات فيها عبارة عن اجهزة متحركة بدون اي بنية تحتية تسمى "MANET "في هذا النوع من الشبكات تتعاون االجهزة ذاتيا لتحديد الطرق في ما بينها والنها متحركة تقوم هذه االجهزة بحساب اكثر من طريق عو ًضا عن حساب طريق واحد لتقليل من احتمالية فشل في االرسال حيث اذا تم فشل في طريق معينة تبقى الطرق االخرة سليمة. وفي ناحية اخرى ولتنوع اهمية البرامج والخدمات التي توفرها هذه االجهزة هناك ما يسمى "بجودى الخدمات Service of Quality" حيث يقوم المستخدم بوضع اولويات للبرامج والخدمات من استهالك المصادر المتاحة, والطريق الشائعة هي ان يقوم المستخدم بوضع حدود على سرعة استعمال الشبكة من قبل البرامج االقل اهمية لترك المصادر متاحة للبرامج الاكثر المهمة بشكل اكثر وهذا الحل يحتوي على الكثير من المشاكل في هذا النوع من الشبكات, حيث ان مواصفات الطرق غير معروفة وغير ثابتة وقد تحتوي او تتغير الى قيم اقل من الحدود الموضوعة للبرمج الغير مهمة فتتساوى البرامج والخدمات االقل اهمية بالبرامج االكثر اهمية مما يعني فشل في جودة الخدمات. من خالل بحثنا عن حلول ودراسة انواع مختلفة من الشبكات وجدنا نوع من تطبيق جودة الخدمات في نوع الشبكات المسمى بInfiniBand حيث يتم تطبيق جودة الخدمات من خالل تغيير عدد الرسال المبعثة من قبل البرامج, حيث تقوم االجهزة بارسال عدد اكبر من الرسال التابعة للبرامج المهمة مقارنة بعدد الرسال التابعة للبرامج االقل اهمية, ويتم ذلك باستخدام الصفوف, حيث تصطف الرسال من البرامج المهمة بصف يختلف عن الصف الذي يحتوي على رسال البرامج الغير مهمة. هذا الحل له فائدتان مهمتان االولى انه ال يوثر عالطريقة التقليدية ويمكن ان يستخدم معها والفائدة الثانية انه وبخالف الطريقة التقليدية, الطريقة الجديدة ال تتاثر بصفات الطريق المحسوبة او بتغير صفاتها فنسبة عدد الرسال تكون نفسها مهما اختلفت الطرق و صفاتها, بعد تطبيق هذا النوع وجددنا تحسين في كفائة االرسال تصل الى 18 %في جودة التوصيل و 10 %في سرعة الوصول مع العلم ان جودة الخدمات لم تفشل على غرار الطريقة التقليدية
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