5,179 research outputs found

    Network Adaptive Interference Aware Routing Metric for Hybrid Wireless Mesh Networks

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    Wireless Mesh Networks provide a reliable, robust and resilient platform for broadband access. Main benefits of using Wireless Mesh Networks are their low cost, robustness, self healing, and self configuring properties. In Wireless Mesh Networks, routing metric determines the path from source to destination. Wireless link conditions can be affected by a number of factors including interference, congestion, mobility, and network topology. Routing metric needs to consider all these factors while making routing decisions. In addition, wireless link conditions do not remain static with time requiring the routing metric to be adaptive. Interference in Wireless Mesh Networks are of two types: inter-channel and intra-channel interference. Existing routing metrics for Wireless Mesh Networks either consider only one of the two interference types or do not capture changing network conditions. In this paper, we propose a new routing metric for Wireless Mesh Networks which takes into account both inter and intra-channel interference and is adaptive to changing network conditions. Our proposed metric is compared with the state of the art and shows throughput improvement of up to 20 percent and latency reduction of 25 percent

    Early Experiences in Traffic Engineering Exploiting Path Diversity: A Practical Approach

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    Recent literature has proved that stable dynamic routing algorithms have solid theoretical foundation that makes them suitable to be implemented in a real protocol, and used in practice in many different operational network contexts. Such algorithms inherit much of the properties of congestion controllers implementing one of the possible combination of AQM/ECN schemes at nodes and flow control at sources. In this paper we propose a linear program formulation of the multi-commodity flow problem with congestion control, under max-min fairness, comprising demands with or without exogenous peak rates. Our evaluations of the gain, using path diversity, in scenarios as intra-domain traffic engineering and wireless mesh networks encourages real implementations, especially in presence of hot spots demands and non uniform traffic matrices. We propose a flow aware perspective of the subject by using a natural multi-path extension to current congestion controllers and show its performance with respect to current proposals. Since flow aware architectures exploiting path diversity are feasible, scalable, robust and nearly optimal in presence of flows with exogenous peak rates, we claim that our solution rethinked in the context of realistic traffic assumptions performs as better as an optimal approach with all the additional benefits of the flow aware paradigm

    A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks

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    In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs

    Performance of TCP/UDP under Ad Hoc IEEE802.11

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    TCP is the De facto standard for connection oriented transport layer protocol, while UDP is the De facto standard for transport layer protocol, which is used with real time traffic for audio and video. Although there have been many attempts to measure and analyze the performance of the TCP protocol in wireless networks, very few research was done on the UDP or the interaction between TCP and UDP traffic over the wireless link. In this paper, we tudy the performance of TCP and UDP over IEEE802.11 ad hoc network. We used two topologies, a string and a mesh topology. Our work indicates that IEEE802.11 as a ad-hoc network is not very suitable for bulk transfer using TCP. It also indicates that it is much better for real-time audio. Although one has to be careful here since real-time audio does require much less bandwidth than the wireless link bandwidth. Careful and detailed studies are needed to further clarify that issue.Comment: 9 pages, 5 figures, ICT 2003 (10th International Conference on Telecommunication
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