22 research outputs found

    Improving Packet Analysis in Wireless Sensor Network using Bit Rate Classifier

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    Remote sensor system (WSN) has risen as a promising innovation. Despite the fact that WSN is a promising innovation, there is still a lot of extra research required before it ?nally turns into a developed innovation. An extensive variety of WSN applications have been proposed, for example, living space checking, natural perceptions and estimating frameworks, wellbeing observing, and so on. In these applications, numerous low power and cheap sensor hubs are sent in an unlimited space to coordinate as a system. This paper assesses the impact of utilization of bit rate investigation on bundle approaching to the switch in the remote sensor system. The fundamental point is to accomplish an effective remote sensor system which ought to be not any more defenseless to parcel misfortune. Alternate parameters are deferral, throughput, bundle conveyance proportion, jitter and vitality. The calculation minimizes the postponement that may happen because of high activity rate by utilizing bit rate classifier in this way enhancing the throughput and different parameters

    Analyzing Linear Communication Networks using the Ribosome Flow Model

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    The Ribosome Flow Model (RFM) describes the unidirectional movement of interacting particles along a one-dimensional chain of sites. As a site becomes fuller, the effective entry rate into this site decreases. The RFM has been used to model and analyze mRNA translation, a biological process in which ribosomes (the particles) move along the mRNA molecule (the chain), and decode the genetic information into proteins. Here we propose the RFM as an analytical framework for modeling and analyzing linear communication networks. In this context, the moving particles are data-packets, the chain of sites is a one dimensional set of ordered buffers, and the decreasing entry rate to a fuller buffer represents a kind of decentralized backpressure flow control. For an RFM with homogeneous link capacities, we provide closed-form expressions for important network metrics including the throughput and end-to-end delay. We use these results to analyze the hop length and the transmission probability (in a contention access mode) that minimize the end-to-end delay in a multihop linear network, and provide closed-form expressions for the optimal parameter values

    Delay Constrained Throughput Analysis of a Correlated MIMO Wireless Channel

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    The maximum traffic arrival rate at the network for a given delay guarantee (delay constrained throughput) has been well studied for wired channels. However, few results are available for wireless channels, especially when multiple antennas are employed at the transmitter and receiver. In this work, we analyze the network delay constrained throughput of a multiple input multiple output (MIMO) wireless channel with time-varying spatial correlation. The MIMO channel is modeled via its virtual representation, where the individual spatial paths between the antenna pairs are Gilbert-Elliot channels. The whole system is then described by a K-State Markov chain, where K depends upon the degree of freedom (DOF) of the channel. We prove that the DOF based modeling is indeed accurate. Furthermore, we study the impact of the delay requirements at the network layer, violation probability and the number of antennas on the throughput under different fading speeds and signal strength.Comment: Submitted to ICCCN 2011, 8 pages, 5 figure

    Packet Arrival Analysis in Wireless Sensor Networks

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    Distributed sensor networks have been discussed for more than 30 years, but the vision of Wireless Sensor Networks (WSNs) has been brought into reality only by the rapid advancements in the areas of sensor design, information technologies, and wireless networks that have paved the way for the proliferation of WSNs. The unique characteristics of sensor networks introduce new challenges, amongst which prolonging the sensor lifetime is the most important. WSNs have seen a tremendous growth in various application areas including health care, environmental monitoring, security, and military purposes despite prominent performance and availability challenges. Clustering plays an important role in enhancement of the life span and scalability of the network, in such applications. Although researchers continue to address these grand challenges, the type of distributions for arrivals at the cluster head and intermediary routing nodes is still an interesting area of investigation. Modelling the behaviour of the networks becomes essential for estimating the performance metrics and further lead to decisions for improving the network performance, hence highlighting the importance of identifying the type of inter-arrival distributions at the cluster head. In this paper, we present extensive discussions on the assumptions of exponential distributions in WSNs, and present numerical results based on Q-Q plots for estimating the arrival distributions. The work is further extended to understand the impact of end-to-end delay and its effect on inter-arrival time distributions, based on the type of medium access control used in WSNs. Future work is also presented on the grounds that such comparisons based on simple eye checks are insufficient. Since in many cases such plots may lead to incorrect conclusions, demanding the necessity for validating the types of distributions. Statistical analysis is necessary to estimate and validate the empirical distributions of the arrivals in WSNs

    TRIDNT: The Trust-Based Routing Protocol with Controlled Degree of Node Selfishness for MANET

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    Low-Latency Millimeter-Wave Communications: Traffic Dispersion or Network Densification?

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    This paper investigates two strategies to reduce the communication delay in future wireless networks: traffic dispersion and network densification. A hybrid scheme that combines these two strategies is also considered. The probabilistic delay and effective capacity are used to evaluate performance. For probabilistic delay, the violation probability of delay, i.e., the probability that the delay exceeds a given tolerance level, is characterized in terms of upper bounds, which are derived by applying stochastic network calculus theory. In addition, to characterize the maximum affordable arrival traffic for mmWave systems, the effective capacity, i.e., the service capability with a given quality-of-service (QoS) requirement, is studied. The derived bounds on the probabilistic delay and effective capacity are validated through simulations. These numerical results show that, for a given average system gain, traffic dispersion, network densification, and the hybrid scheme exhibit different potentials to reduce the end-to-end communication delay. For instance, traffic dispersion outperforms network densification, given high average system gain and arrival rate, while it could be the worst option, otherwise. Furthermore, it is revealed that, increasing the number of independent paths and/or relay density is always beneficial, while the performance gain is related to the arrival rate and average system gain, jointly. Therefore, a proper transmission scheme should be selected to optimize the delay performance, according to the given conditions on arrival traffic and system service capability

    End-to-End Delay Distribution Analysis for Stochastic Admission Control in Multi-hop Wireless Networks

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    A Network Calculus Approach for the Analysis of Multi-Hop Fading Channels

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    A fundamental problem in the delay and backlog analysis across multi-hop paths in wireless networks is how to account for the random properties of the wireless channel. Since the usual statistical models for radio signals in a propagation environment do not lend themselves easily to a description of the available service rate on a wireless link, the performance analysis of wireless networks has resorted to higher-layer abstractions, e.g., using Markov chain models. In this work, we propose a network calculus that can incorporate common statistical models of fading channels and obtain statistical bounds on delay and backlog across multiple nodes. We conduct the analysis in a transfer domain, which we refer to as the `SNR domain', where the service process at a link is characterized by the instantaneous signal-to-noise ratio at the receiver. We discover that, in the transfer domain, the network model is governed by a dioid algebra, which we refer to as (min,x)-algebra. Using this algebra we derive the desired delay and backlog bounds. An application of the analysis is demonstrated for a simple multi-hop network with Rayleigh fading channels and for a network with cross traffic.Comment: 26 page

    On-line residual capacity estimation for resource allocation in wireless mesh networks

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    Contention-based multi access scheme of 802.11 based wireless mesh networks imposes difficulties in achieving predictable service quality in multi-hop networks. In order to offer effective advanced network services such as flow admission control or load balancing, the residual capacity of the wireless links should be accurately estimated. In this work, we propose and validate an algorithm for the residual bandwidth of wireless mesh network. By collecting transmission statistics from the nearby nodes that are one and two hops away and by using a basic collision detection mechanism, the packet delivery failure probability for a given link is estimated. The packet failure probability is used in an analytical model to calculate the maximum allowable traffic level for this link in saturation condition. We evaluate the efficacy of the method via OPNET simulations, and show that the percent estimation error is significantly lower than a recent prominent estimation method; i.e. error is between 0.5-1.5%. We demonstrate that flow admission control is successfully achieved in a realistic WMN scenario based on accurate link residual bandwidth estimates. A flow control algorithm based on residual bandwidth keeps the unsatisfied traffic demand bounded and at a negligibly low level. We also propose a routing metric that uses residual bandwidth as link metric and we show that this routing algorithm results in a significant increase in network throughput compared to other popular metrics
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