Current Issue : January - March Volume : 2016 Issue Number : 1 Articles : 5 Articles
Partitioning has always been a challenge in the design of distributed applications. It allows optimizing the intercommunication\nbetween the system components and so increasing the lifetime of the network. Graph theory methods have often been used to\nperform partitioning in classic distributed systems but seem to be not efficient in ad hoc or wireless sensor networks (WSN). The\nmain reason is related to the topology of these kinds of networks and the presence of multi hop communication. In this paper, we\npropose a new self-organisation of the WSN based on the optimization of the number of jumps between any sensor and the sink.\nThe network is based on a two-level hierarchy structure and organised as a set of clusters with one cluster-head by cluster and a\nsuper-leader for the entire network. The optimisation process has been performed and validated by introducing some parameters,\nbaptized cohesion parameters. The simulation of our approach compared to existing and previously developed protocols shows\nthe efficiency of the method. The results are very interesting and allow projecting several perspectives to improve performances by\nusing other metrics....
We propose a novel energy-aware approach to detect a leak and estimate its size and location in a noisy water pipeline using leastsquares\nand various pressuremeasurements in the pipeline network.Thenovelty in ourwork hinges on the fusion of the duty-cycling\n(DC) and data-driven (DD) strategies, both well-known techniques for energy reduction in a wireless sensor network (WSN). To\nmaximize the information gain and minimize the energy consumed by the WSN, we first study the effects of (a) various levels of\nsensor measurement uncertainty and (b) the use of the smallest possible number of pressure sensors on the overall accuracy of\nour approach. Using the DD strategy only, a noisy environment, and a small number of sensors, the performance of our scheme\nshows that, for small leak sizes, the estimation error in both leak location and size becomes unacceptably high. Next, using as few\nsensors as possible for an acceptable accuracy, we fused the DD strategy with the DC one to minimize the sensing, processing,\nand communication energies. The fusion approach yielded a better performance with significant energy saving, even in noisy\nenvironments. EPANET was used to model the pipeline network and leak and MATLAB to implement, analyze, and evaluate our\nfusion approach....
The contention based medium access method of 802.11 standards is a fundamental cause of poor downlink goodput and high\nlatency over wireless networks, which makes it impossible to provide QoS guarantees. The intensive channel contention leads to\nthe performance degradation.The problem exacerbateswhen the traffic asymmetry between the uplink and the downlink is present.\nWhile prior research works proposed various mechanisms to alleviate the issue, little was done to specifically address the appropriate\nparameter setting in a real world network. This study presents a way to obtain the appropriate access parameters that improves the\nperformance of QoS applications over wireless networks. In particular, we propose AQEDCA, a traffic-aware minimum contention\nwindow adjustment algorithm. We validate our scheme by the extensive real world network tests and the results show that our\nscheme improves the downlink goodput up to 199.13%, decreases the latency up to 54.77%, and can achieve tight QoS guarantees\nas compared to the existing schemes....
This paper tackles the coverage problem in homogenous and heterogeneous wireless sensor networks. The homogenous sensor\nnetwork consists of sensor nodes and relays; however, the heterogeneous sensor network consists of sensor nodes, super nodes,\nand satellite nodes. In the latter network, super nodes and satellite nodes are utilized to demonstrate different scenarios. Super\nnodes consume huge amount of energy, compared to sensor nodes. To address this problem, the aim of this paper is to find the\nbaseline when super nodes are used efficiently, despite the inherited high power consumption. Wolfram Mathematica is used to\ncompare random independent deployment circular analytical model against a much simpler square analytical model.The achieved\nresults showed that the simple square model is very close to circular model when K-coverage is �2....
The management of heterogeneous distributed sensor networks requires new solutions that can address the problem of\nautomatically fusing the information coming from different sources in an efficient and effective manner. In the literature it is possible\nto find different types of data fusion and information fusion techniques in use today, but it is still a challenge to obtain systems\nthat allow the automation or semi automation of information processing and fusion. In this paper, we present a multiagent system\nthat based on the organizational theory proposes a new model to automatically process and fuse information in heterogeneous\ndistributed sensor networks. The proposed architecture is applied to a case study for indoor location where information is taken\nfrom different heterogeneous sensors....
Loading....