Browsing by Author "Vahabi, Maryam"
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- Data gathering approach in dense sensor networksPublication . Vahabi, Maryam; Tovar, EduardoSensor/actuator networks promised to extend automated monitoring and control into industrial processes. Avionic system is one of the prominent technologies that can highly gain from dense sensor/actuator deployments. An aircraft with smart sensing skin would fulfill the vision of affordability and environmental friendliness properties by reducing the fuel consumption. Achieving these properties is possible by providing an approximate representation of the air flow across the body of the aircraft and suppressing the detected aerodynamic drags. To the best of our knowledge, getting an accurate representation of the physical entity is one of the most significant challenges that still exists with dense sensor/actuator network. This paper offers an efficient way to acquire sensor readings from very large sensor/actuator network that are located in a small area (dense network). It presents LIA algorithm, a Linear Interpolation Algorithm that provides two important contributions. First, it demonstrates the effectiveness of employing a transformation matrix to mimic the environmental behavior. Second, it renders a smart solution for updating the previously defined matrix through a procedure called learning phase. Simulation results reveal that the average relative error in LIA algorithm can be reduced by as much as 60% by exploiting transformation matrix.
- Feature Extraction in Densely Sensed Environments: Extensions to Multiple Broadcast DomainsPublication . Vahabi, Maryam; Gupta, Vikram; Albano, Michele; Rangarajan, Raghuraman; Tovar, EduardoThe vision of the Internet of Things (IoT) includes large and dense deployment of interconnected smart sensing and monitoring devices. This vast deployment necessitates collection and processing of large volume of measurement data. However, collecting all the measured data from individual devices on such a scale may be impractical and time consuming. Moreover, processing these measurements requires complex algorithms to extract useful information. Thus, it becomes imperative to devise distributed information processing mechanisms that identify application-specific features in a timely manner and with a low overhead. In this article, we present a feature extraction mechanism for dense networks that takes advantage of dominance-based medium access control (MAC) protocols to (i) efficiently obtain global extrema of the sensed quantities, (ii) extract local extrema, and (iii) detect the boundaries of events, by using simple transforms that nodes employ on their local data. We extend our results for a large dense network with multiple broadcast domains (MBD). We discuss and compare two approaches for addressing the challenges with MBD and we show through extensive evaluations that our proposed distributed MBD approach is fast and efficient at retrieving the most valuable measurements, independent of the number sensor nodes in the network.
- New schedulability analysis for WiDomPublication . Vahabi, Maryam; Andersson, BjörnWiDom is a wireless prioritized medium access control (MAC) protocol which offers a very large number of priority levels. Hence, it brings the potential for employing non-preemptive static-priority scheduling and schedulability analysis for a wireless channel assuming that the overhead of WiDom is modeled properly. One schedulability analysis for WiDom has already been proposed but recent research has created a new version of WiDom with lower overhead (we call it: WiDom with a master node) and for this version of WiDom no schedulability analysis exists. Also, common to the previously proposed schedulability analyses for WiDom is that they cannot analyze message streams with release jitter. Therefore, in this paper we propose a new schedulability analysis for WiDom (with a master node). We also extend the WiDom analyses (with and without master node) to work also for message streams with release jitter.
- Response Time Analysis of Slotted WiDOM in Noisy Wireless ChannelsPublication . Vahabi, Maryam; Tennina, Stefano; Tovar, Eduardo; Andersson, BjörnTimely delivery of critical traffic is a major challenge in industrial applications. The Wireless Dominance (WiDOM) medium access control protocol offers a very large number of priority levels to suit time sensitive application requirements. In particular, assuming that its overhead is properly modeled, WiDOM enables an accurate evaluation of the network response time in the wireless domain, through the power of the schedulability analysis, based on non-preemptive and staticpriority scheduling. Recent research proposed a new version of WiDOM (dubbed Slotted WiDOM), which offers a lower overhead as compared to the original version. In this paper, we propose a new schedulability analysis for Slotted WiDOM and extend it to handle message streams with release jitter. In order to provide a more accurate timing analysis, the effect of transmission faults must be taken into account. Therefore, in our novel analysis we consider the case where messages are transmitted in a realistic wireless channel, affected by noise and interference. Evaluation is performed on a real test-bed and the results from experiments provide a firm validation of our findings.
- Response time analysis of slotted WiDom in noisy wireless channelsPublication . Vahabi, Maryam; Tennina, Stefano; Tovar, Eduardo; Andersson, BjörnWiDom is a wireless prioritized medium access control protocol which offers very large number of priority levels. Hence, it brings the potential to employ non-preemptive static-priority scheduling and schedulability analysis for a wireless channel assuming that the overhead of WiDom is modeled properly. Recent research has created a new version of WiDom (we call it: Slotted WiDom) which offers lower overhead compared to the previous version. In this paper we propose a new schedulability analysis for slotted WiDom and extend it to work for message streams with release jitter. Furthermore, to provide an accurate timing analysis, we must include the effect of transmission faults on message latencies. Thus, in the proposed analysis we consider the existence of different noise sources and develop the analysis for the case where messages are transmitted under noisy wireless channels. Evaluation of the proposed analysis is done by testing the slotted WiDom in two different modes on a real test-bed. The results from the experiments provide a firm validation on our findings.