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Öğe Efficient Deployment of Energy Antenna for Sensor Nodes with RF Charging(2019) Zorlu, Ahmet; Kosunalp, Selahattin; Tabakcıoğlu, Mehmet BarışA sensor node has processor, antenna, sensor and energy units. A large number of sensor nodes generateswireless sensor network (WSN). The main problem of WSN is limited-energy. A great number of MACprotocols are introduced to compensate the energy problem. In order to supply energy to sensor nodes, anexternal solar panel, wind turbine and energy harvester are added to the architecture of the nodes. Moreover,wireless energy transfer is used to meet the energy problem of sensor node. Position, height and operatingfrequency of energy antenna is so important to charge the sensor nodes efficiently. In this study, ray theoreticalmodels are used to calculate the electric field and generate the coverage map. As the energy antenna is deployedto optimum place, charging will complete in a short time.Öğe IoT-TDMA: A performance evaluation of TDMA scheme for wireless sensor networks with Internet of Things(John Wiley and Sons Ltd, 2022) Kosunalp, Selahattin; Kaya, YunusThis article focuses on the design and implementation of an improved version of TDMA scheme for wireless sensor networks (WSNs) exploiting the Internet of Things (IoT) phenomena. The main motivation behind this work is to create an environment for WSNs to benefit from IoT opportunities. An extensive review of the state-of-the-art medium access control (MAC) approaches proposed for IoT is carried out underlying their basic principles and features. An adaptation of TDMA strategy, called IoT-TDMA, is proposed to enhance the channel performances particularly throughput and latency. To test the performance of IoT-TDMA practically, a low-cost node hardware with the capability of Internet connection is essentially designed. IoT-TDMA has been implemented on real-world highly scalable single-hop and multi-hop topologies. Performance results indicate significant improvements in terms of channel throughput and end-to-end delay in comparison to a recently proposed efficient MAC scheme. © 2022 John Wiley & Sons, Ltd.Öğe Medium Access Control Protocols for Wireless Sensor Networks with Ambient Energy(IEEE, 2016) Kosunalp, Selahattin; Tabakcioglu, Mehmet BarisWireless sensor networks (WSNs) have recently been a popular research area with a broad range of applications. One of the most significant constraints of WSNs is energy limitation of sensor nodes. Therefore, energy-efficiency has been considered as primarily design criterion in many medium access control (MAC) protocols developed. In order to solve the issue of limited-energy sources, various recent protocols have focused on energy harvesting from surrounding environment, such as solar, wind and vibration energy, resulting in providing unlimited energy source. Ambient energy exhibits a characteristic of unlimited energy source but not available always due to environmental changes. The focus is now being placed on effective utilization of the time-varying ambient energy. This study aims to provide a review of recently proposed MAC protocols for energy-harvesting WSNs describing their operating principles and underlying features.Öğe Quantification of Honey Adulteration Using a Planar Microstrip Metamaterial-Motivated Sensor and Software-Defined Radio(Ieee-Inst Electrical Electronics Engineers Inc, 2025) Cem Hasar, Ugur; Hasar, Hafize; Kaya, Yunus; Ozturk, Hamdullah; Korkmaz, Huseyin; Kosunalp, Selahattin; Mustafa Ramahi, OmarThis work presents the application of a planar microstrip metamaterial (MM)-motivated sensor in the form of a split-ring resonator (SRR) for the detection and quantification of water adulteration in honey samples. The proposed sensor utilizes inexpensive software-defined radio (SDR) measurements, offering a cost-effective solution. Unlike previous MM sensors employing SRR configuration, our proposed MM-motivated sensor is integrated with a microstrip feedline and an additional vertical bar, enhancing its sensing capability. To enable accurate measurements, a simple calibration procedure based on baseline normalization is implemented, allowing for amplitude-only transmission measurements (|S-21|) using the SDR. A special sample holder was designed to increase the repeatability of measurements. We separately employ two postprocessing techniques, namely, the rolling average (RA) approach and the Savitzky-Golay (SG) filter, to effectively eliminate ripples in the measured |S-21| data obtained from the SDR. For validation and evaluation of the proposed sensor and postprocessing techniques, measurements of flower honey samples with water adulteration levels (delta ) up to 10% (mass-to-mass basis) were also performed using a vector network analyzer (VNA). The resonance frequency of |S21| is utilized as the basis for analysis. We establish a metric function (linear function) that correlates the shift in resonance frequency with delta. It is observed that this function fits to measured resonance frequency values with an R(2 )value greater than 0.96 for both postprocessing techniques with or without the sample holder. By inverting this function, we can predict delta with considerable accuracy for a given resonance frequency by using another linear function. It is observed that percentage variations between predicted and measured delta values are between 1.54% and 6.46% for testing samples with delta = 5% and delta = 7%.
