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Exploring Ground Reflection Effects on Received Signal Strength Indicator and Path Loss in Far-Field Air-to-Air for Unmanned Aerial Vehicle-Enabled Wireless Communication
(2024-11-01)
Duangsuwan, Sarun
;
Jamjareegulgarn, Punyawi
Unmanned aerial vehicle (UAV)-enabled wireless communications are becoming increasingly important in applications such as maritime and forest rescue operations. UAV systems often depend on wireless networking and mobile edge computing (MEC) devices for effective deployment, particularly in swarm UAV-enabled MEC configurations focusing on channel modeling and path loss characteristics for air-to-air (A2A) communications. This paper examines path loss characteristics in far-field (FF) ground reflection scenarios, specifically comparing two environments: FF1 (forest floor) and FF2 (seawater floor). LoRa modules operating at 868 MHz were deployed for communication between a transmitting UAV (Tx-UAV) and a receiving UAV (Rx-UAV) to conduct this study. We investigated the received signal strength indicator (RSSI) and path loss characteristics across channel bandwidths of 125 kHz and 250 kHz and spread factors (SF) of 7, 9, and 12. Experimental results show that ground reflection has minimal impact in the FF1 scenario, whereas, in the FF2 scenario, ground reflection significantly influences communication. Therefore, in the seawater environment, a UAV-enabled LoRa MEC configuration using a 250 kHz bandwidth and an SF of 7 is recommended to minimize the effects of ground reflection.
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A Study of Low Band UWB Localization with Wooden and Metal Bookshelves Based on Measurement Data
(2024-01-01)
Mankong, Thanadon
;
Promwong, Sathaporn
;
Bunlaksananusorn, Chanin
This paper considers the potential of Impulse-Radio Ultra-Wideband (IR-UWB) technology which can be a barcodes replacement in bookshelf management systems. To assess its feasibility, we analyze IR-UWB propagation characteristics within bookshelf environments, particularly focusing on the impact of wooden and metal structures. A measurement-based evaluation scheme is employed, utilizing a vector network analyzer (VNA) alongside microstrip patch antennas for both the transmitter (Tx) and receiver (Rx) operating within a frequency range of 3.2GHz to 4.8GHz. The path loss, received signal strength (RSS), and cumulative distribution function (CDF) of the measured data are then analyzed to evaluate the suitability of IR-UWB for bookshelf management applications. These findings will inform the design of IR-UWB antennas and the overall assessment of this technology in this specific context
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Evaluation of RFID Propagation Channels with Wooden and Metal Bookshelves Based on Measurement Data
(2023-01-01)
Supramongkonset, Jatuporn
;
Rattasuwan, Kotchakorn
;
Promwong, Sathaporn
This paper studies the propagation that occurs in Radio Frequency Identification (RFID). The purpose of this study is to establish a model to study the energy and efficiency of the system. Experimenting with two model of bookshelf models. Wood and metal bookshelves are used as models to measure data. Microstrip antenna are used as a transmitter (Tx antenna) and a receiver (Rx antenna) at frequency of 2.45 GHz channels in co-polarization. From the data of this measurement result, we can observe the tendency of path loss arising from the change in distance and the effect of the signal in both wood and metal bookshelf by the contouring of the path loss signal. The results showed that the co-polarization had higher path loss at increased distances. By path loss modeling using contour method it was found that at measuring point near the edge of the bookshelf There is path loss in the edge of metal bookshelf higher than the edges of wooden bookshelf.
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Characterization of Electromagnetic Wave in Transformer for Partial Discharge Detection
(2023-01-01)
Suwan, Supakorn
;
Tiengthong, Thanadol
;
Southisombath, Phouthong
;
Promwong, Sathaporn
The increasing demand for electricity and the potential risks associated with partial discharge highlights the critical importance of robust transformer condition monitoring. Electromagnetic methods offer a promising approach to monitoring transformer health, benefiting from their ability to minimize external interference and their broad operating bandwidth covering HF, VHF, and UHF frequencies. The IEC 62478 standard provides multiple methodologies to leverage electromagnetic techniques in transformer health assessment, encompassing the analysis of electromagnetic waves through directivity, sensitivity, and transmission properties. In this study, we specifically investigate the transformer's UHF transmission characteristics. A vector network analyzer measures and records both transmitting and receiving elements of the UHF transmission channel and the UHF antenna. The measurements within the transformer tank simulate the realistic transformer environment. An optimum receiver is implemented at the receiver end to optimize the received signal quality. The results are comprehensively evaluated by analyzing the UHF transmission channel's path loss and transmission gain within the transformer. The primary objective of this research is to thoroughly examine the UHF transmission characteristics for efficient transformer condition monitoring, offering valuable insights for researchers and engineers involved in mitigating the risks associated with partial discharge in transformers.
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A new method for prediction 3G path loss propagation in suburban of Thailand
(2012-10-02)
Bhupuok, Wiyada
;
Dejhan, Kobchai
This paper proposes the prediction propagation of path loss band 2100 MHz 3G, the mobile in suburban of Thailand. The selected site is Pathum Thani province which has a few of construction. This experiment measured the signal at different distance and different direction from mobile base stations. The results from experiment will be compared with the calculating value in order to make the new empirical model that will be suitable in suburban of Thailand. The statistical method Root Mean Square Error (RMSE) and Okumura model are used in this paper. © 2012 IEEE.
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Three-ray path loss based on peak power loss for ultra wideband impulse radio systems
(2011-12-01)
Supanakoon, Pichaya
;
Chaiyapong, Saksit
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Promwong, Sathaporn
;
Takada, Jun Ichi
Path loss is important parameter to analyze and design link budget. For indoor environment, there is fading that occurs in path loss. Therefore, accurate path loss model, which is considered fading, is necessary. In this paper, three-ray path loss based on peak power loss is proposed for ultra wideband impulse radio (UWB-IR) systems. The rectangular passband is used as UWB-IR transmitted signal. The extension of Friis' transmission formula is applied for UWB-IR three-ray channel. The received signal is evaluated. The closed form formula of three-ray path loss is derived based on peak power loss. The path loss from proposed model was illustrated and compared with three-ray model based on average power loss and free space model. This model can be used to study the characteristic of fading and extended to multi-ray path loss model for indoor environment. © 2011 IEEE.

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