Realistic Prognostic Modeling of Specific Attenuation due to Rain at Microwave Frequency for Tropical Climate Region

Abstract

Absorption and scattering of propagated microwave radio signals by atmospheric variables, particularly rainfall, remained a major cause of propagation attenuation losses and service quality degradation over terrestrial communication links. The International Telecommunications Union Radio (ITU-R) reports and other related works in the literature provided information on attenuation due to rain and microwave propagation data. Such propagation attenuation information in the tropical region of Nigeria is destitute, especially at lower radio waves transmission frequencies. Therefore, this study addresses this problem by employing 12-year rainfall datasets to conduct realistic prognostic modeling of rain rate intensity levels. A classification of the rainfall data into three subgroups based on the depth of rainfall in the region is presented. Additionally, an in-depth estimation of specific rain attenuation intensities based on the 12-year rainfall data at 3.5 GHz is demonstrated. On average, the three rainfall classes produced rain rates of about 29.27 mm/hr, 73.71 mm/hr, and 105.39 mm/hr. The respective attenuation values are 0.89 dB, 1.71 dB, and 2.13 dB for the vertical polarisation and 1.09 dB, 1.20 dB, and 2.78 dB for the horizontal polarisation at 0.01% time percentage computation. Generally, results indicate that higher rain attenuation of 12% is observed for the horizontal polarisation compared to the vertical polarisation. These results can provide valuable first-hand information for microwave radio frequency planning in making appropriate decisions on attenuation levels due to different rainfall depths, especially for lower frequency arrays.

Assessment and Test-case Study of Wi-Fi Security through the Wardriving Technique

“…It is important to note that the views of [99][100][101][102][103] about various connectivity issues can affect the density and the overall evaluation of a wardriving result based on the variability of several issues highlighted in this paper. e wardriving approach is used in this work to crawl wider regions for examination [104][105][106].…”

“…Because of variable connectivity issues, mobile AP devices (MiFi) may be ON and OFF a wardriving radar, resulting in inconsistent results and datasets at each run. e views expressed in the works [99][100][101][102][103] on various connectivity issues can affect the density and the overall evaluation of a wardriving result based on the variability of the above problems. However, current research endeavour using Artificial Intelligence (AI) and Machine Learning is addressing these issues [110][111][112][113].…”

Tropospheric Influence on Low-band Very High Frequency (VHF) Radio Waves

“…These atmospheric variables causes the propagated waves to vary from its anticipated range. The higher the frequency, the higher its chances of being distorted by tropospheric variables [6]. This weakens the received signal, as some of its energies are reflected, refracted, absorbed, depolarized, scattered and diffracted .…”

“…From (3), ( 4) Putting ( 2) into (4) (5) At the receiving end, let be the power received at the receiving antenna. Under matched conditions and effective aperture of antenna at maximum directivity (6) But, (7) Where λ is the wavelength of the radiated wave and G R is the maximum directivity gain of the antenna Putting ( 7) into (6) Where is in megahertz (MHz) while is in kilometers (Km)…”

Tropospheric Influence on Ultra-High Frequency (UHF) Radio Waves

“…The knowledge of specific attenuation influenced by different atmospheric variables is essential for efficient fade management [48]. Based on this premise, studies on atmospheric effects on radio signals have become imperative for radio engineers and scientists for the proper planning of reliable radio links, power budget and coverage areas [49]. As such, wireless network designers are concerned about the nature of the atmosphere through which the signal propagates from the transmitter to the receiver [50].…”