Evaluation of Ka-Band Rain Attenuation for Satellite Communication in Tropical Regions Through a Measurement of Multiple Antenna Sizes

Abstract

The Ka-band is modifying the mode of legacy communication towards versatile satelliteoriented systems with the beam-spot capability and a high-throughput architecture to provide twice the capability of classic Fixed Satellite Service (FSS) satellites, thus significantly reducing the cost per bit. Given this background, the contribution of precipitation rate and Ka-band downpour attenuation are expected to improve statistical models for effect prediction. The International Telecommunication Union (ITU) and local researchers are working tirelessly to determine the best prediction model for tropical climates. However, persistent and continuous efforts are required because currently available models do not perform well. The current prediction model for large datasets exhibits a certain deviation. Direct beacon measurement has been compared with an available prediction model that analyses rain effects in tropical regions. Theoretically, the size of the antenna and its gain influence the performance of the receiving signal. Size and availability are two factors which cause degradation and outage in the receiving signal. The majority of extant studies focus on a single antenna with a diameter lesser than 2.4m. Theoretically, antennas with a smaller diameter possess a smaller margin in comparison with antennas with larger diameters. This condition could affect the prediction model when the high attenuation causes a rapid outage in a small antenna and lead to the unavailability of measurement results. To study such effects and provide a good recommendation, the current work measures the beacon attenuation data at two locations, namely, Bukit Jalil (Kuala Lumpur) and Cyberjaya (Selangor). The locations are approximately 15 km apart and have antennas from 0.65m to 31.1m in sizes. Analyses using an available prediction model revealed that ITU-R P.618 provides the lowest RMS value of 14.37 with regards to rainfall rate on two selected samples in Malaysia. High-accuracy prediction can be achieved through the contribution of this study, and comparative data can be obtained for future research. This study is an encouraging step towards a highly comprehensive and accurate prediction of tropospheric impairments in Ka-band satellite communications in the tropical region. INDEX TERMS ITU, rain attenuation, Ka-band satellite communication.

Observation of Site Diversity Gain Dependency on Separation Distance Using an Attenuation-Dependent Logarithmic Model in a Tropical Region

“…The gain from the seven SD schemes was extracted at an attenuation pace of 1 dB. The attenuation at CYB-RWG was found to be saturated at approximately 24 dB for 0.01 percent of the time [34] because the usage of the larger diameter of the antenna in the experiment sustains the signal from more severe attenuation compared to that of the smaller antenna used in the other SD scheme [35]. Therefore, all the gains from the other sites were also extracted to the 24 dB value to deliver a fair evaluation, and all gains were stored in a database.…”

Measuring Contention and Congestion on Ad-Hoc Multicast Network Towards Satellite on Ka-Band and LiFi Communication Under Tropical Environment Region

“…The locations are approximately 20km apart, which provides better HTS frequency planning under the beam spot capacity. Two months of attenuation trending data were captured and analysed at two different locations, mainly Bukit Jalil ( Figure 3) and Cyberjaya ( Figure 4) [6]. Based on the rain data obtained, on February, 14 th 2020, Bukit Jalil provides the highest and longest duration of the rain rate as compared with other rainy days and locations at Cyberjaya.…”

“…Each fluctuates in the attenuation (Figure 8 and 9), optimise the link modulation and impact the total bandwidth, including the capacity of a received signal. The recorded rain data are further analysed and plotted using complementary cumulative distribution function (CCDF) to identify the rain rate at R0.01% of the time, which provides the duration of unavailability of RF link for the necessity in implementing a gap-fillers network [6]. During the higher modulation and code rate, the bandwidth is able to boost up to 45Mbps and ≤ 6Mbps during lower code rate and modulation.…”

“…In order to simplify the calculation and the concept in this paper, the data on February 14th, 2020, has been selected and analysed further for the paper. This was due to the recorded high duration of rainfall within the analysed area [6].…”

Propagation From Geostationary Orbit Satellite to Ground Station Considering Dispersive and Inhomogeneous Atmospheric Environments

“…To estimate the characteristics of geostationary orbit (GEO) satellite links for navigation, communications, broadcasting and surveillance, it is necessary to accurately calculate the electromagnetic wave propagation in the atmosphere. In general, the atmospheric environment affects the attenuation and refraction of electromagnetic wave propagation on satellite links [1][2][3][4]. Electromagnetic waves are reflected, refracted and absorbed when they pass through the atmosphere.…”