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.

⁞ABSTRACT With the point in evaluating the performance of the On-the-Move (OTM) Satellite Communication and Light Fidelity (SatCom-LiFi), an extensive study of measurement has been conducted to give a wide vision of the SatCom-LiFi potential under a tropical region. As the interest for OTM network connectivity to offload the C-band capacity arises due to frequency spectrum scarcity, satellite networks offer to balance topographical requirements under tropical environment as the Next Generation Networks (NGN) trend for OTM communication system solutions. To date, mobile satellite terminal propagation model was carried out at temperate regions where further experimental measurement is needed under the OTM scenario in tropical region. This paper discusses on the areas where there are limited real-time data under the OTM scenario (e.g. rain attenuation, power arch) at Ka-band frequency. Integration infers, to be specific, the use of new elements capable in providing performance analysis of all systems involved and to take possible decision, in determining the need for a technically feasible solution. Measurement results reveal that, throughput data rate of 15 Mbps were able to be delivered for more than 80% of the time under the speed of 150 km/h with shielded mesh antenna. In addition to that, this paper reveals the favorable circumstances and inadequacies of OTM network quality, in which the measurement presented plays an important role for future researchers in distinguishing highly accurate predictions.

⁞ABSTRACT Diversified interest in the low-cost broadband satellite has overgrown to support a wide range of services in the satellite network. There is a need to explore alternative parts of optical communication towards Light Fidelity (LiFi) to offload the overcrowded radio frequency segments and improve the overall throughput. Ad hoc networks are the most suitable solution to provide a non-trivial challenge towards system design due to efficiency and quality of service (QoS). Both contention and congestion issues can severely affect the performance of a multicast network where video streaming becomes part of the day-today life. In this paper, we present network congestion characterization related to LiFi and High Throughput Satellite (HTS) under the Ka-band modulation schemes during adverse weather conditions in the tropical region. The heterogeneous network performance presented in this paper comprehensively provides systematic information for Satellite communication (SatCom) & LiFi and optimization of throughput by reducing network contention ratio. The measurement results have shown that when Deep Packet Inspection (DPI) policy is applied, an improvement of 80.26% in the packet delivery ratio is achieved as compared when without a DPI policy. However, using an on-premise Software-defined-wide access network (SD-WAN) alone provides 58.20% improvement in the overall network system. As a result, DPI provides a well managed QoS approach to manage the entire hybrid network, mainly in the tropical environment region. ⁞INDEX TERMS Contention Ratio, QoS, DPI, SD-WAN, LiFi, HTS, Ka-band satellite communication. Hub Antenna Internet Hub NOC Carrier main link Ka-Band Satellite Broadband Remote location antenna 2.4m Satellite Modem

⁞ABSTRACT Ensuring site diversity is a fade mitigation technique used to overcome severe rain-induced attenuation encountered in high-frequency signal communications, especially over tropical regions. However, due to the high cost of deploying diverse equipment and terrestrial infrastructures for connections between two sites, gain prediction models are widely used to evaluate the performance of a given scheme. This article presents a study on the behavior of four parameters that contribute to site diversity gain: site separation distance, link frequency, elevation angle, and baseline orientation angle. A correlation between gain and distance is found in the form of an attenuation-dependent logarithmic function instead of the gain being saturated when the increment of the distance exceeds the convective rain cell extent, as was found in the literature. Therefore, a site diversity logarithmic model, SDLog, is proposed. The analysis utilized seven site diversity experiments conducted in the tropics, i.e., in Malaysia, Singapore, and Guam, USA. The performance of the SDLog model was compared with the performances of existing models, namely, the ITU-R, Hodge, Panagopoulos, Semire, and X. Yeo models. The SDLog model reproduces the experimental datasets with an average root mean squared error (RMSE) of 0.12, while those of the ITU-R, Hodge, Panagopoulos, Semire, and X. Yeo models are 0.226, 0.289, 0.19, 0.192, and 0.311, respectively. These models were also evaluated based on diversity experiments conducted in Indonesia, separate from the former evaluation. The RMSE and mean absolute percentage error (MAPE) of all evaluations are presented, and the SDLog model seems to be convincing.