Copyright © 2018 Authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. International Journal of Engineering & Technology, 7 (2.3) (2018) 22-25 International Journal of Engineering & Technology Website: www.sciencepubco.com/index.php/IJET Research Paper Slant Path Ka-Band rain attenuation statistics in equatorial Malaysia obtained using stratiform convective-synthetic storm technique M. M. Yunus 1,2 *, J. Din 2 , S. L. Jong 3 , H. Y. Lam 4 1 Center of Telecommunication Research and Innovation, Faculty of Electronic and Computer Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia 2 Wireless Communication Centre, Faculty of Electrical Engineering, Universiti Teknologi Malaysia , 81200 Skudai, Johor, Malaysia 3 Faculty of Electrical and Electronic Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Batu Pahat, Johor, Malaysia 4 Faculty of Engineering Technology, Universiti Tun Hussein Onn Malaysia, 86400 Batu Pahat, Johor, Malaysia *Corresponding author E-mail:mawar@utem.edu.my Abstract In the design of satellite communication link, rain attenuation statistics is essential information for system designer to realistically deter- mine link availability and provide means to combat system degradation. Due to the limitation of available measured data in equatorial regions especially for high frequencies (Ka-band and above), the prediction model is the best way to obtain rain attenuation statistics. This paper presents statistical analysis of rain attenuation at Ka-band by applying the Stratiform Convective-Synthetic Storm Technique (SC-SST) model taking advantage from local weather features from rain rate time series. The study on seasonal and diurnal variability is also presented in this paper to provide good insight in the design and implementation of fade margin. Keywords: rain attenuation; satellite communication system; Ka-band; equatorial region; Synthethic Storm Technique; SC-SST 1. Introduction The satellite communication system providers are moving towards Ka- and higher frequency bands to meet higher data rates and bandwidth demands. One inherent drawback of Ka-band satellite systems is increase in signal distortion resulting from propagation effects, which mainly caused by the presence of rain. This effect is more severe in tropical/equatorial region with high rain intensity throughout the year [1][2]. Therefore, it is of great importance to perform comprehensive study on rain attenuation statistics particu- larly at high frequency bands in this region in order to provide high quality of services to the end user. However, tropi- cal/equatorial regions are very much lacking of reliable measure- ment data due to the high cost of experimental setup and requires long periods of data collection [3]. Nevertheless, measured rain rate data are made available in many locations including in the tropics as the rain gauge are easier to install. In this paper, we exploit the Stratiform Convective-Synthetic Storm Technique (SC-SST) [4] to provide reliable rain attenuation time series based on available rain rate time series measured at the location of interest. SC-SST model adapt a basic principle from the conventional Synthetic Storm Technique (SST) [8]. One of main advantage of these models are their abilities to retain local climate peculiarities when generates the rain attenuation induced on a hypothetical satellite link, thus rendering the model effective- ly worldwide [5][6]. Adding to that, SC-SST model introduced separation type of rain events (e.g. stratiform and convective events) in the calculation which lead to a better prediction of rain attenuation in tropical/equatorial region [7]. This paper is first briefly discussed on the basic principle of SC-SST model and parameter used in the estimation. The remain- der of paper is structured as follows: The SC-SST prediction of rain attenuation at Ku-band compared against measurement data is discussed in Section III, which highlights the effectiveness of the prediction model. The analysis is then continue with rain attenua- tion estimation at Ka-band using SC-SST, as well as its seasonal and diurnal variation. 2. Stratiform Convective-Synthetic Storm Technique (SC-SST) Stratiform and convective rain events have different space-time evolution that impacts radio wave propagation on different aspects. Thus, proper discrimination on the rain events would definitely enhance the prediction model of rain attenuation. There are several classification techniques to discriminate the stratiform and con- vective rain available in the literatures [9]-[11]. The most direct method is by using different rain rate thresholds. In [12] the rain events is discriminated by a rain rate threshold of 20 mm/h devel- oped according to radar observation of the rainfall structure while the SAM model [13][7] used a threshold of 10 mm/h based on an exponential shape of the rain spatial distribution. For comprehen- sive result, investigations on different rain rate thresholds for SC- SST estimation is presented in this paper and eventually summa- rize the closed outcomes with the measured data in equatorial site. Similar as SST, the SC-SST modelled vertical structure of the precipitation medium with two layers: a rain layer (layer A) and