RADIOCOMMUNICATIONS NETWORK FACILITIES - SMART POLE

To support the deployment of transmitter sites for mobile communications and IoT applications, the smart pole concept is introduced where the physical structure of the pole can be use not only for installation of transmitter sites, but it can also support other functionalities such as surveillance, environmental sensors, digital information broadcasting, and emergency services. The use of smart poles as structures for the installation of transmitter sites represents an option for telecommunication facility providers, local councils, property developers and other relevant bodies to adopt for a greater installation density of transmitters in applicable geographic area

Estimating tropical rain attenuation on the Earth-satellite path using radar data

Radar-return echoes, known as ‘reflectivity’, are exploited in the course of estimating rain attenuation along a slant path. Relevant radar gates or ‘range bins’ are identified to correlate a specific satellite path. The reflectivity value of each range bin is converted to rainfall rate using established radar reflectivity values – rainfall rates, (Z–R relation). Specific attenuation is then derived for all associated range bins. The attenuation for each bin is the product of specific attenuation and its effective path length. The summation of attenuation endured by all range bins is inferred as the attenuation along the slant path. In this study, an X-band slant path rain attenuation was estimated using 2.85 GHz (S-band) Terminal Doppler Weather Radar (TDWR) data. A technique to estimate rain attenuation by exploitation of radar information is elaborated in this article. Comparisons between the radar-derived attenuation estimations and actual satellite signal measurements are also presented. The findings were verified by comparing the generated values to the directly measured rain attenuation from the Razak satellite (RazakSAT). Radar reflectivity data were obtained from Kuala Lumpur International Airport (KLIA) radar station operated by the Malaysian Meteorology Department (MMD). Preliminary findings using the most recent Z–R relation (i.e. the generated radar-derived rain attenuation estimations) appear to show lower values than the actual measurements

Study of tropospheric scintillation effects in Ku-band frequency for satellite communication system

Scintillation is a rapid fluctuation of electromagnetic waves in terms of phase and amplitude due to a small-scale inconsistency in the transmission path (or paths) with time. Scintillation exists continuously throughout a day whether during raining or clear sky conditions. The raw signal data need to exclude other propagations factors that include signal fluctuations to further understand the scintillation studies. This paper presents the analysis of tropospheric scintillation data from January 2016 till December 2016 at Ku-band frequency of 12.202 GHz beacon signal. The experimental data from MEASAT 3B were collected and analyzed to see the effect of tropospheric scintillation. The elevation angle of the dish antenna is 77.45o. The highlighted objectives are to analyze the scintillation data at Ku-band, and to compare and validate the results with other scintillation models. The result shows that the stipulated scintillation analysis has higher amplitude, which is 0.73 dB compared to other scintillation analysis which has lower scintillation amplitude: 0.45 dB (Karasawa), 0.42 dB (ITU-R), 0.4 dB (Nadirah & Rafiqul), 0.42 dB (Van De Kamp), and 0.11 dB (Anthony & Mandeep)

Rain induced attenuation studies for V-band satellite communication in tropical region

Satellite communications operating at 10 GHz and above in the tropics suffer severe signal degradation due to rain. Attenuation due to rain at 38 GHz had been measured for a period of 20 months in Malaysia. Analyses carried out include seasonal variations, diurnal effects and the annual cumulative distributions. Obtained results were compared with several established prediction models including the ITU-R. The rain fade characteristics were also investigated in determining the levels of signal loss and fading. In addition, the studies highlight several potential fade mitigation techniques that can be embarked. These fundamental aprehensions are very critical for future earth space communication link design and can be exploited as preliminary groundwork plan for the researchers as well as engineers

Two-year rain fade empirical measurement and statistics of earth-space link at ka-band in Malaysia

Satellite communication links at a frequency above 10 GHz experience severe attenuation due to rain, particularly in tropical regions. Reliable long-term rain fade empirical data for Ka-band satellite link in Malaysia and tropical areas are indeed limited. The main objective of this paper is to provide and present the findings of an empirically measured rain fade at the Ka-band of 20.01 GHz and the cumulative distribution analysis. An 8.1 m dual Gregorian dish antenna with 21 dB/K G/T and a meteorological standard dual type tipping bucket are used to measure the Ka-band beacon signal emanating from the MEASAT-5 satellite and the rainfall intensity, respectively, for a period of two years. Cumulative distribution of rain fade for monthly, annual and monsoon seasons were compiled to reflect the accurate changes in Malaysian weather. The measured rain fade is at 10 dB and 29 dB for the exceeded percentage of 0.3% and 0.1%, respectively. At rain fade of 33 dB, the receiver begins to saturate, resulting in a QoS of 99.9% for the Ka-band. The finding provides an insight to the actual rain fade experience for the practical implementation of Ka-band satellite link and future studies of rain fade models in tropical regions