Presentation on theme: "Rain Attenuation in Satellite Communications"— Presentation transcript:
1 Rain Attenuation in Satellite Communications Associate Professor Dr.Yagasena AppannahFACULTY OF INTEGRATIVE SCIENCES AND TECHNOLOGYSchool of Engineering and Computer TechnologyQUEST INTERNATIONAL UNIVERSITY PERAK22nd August 2013
2 What is Rain Attenuation ? The attenuation of a signal due to rain is the extent to which the strength of a signal is reduced when passing through rain from a transmitter to a receiver, Also called rain fade.
5 Factors Affecting Satellite-Earth Link in Rain Frequency of operationElevation angle of satelliteSlant-path lengthRain rateRain height
6 How does it affect you ?All forms of wireless terrestrial and extra-terrestrial mode of communication will be disrupted.Example:Satellite TVSatellite data transmissionMobile communication
7 Why Study Rain Attenuation ? Rain attenuation is a major constraint in satellite link design above 10 GHz.The International Telecommunication Union (ITU) model is based on data collected predominantly from temperate regions. Hence not accurate for use in tropical & equatorial regions
8 Rainfall Classification Stratiform Rain – medium & low intensity, wide area, long duration.Convective Rain – high intensity, small area, short duration.
32 Comparison With Other Tropical Countries LocationFrequency(GHz)Elevation (deg)Attenuation (dB)Rain rate (mm/hr)Malaysia12.25540.134.10124.7Singapore11.19842.932.00125.5Thailand12.74845.025.00100.0Indonesia12.24764.717.00120.0
35 Rain Mitigation Techniques Site DiversityPower ControlFrequency DiversityData Rate Reduction
36 ConclusionITU satellite-earth propagation model underestimates the rain attenuation in tropical and equatorial regions.Two-Part model must be incorporated into ITU prediction model to accommodate different rainfall characteristics for more accurate prediction.
37 Firm sues MEASAT over dishes Wednesday September 29, 2010By NURBAITI HAMDAN and ONG HAN SEANKUALA LUMPUR: A TV support equipment supplier is suing Astro’s subsidiary Measat Broadcast Network Systems Sdn Bhd and another company for more than RM1.3bil over an alleged breach of a “non-disclosure agreement”.AV Asia Sdn Bhd claimed that its confidential information was used by Measat to reduce the problem of rain fade – a situation where the satellite transmission would be interrupted during rain.According to the statement of claim, the Malaysian Communications and Multimedia Commission made recommendations for Measat to conduct studies on the use of different satellite dishes to reduce rain fade in May 2008.
38 Astro satellite issue: Trouble beyond rain KUALA LUMPUR: Astro customers have been left confused over unsettling revelations in a RM1.3 billion suit involving “leaked” confidential data for a new satellite dish that reduces signal loss during rainstormsOn rain fade, AV Asia’s chief executive officer Mr.XXX claimed Astro, while using the new dish, was not installing it correctly. “If installed using a digital level meter, it would definitely reduce rain fade. Right now, they're installing it manually,” he said.Posted by Global News-n-Views at Saturday, October 02, 2010