scholarly journals Rain attenuation statistics over 5G millimetre wave links in Malaysia

Author(s):  
Mustafa Ghanim ◽  
Manhal Alhilali ◽  
Jafri Din ◽  
Hong Yin Lam

<p>Millimetre wave band is a solid contender to be utilized for the future 5G wireless systems deployment. Rain-induced attenuation is a major disadvantage at these frequencies. This paper presents statistics of rain-induced attenuation and rainfall data for two years of horizontally polarized links propagating at 38 GHz and 26 GHz over a terrestrial path link of 301 meters. From the analysed datasets, a rain rate around 116 mm/h exceeded at 0.01% of the time of an average year, while the links recorded 16 and 9.5 dB at the same percentage of time for 38 and 26 GHz respectively. The study aims to identify the prediction model that deliver most reasonable predictions for 5G links operating in Malaysian tropical climate. ITU-R P.530-17, Mello’s, and Ghiani’s models were all examined. Using ITU-R model, relative error margins of around 3.8%, 30% and 49.7% alongside 22.3, 9.5, 33% were obtained in 0.1%, 0.01% and 0.001% of the time for 26 and 38 GHz respectively.  Curiously, ITU-R model demonstrates better predictions to measured rain attenuation with lower error probability. This study highlights the need for new prediction models for short path-length 5G links and helps to improve the design of terrestrial links operating at millimetre wave frequencies in tropical regions.</p>

2021 ◽  
Vol 6 (2) ◽  
pp. 27-37
Author(s):  
Abayomi Isiaka O. Yussuff ◽  
◽  
Kabir Momoh ◽  

This work concerns the evaluation of the performances of some selected rain attenuation models at two different locations in Lagos, Nigeria at 12 and 40 GHz. Scarcity of rainfall data in the tropical regions resulted in abysmal research efforts into the causes and solutions to satellite signal outages, this was further exacerbated by the convective tropical rain precipitations. The globally adopted ITU-R model, had been declared unsuitable for predicting rain attenuation in the tropics by several researchers in the literature. Two-year (January 2016 to December 2017) local rainfall data were sourced from the Nigerian Meteorological Services (NIMET) for two coastal stations (Ikeja and Oshodi). Rain attenuation exceeded for rain rate at 0.01% of the time, was computed after the 1-hour rain rate integration time which was sourced from NIMET was converted to 1-minute integration time. Attenuation exceeded for other percentages of time were also obtained using statistical interpolation and extrapolation methods. The collected data were tested with ITU-R, SST, SAM, DAH and Silva Mello et al. For Ikeja at 12 GHz, the SST was observed to closely match the measurement attenuation at 0.01%≤p≤1% of time exceeded; closely followed by Silver Mello. For Oshodi also at 12 GHz, SST intersected with the measured attenuation at 0.01%≤p≤0.03%, and p=0.1% of time. However, at 40 GHz, all the prediction models performed poorly by underestimating the measurement for Ikeja, although SST showed the best effort. The SST model matched the measurement, especially at p=0.03% and p=0.5% for Oshodi at 40 GHz, closely followed by Silva Mello which matched the measurement at p=0.05% and p=0.1%, while ITU-R, SAM and DAH largely underestimated the measurement. The SST was therefore affirmed the overall best performed rain attenuation prediction model for both stations at both frequency bands; closely followed by the Silva Mello. ITU-R, SAM and DAH on the other hand performed poorly. The findings arising from this work could present useful information to satellite equipment designers and manufacturers, while at the same time ensuring that service providers conform to the required service level agreements


2018 ◽  
Vol 29 (8) ◽  
pp. e3450 ◽  
Author(s):  
Ibraheem Shayea ◽  
Tharek Abd. Rahman ◽  
Marwan Hadri Azmi ◽  
Arsany Arsad

2021 ◽  
Author(s):  
Waheeb Tashan ◽  
Ibraheem Shayea ◽  
Sultan Aldirmaz-Colak ◽  
Tharek Abdul Rahman ◽  
Ayman A. El-Saleh ◽  
...  

Author(s):  
A. I. O. Yussuff

The restrained use of millimeter bands is due to severe rain attenuation. Attenuation is caused when rain cells intersects radio wave’s propagation path; resulting in deep fades. The effect of rainfall is more severe in tropical regions characterized by heavy rainfall intensity and large raindrops; hence, rain attenuation analyses are essential to study rain fade characteristics for use in earth-space link budget analysis, for outage prediction resulting from rain attenuation. Tropical regions are particularly challenged with signal outage, necessitating the formulation and development of suitable prediction model(s) for the region. Therefore, extensive knowledge of the propagation phenomena mitigating system availability and signal quality in these bands are required. Daily rainfall data were collected from the Nigerian Meteorological Services for Lagos for spanning January to December 2010. Results showed that although, the ITU-R model out-performed the other prediction models under consideration, none of prediction models matched the measurement data.


2011 ◽  
Vol 3 (4) ◽  
pp. 477-483 ◽  
Author(s):  
Amuda Yusuf Abdulrahman ◽  
Tharek bin Abdulrahman ◽  
Sharul Kamal bin Abdulrahim ◽  
Ulaganathen Kesavan

This paper presents the results of direct rain attenuation measurements carried out on four experimental microwave links, installed at UTM, Malaysia. The links operate at frequencies of 15, 22, 26, and 38 GHz and the cumulative distribution function for different rain rates have been generated from the measured 4-year rain gauge data. The experimentally measured attenuation data have been compared with International Telecommunication Unior-R rain attenuation predictions; and it has been found that the latter have underestimated the measured values, especially at higher rain rates. The deviations have been modeled as a function of rain rate exceedances R%p. It is hoped that the study will provide useful information for estimation of rainfall attenuation on microwave links in tropical regions that have similar situation to Malaysia.


Author(s):  
Islam Md Rafiqul ◽  
Md Moktarul Alam ◽  
Ali Kodhim Lwas ◽  
Sarah Yasmin Mohamad

Attenuation due to rain is an important constraint in microwave radio link design especially at frequencies above 10 GHz. It restricts the path length of radio communication systems and limits the use of higher frequencies for line-of-sight microwave links and satellite communications. In order to predict the attenuation due to rain accurately rainfall intensity is required with 1-minute integration time. Rainfall is a meteorological phenomenon with complex structure due to its variability in space, duration and occurrence frequency, particularly in tropical and equatorial regions. Since, the statistical distribution of rain attenuation is obtained from the rain rate distribution for the region considered, it should be noted that the accuracy of the rain rate measurement affects the accuracy of the attenuation estimation. This paper presents rain intensity with 1-minute integration time measured for 6 years in Malaysia, it’s distribution, comparison with other prediction models and impact on high frequency microwave links.


2021 ◽  
Vol 13 (10) ◽  
pp. 1965
Author(s):  
Md Abdus Samad ◽  
Feyisa Debo Diba ◽  
Dong-You Choi

Satellite communication is a promising transmission technique to implement 5G and beyond networks. Attenuation due to rain begins at a frequency of 10 GHz in temperate regions. However, some research indicates that such attenuation effects start from 5–7 GHz, especially in tropical regions. Therefore, modeling rain attenuation is significant for propagating electromagnetic waves to achieve the required quality of service. In this survey, different slant link rain attenuation prediction models have been examined, classified, and analyzed, and various features like improvements, drawbacks, and particular aspects of these models have been tabulated. This survey provides various techniques for obtaining input data sets, including rain height, efficient trajectory length measurement techniques, and rainfall rate conversion procedures. No survey of the Earth–space link models for rain attenuation is available to the best of our knowledge. In this study, 23 rain attenuation models have been investigated. For easy readability and conciseness, the details of each model have not been included. The comparative analysis will assist in propagation modeling and planning the link budget of slant links.


MAUSAM ◽  
2021 ◽  
Vol 68 (4) ◽  
pp. 621-632
Author(s):  
MEHRAN BEHJATI ◽  
JIT SINGH MANDEEP ◽  
MAHAMOD ISMAIL ◽  
ROSDIADEE NORDIN

Rainfall is a major destructive factor which severely reduces the quality and reliability of propagated signals in satellite communications. Hence, rain-attenuation prediction plays a vital role in the satellite radio link planning and engineering. The accuracy of the rain-attenuation prediction models depends on two things; (i) the accuracy of rain-rate information and (ii) the area of study. Therefore, selecting an appropriate rain-attenuation prediction model for a new site without having any specific prediction model and experimental measured rain-rate would be challenging. In this regard, this letter takes advantage of climatology skills to find an accurate model for such kind of areas. To do so, we study the Urmia-site (37.55° N, 45.1° E) and its communication link with the Eutelsat 25A (25.5° E), where there is no available experimental measured data and specific prediction models for that site. Therefore, based on the meteorological skills, the Yong-in site in South-Korea (37.43° N, 126.93° E) was chosen, as a homogeneous area with Urmia, which has available measured data of rainfall and rain-attenuation. Afterward, the most common used global prediction models are applied to Yong-in and the results are compared with the existing measurements. Consequently, the more accurate rain-rate and rain-attenuation prediction models are investigated and generalized to Urmia, which are the ITU-R P.837-5 model with 34% r.m.s. and the Joo-Hwan model with 18% r.m.s., respectively. Finally, the amount of rain-attenuation in different useful frequency bands (10-50 GHz) is investigated for Urmia by the Joo-Hwan model.


2019 ◽  
Vol 8 (3) ◽  
pp. 951-959
Author(s):  
Md. Moktarul Alam ◽  
Islam Md. Rafiqul ◽  
Khairayu Badron ◽  
Farah Dyana A. R. ◽  
Hassaan Dao ◽  
...  

The utilization of satellites for communication systems has expanded considerably in recent years. C and Ku-bands of frequencies are already congested because of high demand. Future directions of satellite communications are moving towards Ka and V-bands. Earth to satellite communications are moving towards higher frequency bands in future which are more sensitive to environment. Rain causes severe degradation in performances at higher frequency bands specially in tropical regions. Several mitigation techniques are proposed to design reliable system. Time diversity is one of the potential candidate for it. However, time diversity analysis requires measured rain attenuation data. For future high frequency link design those data are not available at most of the places. This thesis proposes a method to utilize 1-minute rain rate to analyze time diversity technique at any desired frequency. This paper proposes a method to utilize 1-minute rain rate to analyse time diversity rain rate gain. In proposed method, it is assumed that rain rate gain with delay can represent rain attenuation gain with delay for same period of time at same location. The characteristics of rain rate and rain attenuation almost same because the attenuation causes due to rain.  One year measured rain rate in Malaysia is used to predict rain rate gain. The measured gain at 12.225 GHz signal is compared with that predicted by ITU-R based on rain rate measurement and is found good agreement. Hence it is recommended that the time diversity gain can be predicted using measured rain rate for any desired frequencies.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Hammed O Busari ◽  
Olaosebikan A Fakolujo

Rain-induced attenuation of microwaves poses a serious challenge to signal availability beyond 10 GHz frequencies. The challenges are even more pronounced in the subtropical and tropical regions with high intensities of rain which is more accompanied with thunderstorms. Nigeria has an equatorial and tropical climate, which is identified by controlling rainfall. Rain is the significant attenuation factor of various communication signal above 10 GHz frequencies. Therefore, for effective utilization of the microwave bandwidth during rainfall, it is required to form the correlation between this attenuation effect and the bandwidth at various rainfall rate and frequencies at a particular interest location. Therefore , using propagation modelling, the point rainfall and  rain effects for frequencies was concurrently  considered between 11 and 40 GHz (i.e. Ku, and Ka) for satellite communication service on earth-space path at Ibadan in Oyo state , Nigeria by using rainfall data for the period of five (5) years (January 2014 to December 2019).Keywords- Rain Attenuation, Rain Rate, Bandwidth, Propagation Modelling


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