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Next-generation 5G cellular networks are expected to operate on the millimeter wavelength frequencies (e.g., 28 GHz and 38 GHz) to offer broader bandwidths and higher data rates. In this frequency band, rain is a major impairment to received signal power. This work aims to improve predictions of rain attenuation for 5G wireless networks operating at 28 GHz and 38 GHz in heavy rain regions, by exploiting...
Site diversity is one of the advanced techniques that aim to mitigate propagation impairments affecting satellite communication (SatCom) systems operating above 10 GHz. In this work, we exploit two years of weather radar data collected at Johor (Malaysia) to simulate a site diversity SatCom system operating at 18.9 GHz with two links pointing to the WINDS satellite (elevation angle equal to 44°)....
This work evaluates the spatial features of the synthetic rain cell profile based on two years of real rain cells database extracted from weather radar observation located in Kluang, Johor, Malaysia. Single rain cells modeled by an analytical exponential and Gaussian profile are evaluated and investigated based on certain features of real rain cells such as maximum rain rate and root mean square rain...
The design of the Witricity device is shown in this paper and its lateral and angular misalignment are investigated. The device, which includes transmitter and receiver, has identical design purposely to resonate at a same frequency range. The coupling efficiency degrades as the lateral and angular misalignments are increased. The Witricity device is able to transfer power efficiently at 2 cm distance...
This work investigates the physical structure and geometrical features of rain cells based on two years of meteorological observations collected by a radar located at Kluang, Johor, Malaysia. Raw radar data are duly processed and rain cells are identified to carry out a detailed investigation on some features of the rain cells such as the mean rain rate, the equivalent minor and major axis length...
Satellite communication systems are swayed towards superior capacity. Millimeter wave offers a huge bandwidth allocation, involves small-sized antenna requirement and experiences less congested spectrum environment. However, rain posses a crucial intimidation to such satellite communication links especially in tropical region where the hydrometeors can severely affect the signal. Rain is the factor...
The nature of an Open Source Software development paradigm forces individual practitioners and organization to adopt software through trial and error approach. This leads to the problems of coming across software and then abandoning it after realizing its lack of important qualities to suit their requirements or facing negative challenges in maintaining the software. These contributed by lack of recognizing...
ITU proposes that the fraction of time during which a pre-selected threshold is exceeded in the worst-month within a year is referred to as “the annual worst-month time fraction of excess”. This relates directly to situation where accumulation of outages at a specific threshold in one specific month has the worse effect on the transmission link than if compared to the accumulation that were distributed...
Measurements of 26 GHz attenuation due to rain were acquired from a microwave link set-up in Malaysia, a country in one of the most extreme weather with regard to rainfall rates. The data were analyzed with particular interest assessing the performance of Time Diversity as a conceivable fade mitigation technique in broadcast applications. The technique entails a process of retransmission of signals...
CYP2D6 plays a major role in the metabolism of tamoxifen, and polymorphism of P-glycoprotein has been associated with resistance of many drug therapies. This study investigates the clinical impact of genetic variants of CYP2D6 and ABCB1 in breast cancer patients treated with tamoxifen. Blood samples from 95 breast cancer patients treated with tamoxifen were collected and genotyped for CYP2D6...
Links both terrestrial and Earth-space operating at bands higher than 10GHz inevitably suffer severe signal degradation due to rain fade particularly in the tropics. The study had investigated the likely impacts of rain fading on the links performance at 26GHz frequency, where rain attenuation at 26GHz had been measured for a period of over one year in Malaysia. Studies include in the attempt to quantify...
The assessment of the variability of rainfall characteristics in the equatorial regions is a key problem in estimating adequate fade margin due to rain attenuation in satellite communication systems. Based on one year of disdrometer data that have been collected in Kuala Lumpur, Malaysia, this paper investigates the general characteristics of the raindrop size distribution (DSD) and the dependence...
Tropical and equatorial region exhibits significantly higher rainfall rate with regard to temperate region leading to extreme attenuation for satellite communication links. One relevant issue for radiowave propagation modeling in this particular region is the different structures of precipitation which play an important role in estimating rain fade. To this aim, an investigation of the rain characteristics...
This paper presents the application of the Lowered EXCELL model to discriminate between stratiform and convective precipitation in Kuala Lumpur, Malaysia, which is located in the equatorial region. The model generates two longterm cumulative distribution functions (CDFs) that separately account for the two different types of rain, based on the input rainfall statistics reflecting the local climatology...
The aim of this paper is to provide additional information about the performance of the SC EXCELL model, specifically when applied to the prediction of rain attenuation in equatorial and tropical regions. The model generates a long-term rain attenuation Cumulative Distribution Functions (CDF) that separately accounts for stratiform and convective precipitation. The model assessment in estimating attenuation...
A decade ago, the operating frequencies of most available satellites in the tropics were C band, S-band and Ku-band. The V-band satellite links were initially confined mainly to temperate regions. Recently however, this new service has gradually been introduced worldwide including the tropical regions. In the future, new satellites in the tropical and equatorial will also have no alternative but to...
Satellite links operating at frequencies above 10 GHz in the tropics typically suffer severe signal degradation due to rain. The study attempts to investigate the impacts of rain on the performance of satellite-Earth links at V-band frequency. Attenuation due to rain at 38 GHz had been measured for a period of 20 months in Malaysia. Studies are being conducted to quantify the rain-induced degradations...
Telemedicine system requires an acceptable network quality of service and cost. IEEE 802.11 wireless LAN technology has been developed to provide scalable and low cost network. For telemedicine application however, the technology does not fulfil the quality of service requirement yet. In order to overcome this problem, a cross layer design of wireless LAN is proposed. The design is based on IEEE 802...
Telemedicine system requires an acceptable network quality of service and cost. IEEE 802.11 wireless LAN technology has been developed to provide scalable and low cost network. For telemedicine applications however, the technology does not fulfill the quality of service requirement yet. In order to overcome this problem, a new cross layer design of wireless LAN is proposed. The design is based on...
A new frequency reuse scheme which reduces co-channel interference must be used to deploy over 20-GHz band fixed wireless access (FWA) systems in expanding service areas. Also, the capacity has become of primary importance in broadband wireless access (BWA) networks to provide multimedia services or other digital services requiring high capacity traffic channels. The co-channel interference and rain...
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