UWB channel characterization in 28 ghz millimeter waveband for 5G cellular networks

The demands of high data rate transmission for future wireless communication technologies are increasing rapidly. The current bands for cellular network will not be able to satisfy these requirements. The millimeter wave (mm-wave) bands are the candidate bands for the future cellular networks. The 28 GHz band is the strongest candidate for 5G cellular networks. The large bandwidth at this band is one of the main parameters that make the mm-wave bands promising candidate for the future cellular networks. To know the wideband channel behavior in mm-wave bands, the wideband channel characterizations are required. In this paper, the 3D WINNER model is used to model the wideband channel at 28 GHz band. Based on this model, the time dispersion parameters at 28 GHz mm-wave band are investigated. The root mean square delay spread and the mean excess delay are the main parameters that can be used to characterize the wideband channel. Morever, the cumulative distribution function (CDF) is used to model the RMS delay spreads. The results show that the RMS delay spread varies between 4.1 ns and 443.7 ns

Sequence analysis of the VSX1 and SOD1 genes in families with Keratoconus and a review of the literature

AbstractObjectiveKeratoconus (KC) is a non-inflammatory disorder of the cornea in which the cornea becomes thin and conical, inducing myopia and irregular astigmatism and resulting in mild to marked impairment of vision. The present study was designed to screen two candidate KC genes to identify pathogenic sequence variants responsible for KC in Saudi families.MethodsPeripheral blood samples from members of five Saudi families with KC from the Northern region were collected. Genomic DNA was isolated, and bidirectional sequencing was performed of all coding exons of VSX1 and SOD1 genes using Sanger sequencing.ResultsAll five of the KC families showed a pattern of autosomal recessive inheritance. Phenotyping of these families was performed by a senior ophthalmologist. Sequence analysis of the VSX1 and SOD1 genes failed to reveal any pathogenic sequence variant that could account for KC in the affected individuals.ConclusionOur failure to detect sequence variants in two of the known KC associated genes triggers an interest in other known KC candidate genes, including miR-184, DOCK9, IL1RN and SLC4A11. Future genotyping with dense SNP arrays followed by exome sequencing in these families will be a useful approach to identify the gene(s) underlying KC in this Saudi cohort, which may be different from those reported elsewhere

Internet protocol MANET vs named data MANET: A critical evaluation

Many researches have been done in the field of mobile networking, specifically in the field of ad-hoc networks.The major aim of these networks is the delivery of data to a given node at the destination, irrespective of its location.Mobile Ad-hoc Network (MANET) employs the traditional TCP/IP structure to provide end-to-end communication between nodes (we named this type of architecture is IP-MANET).However, due to their mobility and the limited resource in wireless networks, each layer in the TCP/IP model requires redefinition or modifications to function efficiently in MANET. Named Data MANET (NDMANET) architecture is a recently emerging research area. The in-network chunk-based caching feature of NDN is beneficial in coping with the mobility and intermittent connectivity challenges in MANETs.In the natural disaster field, MANET is considered a challenging task because of the unpredictable changes in the network topology due to the absence of any centralized control.The goals of this paper have two ways: first, this study provides a performance comparison of IP-MANET to ND-MANET in terms of throughput, delay, and packet loss.While the second contribution is to identify which architecture has an impact on the natural disaster (i.e., Flooding disaster) in rural areas and suggests which one may perform better.For experimental purposes, our analyses IP-MANET and ND-MANET by extensive simulations in the NS 3 simulator under a number of different network scenarios, and show that how number of nodes and variety packets size affect their performance

Window-based channel impulse response prediction for time-varying ultra-wideband channels

This work proposes channel impulse response (CIR) prediction for time-varying ultra-wideband (UWB) channels by exploiting the fast movement of channel taps within delay bins. Considering the sparsity of UWB channels, we introduce a window-based CIR (WB-CIR) to approximate the high temporal resolutions of UWB channels. A recursive least square (RLS) algorithm is adopted to predict the time evolution of the WB-CIR. For predicting the future WB-CIR tap of window wk, three RLS filter coefficients are computed from the observed WB-CIRs of the left wk-1, the current wk and the right wk+1 windows. The filter coefficient with the lowest RLS error is used to predict the future WB-CIR tap. To evaluate our proposed prediction method, UWB CIRs are collected through measurement campaigns in outdoor environments considering line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. Under similar computational complexity, our proposed method provides an improvement in prediction errors of approximately 80% for LOS and 63% for NLOS scenarios compared with a conventional method

Indoor path loss model for 4G wireless network at 2.6 GHz

In this paper, a short-range, narrowband indoor propagation at 2.6 GHz was measured and modeled. The measurement campaign was conducted to characterize the path loss (PL) of Radio frequency (RF) at the Razak School building corridor. The corridor has unique structure and segmented in different sections. The irregular structure of corridor, further with various interior material used gives the unique characterization to the received power. The research work made in this paper is predominately targets to characterizing radio link of 2.6 GHz frequency in typical indoor corridor

Economic Valuation of Mangrove Forest Ecosystem in Waidoba Island, South Kayoa District, South Halmahera Regency

Mangrove Forest ecosystems have distinctive characteristics and forms and have functions and benefits as development resources both as economic resources and ecological resources that have long been felt by the Indonesian people, especially for the people who live around that area. This research aims to identify the types of utilization of mangrove forest ecosystems and to analyze the total economic value of mangrove forest ecosystems in the area of Waidoba Island, South Kayoa District, South Halmahera Regency. The sampling method in this study used a purposive sampling method. Based on the results identification of the benefits and functions of the mangrove forest ecosystem in Waidoba Island area, Kayoa Selatan District, that there were (4) four types of mangrove forest ecosystem benefits, namely (1) direct benefits (2) indirect benefits, (3) optional benefits and (4) benefits of existence. While the results of costs and benefits of the total economic value of mangrove forest ecosystem in Waidoba Island area of South Kayoa District were obtained Rp. Rp.170.520.720.104/year or Rp.418.014.659,-/ha/year. This total economic value was the benefit value of mangrove forest ecosystem that utilized by the community covering an area of 407.93 Ha

The Effect of Misuse of Topical Corticosteroids on Skin

Objectives: To assess the frequency of misuse of TC on skin , commonly used steroids and the most common dermatological problems resulting from it, as well as, to analyze the motives for such practices with the aim to raise awareness about this problem in Mosul city. Methods: The study included 155 patients aged 0.8-49 years with dermatological disorders who attended Outpat­ient Department of Dermatology in Al-Salam Teaching Hospital in Mosul City . Inclusion criteria: those who had used TC without medical advice; continued use after short prescription regardless of the duration ;TC used incorrectly or used them for certain skin problems for which steroids are not indicated; Wrong indication (acne); undiagnosed dermatosis as well as a history of TC use continuously(for more than1 month) or intermittently (for more than 3 months) due to any purpose, and presented with ≥ 1 of the side-effects of these drugs as the chief complaint were criteria used to define unjustifiable/inappropriate use. Patients with natural rosacea; those denying any history of using TC or who not consenting to answering the questionnaire; pregnant women; patients who were using prescribed TC regardless of the duration or side effects such as asthma, rheumatoid arthritis; patients with comorbidities that resembled/could cause changes similar to TC side-effects (polycystic ovaries / Cushing's syndrome/thyroid disorders)were excluded from the study. A questionnaire was designated and skin was examined to study patients. Results: Of the 155 subjects misused TC most were females 98(63.23%)  and 57(36.77%) were males; of low social class 45(29%). The majority 123(85.2%) thought that corticosteroid use was safe and 56(36.1%) did not feel guilty for using such medications. Eighty fife(55 %)patients reported that physician and pharmacists advised them for the first time to use TC. Ninety eight (63.3%) patients obtained the drug from the pharmacies, 30(19.3%)from nurse staff and 27(17.4%) from cosmetic shop/Beautician. lightening of the skin (30.6%)  was the main indication for use TC. Potent and very potent preparations were the main TC used by patients.Almost all had some features of TC side effects. Conclusion: Inappropriate use of TC is a big problem in our country. Easy availability of very potent products without a prescription makes misuse very common which has a huge impact on derm­atological practice. It is responsible for a significant proportion of visits to dermatolo­gy clinics. It is a multiphase problem that needs the cooperation of different sectors in the community to overcome it. Education of the general public through special media programs and the introduction of a continuing medical education programs for medical and paramedical personnel as well as controlling the easy intake from pharmacies are probably the most important steps that could be taken to reduce this problem

Design and validation of an adaptive CubeSat transmitter system

CubeSat in low earth orbit (LEO) primarily uses an amateur radio-band transmitter with a fixed specification. Nevertheless, the LEO satellite does not have an orbital velocity that equates to one sidereal day. Therefore, the ground station antenna views the satellite at different elevation angles which result in varied propagation path lengths. In this paper, an adaptive transmitter is designed to optimise the LEO satellite communication link and overcome the variability of the propagation path length issue due to different ground station elevation angles. A satellite communication link and operation analyses are performed to identify the relationship between the variation of the elevation angle so as to determine the optimum signal-to-noise ratio (SNR), improve data rate and increase the power efficiency of an adaptive link. Based on the results, a model is developed to control the adaptive configuration. The SNR and power consumption performance of the developed transmitter is compared with commercial transmitters. The results indicate that the transmitter output power is adjustable from 0.5 W to 1 W, and the data rate is selectable between 9600 bps and 19,200 bps. Compared to other CubeSat transmitters, the developed adaptive transmitter demonstrates more than 20% improvement in terms of SNR optimisation, additional throughput and power reduction

Comparative study of indoor propagation model below and above 6 GHz for 5G wireless networks

It has been widely speculated that the performance of the next generation based wireless network should meet a transmission speed on the order of 1000 times more than the current cellular communication systems. The frequency bands above 6 GHz have received significant attention lately as a prospective band for next generation 5G systems. The propagation characteristics for 5G networks need to be fully understood for the 5G system design. This paper presents the channel propagation characteristics for a 5G system in line of sight (LOS) and non-LOS (NLOS) scenarios. The diffraction loss (DL) and frequency drop (FD) are investigated based on collected measurement data. Indoor measurement results obtained using a high-resolution channel sounder equipped with directional horn antennas at 3.5 GHz and 28 GHz as a comparative study of the two bands below and above 6 GHz. The parameters for path loss using different path loss models of single and multi-frequencies have been estimated. The excess delay, root mean square (RMS) delay spread and the power delay profile of received paths are analyzed. The results of the path loss models show that the path loss exponent (PLE) in this indoor environment is less than the free space path loss exponent for LOS scenario at both frequencies. Moreover, the PLE is not frequency dependent. The 3GPP path loss models for single and multi-frequency in LOS scenarios have good performance in terms of PLE that is as reliable as the physically-based models. Based on the proposed models, the diffraction loss at 28 GHz is approximately twice the diffraction loss at 3.5 GHz. The findings of the power delay profile and RMS delay spread indicate that these parameters are comparable for frequency bands below and above 6 GH