Spectrum Sharing Method for Cognitive Radio in TV White Spaces: Enhancing Spectrum Sensing and Geolocation Database

( Walid A. Hassan ),( Han Shin Jo ),( Maziar Nekovee ),( Chee Yen Leow ),( Tharek Abd Rahman ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.8

This paper proposes a system called Wireless Link based on Global Communication Channel (WLGCC) to enhance the spectrum sharing between digital broadcasting (DB) services and the cognitive radio (CR) system in the licensed band of 470-790 MHz. The WLGCC aims to enhance the spectrum sensing and geolocation database (GLD) spectrum sharing methods in the CR system. Spectrum sensing can be enhanced by receiving the status of the used frequencies from the WLGCC, thereby eliminating the need for a low detection threshold (i.e., avoiding the hidden node problem). In addition, the GLD can be enhanced by providing a reliable communication link between the database and the CR device in the form of an unused TV white space that is reserved as the proposed Global Communication Channel (GCC). This paper analyzes the coexistence of the new WLGCC system and the DB service in terms of avoiding additional interference. Specifically, we mathematically determine the WLGCC parameters, such as the in-band and out-of-band power levels, and operation coverage, and verify them using Monte Carlo simulation. The results show that WLGCC does not degrade the existing DB service and reliably transmits information of the vacant (or used) frequency bands to the CR.

A Spectrum Sharing Model for Compatibility between IMT-Advanced and Digital Broadcasting

( Walid A. Hassan ),( Tharek Abd Rahman ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.9

Recently, the International Telecommunication Union allocated the 470-862 MHz band to the digital broadcasting (DB) service. Moreover, the 790-862 MHz sub-band will be allocated to the next-generation mobile system, known as the International Mobile Telecommunication - Advanced (IMT-A), and to the DB on a co-primary basis in the year 2015. Currently, two candidate technologies are available to represent the IMT-A system; the Mobile WiMAX and Long Term Evolution - Advanced (LTE-A). One of the main criteria of the IMT-A candidate is to not cause additional interference to the primary service (i.e., DB). In this paper, we address the spectrum sharing issue between the IMT-A candidates and the DB service. More precisely, we investigate the interference effect between the DB service and the mobile network, which could be either LTE-A or WiMAX. Our study proposes a spectrum sharing model to take into account the impact of interference and evaluates the spectrum sharing requirements such as frequency separation and separation distance. This model considers three spectrum sharing scenarios: co-channel, zero guard band, and adjacent channel. A statistical analysis is performed, by considering the interferer spectrum emission mask and victim receiver blocking techniques. The interference-to-noise ratio is used as an essential spectrum sharing criterion between the systems. The model considers the random distribution of the users, antenna heights, and the bandwidth effect as well as the deployment environment in order to achieve spectrum sharing. The results show that LTE-A is preferable to WiMAX in terms of having less interference impact on DB; this can eventually allow the operation of both services without performance degradation and thus will lead to efficient utilization of the radio spectrum.

Simulation Model for Compatibility between LTE-Advanced and Digital Broadcasting in the Digital Dividend Band

Walid A Hassan,Han Shin Jo,Tharek Abd Rahman 한국산학기술학회 2013 SmartCR Vol.3 No.5

The switch from analog to digital television broadcasting (DB) has freed up a newly available spectrum called the digital dividend (DD) band. This band is expected to be used for both International Mobile Telecommunication-Advanced (IMT-A) and terrestrial DB, which could lead to performance degradation for both services. In this study, a simulation model is proposed to identify the requirements for coexistence between the new system (i.e., IMT-A) and the primary system (i.e., DB) in the DD band. Our model evaluates the compatibility between the two services by considering a feasible spectrum allocation: (i) the frequency plan for DB recommended by the International Telecommunication Union (ITU) in 2006 and (ii) the European preferred harmonized spectrum for mobile channel assignment proposed in 2009. Using the Monte Carlo method, we quantify the minimum distance between the systems to ensure reliable services for a given frequency guard band. We also propose a practical guideline for efficient spectrum sharing, which will increase the efficiency of DD spectrum usage between administrations. Unlike the previous studies where the services can coexist in all adjacent channels, our results show that coexistence is possible for a limited number of adjacent channels and for a specific sharing scenario.

Cross Border Interference between IMT-Advanced and DVB-T in the Digital Dividend Band

Walid A Hassan,Han-Shin Jo,Zaid A Shamsan,Tharek A Rahman 보안공학연구지원센터 2013 International Journal of Multimedia and Ubiquitous Vol.8 No.5

Effectiveness of Active Rehabilitation Program on Sports Hernia: Randomized Control Trial

Walid Ahmed Abouelnaga,Nancy Hassan Aboelnour, 대한재활의학회 2019 Annals of Rehabilitation Medicine Vol.43 No.3

Objective To determine whether an active rehabilitation program that involves repetitive effortful muscle contractions, including core stability, balancing exercises, progressive resistance exercises, and running activities, after a sports hernia, is effective. Methods Forty soccer players with sports hernias were randomly divided into two equal groups: group A (active rehabilitation program) and group B (conventional treatment). The methods of assessment included a visual analog scale (VAS) and hip internal and external range of motion assessments. Group A received conventional treatment (heat, massage, transcutaneous electrical nerve stimulation, and mobilization) plus an active rehabilitation program, while group B received only conventional treatment. Three treatment sessions were given each week for 2 months. Evaluations were performed pre- and post-treatment. Results A decrease in VAS was seen in both groups at the end of treatment, 80.25% in group A and 41.93% in group B. The difference between the two groups was statistically significant (p=0.0001), whereas there were no statistical differences in internal and external rotation between the groups at the end of treatment (p>0.05). After treatment, an improvement in outcome measures of group A compared to group B (p=0.01) was seen. Thirteen patients in group A and only three patients in group B returned to sports activities without groin pain. Conclusion Active rehabilitation was effective for sports hernia management measured by a decrease in pain and the return to sports.

Molecular identification of fruit bats, natural host of Nipah virus in Bangladesh, based on DNA barcode

Md. Maharub Hossain Fahim,Walid Hassan,Afia Afsin,Md. Mahfuzur Rahman,Md. Tanvir Rahman,임상진,Oh Yeonsu,박영철,Hossain Md. Faruquee,Md. Mafizur Rahman 한국생태학회 2024 Journal of Ecology and Environment Vol.48 No.2

Background: Fruit bats are natural carriers of Nipah virus (NiV ). The primary objective of this study is to identify potential reservoir species in a selected geographic regions. It is necessary to determine an accurate species identification of the associated reservoir bat species distributed in a specific region. Results: In this study, we collected 20 different bat specimens from the NiV-prone area of the Kushtia district. Among these, 14 were tissue samples (BT-1–14) and six were fecal sam- ples (BF-1–6). We used the mitochondrial gene cytochrome b, one of the most abundant and frequently used genetic markers, for polymerase chain reaction amplification and se- quencing. Out of the 20 samples, 12 tissue samples and 2 fecal samples were successfully amplified and sequenced. However, two tissue samples and four fecal samples yielded chimeric sequences, rendering them unsuitable for annotation. The sequences of the suc- cessfully amplified samples were compared to those deposited in the National Center for Biotechnology Information database using basic local alignment search tool to identify the bat specimen collected. The study identified six different bat species using both morpho- logical and genetic data, which may carriers of the NiV. Conclusions: Our results suggest that additional research should be conducted to gath- er more information on fruit bats from different localities across the country. The study contributes to the establishment of appropriate measures for NiV carrying disease control and management.

A novel 1,3,4‑thiadiazole modified chitosan: synthesis, characterization, antimicrobial activity, and release study from film dressings

Mohamed Ahmad E.,Elgammal Walid E.,Dawaba Aya M.,Ibrahim Ahmed G.,Fouda Amr,Hassan Saber M. 한국응용생명화학회 2022 Applied Biological Chemistry (Appl Biol Chem) Vol.65 No.4

Herein, two new polymers designated as Cs-EATT and Cs-BATT have been synthesized via linking the chitosan with the synthesized 1,3,4-thiadiazole compounds. They were characterized using 1 H, 13 C-NMR, FT-IR, TGA, Elemental analysis, Mass spectrum, and UV–vis spectrophotometer. The synthesized polymers exhibit high activity to control the growth of pathogenic bacteria ( S. aureus , B. subtilis , E. coli, and P. aeruginosa ), and unicellular fungi ( C. albicans ). The MIC values were in the range of 25–100 µg mL –1 for Cs-EATT and 25–200 µg mL –1 for Cs-BATT with varied clear zones. The new polymers were mixed with three film-forming agents: polyvinyl alcohol, hydroxyethyl cellulose, and carboxymethyl cellulose to form six film dressings designated as E1, E2, and E3 for Cs-EATT, and B1, B2, and B3 for Cs-BATT, respectively. The evaluation of film dressings showed that the formed films had transparency, uniformity, homogeneity, elasticity, and non-irritation pH values for skin within the normal range. The maximum percentages of Cs-E/B-ATT content were recorded for film dressings E2 and B2, with values of 92.5% and 94.9%, respectively. Also, the release percentages varied according to film dressing formulation, with values in the ranges of 83.88–93.2% for Cs-EATT and (87.7–97.35%) for Cs-EATT after 9 h.

Molecular identification of fruit bats, natural host of Nipah virus in Bangladesh, based on DNA barcode

Md. Maharub Hossain Fahim,Walid Hassan,Afia Afsin,Md. Mahfuzur Rahman,Md. Tanvir Rahman,Sang Jin Lim,Yeonsu Oh,Yung Chul Park,Hossain Md. Faruquee,Md. Mafizur Rahman The Ecological Society of Korea 2024 Journal of Ecology and Environment Vol.48 No.1

Background: Fruit bats are natural carriers of Nipah virus (NiV). The primary objective of this study is to identify potential reservoir species in a selected geographic regions. It is necessary to determine an accurate species identification of the associated reservoir bat species distributed in a specific region. Results: In this study, we collected 20 different bat specimens from the NiV-prone area of the Kushtia district. Among these, 14 were tissue samples (BT-1-14) and six were fecal samples (BF-1-6). We used the mitochondrial gene cytochrome b, one of the most abundant and frequently used genetic markers, for polymerase chain reaction amplification and sequencing. Out of the 20 samples, 12 tissue samples and 2 fecal samples were successfully amplified and sequenced. However, two tissue samples and four fecal samples yielded chimeric sequences, rendering them unsuitable for annotation. The sequences of the successfully amplified samples were compared to those deposited in the National Center for Biotechnology Information database using basic local alignment search tool to identify the bat specimen collected. The study identified six different bat species using both morphological and genetic data, which may carriers of the NiV. Conclusions: Our results suggest that additional research should be conducted to gather more information on fruit bats from different localities across the country. The study contributes to the establishment of appropriate measures for NiV carrying disease control and management.