Improving Adaptive Quality of Service for Multimedia Wireless Networks Using Hierarchical Networks Approach

Multimedia traffic is expected to populate the next generation wireless networks. As in wireline networks, the wireless network must able to provide a guaranteed quality of service (QoS) over the lifetime of mobile connections. Some challenging problems such as user mobility, limited frequency spectrum and shortage of bandwidth, influence the QoS provisioning for the users. This thesis examines into the issue of delivering a guaranteed quality of service (QoS) for multimedia services in wireless environment. A PhD candidate, Prihandoko have proposed an Adaptive QoS (AdQoS) model to guarantee the delivery of multimedia services. That work have been adopted and extended by means of a hierarchical network approach, calling it as Improved AdQoS model.The main objective that the Improved AdQoS framework tries to accomplish is to reduce the New Call Blocking Probability (NCBP) and Handoff Call Dropping Probability (HCDP). The key feature of this framework is the integration of the hierarchical network together with the modified Call Admission Control (CAC) algorithm and the bandwidth reallocation scheme. These schemes are developed to control the bandwidth operation of ongoing connections when the system is overloaded depending on the movement speed of a particular user assuming the speed of a mobile user would not be changed throughout the duration of a connection. The performance of the system is evaluated through simulations of a cellular environment under three different scenarios. Scenario A represents an area with 80% slow speed users and 20% fast speed users, Scenario B represents an area with a population of 40% slow speed users and 60% fast speed users while Scenario C represents an area with 20% slow speed users and 80% fast speed users. When compared with the scheme proposed Prihandoko in the literature, the simulation results show that our proposed scheme reduces the new call blocking probabilities, the handoff dropping probabilities and reduces significantly the probability of terminating call

Lie group analysis for the effect of viscosity and thermophoresis particle deposition on free convective heat and mass transfer in the presence of suction/injection

An analysis has been carried out to study heat and mass transfer characteristics of an incompressible and Newtonian fluid having temperature-dependent fluid viscosity and thermophoresis particle deposition over a vertical stretching surface with variable stream condition. The Rosseland approximation is used to describe the radiative heat flux in the energy equation. The vertical surface is assumed to be permeable so as to allow for possible wall suction or injection. The governing differential equations are derived and transformed using Lie group analysis. The transformed equations are solved numerically by applying Runge-Kutta Gill scheme with shooting technique. Favorable comparisons with previously published work on various special cases of the problem are obtained. Numerical results for the velocity, temperature and concentration profiles for a prescribed temperature-dependent fluid viscosity and thermophoresis particle deposition parameters are presented graphically to elucidate the influence of the various physical parameters

New call blocking probability (NCBP) in improved adaptive quality of service (AdQoS) for wireless multimedia communications using hierarchical cellular approach

The maintenance of quality of service (QoS) in a wireless environment is a difficult problem. Most researchers have already acknowledged adaptive techniques as the appropriate method to deal with the fluctuation of QoS in a wireless cellular network. This paper proposes an improved new call blocking probability (NCBP) from an adaptive QoS (AdQoS) to support the QoS guarantee. Besides using an adaptive technique, this method utilizes a hierarchical cellular approach with a bandwidth reallocation algorithm to determine the acceptance or rejection of a new call. The approach would improve the NCBP performance of the multimedia application over high-speed wireless cellular networks

Challenges of Learning English in 21st Century: Online vs. Traditional During Covid-19

Free online resources are user-friendly technologies which have become available through the Internet in recent years and gaining popularity during Covid-19. Since learners use smartphones, free online resources are easily accessible. Books are portable, but learners find it somewhat difficult to learn English language via books which may only be available in the classroom context, whereas free online resources are easily accessed. The purpose of this study is to identify learners’ perception learning English via free online resources and traditional learning. Quantitative and qualitative methods were employed in the present study. Twenty-five international pre-elementary intensive English students took part in this study. It was found that learners perceived the free online resources as valuable tools for learning English in relation to reading, conversation, and vocabulary and also free online resources help promote free learning norms in learning the English language. The learners also had constructive attitudes towards free online resources. Free online resources always provide a motivating learning environment, enhance learners’ analytical and critical thinking skills, and encourage social interaction between teachers and learners, learners and their peers, and learners and other participants

Challenges Faced by Hearing Impairment Students During COVID-19

Social distancing and other protocols required during the COVID-19 pandemic have been particularly difficult for students who are disabled, especially hearing impairments students. During the Covid-19, many disabled students were impacted physically, mentally and their interactions may have been hindered. That could be one of the barriers for full and active participation in society during the Covid- 19. Therefore, this study aims to discover the challenges faced by hearing impairment students how it affects the communication and mainstreaming process. The data was collected from ten hearing impairments students and analysed qualitatively. The participants were aged between 19-22 and currently studying foundation programme in culinary arts in a skill transformation center. The participants were interviewed using impromptu interview questions via WhatsApp, which lasted about ten minutes for each participant. The findings show that there were four challenges faced by the hearing impairment students; hearing devices, disruption to comprehend the lesson, not familiar with the online devices and emotionally affected during online classes. The findings further reveal that the hearing impairment students hampered their social interactions skills towards others during the pandemic. It is hoped the findings would be useful for academicians, counsellors, doctors and other job professions to explore further research on hearing impairments and the framing of methodology to assist the hearing impairments in engaging with the society during the pandemic