Performance Analysis of Grid-tied Sine-wave Inverters in a Hybrid Power System

The inverter performance model provides a new opportunity for accurately monitoring the performance and health of the inverter in real time. Grid-tied inverter monitoring can be accomplished by using a data acquisition system which provides a periodic measurement of dc voltage and power, as well as true ac power. In real time, inverter’s efficiency can be calculated empirically and compared to the inverter efficiency determined using the inverter performance model. Deviations between measured and calculated inverter efficiency would provide direct evidence of inverter malfunction or degradation in performance. It is likely, given experience, that the nature of the deviations would provide the diagnostic information needed to define required inverter maintenance for optimum future performance. Keywords: Performance model, Grid-tied Inverter monitoring, Data acquisition, Measured and calculated efficiency, Maintenanc

Predicting Internet Bandwidth in Educational Institutions using Langrage’S Interpolation

This paper addresses the solution to the problem of Internet Bandwidth optimization and prediction in the institution of higher learning in Nigeria. The operation of the link-load balancer which provides an efficient cost-effective and easy-to-use solution to maximize utilization and availability of internet access is extensively discussed. This enables enterprises to lease for two or three ISP links connecting the internal network to the internet. The paper also proposes the application of the Langrage’s method of interpolation for the predictability of internet bandwidth in the institutions. The analysis provides a unique graphical solution of effective actual bandwidth (Mbps) and the corresponding acceptable number of internet Users (‘000) in the institutions. The prediction allows us to view the actual internet bandwidth and the acceptable number of internet Users as the population of users’ increases. Keywords: Internet Bandwidth, Optimization, Link-Load Balancer, Prediction, Maximized Utilization, Availability of Internet access

Implementation of Closed-circuit Television (CCTV) Using Wireless Internet Protocol (IP) Camera

This paper presents three techniques for configuring, interfacing and networking of a wireless IP-based camera for real-time security surveillance systems design. The three different real-time implementation techniques proposed for configuring, interfacing and networking the IP camera are: 1). accessing the IP-based camera using the WANSCAM or XXCAM vendor software, 2). accessing the IP-based camera via Firefox® web browser , and 3). accessing the IP camera via MATLAB with SIMULINK on an internet ready system. The live streaming video based on the proposed techniques can be adapted for image detection, recognition and tracking for real-time intelligent security surveillance systems design.  The paper also carried out a thorough comparative analysis of the three methods of achieving video streaming resulting from the output of the IP-based cameras. The analysis shows that the WANSCAM or XXCAM software displays the best video animations from the IP-based cameras when compared with the performance of the other methods. Keywords: Closed-circuit television, Internet protocol, Security surveillance, IP-based cameras, Wireless networking, animation

A Survey of IP Address for Next Generation Internet Services

This paper surveys the problem of the astronomical growing demand of Internet Systems participating in the public network which has led to the depletion of allocated Internet Protocol version 4.0 (IPV4) addresses. Already, four out of the Regional Internet Registry (RIR) namely: ARNIC, RIPE, LACNIC and ARPIN have exhausted their allocated IPV4 addresses while the fifth AFRICNIC (Africa’s RIR) is reportedly depleted. We also examine the limitations of IPV4, the features of IPV6 and different modes of operating IPV6 standard. Findings shows that the current population of the world is over 6billion people with a projection of 9billion people by the year 2050 and IPV6 can conveniently accommodate 2128 devices. This paper also proposes the migration from the present Internet Protocol version 4.0(IPV4) to a new Internet Protocol version 6.0(IPV6) addresses. This research work has shown that deploying the IPV6 could only be the possible solution to sustaining Internet Services globally. Keywords: Internet Systems, Internet Protocol Address, IP address depletion, Migration

Performance Analysis of NICs and Its Interactivity with Internet Services

This paper analyses the problem of slow data or video streaming on the World Wide Web internet through the network interface cards (NICs). The service of the entire network and internet connectivity largely rest on the installed Network Interface Cards (NICs). The performance of the various NICs such as 10Mbps, 100Mbps, 1,000Mbps and 10,000Mbps were examined using different message data sizes on the network. Also, the paper extensively discusses the performance of 10Gbps Ethernet card such as: data transmission time and throughput. The fact remained that the major backbone of the Internet network is the transmission control protocol (TCP) which is designed for reliable sending of data over the internet. The TCP as the protocol of the NIC is used for browsing web and downloading or uploading files. Additionally, the paper also examines the TCP feedback mechanism that is able to detect loss packets and retransmit them. Also, the TCP is able to dynamically adapt its packet sending rate to the network conditions in order to achieve the highest possible throughput. However, this paper proposes the use of the 10Gbps Ethernet card for the Internet Servers and Workstations for effective and fast internet access in all public networks. Keywords: Ethernet Card, Transmission Control Protocol, Data transmission time, throughput.

A Robust Solution to Unreliable 900MHz GSM Communication Services during Rainfall

This paper presents an insight into network performance evaluation and quality of service (QoS) improvement of GSM cellular system services during rainfall. The components of QoS and mechanisms of analyzing and evaluating them are discussed. The paper also identifies the important key performance indicators (KPIs) for QoS evaluation which are used in evaluating the poor GSM network during rainfall. Five assessment parameters (i.e. network accessibility, service reliability, connection quality, and radio propagation and rain attenuation) for evaluating QoS on the network were employed. Prior to the development of this research, result shows that QoS of GSM system in the country is unreliable. It is also found that GSM network accessibility and reliability in the country are unsatisfactory during rainfall. The paper is concluded with recommendations which include the GSM link budget that incorporated the rain attenuation factor that would definitely improve the QoS of poor GSM network services in order to enhance effective and efficient telecommunication system in the country. Keywords: GSM networks, Key performance indicators, Rain attenuation factor, GSM link budget, Assessment parameters. Rainfal

A SYSTEMATIC EVALUATION OF LINK BUDGET FOR EFFECTIVE 900MHz GSM COMMUNICATION SERVICES

This paper describes the various basic parameters necessary to determine a high level link budget for radio communication operating at 900MHz spectrum band. It considers a typical Lagos terrain by using the Okumura and Hata prediction model in calculating the path loss between a transmitter and mobile receivers. In this paper, the rain attenuation calculation from the updated ITU model was incorporated into the link budget to improve GSM communication during rainfall. These parameters can be used to predict a reliable communication ranges for the design and implementation of future GSM communication systems. Keywords: 900MHz Spectrum Band, Prediction model, Link-budget, Path loss, Rain attenuation, Communication ranges, GSM Communication

A Robust Analysis of Dual-Band Wireless LAN (4G-WLAN) for Effective Internet Access: A Review Paper

This paper presents the findings of a comprehensive study of dual-band WLAN for internet access. It gives an exposition of the architecture of the 4G-WLAN routers which is a more advanced and the latest technology that uses Adaptive Modulation and Coding (AMC) to dynamically react to channel fluctuations while maintaining bit-error rate targets of the transmission. It also x-rays the part played by the internet service providers (ISP), the access providers (i.e. Dial-up, DSL, Satellite and fibre optics) which are responsible for high data throughput and cost of connection. This paper also discusses the IP addressing methods of the connected devices (i.e. BOOTP and DHCP) which depict the Transmission Control Protocol/Internet Protocol (TCP/IP) of the network.  The system clearly provides added convenience of Internet access and the extent of mobility the wireless routers can bring to computer networks and users. This technology provides a platform for future expansion. Keywords— Dual-Band WLAN, 4G-WLAN Router, AMC, Internet access provider, Data throughput, TCP/IP, Access provide

Performance Analysis of Stepped-Slot Antenna for Wireless Aeronautical Communication Services

This paper extensively studies the design, construction and operation of a broadband printed slot antenna. In this research work, the coplanar waveguide (CPW)-fed conventional rectangular slot antenna is designed and then the rectangular shape is modified by a stepped configuration to achieve higher bandwidth for both transmission and reception. The paper explains that the signal transmitted or received by the antenna is in the ultra wide radio frequency band. The mathematical analyses of the magnetic vector potential from the short slot were used to evaluate the total current distribution on the entire stepped-slot. The simulated results using Integrated Electronics with three-dimensional graphical output display (IE3D) software are verified by measurement and the results show that the printed stepped-slot antenna can be used for ultra wide band (UWB) communication in the frequency range of 3.1GHz – 5.7GHz. The performance and effectiveness of the printed-slot antenna finds its applications in radar antennas used with modern aircraft. Keywords: Stepped-slot antenna, broadband, coplanar waveguide, bandwidth, Ultra wide-band communication, aircraf

Analysis Techniques on Yagi-Uda Antenna Configured for Wireless Terrestrial Communication Applications

The paper focuses on analysis and operation of Yagi-Uda antenna which is usually excited at frequencies between 30MHz and 3GHz with coverage of 40 to 60km.  The length of the reflector is selected approximately equal to 0.55wavelength of the radiated signal. The optimum spacing between the reflector and the driven element is chosen between 0.15wavelength and 0.25wavelength. The length of the reflector has a large effect on the front-to-back ratio and antenna input impedance. For the dipole driven element, a length of 0.47wavelength was chosen to ensure good input impedance to a 50 ohms feed line. In this paper both empirical and measured data were collated to ensure a solid and efficient analysis of the parameters of this antenna. However, the paper has successfully presented a comprehensive analysis of the design, implementation and operation of the end-fire antenna configured for wireless terrestrial communication services. Keywords: Yagi-Uda antenna, Coverage, Reflector, Dipole driven element, end-fire, Wireless terrestrial communication service