Communication Engineering

One of significant change in learning process is exam implementation applying a computer-based test (e-exam) rather than paper-based test. Many institutions currently use wireless network with bring your own device (BYOD) policy for their e-exam implementation, due to limitation of space and user terminals. Moreover it is hard to maintain the availability of reliable signal quality in wireless network for all users during e-exam process. Therefore, this research proposes a development of time adaptive for mobile exam (TAMEx) framework to provide all users with good quality of service of e-exam in wireless network environment when dealing with signal quality variations. The received signal strength indication (RSSI) is the main indicator of the signal quality. The framework supports e-exam implementation in wirelesslocal area network and the use of BYOD mechanism. The research shows that the framework successfully has provided time compensation for the users who experienced temporary connection loss due to bad signal quality. The result exhibits that tiny processing time has been needed for signal loss detection, user’s request of compensation time, and server’s execution. In conclusion, the TAMEx could guarantee good services for all users who doing e-exam in wireless network environment.

In this paper, dielectric resonator antenna (DRA) with enhanced gain operating on the higher order mode (15) is presented. The dielectric resonator antenna with dielectric constant of 10 and loss tangent of 0.002 is used. The DRA is fed by microstrip line through an aperture slot. The proposed antenna is designed at 26 GHz and achieved a gain of 7.9 dBi with corresponding simulated radiation efficiency of 93%. The impedance bandwidth of 1.5 GHz from 25.1 GHz to 26.6 GHz has been achieved. The reflection coefficient, antenna gain, radiation patterns, and efficiency of the antenna are studied. Simulations are performed using CST microwave studio, and their results are presented.

To mitigate the spread of the Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), a plethora of technology-based contact tracing (CT) applications have been proposed, designed, and deployed by private and government entities in various countries globally in order to return society to some semblance of normalcy. Although most of the modifications done on the underlining protocols mostly focus on the privacy and ethical concerns of these solutions, pragmatic applications within developing countries are not considered, as applications in most cases are considered to be ubiquitous. This disparity leads to a design-reality gap as the involved entities fail to pay attention to the local conditions in which these systems could be deployed. In this work, an in-depth analysis of state-of-the-art technology-based CT protocols is discussed while considering the compatibility of these designs with the reality of lopsided levels of digital divides and other structural inequalities in developing countries. In addition, a number of existing solutions implemented in developing countries are delineated. Furthermore, pragmatic applications that consider social and technological infrastructures to bridge the gaps in these infrastructures are discussed as well as possible recommendations that could be implemented to effectively mitigate the spread of pandemic outbreaks in developing countries.

The ultra wide band (UWB) antennas play a vital role in supporting different wireless standards and are suitable for wide variety of applications. This paper is aimed to present a novel UWB dual notch microstrip antenna with modified ground plane. The antenna is designed to operate in UWB ranging from 2 GHz to 12 GHz with multi band operation. This will help in operating the antenna for different operations independently. The proposed structure will operate in two notch bands 3.3-4 GHz (Wi-MAX), 5.05-5.9 GHz (WLAN) and the structure is suitable for long distance communications because of its increased directivity. The structure can also be used for X-Band applications for various applications of traffic control, weather forecasting and vehicle speed detection systems. It is observed that, the proposed structure is offering a gain of 5.2 dBi with improved directivity with a beam width of 42.23 0. This makes the antenna structure suitable for long distance satellite communications. The antenna is supporting the circular polarization at higher the frequencies and can be useful for the upcoming 5G mobile applications. Moreover, the proposed structure offers the less interference at the receiver. The structure is found to be smaller in dimensions, easily fabricated at low costs and can be integrated into any compact wireless devices. The structure is simulated using a commercially available software Ansys-HFSS and is analyzed. Keywords: 5G Communications Band width Dual T-shaped stub High directivity High gain Satellite applications This is an open access article under the CC BY-SA license.

India's population is reached beyond 1.2 billion and the population rate is increasing day by day then after 25-30 years there will be serious problem of food, so the development of agriculture is necessary. Today, the farmers are suffering from the lack of electricity, less rain and improper management of pesticide. The main aim of this paper is to provide an automatic agricultural system thereby saving time, money & power of the farmer. With the automated technology of agriculture the human intervention can be minimized. This paper mainly consists of automatic irrigation, pesticide sprinkling and solar operated tractor. An automatic irrigation system consists of sensor which senses the change in temperature and humidity in the soil and gives an interrupt signal to the ARDUINO controller which in turn sends a message to the user through GSM technology. Pesticides are sprinkled according to the requirement of the plants and this is operated based on solar power. Tractors are also made to run using solar power.

This paper is demanded to study Handover Based on X2 Interface in LTE Network. Handover procedure in LTE Network has been intensely advanced when compared to the earlier 3GPP criteria. In this paper, the handover process describes takes the proficiency of communication networks in possession the communication link is working. In unusual, X2 handover is obtainable to let neighboring eNBs to keep the user mobility deprived of the contribution of the central network. X2 is an interface that must be spread when the manner of shifting data of time of handover between two eNodeB contiguous sectors in LTE. The capacities of interface X2 also manipulate of the time on handover process, so it is required to examine the function of interface X2 when handover occur between eNodeB in LTE. This paper learns the operation performance of the X2 handover from the UE perspective. Keyword: X2 handover, RSRP procedure 1.INTRODUCTION Occasionally, when you are looking internet in your car/bus, the internet is slower or even separate because 3G networks reportage cannot cover greatly while you are moving at high speed. Scientifically, this problem occurred because the handover/hand-off is malfunction. LTE as the next generation offers a lot of features such as a very high data speed and low transfer delay which let the user to use many application instantaneously without any disconnection and buffering although the user travels with very high speed movement. Long term evolution (LTE) is the succeeding generation after Universal Mobile Telecommunications System (UMTS) system which developed by 3GPP announcement 8. LTE as the fourth generation offers a high transmission speed and high mobility to the user. Mobile data continuous improvement appears efficient technologies to sate the needed quality of service (QoS) of the new services. Mobility is a one of the significant structures of current and next generation cellular systems that permits the users to modify purely their point of attachments while using their data and voice services. Handover in Long Term Evolution (LTE), as in earlier creation of cellular systems, is a technique to handover a user equipment (UE) and its circumstance from a source progressed NodeB (eNB) to a goal eNB. It requirements efficient handover decision algorithms in order to increase both UE and network performance and quality. Handover is a "UE-assisted network-controlled" process in that the quantity is designated by UE, and the decision is arranged by the network, i.e. eNBs and/or Mobility Management Entity (MME). Several works have been done competing the S1 and X2 handover in terms of the EPC signaling load and the outcomes evidences that X2 handover can decrease EPC signaling load more than six times compared with S1 handover. X2 handover can be a sort of resolution to reduce the capacity influence to the EPC and to increase the dependable arriving handover [1], [2]. In adding, it exposes that the X2 handover producing time decreases with the increase on the eNB communication power and vehicle speed using RSRP standard on the MATLAB platform [3]. This paper will effort on X2 handover in LTE that happens between eNBs [4]. In most of the events, both source and target eNBs are linked to the similar MME and are situated in the identical tracking area (TA). The capacity belongings cover the handover are placed in the same tracking area (TA). The measurement events cover the handover between two cells complementary the X2 interface between the eNBs. 2.LTE ARCHITECTURE

The satellite communication providea utilization of radio frequency links. Specific frequencies are dedicated for satellite correspondences through global administrative and coordination procedures which keeps impedance amongframeworks. Over typical work, the satellite receives uplinked indicator fromearth. Progressions its frequency marginally will keep away from self-intervention then re-transmits signal ahead the downlink on the land. Pathloss depicts characteristic Propagate outside the sending signal front as it goes bythe space. A  software defined radio (SDR) is a flexible technology that aimsto replace all hardware by software to enables the design of adaptive communications systems such as changing frequencies, modulation schemes and data rates. Applied to small satellites, some of the implications areincreased data through put when down-linking or up-linking by varying communications parameters and making use of one hardware design and implementation for communicating for many missions, just by updating the software. Therefore, development time for small satellite communication systems can be reduced in the future. This paper analyzes, design and software implementation of radio frequency satellite communications links under noisy channels such as phase/frequency offsets and noise temperature. Modulation schemes such as 64QAM system is used based on Matlab tools to implement the results. Obtained results shows a good response that get the goal from the paper.

This work presents a 28 GHz Dual Element Multiple Input Multiple Output (MIMO) Planar Inverted-F Antenna for millimeter wave 5G mobile terminal. The antenna design employs PIFA design concept as it is a common antenna type use for mobile phone as it provides wide bandwidth and good performance. The antenna design begins with a characterization of the single element PIFA design and then extended to Dual Element MIMO PIFA design. The single element PIFA design is enhanced to MIMO design by extending the ground plane and locate the second PIFA at the other end. Isolation between the antenna elements of the MIMO PIFA is analyzed by varying the gap distance between the antenna elements. The result for Envelope Correlation Coefficient, Diversity Gain and Multiplexing Efficiency is also presented. The simulation computed using Computer Simulation Technology (CST) Microwave Studio software.