Computer Engineering Commons^™

Two-Layered Blockchain-Based Admission Control For Secure Uav Networks, Müge Özçevi̇k

Turkish Journal of Electrical Engineering and Computer Sciences

The frequent replacement requirement of UAVs for recharging outputs an extreme number of messaging for admission control of end-users. There are many studies that try to optimize the network capacity in an energy-efficient manner. However, they do not consider the security of data and control channels, which is the urgent requirement of 5G. Blockchain handles secure systems. However, the high numbered transactions in blockchain may cause bottlenecks while considering computational delay and throughput of end-user. In UAVs, a high percentage of battery is consumed for computational tasks instead of communication tasks. Therefore, to handle security by considering the computational needs, …

Dual-Polarized Elliptic-H Slot-Coupled Patch Antenna For 5g Applications, Emre Alp Mi̇ran, Mehmet Çi̇ydem

Turkish Journal of Electrical Engineering and Computer Sciences

A dual-polarized, slot-coupled dielectric patch antenna design is presented in sub-6 GHz for 5G base stations. Proposed antenna is implemented using two dielectric patch layers (main patch and parasitic patch) above a feeding line layer. Excitation is realized by crossed elliptic-H slots in order to create orthogonal ± 45$^{\circ}$ polarizations. Through the use of patches at proper heights together with elliptic-H slots, significant improvement in impedance bandwidth, matching level, isolation and front-to-back ratio is acquired. Prototype antenna has an impedance bandwidth of 18.5\% (3.23--3.85 GHz) for $ S_{11} $, $ S_{22} $ $

Energy Efficiency In Cmos Power Amplifier Designs For Ultralow Power Mobile Wireless Communication Systems, Selvakumar Mariappan, Jagadheswaran Rajendran, Norlaili Mohd Noh, Harikrishnan Ramiah, Asrulnizam Abd Manaf

Turkish Journal of Electrical Engineering and Computer Sciences

Wireless communication standards keep evolving so that the requirement for high data rate operation can be fulfilled. This leads to the efforts in designing high linearity and low power consumption radio frequency power amplifier (RFPA) to support high data rate signal transmission and preserving battery life. The percentage of the DC power of the transceiver utilized by the power amplifier (PA) depends on the efficiency of the PA, user data rate, propagation conditions, signal modulations, and communication protocols. For example, the PA of a WLAN transceiver consumes 49 % of the overall efficiency from the transmitter. Hence, operating the PA …

Design And Characterization Of A Compact Single-Layer Multibeam Array Antennausing An 8×8 Butler Matrix For 5g Base Station Applications, Intan Izafina Idrus, Tarik Abdul Latef, Narendra Kumar Aridas, Mohamad Sofian Abu Talip, Yoshihide Yamada, Tengku Faiz Tengku Mohmed Noor Izam, Tharek Abd. Rahman

Turkish Journal of Electrical Engineering and Computer Sciences

A multibeam array antenna employing a Butler matrix is a promising solution for fifth generation (5G) base stations. Due to inaccurate phase differences between output ports in the Butler matrix, the radiation characteristics could show incorrect main beam directions. In addition, the literature has also reported the issue of high amplitude imbalance in the Butler matrix. This paper presents a single-layer multibeam array antenna fed by an 8×8 Butler matrix operating at 28 GHz for 5G base station applications' a more cost-effective solution for large-scale production. The Butler matrix consists of twelve quadrature hybrids, sixteen crossovers, and eight phase shifters. …

Electromagnetic Radiation Exposure Of Multioperator Co-Sited Urban Base Stations, Ni̇yazi̇ Korkut Uluaydin, Tomasz Dlugosz, Şaban Seli̇m Şeker

Turkish Journal of Electrical Engineering and Computer Sciences

Mobile network operators (MNOs) concurrently use different generations of wireless technologies. The base stations (BSs) of different technology generations are co-located in order to decrease operational costs. Furthermore, the MNOs cooperate in order to co-site their base stations. Such an urban site includes more than 25 actively radiating antennas on average with different frequencies and modulations. Electromagnetic radiation (EMR) measurements performed in such an environment may have reduced accuracy. In this paper, the authors propose a new approach for the measurement of EMR in multiple mobile technology interwoven urban BS sites, where more than one operator exists. The maintenance activities …

Nb-Iot: A Network Slice For Massive Iot, Xhafer Krasniqi

UBT International Conference

Network virtualisation is a concept that has been around for some time now, but the concept of network slicing is more recent and only started to be mentioned in the context of 5G. In essence, network slicing is a specific form of network virtualisation that enables sharing of physical resources by multiple logical network slices used to serve different applications and use cases. One such a use case would be to allocate network resources to small things, e.g. sensors and very low power consumption objects. To allow these small objects access to network resources or to a slice of such …

Path Loss Model For Indoor Emergency Stairwell Environment At Millimeter Wave Band For 5g Network, Ahmed Mohammed Alsamman, Tharek Abd Rahman, Mohd Nour Hindia, Jamal Nasir

Turkish Journal of Electrical Engineering and Computer Sciences

The unused millimeter-wave (mmWave) spectrum offers a superb opportunity to increase mobile broadband capacity due to the enormous amount of available bandwidth. Different candidate operating frequencies for 5G wireless networks are available at the mmWave band. For 5G wireless networks, the emergency case is one of the applications. This paper presents the outcome of indoor emergency stairwell measurement campaigns for 5G system at 26 GHz, 28 GHz, 32 GHz, and 38 GHz, which were conducted at the University Technology Malaysia, Kuala Lumpur, Malaysia. To effectively evaluate the performance of 5G wireless systems in these different bands, single- and multifrequency path …

A Critical Overview Of Data Mining For Business Applications, George Telonis, Peter P. Groumpos

UBT International Conference

Everybody looks to a world that does not remain the same. Furthermore no one can deny that the world is changing, and changing very fast.

Technology, education, science, environment, health, communicating habits, entertainment, eating habits, dress - there is hardly anything in life that is not changing. Some changes we like, while others create fear and anxiety around us. Everywhere there is a feeling of insecurity.

What will happen to us tomorrow, or what will happen to our children, are questions we keep frequently asking. One thing, however, is clear.

It is no more possible to live in the way …

A Novel And Realistic Hybrid Downlink-Uplink Coupled/Decoupled Access Scheme For 5g Hetnets, Nadeem Sial, Junaid Ahmed

Turkish Journal of Electrical Engineering and Computer Sciences

Cell association in present day heterogeneous networks (HetNets) is still based on the technique used by homogeneous cellular networks despite power and coverage area disparities of network nodes. In ongoing policy, both uplink (UL) and downlink (DL) associations are coupled based on DL characteristics, which introduces UL-DL asymmetry and cell load imbalances. Recently, decoupled cell association, also known as downlink-uplink decoupling (DUDe), has been introduced in 3rd Generation Partnership Project (3GPP) Release 12 to improve uplink performance, load balancing, and cell capacity. In DUDe, characteristics of both DL and UL channels can be considered. By using this concept, various theoretical …