LTE and Wi-Fi Coexistence in Unlicensed Spectrum with Application to Smart Grid: A Review

Long Term Evolution (LTE) is expanding its utilization in unlicensed band by deploying LTE Unlicensed (LTEU) and Licensed Assisted Access LTE (LTE-LAA) technology. Smart Grid can take the advantages of unlicensed bands for achieving two-way communication between smart meters and utility data centers by using LTE-U/LTE-LAA. However, both schemes must co-exist with the incumbent Wi-Fi system. In this paper, several co-existence schemes of Wi-Fi and LTE technology is comprehensively reviewed. The challenges of deploying LTE and Wi-Fi in the same band are clearly addressed based on the papers reviewed. Solution procedures and techniques to resolve the challenging issues are discussed in a short manner. The performance of various network architectures such as listenbefore- talk (LBT) based LTE, carrier sense multiple access with collision avoidance (CSMA/CA) based Wi-Fi is briefly compared. Finally, an attempt is made to implement these proposed LTEWi- Fi models in smart grid technology.Comment: submitted in 2018 IEEE PES T&

High gain 5G MIMO antenna for mobile base station

This article presented a millimeter wave antenna which operated at 38 GHz for 5G mobile base station. The MIMO (Multiple Input Multiple Output) antenna consisted of 1x10 linear array configurations. The proposed antenna’s size was 88 x 98 mm^2  and printed on 1.575 mm-thick Rogers Duroid 5880 subsrate with dielectric constant of ε_r= 2.2 and loss tangent (tanδ) of 0.0009. The antenna array covered along the azimuth plane to provide the coverage to the users in omnidirection. The simulated results showed that the single element antenna had the reflection coefficient (S11) of -59 dB, less than -10 dB in the frequency range of 35.5 - 39.6 GHz. More than 4.1 GHz of impedance bandwidth was obtained. The gain of the antenna linear array was 17.8 dBi while the suppression of the side lobes was -2.7 dB.  It showed a high array gain throughout the impedance bandwidth with overall of VSWR were below 1.0646. It designed using CST microwave studio

Fairness-Oriented Link Scheduling for a D2D-enabled LTE-U/Wi-Fi Coexistence Network

To avoid spectrum crunch and improve spectrum efficiency, the use of unlicensed spectra and the introduction of D2D communication will be areas of focus in communication development. However, in the existing unlicensed spectrum coexistence mechanism, different ways of communication are seen as hindering each other. In this paper, we deliberate the coexistence of a D2D-enabled LTE network with Wi-Fi under an unlicensed band. Unlike previous coexistence mechanisms, we allow co-channel transmission, and our goal is to make full use of the advantages of D2D proximity communication and achieve fairness in co-channel transmission. First, we modeled the coexistence network and derived the expressions coverage probability of all types of receivers. Based on the analytical model and simulation results, we prove that D2D communication can be exploited to achieve fairness requirements in co-channel transmission over the unlicensed band. We rephrase the fairness schedule problem as a mixed-integer nonlinear optimization problem for D2D density and transmit power, and we use an Ortho-MADS algorithm to solve it. The simulation results show that the proposed scheme can use D2D communication to improve the fairness of the system

A survey of symbiotic radio: Methodologies, applications, and future directions

The sixth generation (6G) wireless technology aims to achieve global connectivity with environmentally sustainable networks to improve the overall quality of life. The driving force behind these networks is the rapid evolution of the Internet of Things (IoT), which has led to a proliferation of wireless applications across various domains through the massive deployment of IoT devices. The major challenge is to support these devices with limited radio spectrum and energy-efficient communication. Symbiotic radio (SRad) technology is a promising solution that enables cooperative resource-sharing among radio systems through symbiotic relationships. By fostering mutualistic and competitive resource sharing, SRad technology enables the achievement of both common and individual objectives among the different systems. It is a cutting-edge approach that allows for the creation of new paradigms and efficient resource sharing and management. In this article, we present a detailed survey of SRad with the goal of offering valuable insights for future research and applications. To achieve this, we delve into the fundamental concepts of SRad technology, including radio symbiosis and its symbiotic relationships for coexistence and resource sharing among radio systems. We then review the state-of-the-art methodologies in-depth and introduce potential applications. Finally, we identify and discuss the open challenges and future research directions in this field

Cost-Effective Network Planning and Operation for Rural Communities.

PhD Theses.Broadband Internet access is central to the regeneration of remote communities and reducing the digital divide between rural and urban regions. This thesis focuses on rural communities with limited financial resources, environmental issues including long reach from conurbations, and mountainous or otherwise adverse terrain, typically with limited access to a wired power supply. As such, regular access technologies based on cable or fibre optics are not financially viable. To overcome this challenge, we consider the deployment of a Free-Space Optical (FSO) based relay network as the primary technology, using diversity to provide resilience to atmospheric effects. The aim of this research is to design and evaluate a rural network planning and traffic engineering framework employing FSO communication using light emitting diodes/lasers to construct backhaul rural network infrastructures. FSO systems are relatively cheap and easy to implement [1]. Various proof-of-concept technologies already exist [2] [3] [4]. However, the focus of this work is on the design of a flexible network-planning tool together with a robust management framework that is designed to operate over such an infrastructure to ensure it functions efficiently despite changes in load or communication channel outages. Although the work concentrates on an FSO based infrastructure, this could be extended to support heterogeneous networks employing a combination of technologies. More precisely, this research first describes a novel network planning tool with an intelligent resource management system based on a Multi-Objective Evolutionary Algorithm (MOEA) that determines the suitable location of FSO relay nodes, taking into account end-to-end link speed which is bitrate of user data and the degree of path diversity coupling with battery power. This MOEA approach can account for Line-of-Sight occlusions and allows various compromises to be selected from a Pareto front to suit individual needs. We provide suitable results to show the satisfactory operation of the tool and outline avenues for future development. Following on from this, we design and evaluate an intelligent traffic-engineering framework to make the best use of the deployed infrastructure that can adapt to environmental changes. This aims to ensure a good service is maintained at all times by suitable reconfiguration