The smart grid concept continues to evolve and various methods have been developed in order to enhance the energy efficiency of the electricity infrastructure. Demand Response (DR) is considered as the most cost-effective and reliable solution for the smoothing of the demand curve, when the system is under stress. DR refers to a procedure that is applied to motivate changes in the customers' power consumption habits, in response to incentives regarding the electricity prices. In this paper, we provide a comprehensive review of various DR schemes and programs, based on the motivations offered to the consumers in order to participate in the program. We classify the proposed DR schemes according to their control mechanism, to the motivations offered to reduce the power consumption and to the DR decision variable. We also present various optimization models for the optimal control of the DR strategies that have been proposed so far. These models are also categorized, based on the target of the optimization procedure. The key aspects that should be considered in the optimization problem are the system's constraints and the computational complexity of the applied optimization algorithm.

MmWave radio, although instrumental for achieving the required 5G capacity Key Performance Indicators (KPIs), necessitates the need for a very large number of Access Points, which places an immense strain on the current network infrastructure. In this article, we try to identify the major challenges that inhibit the design of the Next Generation Fronthaul Interface in two upcoming distinctively highly dense environments: i) in Urban 5G deployments in metropolitan areas and ii) in ultra-dense Hotspot scenarios. Secondly, we propose a novel centralized and converged analog Fiber-Wireless Fronthaul architecture, specifically designed to facilitate mmWave access in the above scenarios. The proposed architecture leverages optical transceivers, optical add/drop multiplexers and optical beamforming integrated photonics towards a Digital Signal Processing analog fronthaul. The functional administration of the fronthaul infrastructure is achieved by means of a packetized Medium Transparent Dynamic Bandwidth Allocation protocol. Preliminary results show that the protocol can facilitate Gbps-enabled data transport while abiding to the 5G low-latency KPIs in various network traffic conditions.

In this work, the concept of dual-band resistance compression networks is introduced and applied to the design of rectifier circuits with improved performance. The use of resistance compression networks (RCNs) minimizes the sensitivity of rectifier circuits to variations in the surrounding environment, such as input power level and changes in the rectifier load. The proposed dual-band RCN can be used as the matching network located between the antenna and the rectifying element of a dual-band rectifier for energy harvesting applications. A dual-band (915 MHz / 2.45 GHz) rectifier based on RCN is designed and characterized showing improved performance in comparison with a conventional dual-band envelope detector by exhibiting improved RF-dc conversion efficiency and reduced sensitivity versus output load and input power variations.

Electrification of transportation is considered as one of the most promising ways to mitigate climate change and reduce national security risks from oil and gasoline imports. Fast Charging Stations (FCS) that provide high Quality of Service (QoS) will facilitate the wide market penetration of Electric Vehicles (EVs). In this paper, we analyze the operation of a FCS by employing a novel queuing model. Our analysis considers that the various EV models are divided into classes based on their battery size; then we compute the EVs' mean waiting time in the queue, taking into account the number of Charging Spots (CS) of the FCS, as well as the stochastic arrival process and the stochastic recharging needs of the various EV classes. Furthermore, the high precision of our analysis is confirmed through simulations. Therefore, our model may be utilized by existing FCS operators that need to provide high QoS, or by future investors for an efficient installation design.

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