The smart grid is conceived of as an electric grid that can deliver electricity in a controlled, smart way from points of generation to active consumers. Demand response (DR), by promoting the interaction and responsiveness of the customers, may offer a broad range of potential benefits on system operation and expansion and on market efficiency. Moreover, by improving the reliability of the power system and, in the long term, lowering peak demand, DR reduces overall plant and capital cost investments and postpones the need for network upgrades. In this paper a survey of DR potentials and benefits in smart grids is presented. Innovative enabling technologies and systems, such as smart meters, energy controllers, communication systems, decisive to facilitate the coordination of efficiency and DR in a smart grid, are described and discussed with reference to real industrial case studies and research projects.

Demand response and smart grids—A survey

This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

With the explosive growth of mobile data demand, the fifth generation (5G) mobile network would exploit the enormous amount of spectrum in the millimeter wave (mmWave) bands to greatly increase communication capacity. There are fundamental differences between mmWave communications and existing other communication systems, in terms of high propagation loss, directivity, and sensitivity to blockage. These characteristics of mmWave communications pose several challenges to fully exploit the potential of mmWave communications, including integrated circuits and system design, interference management, spatial reuse, anti-blockage, and dynamics control. To address these challenges, we carry out a survey of existing solutions and standards, and propose design guidelines in architectures and protocols for mmWave communications. We also discuss the potential applications of mmWave communications in the 5G network, including the small cell access, the cellular access, and the wireless backhaul. Finally, we discuss relevant open research issues including the new physical layer technology, software-defined network architecture, measurements of network state information, efficient control mechanisms, and heterogeneous networking, which should be further investigated to facilitate the deployment of mmWave communication systems in the future 5G networks.

A survey of millimeter wave communications (mmWave) for 5G: opportunities and challenges

Cognitive radio (CR) is the enabling technology for supporting dynamic spectrum access: the policy that addresses the spectrum scarcity problem that is encountered in many countries. Thus, CR is widely regarded as one of the most promising technologies for future wireless communications. To make radios and wireless networks truly cognitive, however, is by no means a simple task, and it requires collaborative effort from various research communities, including communications theory, networking engineering, signal processing, game theory, software-hardware joint design, and reconfigurable antenna and radio-frequency design. In this paper, we provide a systematic overview on CR networking and communications by looking at the key functions of the physical (PHY), medium access control (MAC), and network layers involved in a CR design and how these layers are crossly related. In particular, for the PHY layer, we will address signal processing techniques for spectrum sensing, cooperative spectrum sensing, and transceiver design for cognitive spectrum access. For the MAC layer, we review sensing scheduling schemes, sensing-access tradeoff design, spectrum-aware access MAC, and CR MAC protocols. In the network layer, cognitive radio network (CRN) tomography, spectrum-aware routing, and quality-of-service (QoS) control will be addressed. Emerging CRNs that are actively developed by various standardization committees and spectrum-sharing economics will also be reviewed. Finally, we point out several open questions and challenges that are related to the CRN design.

Cognitive radio networking and communications: an overview

Millimeter wave (mmWave) communications have recently attracted large research interest, since the huge available bandwidth can potentially lead to the rates of multiple gigabit per second per user Though mmWave can be readily used in stationary scenarios, such as indoor hotspots or backhaul, it is challenging to use mmWave in mobile networks, where the transmitting/receiving nodes may be moving, channels may have a complicated structure, and the coordination among multiple nodes is difficult To fully exploit the high potential rates of mmWave in mobile networks, lots of technical problems must be addressed This paper presents a comprehensive survey of mmWave communications for future mobile networks (5G and beyond) We first summarize the recent channel measurement campaigns and modeling results Then, we discuss in detail recent progresses in multiple input multiple output transceiver design for mmWave communications After that, we provide an overview of the solution for multiple access and backhauling, followed by the analysis of coverage and connectivity Finally, the progresses in the standardization and deployment of mmWave for mobile networks are discussed

Millimeter Wave Communications for Future Mobile Networks

In this paper, a novel broadcast protocol is proposed for the receiver initiated transmission (RIT) media access control (MAC) protocol based wireless smart utility network (Wi-SUN) systems. The RIT protocol adopted by IEEE 802.15.4e achieves the low power consumption by switching the short wake-up state and the long sleep state, however, the protocol does not support broadcasting because terminals with the protocol are in the sleep state mostly. In the proposed protocol, terminals follow to adjusted periodical listening instructions that are unicasted, and the broadcasting frame transmitted at the periodical timing. Computer simulations are carried out to evaluate the required time for the layer 2 (L2) address resolution, as a typical case of the proposed broadcast protocol. The evaluation shows broadcasting is achieved by the proposed protocol and it is found that the average required time to finish the L2 address resolution is about 16s when a personal area network coordinator (PANC) performs broadcasting with repeat listen interval of 5.0s and the number of terminals is 100. Also, the evaluation results show that the proposed protocol has the flexibility that achieves broadcasting without setting parameters regardless of the number of terminals. By the proposed RIT based broadcast system, very low-power consumption internet protocol (IP) transmission in the Wi-SUN can be implemented within the permissible delay.

A Broadcast Protocol for IEEE 802.15.4e RIT Based Wi-SUN Systems

In this study, we developed a 5th generation mobile communication (5G) physical layer (PHY) experimental platform based on software-defined radio (SDR), which makes it easy to customize the transmission and reception process. The developed platform consists of an SDR-based transmitter and a receiver. Digital baseband processing is performed using internal software-based programs. Therefore, it can be used to evaluate the wireless communication performance of 5G (or user-defined modified/customized 5G) not only in a laboratory but also in any field. In addition, as an example of the use of this platform, we proposed signal processing that can receive signals at speeds of 500 km/h or higher and performed an experimental evaluation by running it on the developed platform. Through laboratory experiments in a multipath fading environment using a fading emulator, performance of the developed platform was validated. Moreover, it was confirmed that this platform can satisfy the required block error rate of 0.1 even in a multipath environment at a velocity of approximately 630 km/h, which exceeds the requirements of 5G. Therefore, it has sufficient resilience to be used in high-moving-speed environments. This platform is expected to enable simple testing and evaluation of various new PHY technologies.

https://doi.org/10.1109/ojvt.2023.3237390

Software-Defined Radio-Based 5G Physical Layer Experimental Platform for Highly Mobile Environments

The vector effective length of a half wavelength-dipole becomes almost zero when a reactance of about 500 ohm is loaded to its center. Since the current integral is almost zero when the vector effective length is zero, the electric influence on other antennas and to the radiation field is smaller than an open-circuited dipole. On the other hand, although other antennas affect the amplitude of the current distribution, the shape of the distribution does not change. Therefore, the vector effective length should be kept to zero. Accordingly, not only the influence on other antennas but also the influence by other antennas can be neglected. Dipoles are, therefore, thought to be almost electrically invisible. Lines composed with electrically invisible dipoles joined in series with a connector of open stubs are also thought to be electrically invisible. A surface containing such lines arranged in parallel is thought to be electrically transparent for radio waves at the same frequency at which the dipoles become electrically invisible. In this paper, we examine analytically the transparency of such surfaces.

Radio-wave transparent surface containing lines loaded with impedance at regular intervals

MIMO SDM (multiple-input multiple-output space division multiplexing) transmission is a promising technology to improve the frequency usage in mobile radio communications. SDM transmission uses mutually orthogonal channels to simultaneously transmit different substreams at the same frequency. An SDM system that uses the eigenbeams is focused on, and the site dependence of bit error rate (BER) for each substream is predicted by using ray tracing. Results show that the SDM beamforming does not significantly alleviate the BER degradation due to multipath, and that the SDM transmission is sensitive to an environmental change. We conclude that the robustness is a key to implement the SDM eigenbeam transmission.

http://ieeexplore.ieee.org/iel5/9709/30648/01414743.pdf

Site-dependent BER due to MIMO beamforming predicted by using ray tracing

This paper proposes a load balancing algorithm for a layer 2 routing (L2R) protocol of IEEE 802.15.4/4g/4e based wireless smart utility network (Wi-SUN) systems to achieve low-power consumption mesh networking. In the conventional link quality based routing method scheme discussed in IEEE 802.15.10 Draft 01, the fairness of cumulative number of sending packets has not effectively been achieved. Therefore, it may cause that many terminals send packets to a certain terminal. In the proposed method, the number of sendings is used to select the path of routing as well as link quality. The performance of the proposed routing method is evaluated by computer simulation. As the result, the proposed scheme can improve the maximum sending ratio that evaluates the cumulative number of sending packets by 59% with no degradation of the average sending times and end-to-end success rate (E2E-SR) compared with the conventional routing scheme that is one of the candidate schemes discussed in IEEE 802.15.10 Draft 01.

Hiroshi Harada

Papers

A Broadcast Protocol for IEEE 802.15.4e RIT Based Wi-SUN Systems

Software-Defined Radio-Based 5G Physical Layer Experimental Platform for Highly Mobile Environments

Radio-wave transparent surface containing lines loaded with impedance at regular intervals

Site-dependent BER due to MIMO beamforming predicted by using ray tracing

A Load Balancing Algorithm for Layer 2 Routing Based Wi-SUN Systems