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

Wireless technology that can conFigure wide-area IoT systems with high data rates is required toward 6G. To further expand area coverage, it is necessary to improve the data rate of the conventional machine type communications (MTC) such as LTE-M and mMTC at the edge of the coverage area. In this paper, we propose an orthogonal frequency division multiplexing (OFDM) with symbol-edges truncating transmission (STTOFDM) for data rate enhancement. In the proposed STT-OFDM scheme, only a part of the cyclic prefix (CP)-OFDM symbols, which is the legacy communication scheme adopted to 4G and 5G, is transmitted. On the receiver side, zeros are inserted where the no transmission took place at the transmitter side before normal OFDM demodulation is performed. The energy per one-symbol transmission is expected to be reduced by the proposed STTOFDM. We evaluate the achievable throughput and show the usefulness of the proposed STT-OFDM scheme. The proposed STT-OFDM can improve the throughput of the CP-OFDM by about 1.5 times even in low SNR environments.

Highly Efficient OFDM Applying Symbol-Edges Truncating Transmission Technique

In this paper, we propose a dependable source routing scheme for multi-hop networks based on the receiver-initiated media access control (MAC) protocol. In the proposed scheme, multiple candidates of relay terminals can be loaded in routing information, so the route is not specified uniquely. The following two effects are expected to the proposed scheme. The first is the improvement of communication reliability by avoiding disturbed link. Second is the improvement of the delay and current consumption by shortening the waiting time for communication timings. To show the effectiveness of the proposed scheme, we conduct computer simulations that suppose a multi-hop network based on the feathery receiver-initiated transmission (F-RIT) protocol in stable channel conditions. In the evaluation, the data are collected by polling communications, and the proposed scheme is applied to downlink communications. The results show the effectiveness of the proposed scheme that improves the delay by up to 41.3% and current consumption by up to 13.5% under a specific condition for the evaluation.

Dependable Source Routing Scheme for Multi-Hop Networks Based on Receiver-Initiated MAC Protocol

IEEE 802.22 is a standardized WRAN (Wireless Regional Area Network) system that operates in TVWS (TV White Spaces) and aims to achieve an effective spectrum utilization. Since IEEE 802.22 offers excellent propagation characteristics in the UHF (Ultra High Frequency) band, it is expected to support a cost-effective wireless communication system in rural areas. To provide a long-distance wireless communication, it is important for the receiver design to compensate a multipath fading attributed to large differences in path lengths, while existing multipath fading channel profiles applicable to IEEE 802.22 has generalization and statistical limitations. To generally and stochastically reproduce the multipath propagation characteristics in an actual wide area environment, an algorithm to obtain a statistical channel model extracted from the field experiment data is required. In this study, we develop a novel channel modeling algorithm based on the conventional S-V (Saleh-Valenzuela) modeling algorithm that offers an approach to model and reproduce the multipath characteristics in an actual environment. The proposed channel modeling algorithm applies a dynamic GEV (Generalized Extreme Value) distribution fitting for the amplitude fluctuation of individual arrival cluster. We also evaluate the channel reproduction performance of the proposed algorithm by computer simulation using channel modeling factors calculated from the experiment result with a FE (Fading Emulator). As a result, by applying the proposed algorithm, the multipath fading characteristics measured in the experiment can be modeled, and its reproducibility is confirmed with regard to relative path power distribution, rms delay spread distribution, and BER characteristics.

Channel Modeling Algorithm for TVWS-based IEEE 802.22 WRAN System in Rural Areas

Enhanced F-RIT Protocol for Wireless Smart Utility Networks with High Traffic Bi-Directional Communications

This study introduces a white space device (WSD) prototype developed for the white space technology trial organised by Infocomm Development Authority of Singapore (Singapore Trial). A draft regulation was issued by the Infocomm Development Authority for the Singapore Trial. To meet the strict requirements on some performance criteria defined in the draft regulation, some solutions on designs of the system and algorithm are developed and adopted to the WSD prototype. The prototype has a complete design of hardware and software to realise real-time and intelligent operations of periodical spectrum sensing and database access, dynamic frequency selection and non-continuous transmission featured with low adjacent channel power leakage and power control. During the Singapore Trial, tests were conducted to check the above cognitive radio (CR) technologies and CR-enabled operations. The official test results verify the effectiveness of implemented system and algorithm designs.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-com.2014.0179

Hiroshi Harada

Papers

Highly Efficient OFDM Applying Symbol-Edges Truncating Transmission Technique

Dependable Source Routing Scheme for Multi-Hop Networks Based on Receiver-Initiated MAC Protocol

Channel Modeling Algorithm for TVWS-based IEEE 802.22 WRAN System in Rural Areas

Enhanced F-RIT Protocol for Wireless Smart Utility Networks with High Traffic Bi-Directional Communications

White space cognitive radio prototype and its test results for white space trial