NEWS & UPDATE

March 24, 2023

It is my great pleasure and honor to be selected as the Co-Chair of IEEE Future Networks Massive MIMO Working Group. 

There will be so many new technological trends to be excited about. We will soon release a 2023 version of our roadmap document. 

The 2022 version can be checked from here: https://futurenetworks.ieee.org/roadmap

March 15, 2023

I have been appointed as an IEEE Standards Association (SA) officer to facilitate the IEEE P1942.1 standard. 

November 09, 2022

It is a great pleasure and honor to have a published paper 'A Lunar Backup for Humanity' contributed by Authors: Carson Ezell (Harvard University), Professor Alexandre Lazarian (UW-Madison/Universidad Bernardo O’Higgins), and Professor Abraham Loeb (Harvard University), to my GEed Special Issue at Signals MDPI: "Enabling A More Prosperous Space Era".

This is a very interesting and inspiring paper that should trigger wide attention across various communities, societies, and governments. 'Buying the lunar insurance' is a practical and promising solution. With becoming multi-planetary species as a long-term call (perhaps centuries or even longer) for humanity, near-Earth celestial bodies such as the Moon should be put to better use for the bigger-picture good such as 'Lunar Backup Record of Humanity' proposed by the authors. I suppose this will become a more urgent reality, since enabling a more prosperous space era is enabling a better survival chance for all mankind.  

Unfortunately, the unexpected disruptions to the supply chains and resources delay our pace of becoming a multi-planetary species.  The humanity, as a whole, needs to be reunified again, by a better, altruistic call, to realize self-evolution/upgrading and cope with bigger challenges and unveil more mysteries from the broad cosmos. 

October 04, 2022

Today is IEEE Day! 

I gave an Invited Talk at IEEE Future Networks 2nd Massive MIMO Workshop

Enabling A More Prosperous Space Era: A Massive MIMO Perspective

The PDF version of the presentation slides is available from: https://github.com/DrYimingHUO/Enabling-A-More-Prosperous-Space-Era-A-Massive-MIMO-Perspective/blob/main/Space_Era_Y.%20HUO_Oct_2022_M-MIMO_Workshop.pdf

October, 2022 

IEEE Future Networks 2nd Massive MIMO Workshop

3-5 October 2022 |  Free & Virtual 

https://futurenetworks.ieee.org/conferences/future-networks-massive-mimo-workshop-2022

The program and recording are available for downloading now from:

Watch Day 1 Presentations

Watch Day 2 Presentations

Watch Day 3 Presentations

Overview

The IEEE Future Networks Massive MIMO Workshop aims to bring together researchers, practitioners, as well as technology decision-makers to form a vision on the use of multi-antenna and related techniques in wireless communications over the upcoming decade and beyond. The focus of the Workshop will be on the latest developments in Massive MIMO challenges and opportunities—from fundamental research, experimental results, system architecture, and applications.

Event Program

Monday 3 October 2022 (NOTE: All times are Eastern Time US)

 08:00-08:30   

 Intelligent Omni-Surfaces enabled massive MIMO: Simultaneous Refraction   

 and Reflection for Full-dimensional Wireless Communications

 Boya Di (Peking University),

 Hongliang Zhang (Princeton University) 

 08:30-09:00 

 Optimized Precoding for MU-MIMO With Fronthaul Quantization 

 Yasaman Khorsandmanesh,

 Emil Björnson (KTH Royal Institute of Technology) 

 09:00-09:05 

 Break

 09:05-10:00 

 Keynote: Multi-Agent Autonomous Networking: From Low VHF to Massive MIMO    

 Brian Sadler (Army Research Lab) 

 10:00-10:30 

 Polar coded massive MIMO for Ultra-Reliable Low Latency Communications (URLLC)  

 Madhusudhanan Natarajan (MVJ College of Engineering) 

 10:30-11:00

 Satellite communication Applications and Recent technologies

 Sanjeev Kumar Gupta (Indian Space Research Organization)  

 11:00-11:05

 Break

 11:05-12:00

 Keynote: Evolution of MIMO Technology for 5G and Beyond

 Yang Li (Samsung Research America)

 12:00-12:30

 Fingerprinting based Localization in Massive MIMO Set-Up using Deep

 Spatio-Temporal Network in Confined Spaces

 Kandarpa Kumar Sarma (Gauhati University)

 12:30-13:00

 Importance of User-Centric Multi-Domain Service Orchestration

 Swaminathan Arunachalam (HCL)

Tuesday 4 October 2022 (NOTE: All times are Eastern Time US)

 09:00-09:30  

 Designing and Deploying Open RAN: Architecture and Outlook

 Eddy Chiu (ASTRI)

 09:30-10:00 

 Channel hardening in real environments

 Sara Willhammar, Fredrik Tufvesson (Lund University) 

 10:00-10:05 

 Break

 10:05-11:00 

 Keynote: Spectrum for NextG: licensed, unlicensed or shared?

 Monisha Ghosh (U of Notre Dame)

 11:00-11:30 

 AI for 5G-Advanced and application to massive MIMO

 Xingqin Lin (NVIDIA)

 11:30-12:00

 Enabling a More Prosperous Space Era: A Massive MIMO Perspective   

 Yiming Huo (University of Victoria)  

 12:00-12:05

 Break

 12:05-13:00

 Keynote: High-speed molecular communication: a solution for 6G?   

 Andrew Eckford (York University)

Wednesday 5 October 2022 (NOTE: All times are Eastern Time US)

 08:30-09:00 

 Energy-Efficient Cell-Free Massive MIMO on Top of C-RAN

 Özlem Tugfe Demir (TOBB University of Economics and Technology)

 09:00-09:05 

 Break

 09:05-10:00 

 Keynote: Next-generation Wireless Networks will be “Multi-function”    

 Ashutosh Sabharwal (Rice University)

 10:00-10:30 

 Challenges of Ultra-Massive MIMO at THz Frequencies

 Javier Lorca (InterDigital)

 10:30-11:00

 Efficient Deep-Learning Models for Future Blockage Prediction and

 Beam Selection for mmWave Systems

 Satya Kumar Vankayala (Samsung R&D Institute)  

 11:00-11:05

 Break

 11:05-12:00

 Keynote: Next generation mobile from a US perspective

 Ali Khayrallah (Ericsson)

 12:00-12:30

 Non-Coherent Multiuser Massive MIMO-OFDM for high-speed communications   

 Kun Chen-Hu, Ana García Armada (Universidad Carlos III de Madrid) 

 12:30-13:00

 Coarse Quantization for Massive MIMO

 Reza Mohammadkhani (University of Sussex)

 13:00-13:30

 AI-enabled massive MIMO for industry 5.0

 Shahid Mumtaz (Instituto de Telecomunicações)

Past Events

2021 IEEE Future Networks Massive MIMO Workshop

Keynote Speakers

Brian Sadler

(Army Research Lab) 

Monisha Ghosh

 (University of Notre Dame) 

Ashutosh Sabharwal

(Rice University)

Yang Li

(Samsung Research America) 

Andrew Eckford

(York University)

Ali Khayrallah

(Ericsson)

Why Present at the Massive MIMO Workshop?

• The Workshop provides a platform for academics and industry participants to timely discuss breakthrough research, future directions, and lessons learned about topics that are relevant to Massive MIMO.

• Being under the IEEE Future Networks initiative, the Workshop is promoted within and beyond the IEEE community and reaches a worldwide audience. Future Networks workshops, seminars, podcasts, and white papers enjoy a wide circulation and attendance.

• Streamlined proposal submission (max 2 pages) process to engage the 5G and beyond community as soon as researchers can provide solutions that impact system requirements and practitioners who can provide feedback on fundamental concepts.

• The format of the Massive MIMO Workshop emphasizes the need to create an environment for speedy discussions and dialogues to maximize interactions for both the presenters and the audience.

• You will help shape the direction and the focus of the future Massive MIMO Workshops in the coming years.

Topics of Interest

The Massive MIMO Workshop seeks speaker presentation proposals in the following topical areas. The topics below are not meant to be exhaustive. The Workshop welcomes proposals on related topics or other topics of interest to the Massive MIMO community.

• Cell-free Massive MIMO

• Single User Massive MIMO

• Reconfigurable Intelligent Surfaces (RIS) for Future Wireless Communications

• Signal processing, detection, and energy efficiency

• Massive MIMO joint radar-communications

• THz-band Ultra Massive MIMO (UM-MIMO)

• Massive MIMO visible light communication (VLC)

• Unmanned aerial vehicle (UAV)-based base stations

• Open radio access network (RAN) Massive MIMO

• Coordinated Massive MIMO and RAN orchestration

• Artificial intelligence and machine learning techniques for Massive MIMO

• 5G/6G Cellular Systems and Heterogeneous Networks

• 6G Ultra Massive MIMO Beamforming architectures

• Massive MIMO and physical layer security

• Massive MIMO measurement results and commercial deployment case studies

Organizing Committee

Chris Ng 

IEEE Future Networks Massive MIMO WG

Kumar Vijay Mishra  

United States Army Research Laboratory

Yiming Huo 

University of Victoria

Nasir Hussain

Samsung Electronics America

Harish Kumar Sahoo   

Veer Surendra Sai University of Technology

Yang Miao 

University of Twente

Ahmet Serdar Tan

InterDigital

Suma Pannala 

IEEE Future Networks Massive MIMO WG

Muhammad Imran Aslam    

NED University Karachi

Contact Persons

Please direct any questions or comments to the 2nd Massive MIMO Workshop contact persons below.

Chris Ng

IEEE Future Networks Massive MIMO WG  

 chris.ng@gmail.com

Kumar Vijay Mishra  

United States Army Research Laboratory

 kvm@ieee.org

August 06, 2022

A new special issue titled "Enabling a More Prosperous Space Era: A Signal Processing Perspective" has been on line:

https://www.mdpi.com/journal/signals/special_issues/TO24Y2D5D3

Dear Colleagues,

To quote Dr. Carl Sagan in the TV series Cosmos, “The cosmos is also within us, we’re made of star-stuff. We are a way for the cosmos, to know itself”. Curiosity and courage have been constantly motivating and inspiring humanity to explore the broad universe and unveil many of its mysteries. A historical milestone was marked on July 12, 2022, when the first full-color images and spectroscopic data of the James Webb Space Telescope (JWST) were released to unfold the infrared universe. This symbolized the dawn of a new era in astronomy. Due to technological advancements over the last decades in space exploration, deep-space communications, remote sensing, observatory instrumentation, artificial intelligence, etc., many phenomenal discoveries have been continuously made to refresh our understanding of the cosmos. Today, this rate of refresh is even faster than ever, thanks to a possible “technological singularity” that arrived at an accelerated pace due to numerous catalysts.   

At this very moment, of the fast reshaping of history in human civilization, we provide a platform for visionary researchers from various backgrounds to share and exchange insightful thoughts, ideas, and visions on addressing the future technical challenges in space exploration as well as on new scientific solutions and methods in astronomical research. We sincerely welcome various forms of submission, including original technical papers, technical reviews, and tutorials. With a focus on the advanced signal processing techniques, topics of particular interest include but are not limited to:

1) Signal processing, imaging processing, artificial intelligence (AI), machine learning, and deep learning techniques and methods in astronomy and cosmology.

2) Recent scientific progress in planetary sciences research, with a focus on remote sensing and radar signal processing.

3) Recent research progress from investigations and analyses of atmospheres, surfaces, interiors, and magnetic fields of terrestrial and giant planets, planetary satellites, and rings, with demonstration of signal and/or image processing techniques.

4) Recent research progress from solar and stellar studies assisted by advanced signal and/or image processing techniques. Subtopics might include recent investigation on stellar nucleosynthesis, solar heating and energy transport, solar wind, solar flare, etc.

5) Observation, mapping, simulations, and analysis of the Milky Way galaxy, extragalactic systems, exoplanets, supernovae, black holes, quasars, etc., with a focus on advanced signal and image processing techniques.  

6) Observation, mapping, sensing, and tracking of asteroids, comets, solar and interstellar objects, with signal and/or image processing techniques demonstrated.

7) Recent progress in the search for extraterrestrial intelligence (SETI), with a focus on signal processing, image processing, and AI techniques.

8) Current development and future trends of instrumentation for space exploration and communications, astronomical observation, and cosmological research—for example, planetary probes and rovers, next-generation space telescopes, and next-generation very large arrays.

Dr. Yiming Huo

Guest Editor

July 15, 2022

I have been notified by MDPI Signals that my published research work which is titled "Internet of Spacecraft for Multi-Planetary Defense and Prosperity"  (officially published at Signals,  https://www.mdpi.com/2624-6120/3/3/26 ) has been selected as Editor's Choice

The author feels truly grateful for the honor.

July 08, 2022

Recently, Forbes featured my research work which is titled "Internet of Spacecraft for Multi-Planetary Defense and Prosperity"  (officially published at Signals,  https://www.mdpi.com/2624-6120/3/3/26 ) 

Original coverage by Forbes July 07, 2022:

Do We Need An ‘Internet Of Spacecraft?’ Elon Musk And Jeff Bezos Could Protect Us From Massive Asteroid Strikes Says Scientist

https://www.forbes.com/sites/jamiecartereurope/2022/07/07/do-we-need-an-internet-of-spacecraft-elon-musk-and-jeff-bezos-could-protect-us-all-from-massive-asteroid-strikes-says-scientist/?sh=7f43eb94fb54

-------------------------------------------------------------------------------------------------------

P.S. 

Author is both honored and humbled to appreciate the broad recognition for this research work.  This will motivate the author to advance more promising technology to better serve All Mankind.

Acknowledgments: 

The author would like to express sincere gratitude to the great minds and pioneers who have dedicated their efforts and even life to astronomy and space exploration. 

They are my true super heroes I  have been looking up to since my childhood.

Jun. 28, 2022

After rigorous technical peer review, revision, and production over last couple of months, the paper titled "Space Broadband Access: The Race Has Just Begun", has been formally published by IEEE Computer magazine, for the Cover Feature "Predicting Technologies That Advance Humanity". organized by Professor Phil Laplante from the Pennsylvania State University, and Dr. Dejan Milojicic from Hewlett Packard Labs. 

The article is available from here:  https://ieeexplore.ieee.org/document/9810065

Citation: Y. Huo, "Space Broadband Access: The Race Has Just Begun," in Computer, vol. 55, no. 7, pp. 38-45, July 2022, doi: 10.1109/MC.2022.3160472.

Abstract:

Recent years have witnessed an exponential growth of the commercial space industry, including rocket launch, satellite network deployment, private space travel, and even extraterrestrial colonization. Several trends are predicted in this unprecedented transition to an era of space-enabled broadband access.

More reading about the third annual "Predictions" issue of Computer is available from here:  https://ieeexplore.ieee.org/document/9810050

Comments by Editors:  "The articles in this special issue are visionary, looking beyond current horizons and into the future of, for example, space travel, convergence of mega data centers and high-performance computing (HPC) supercomputers, and the future of ML training"

Last but not least, researchers from Google Brain (including Google Senior Fellow and SVP, Dr. Jeff Dean) and UC Berkeley also contribute one paper in the same special issue, titled "The Carbon Footprint of Machine Learning Training Will Plateau, Then Shrink"

https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9810097

Jun. 26, 2022

The following Emmy Award winning short-film has given me INFINITE movement and inspiration

"NASA at Saturn: Cassini's Grand Finale"

Sometimes, 

a Machine-Type, 

can be such really lovable, 

and deserves to be named 

as a HERO who moves us to shed tear. 

What a fabulous universe.

Jun. 22, 2022

After technical review and revision, the invited journal paper which is titled "Internet of Spacecraft for Multi-Planetary Defense and Prosperity"  is officially published at Signals,  https://www.mdpi.com/2624-6120/3/3/26

Please cite through: Huo, Y. Internet of Spacecraft for Multi-Planetary Defense and Prosperity. Signals 2022, 3, 428-467. https://doi.org/10.3390/signals3030026 

Abstract

Recent years have seen unprecedentedly fast-growing prosperity in the commercial space industry. Several privately funded aerospace manufacturers, such as Space Exploration Technologies Corporation (SpaceX) and Blue Origin have transformed what we used to know about this capital-intense industry and gradually reshaped the future of human civilization. As private spaceflight and multi-planetary immigration gradually become realities from science fiction (sci-fi) and theory, both opportunities and challenges will be presented. In this article, we first review the progress in space exploration and the underlying space technologies. Next, we revisit the K-Pg extinction event and the Chelyabinsk event and predict extra-terrestrialization, terraformation, and planetary defense, including the emerging near-Earth object (NEO) observation and NEO impact avoidance technologies and strategies. Furthermore, a framework for the Solar Communication and Defense Networks (SCADN) with advanced algorithms and high efficacy is proposed to enable an Internet of distributed deep-space sensing, communications, and defense to cope with disastrous incidents such as asteroid/comet impacts. Furthermore, perspectives on the legislation, management, and supervision of founding the proposed SCADN are also discussed in depth.

Keywords: space exploration; Internet of spacecraft; extra-terrestrialization; multi-planetary civilization; near-Earth object (NEO); Internet of distributed deep-space sensing; solar communication and defense network (SCADN); multi-planetary defense; space edge computing; space edge artificial intelligence (AI); legislation

May 18, 2022

A preprint of an invited paper submitted to a journal is now available:

https://drive.google.com/file/d/1byyX2vU0vgi5sgyyldmGuBTQtuuS9tSq/view?usp=sharing

Nov. 18, 2021

Journal Signals Special Issue "Internet of Things for Smart Planet: Present and Future" is officially online now!

https://www.mdpi.com/journal/signals/special_issues/Internet_Things_Smart_Planet_Present_Future

The submission deadline is 31 August 2022.  If you are interested in submitting a paper to this special issue, please feel free to let me know.  

Special Issue Information

The Internet of Things (IoT), since it was first conceptualized in the early 1980s, has continually drawn intense attention and shaped our world. Thanks to the rapid advancements in wireless communication and artificial intelligence (AI) technologies, particularly in recent years, IoT technologies and ecosystems have also witnessed enormously rapid evolution; consequently, the massive deployment has altered our present life in our cities and planet to a great extent. For example, IoT-based smart home automation, smart agriculture and smart oceans, satellites, and unmanned aerial vehicle (UAV)-assisted IoT networks have been gradually developed and deployed from theory to reality. 

However, our civilization continues to envision and expect further transformation of our current lifestyle and society. To fulfill these expectations, some future concerns may be worth discussing first. For example, how will IoT technologies be deployed more energy- and cost-efficiently to connect the unconnected? How can Industrial IoT (IIoT) be better served as the catalyst of Industry 4.0?  How will IoT technologies accelerate, reform, and reshape education, health care, home entertainment, and even the metaverse. With a more daring but still realistic vision based on the unprecedented advancement of space technology and incremental investment in the space industry, IoT technologies can be applied to more application scenarios beyond our current planet of residence, since it is expected that scientists will “make humans a multiplanetary species” (quoting Mr. Elon Musk) .

In this Special Issue, we provide a platform to authors from various research backgrounds and areas to share and exchange extraordinary thoughts and address future challenges in enabling more high-performance scenarios of application of IoT technologies. Topics of interest include (but are not limited to):

• Critical underlying information and communication technologies to enable future IoT systems and networks;

• Internet of Things for smart home, smart factory, smart agriculture, smart cities, and smart planet;

• Fusion of Artificial Intelligence with the Internet of Things;

• Emerging system-on-chip (SoC) and hardware designs for IoT systems: trends and challenges;

• Integrated Space-Air–sea-Ground networks for IoT networks;

• Enabling technologies for Internet of Satellites/Spacecraft;

• Cloud/fog/edge-based computing enabled IoT data solutions;

• Blockchain-enabled Internet of Things;

• Cybersecurity technologies for secure IoT devices and networks;

• Design and deployment of practical IoT systems and networks for vertical application scenarios;

• Internet of Medical Things, IoT for smart health and emotion care;

• Enabling Metaverse, persistent online 3-D virtual environments, through IoT technologies;

• FinTech cybersecurity empowered by the secure IoT technologies;

• Energy harvesting and wireless power transfer technologies for massive IoT networks.

Nov. 11, 2021 

Dr. Yiming Huo has been invited and agreed to serve as Guest Editor of Signals. Dr. Minh Tu Hoang has been recommended to serve as co-Guest Editor. We are excited to launch a Special Issue on IoT technologies with MDPI!

IEEE FUTURE NETWORKS 1st Massive MIMO Workshop has been successfully held virtually, 8-10 November, 2021. All streaming videos and presentations are available to view now at IEEE Future Networks 1st Massive MIMO Workshop  As organizing committee, Dr. Huo has served as TPC Co-Chair, Publicity Co-Chair and Session Chair.  

More than 800 people registered through IEEE directly, and more than 3,000 people registered through Linkedin event. Three morning keynote speeches have been live streamed simultaneously on Linkedin. Sincere thanks to IEEE, organizing committee, speakers and attendees.

Special thanks to IEEE, and General Co-Chairs,  Dr. Webert Montlouis, Dr. Kumar Vijay Mishra, Dr. Chris Ng and other colleagues in the team to make it happen successfully! 

Nov. 09, 2021

Dr. Yiming Huo chaired one Session at IEEE FUTURE NETWORKS 1st Massive MIMO Workshop, Tuesday, Nov. 9, 2021. 

IEEE Future Networks 1st Massive MIMO Workshop 

10:00-10:30, ET, Tue. Nov. 9, 2021, Prof. Qingqing Wu, from State Key Laboratories, University of Macau, has presented his topic, "Intelligent Reflecting Surface Aided Wireless Energy and Information Transmission for 6G".

10:30-11:00, ET, Tue. Nov. 9, 2021, Prof. Shuai Nie and Prof. Mehmet Can Vuran, from University of Nebraska-Lincoln, have presented their topic, "Link Performance Analysis of Reconfigurable Intelligent Surfaces-Assisted Millimeter Wave Communications for Rural Connectivity" 

Oct. 13, 2021

Dr. Yiming Huo served as the Panelist  at Future Networks Towards 2031: INGR Panel Series, IEEE 5G World Forum, Oct. 13, 2021. 

IEEE 5G World Forum, 2021 

IP-1: INGR Panel: Millimeter Wave and Massive MIMO – Deployment Challenges and New Trends

Panel Time: 11:00am ET US

Description: Recently, we’ve seen the initial deployment results of 5G millimeter wave (mmWave) and Massive MIMO systems and the beginning of research activities to address the requirements of 6G and beyond. In this panel, we invite a group of researchers and practitioners to review the lessons learned from the early mmWave & Massive MIMO deployment results and explore future trends: What are the challenges and opportunities for mmWave & Massive MIMO researchers? Which fundamental research direction(s) may drive the next generation mmWave & Massive MIMO innovations?

Speakers:

Chris Ng, Director of Systems Engineering Products, Blue Danube Systems

Dr. Alberto Valdes Garcia, Principal Research Staff Member and Manager, IBM Research

Dr. Paolo Gargini, Fellow, IEEE/Intel

Dr. Naveen Yanduru, Vice President and General Manager, Renesas Electronics

Dr. Kumar Vijay Mishra, Senior Fellow, United States Army Research Laboratory

Dr. Yiming Huo, Research Associate, University of Victoria

Dr. Kasturi Vasudevan, Professor at Dept of EE, IIT Kanpur

July 20, 2021

An article published at World Economic Forum (WEF) has cited our research published at the top-tier journal: IEEE Internet of Things Journal, in 2020. The WEF article titled "Scientists aim to build a detailed seafloor map by 2030 to reveal the secrets of the deep", can be accessed here:

https://www.weforum.org/agenda/2021/07/scientists-seafloor-map-2030-data/

Our paper titled "Cellular Communications in Ocean Waves for Maritime Internet of Things", is an R&D result between us and our industrial collaborator: MarineLabs Data Systems, Inc. The formal paper is available from here: https://ieeexplore.ieee.org/document/9072093 

The open access is available from here: https://arxiv.org/pdf/2004.07417 

Abstract:

The rapid advancement of Internet of Things (IoT) and fifth generation and beyond technologies is transforming the marine industry and research. Our understanding of the vast sea that covers 71% of the Earth's surface is being enhanced by the various ocean sensor networks equipped with effective communication technologies. In this article, we begin with a review of the research and development status-quo of Maritime IoT (MIoT) enabled by multiple wireless communication technologies. Then, we study the impact of sea waves on radio propagation and the communications link quality. Due to the severe attenuation of sea water to radio-frequency electromagnetic wave propagation, large ocean waves can easily block the communication link between a buoy sensor and a cell tower near shore. This article for the first time uses the ocean wave modeling of coastal and oceanic waters to examine the condition of line-of-sight communications. Real wave measurement data parameters are applied in the numerical evaluation of the developed model. Finally, the critical antenna design taking into account the wave impact is numerically studied with implementation solutions proposed, and the system hardware and protocol aspects are discussed.