NTT Technical Review

August 2021 Vol. 19 No. 8
View from the TopShinya Tachimoto, Senior Vice President, Head of NTT Information Network Laboratory
Group

Front-line Researchers

Kunio Kashino, Senior Distinguished Researcher, NTT Communication Science Laboratories
and Bio-Medical Informatics Research Center, NTT Basic Research Laboratories

Feature Articles: Initiatives for Smart Agri—Making Japanese Agriculture a Growing
IndustryNTT’s Vision for the Future of Agriculture—Initiatives for the Entire Food Value Chain Using
IOWN-related Technologies



Future-oriented Agriculture—Strawberry Plant Factory Based on Regional Collaboration



Local Food Waste Recycling Solutions for Addressing the Sustainable Development Goals

“Fisheries +d”: NTT DOCOMO’s Solution Co-creation for the Fisheries Industry

High-quality, High-yield Organic Farming with BLOFware®.Doctor

Regular Articles
Multi-radio Proactive Control Technology (Cradio®): A Natural Communication Environment
where Users Do Not Need to Be Aware of the Wireless Network

Local Light Injection and Detection Technology for Optical-fiber Identification

Global Standardization Activities
Standardization Trends in the Disaggregation Technology of Access Systems at the Broadband
Forum

Practical Field Information about Telecommunication Technologies


Grounding-system Evaluator for Preventing Lightening Damage to Telecommunications Center
Buildings

External Awards/Papers Published in Technical Journals and Conference Proceedings

View from the Top

Develop Your Technical and Social
Perspectives While Nurturing Your
Inspiration
Shinya Tachimoto
Senior Vice President, Head of NTT
Information Network Laboratory Group
Overview

The NTT Information Network Laboratory Group aims to create a compassionate and flexible information-network infrastructure that connects
everything. Researchers at the laboratory group are working diligently withpride, joy, and responsibility in creating technologies that will be implemented in society. We asked Shinya Tachimoto, senior vice president, headof the NTT Information Network Laboratory Group, about the capability
required of top management of laboratories and the skills researchers
should have in regard to research and development.
Keywords: NTT Information Network Laboratory Group, R&D, discussion

Continuity of research and development—Could you tell us about the NTT Information
Network Laboratory Group?
The NTT Information Network Laboratory Groupis promoting research and development (R&D) of
technologies to construct simple, smart, and sustainable networks that will contribute to the developmentof an information-network infrastructure that connects everything.
To make the Innovative Optical and Wireless
Network (IOWN)—a future communication infrastructure proposed by NTT—a reality, while maximizing the potential of transport networks by promoting all-photonics technology, we are focusing on two
initiatives: (i) R&D of flexible networks throughCognitive Foundation that enables prompt service
provision and optimization of value chains and (ii)
R&D of innovative environmental energy technology
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Vol. 19 No. 8 Aug. 2021

that contributes to achieving zero environmental
impact.
The NTT Information Network Laboratory Groupis engaged in such R&D at three laboratories: (i) the
Network Service Systems Laboratories, which conducts R&D of a future information-network infrastructure and the network services provided on it; (ii)the Access Network Service Systems Laboratories,
which conducts R&D on access networks that coverservice areas by linking optical and wireless networks and the access services provided on them; and(iii) the Space Environment and Energy Laboratories,
which conducts R&D on next-generation energy
technology and sustainable system technology toachieve zero environmental impact, as well as environmental adaptation technology to adapt to global
climate change and build a resilient society. With
approximately 500 enrolled researchers, these threelaboratories are positioned at the core of R&D on
information and communication technology in Japan.
1View from the Top

Together they aim to contribute to society through awide array of research results, ranging from researchon elemental technologies (including energy technology) to architectures of entire information networks
and network operations.
The Musashino base in Tokyo, where the NTT
Information Network Laboratory Group is located,
has been a hub of R&D on telecommunication networks in Japan, starting from the ElectricalCommunication Laboratory of the Ministry ofCommunications to Nippon Telegraph and Telephone
Public Corporation and NTT. Initially, the R&D wascentered on telephony, and a telephone network was
constructed on the basis of the results of that R&D,
and many of the devices and systems configuring the
network were based on specifications devised at thelaboratory. As the era of telecommunication networks
changes from telephony to the Internet, general-purpose products and open platforms have been used forthe devices and systems that make up the network.
Adapting to this trend, we have expanded our R&D tocover various network functions, services, and operations that use those products and platforms. As wehead toward the IOWN era, the core technology ofcommunication and information processing will shift
from electronics to photonics. We want to take thisopportunity to implement our research results into
networks and systems and expand them globally.
From the birth of R&D on telecommunication to thepresent and into the future, we have taken the challenge of developing new technologies while inheriting the results and expertise of the past and flexibly
adapting our style of R&D and social contributions to
the times.
—Could you tell us the important point for R&D
activities adapting to the changing times?
I believe there are three approaches to R&D. The
first is pursuing the advancement of technology fromthe perspective of a researcher. In other words, R&D
is promoted on the basis of technological evaluation
to steadily improve a technology, for example, toachieve 10% increase in performance or a decrease incost. The second is R&D from the perspective ofsociety. In other words, R&D is carried out by setting
up one’s own R&D theme according to his/her desire
to change the society for the future, make society better, or solve issues facing society. The third is R&D
driven by inspiration. In other words, R&D islaunched by the inspiration through which one day
one suddenly thinks of something that will be of great
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use to society or one somehow combines two mechanisms from completely different fields and come up
with a completely new mechanism.
I think that the technological and social perspectives can be cultivated to some extent through learning. For example, R&D from the technological perspective is the style of R&D that many researchers
had been doing since university days; for instance,
one could create the next “new” technology by reading papers or repeatedly examining ways to improve
the shortcomings and issues that were clearly identified from the results of one’s experiments. R&D fromthe social perspective involves considering how to
use one’s technology on the basis of daily life andinformation about the world. Even if a problem is in
a completely different field, it may lead to an idea thatyour technology can be used to solve that problem.
However, I think that the third one, inspiration, isoften triggered by chance and is not something thatcan be acquired through learning. As well as increasing your knowledge base in preparation for inspiration, you should constantly ask yourself the question,2

View from the Top“What if...?”
In many cases, it has been difficult to introduce
research results in a timely manner because conventional information networks and the systems thatcompose them must be operated for a long time once
they have been constructed for a specific service.
However, as the world is ever changing and at a faster
rate, it is important to have a vision of how to use thetechnology from the initial stage of research and tolink that vision to development. This vision is exactly
what IOWN is all about, and it is important to coordinate various research projects to develop a network toachieve this vision, which includes the All-Photonics
Network. Networks will become virtualization-basedin the future. By taking advantage of the flexibility
that comes with virtualization, I believe that it will bepossible to implement research results partially or
temporarily and refine them in a timely manner while
operating the system—something that has been difficult to do.

Discuss fully and make judgments and decisions
that stakeholders are satisfied with
—Please tell us about the management of researchers
based on your experience as an engineer.
I have been engaged in development activities forquite a long time. I majored in mechanical engineering and conducted R&D on robots at university. After
joining NTT, I was initially engaged in the development of telephone-switching systems then the development of the asynchronous transfer mode in the
1990s and next-generation networks (NGNs) in the
2000s. In those days, I felt great joy and satisfaction
when the results of my R&D were released to theworld and used by people. As the senior vice president, head of the laboratory group, I am grateful to beable to think about—together with many otherresearchers—how to use our technology and consider
future directions from a broader perspective than
before while maintaining the same awareness andattitude toward contributing to society.
It is a real pleasure to be able to discuss matters ofconcern with researchers. In particular, it is very
rewarding to be able to drive the process that guides
our R&D in the right direction. Of course, there areresponsibilities associated with my position, so I
might ask myself if what I said is really correct or I
might change my direction, if necessary, throughinformation, people’s reactions, and discussions. I
think my job encompasses the whole process of setting those directions.
I think there are three points that must be considered when making such decisions and judgments.
The first is the correctness of information. The second is whether the discussion was sufficient and avariety of viewpoints was taken into account insteadof a particular opinion. The third is whether there ispotential that the idea will be materialized andachieve results. At times, I am asked to make a blackor white decision immediately; however, I always
make a judgment or decision on the basis of thesepoints. The environment surrounding R&D is constantly changing, so I try to discuss the best solution
for each situation and make a decision that satisfies
the stakeholders.
—Even though you are busy, you frequently hold discussions.
Discussions are carried out not only in large meetings but also in individual meetings on each research

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View from the Top

topic. By understanding the details of a topic, I sometimes encourage researchers to adopt a different perspective. We also have inspirational discussions that I
talked about earlier. Talking about the possibility ofsomething might completely and unexpectedly leadto new development; conversely, it might cause confusion. Looking back on my research life, I believethat it is important for researchers to discuss eachother’s opinions and ideas, even if they are just random thoughts, and to think from different perspectives in response to those opinions.
To prevent the spread of COVID-19, remote work
has become a mainstay, so it has become difficult tohave opportunities for face-to-face discussions, andmost discussions are held online. Inspirational conversations are transmitted differently when they areheard through a computer than when they are said
face to face. Moreover, the way in which the message
is conveyed and resonates differs considerably incomparison with that when we look each other in theeye or draw a picture on a whiteboard and post questions such as, “Well, what about this?” From a different viewpoint, this difference is an issue for consideration. The promotion of smooth communication in aremote society, such as the difference between online
and face-to-face communications in how the message
is communicated as a real feeling and how to eliminate frustrations, is a major theme for the future.

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Talk about the world that our technology will
make possible—You make convincing judgments and decisions
through discussions; that is, you value not only
research results but also the process leading up to thedecisions.
The hardest part of the discussion, judgment, anddecision-making process is telling a researcher disappointing conclusions I have made. For example,
researchers may have to interrupt their research orchange their theme owing to changes in the environment. Doing so is difficult regardless of how big or
small the subject is because the researcher has beenworking on it diligently. However, offshoots always
grow from the hard work that has been put into a particular research theme. The technologies and materials that researchers have worked on and studied will
be useful in certain ways in new fields, so I encourage
researchers to connect them to those fields.
I certainly don’t want to force researchers, whohave strong individuality and various motivations, togo in a specific direction. Rather, I think it’s important to let researchers look in different directions andbe on the cutting edge of each direction. I think that’s
what’s necessary in the future, so we’ll lay the rails
for the future in a certain way, but it is not forbidden
to go off the rails because going off the rails can getyou in the right position in the future. Therefore, I
want to develop each offshoot, and I want all our
researchers to do what they need to do now and growthe offshoots for the future.
4

View from the Top—Please give a message to researchers and engineers inside and outside the company.
I hope that you will broaden the scope of yourresearch by adding offshoots one after another, incorporating various styles and information according to
the changes in society and the environment of thetime while keeping your own style. I believe that thisapproach will broaden the scope of your life in the
future.
I have learned a lot from the various comments on
the news that flood the Internet. In the past, we did
not have much exposure to anything other than the
exemplary solutions organized through the mass
media, but now, for better or worse, many people canspeak freely on the Internet, and we are less likely tosettle for such exemplary common solutions. In an
uncertain world, I think it is important to understandwhere you stand in regard to the vast and multifaceted
comments directed arbitrarily at will. It is very difficult to scrutinize and discern facts in the midst ofdivergent and untruthful information; even so, you
can learn many things. For example, you may discover certain issues that we must solve as carriers andproviders of information and telecommunications.
One of the major conditions for being recognized asa global researcher is that your achievements aretechnically superior. In addition to following thebasic style of researchers, namely, communicating
the excellence of your research and technology at
academic conferences and in papers, you should

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always be aware of your contribution to society.
While being recognized by experts for your technology, talk to the general public about the world inwhich that technology is implemented with words
such as, “My technology can create such a world in
the future.”Interviewee profile
Career highlights
Shinya Tachimoto joined NTT in 1990 andworked on the development of switching systems
at NTT Exchange Systems Research Laboratories.
He had a key role in NGN system development
and network integration testing and was also
responsible for developing mobile network service applications at NTT DOCOMO. He becamea manager of the Second Division (currently
Technology Planning Department) at NTT holding company in 2000, senior researcher at NTT
Network Service Systems Laboratories in 2003,
senior manager at the Core Network Development
Department of NTT DOCOMO in 2009, project
manager at NTT Network Service Systems
Laboratories in 2014, and the vice president, headof NTT Network Service Systems Laboratories in2018. He has been in his current position since
July 2020.

5

Front-line Researchers

Contemplate the Essence of a
Problem from Multiple Perspectives
Kunio Kashino
Senior Distinguished Researcher, NTT
Communication Science Laboratories
and Bio-Medical Informatics
Research Center, NTT Basic ResearchLaboratories
Overview
Auscultation (auditory diagnosis) has been used for centuries in
the fields of health screening and medical care. It has the advantage of being repeatable and non-invasive while providing immediate results; however, because it is conducted in close proximity
to the patient, it is challenging to perform on patients suspected of carrying infectious diseases. We
interviewed Kunio Kashino, a senior distinguished researcher, who is working on teleauscultation withan eye toward addressing the above challenge and the future of health management, about the progressof his research activities and his attitude as a researcher.
Keywords: auscultation, telestethoscope, AI auscultation

Development of a telestethoscope that can collectand analyze biological sounds remotely—Could you tell us about your current research?
When I was interviewed about six years ago, wetalked about my research on scene analysis and media
exploration based on media information, which I
described as “creating a media dictionary.” Since
then, I have also started research on teleauscultation
and artificial intelligence (AI) auscultation in July
2019 while concurrently working at the Bio-Medical
Informatics Research Center.
We often see stethoscopes around doctors’ necks
when we are examined at medical institutions.
According to medical professionals, sounds comingfrom inside the body (biological sounds) via stethoNTT Technical Review

Vol. 19 No. 8 Aug. 2021

scopes contain a wealth of information. Last year, wedeveloped a system called the “telestethoscope,”
which enables the collection and analysis of suchsounds from a remote location (Figs. 1 and 2). The
system consists of a wearable device worn by thepatient and a receiving terminal (e.g. the tablet in theright photo in Fig. 1) operated remotely.
During auscultation, it is necessary to hear sounds
at various places on the body. Accordingly, 18 acoustic sensors are installed in the wearable device of thecurrent prototype telestethoscope. The 18-channel
acoustic signals captured by these sensors are simultaneously collected with a 1-channel electrocardiographic waveform. On the screen of the receiving
tablet, an outline of the torso is shown, and the part of
the torso to be listened to can be specified by touching
it on the screen or clicking on it with a mouse. The
6

Front-line Researchers

Fig. 1. Telestethoscope.

Electrocardiographic waveform

Acoustic-sensor signal (18 channels)

Specify the place to listenEnter findings, etc.

Fig. 2. Screenshot of receiving tablet of telestethoscope.

sound emitted at that part (an estimated sound synthesized from signals from the multiple sensors) canthen be heard. The acoustic signal waveforms captured by each sensor are also displayed on the screen,
and it is possible to listen directly to those acquired
raw waveforms. Taking computer analysis into consideration, the system is designed to obtain more
information spatially and in frequency domains compared with ordinary stethoscopes, namely, not only
the main frequency bands used in conventional auscultation but also other bands. All received signals arerecorded so that they can be listened to at any time.
If this telestethoscope is put into practical use for
medical purposes, it will enable medical professionals to conduct auscultation from a separate room
without directly coming into contact with the patientor during online medical treatment (teleauscultation).
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Once we establish a technology for automaticallyanalyzing the collected sounds, the telestethoscope
will not only enable a medical professional to listen
to the sounds from a sick person remotely but alsoenable a healthy person to use it on a daily basis for
self-healthcare by using AI to analyze the sounds.
In fact, we are currently researching AI auscultation
which analyzes internal bodily conditions on thebasis of biological sounds (Fig. 3). An example ofsuch research is translating the meaning of the captured biological sounds into words. We have developed a unique technology that directly translates
bio-sound signals into a series of words. Unless you
are an expert, you will not be able to clearly understandthe meaning of your own biological sounds when you
listen to them; however, by going through a “translator,” so to speak, you will benefit from being able to7

Front-line Researchers

Wearable device(acoustic sensor arrays)

Teleauscultation
SoundsCapturing sounds fromvarious locations

Diastole
S1

SystoleS2

Diastole

Example 1
Conversion to
moving images

Visualization
Example 2
Conversion to sentences

Observation by
medical personnel

150
LV pressure (mmHg)

Step 1
Estimation of cardiac cycle and states fromthe sounds

Network

Aortic valve
closing
100

Aortic valve
opening

ESPVR
50

Step 2
3D cardiac-shape estimation from the estimatedstates using physical constraints

Mitralvalve
closing

Mitralvalve
opening00Detail levels

Examples of generated texts

SimpleThe heart sounds are abnormal.

Detailed

The heart sounds are abnormal. Theremay be a problem with one of theheart valves. The first sound is normal,
and the second sound is split. Thereis a systolic murmur.

EDPVR
50
100
LV volume (ml)Example of physicalconstraints

150

Estimated change of left ventricular shapes
EDPVR: end-diastolic pressure-volume relationship
ESPVR: end-systolic pressure-volume relationship
LV: left ventricularFig. 3. AI auscultation.

understand the state of your own body. In particular,
by taking advantage of using sentences rather thanjust indicating words such as the name of a disease,this technology is designed to convert biologicalsounds to sentences with the desired level of detail on
the spot, for example, the presence and degree ofabnormalities and changes over time since the lastcheckup.
—Your research on telestethoscope and AI auscultation is generating high expectations. What difficulties
are there in making them practical?
We have faced a few difficulties; for example,
diagnostic-imaging technology is making remarkableprogress year after year, and automated diagnosis
using AI is being actively researched. In contrast,
auscultation data are rarely collected and usually discarded without being recorded. Therefore, we had nochoice but to start our research by collecting data andbuilding the equipment to do so ourselves.
It has also been a very interesting challenge toreproduce the skills of medical professionals on acomputer. There are aspects in common with auditory-scene analysis, which I have been working on forthe past 30 years. When a person hears a sound, vibration generated somewhere by a physical cause istransmitted through a medium and shakes the eardrum. Auscultation is the problem of estimating thecauses of the (mixtures of) vibrations transmitted. To
solve this problem, it is necessary to use as much
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information as possible in addition to the vibration
waveform. Just as medical professionals make judgements on the basis of their anatomical knowledge andmedical experience, computers will need to fully use
physical models of the body’s organs and statisticalmodels learned from a huge amount of case data.
Although how to achieve this is a point of difficulty,
it is also a point to which we can apply our ingenuity.
When we focus on sounds generated inside thebody, however, we come across something new that
we do not in typical computational auditory-scene
analysis research. For example, research on acoustic
signal processing has mainly focused on the scenario
in which the medium for transmitting sound is a uniform substance such as air or water. However, in thebody, sound is transmitted through multiple media
with significantly different physical properties, suchas bone, muscle, air in the lungs, fat, and liquid, aremixed in a small space. I think this mixed media
makes teleauscultation or AI auscultation an evenmore challenging problem than conventional auditory-scene analysis.
The key to advancing research is to have aninterest inherent in the research and maintainthat interest—What are some of the things that you keep in mind
when you set research themes and problems?
It seems to me that the more complex the problem,
8

Front-line Researchers

the more important it is to think straightforwardly andsimply. I also think that to find a problem, set a
research theme, and solve the problem, it is important
to contemplate what the real problem is. What is theessence of the problem? I also think that a researcher
should take a balanced attitude among three perspectives, namely, a first-person perspective focused on
yourself such as what you want to do and how you
can increase your productivity as a researcher, a second-person perspective focused on other people thatyour research results directly target, and a third-person perspective other than these two perspectives. In
particular, if you do not pay careful attention to thethird-person perspective, you will tend to be draggedback by the first- or second-person perspective.
In a sense, what I said could be similar to a marketing strategy. Modern marketing emphasizes theimportance of efforts to find latent needs that have notyet emerged from multiple perspectives, breaking
away from conventional approaches such as productcentric perspective, namely, “We want to sell thisproduct,” as well as an existing-market perspective,
namely, “This type of product is selling well.” Thisway of thinking can also be applied to basic research.
It is also about asking what kind of research can bringwhat kind of value to whom at what time from an
objective perspective. Having said that, it is difficult
to predict research value. Sometimes value in one’s
research may be discovered in a field where you do
not expect. Therefore, I try to have both conviction
and an eye for the unpredictable.
—So, what does it take to have strengths as a
researcher?
From my viewpoint, it seems that all the researchers around me have unique strengths; however, they
do not necessarily recognize their strengths as such.
They just say they like what they are doing. Things
that are not too tough for a person to do are often seenas that person’s unique strength in the eyes of others.
With that in mind, I think the key to advancing
research is to have an interest inherent in the researchitself. It may be important for researchers to be able
to have the interest inherent in the problem and theway of solving it and maintain that interest.
As exemplified by teleauscultation and AI auscultation, it seems that auscultation is going against thetimes as diagnostic-imaging equipment is being
developed and used in the medical field and its importance is increasing. However, I believe that by infusing new technology into auscultation, its usefulness
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will be reevaluated in the context of an aging society,new medical treatments, and self-healthcare. What’smore, the extraordinary skill of estimating what ishappening inside the body, which is invisible to theeye, from a one-dimensional waveform, has actually
been used in the medical field for 200 years, so justthinking about it seems quite interesting to me.
The importance of teamwork—Please give some words of advice to our juniorresearchers.
Through my recent research activities, I realizedthat I have a lot to learn from people with diverse
experiences, not only members of my own researchteam but also non-researchers. Communicating withthese people is invaluable. The Bio-Medical Informatics Research Center assembles people with various backgrounds from multiple NTT laboratories.
Our team at the Center has been actively collaborating with external research institutes and medical
institutions, so we are having more opportunities tomeet with doctors and other medical professionals.
These meetings are beneficial, and remind me of theimportance of teamwork.
For teamwork to function properly, it is necessary
to build relationships between members and enhance
the strength of each member. It is important to create
an atmosphere in which junior and senior people canrespect each other’s strengths and contributions,regardless of age or position. I want to ask all our
employees, especially those in a higher position in theworkplace in relation to younger employees, toalways keep that in mind.
I think it is beneficial for researchers to not only
develop their existing specialties but also diversify
their specialties. For example, a person who studied
sound processing at university then joined the company may also take up language processing, and if an
opportunity to work on tasks other than researchcomes up, it would definitely be worth the experience. In my case, prior to joining the company, in
addition to pursuing my doctoral research on acoustic-information processing, I was involved in agile
development of commercial systems in an emerging
industry at the time. After joining the company, I had
the opportunity to learn about image processing andBayesian inference theory. I also had many opportunities to work with people from NTT operating companies. Looking back on those experiences, I realizethat they have all been useful in regard to my current
9Front-line Researchers

work. I hope that you all will take advantage of every
opportunity.

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Interviewee profile
Kunio Kashino
Senior Distinguished Researcher at NTT
Communication Science Laboratories and BioMedical Informatics Research Center, NTT Basic
Research Laboratories, and Visiting Professor at
National Institute of Informatics (NII).
He received a Ph.D. from the University ofTokyo in 1995. His research interest includes
audio and video analysis, synthesis, search, andrecognition algorithms and their implementation.
He is a fellow of the Institute of Electronics,
Information and Communication Engineers(IEICE), and a member of the Institute ofElectrical and Electronics Engineers (IEEE), theAssociation for Computing Machinery,
Information Processing Society of Japan, theJapanese Society for Artificial Intelligence, and
the Acoustic Society of Japan.

10Feature Articles: Initiatives for Smart Agri—Making
Japanese Agriculture a Growing Industry

NTT’s Vision for the Future ofAgriculture—Initiatives for the
Entire Food Value Chain Using
IOWN-related Technologies
Yoshikazu Kusumi, Takuya Murayama,
and Kanji Yoshitake
Abstract

Since 2014, NTT has positioned agriculture as one of its priorities. By using the latest information andcommunication technology and collaborating with industry-leading partners, NTT has carried out
group-wide initiatives to promote Smart Agri to solve problems in the entire food value chain, i.e., fromproduction to distribution, sales, and consumption, in primary industries, such as agriculture, forestry,
and fisheries. This article overviews the NTT Group’s initiatives and describes the latest examples of
initiatives that will lead to the digital agricultural revolution.
Keywords: IOWN, Remote World, food value chain

1. Overview of NTT Group’s initiatives
Primary industries, such as agriculture, forestry,
and fisheries, are indispensable for the survival of
humankind. However, they face a variety of challenges, including resolving labor shortage, aging
population, unstable income due to unseasonable
weather, as well as ensuring food security to deliversafe and secure food and nutrition to the public in theface of the recent coronavirus pandemic. As a means
to overcome these challenges, technologies such as
AgriTech*1 and FoodTech*2 are attracting attention.
Since 2014, the Research and Development Planning Department of NTT has been leading the NTT
Group’s initiatives for primary industries. In collaboration with NTT laboratories, which develop advanced
technologies, and about 30 NTT Group companies
with outstanding services, we are promoting a wide
range of initiatives with an eye on the entire foodvalue chain, i.e., from production to distribution,
sales, and consumption [1]. These initiatives include
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Vol. 19 No. 8 Aug. 2021

strategy formulation, research and development(R&D), development of services for commercialization, and dissemination of information on the resultsof such efforts. By combining NTT’s Innovative
Optical and Wireless Network (IOWN)*3 with groupcompanies’ nationwide telecommunication infrastructures, assets, and network services, we will
enable innovations in food and agriculture and create
new value (Fig. 1).
Specifically, we aim to build an ecosystem thatmakes it possible to optimize the entire food value*1 AgriTech: Technology used in agriculture, horticulture, and aquaculture for improving yields, efficiency, and profitability.
*2 FoodTech: Technology that combines food and information technology (IT). Its wide range of applications includes reduction offood waste and loss by reviewing the supply chain—from production to processing, distribution, and consumption—of food byusing IT, smart agriculture using Internet of Things and artificial
intelligence, and smart kitchens, where the Internet and kitchen
appliances are linked.
*3 IOWN: A next-generation communication infrastructure that
NTT is promoting for practical use around 2030.

11

Feature Articles

Eliminate distortion andimbalance of logistics tobecome a profitable industry
Reduction in wastefultransportation and food loss
From rural to urban
Transactions before shipping
Prediction of future
Prediction of future demand
production and quality

Agri digital twin

Virtualworld
Feedback

NTT Food Value
Chain Platform

Analysis results Production(transaction information
information
Qualityand production information
instructions)

Update of data
Various networks
Solutions to increase
production and easelabor shortage

Increased production anddramatic improvement in quality Real world
A vibrant industry into which
Production
Distribution and sales
younger generations
Production innovation
want to enter

IOWN innovationthat pushes theboundaries

Food digital twin

Creation of innovative production and foodsupport technology that steps into fields ofunmanned agriculture and gene technology

×

Sales trends
Demandinformation

Analysis results
Feedback(transaction
information, etc.)

Joy andexcitement of
eating, demand stimulation

Consumption and foodNew eating experienceand excitement

ing
tand
Outsshnessefr

Enjoy fresh, high-quality food
Toward an industry thatbrings food safety/security,
joy, and healthCreation of technology for simulating
agricultural-product distribution,
creating a virtual market

Fig. 1. A vision for food and agriculture.

chain. This will be enabled by combining multiple
efforts such as (i) automating agriculture by remotecontrol robotics such as agricultural machinery anddrones; (ii) digital transformation (DX) in the distribution of agricultural products by simulating realworld information on production and distribution
sites in a virtual world and feeding back the results ofsupply-and-demand forecasts to the real world; and(iii) digital breeding by using bio-technology, microorganisms, genetic technology, etc. to improve thepotential of crops, thus dramatically improving productivity and quality.
The NTT Group’s current capabilities include
greenhouse farming (solar and artificial), outdoor
cultivation (including organic farming), livestock,fisheries, weather, map, and topographical information as well as services and technologies that contribute to distribution, sales, and consumption, while
meeting the United Nations’ Sustainable Development Goals (SDGs) (Fig. 2). From among those capabilities, initiatives of NTT Group companies in theareas of plant factories using artificial light [2], foodwaste recycling solution toward achieving the SDGs[3], fisheries [4], and organic farming using information and communication technology (ICT) [5] are
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

introduced in the Feature Articles in this issue.
2. Example initiative 1
Regarding agricultural automation, NTT signed anindustry-government-academia comprehensive
cooperation agreement in 2019 with fellow signatories Hokkaido University, Iwamizawa City in Hokkaido, NTT EAST, and NTT DOCOMO. Since 2020,
Kubota Corporation, a leading manufacturer of agricultural machinery, and other companies have signed
up to this initiative, which has been further deepened
by using the projects of the Ministry of Agriculture,
Forestry and Fisheries and the Ministry of Internal
Affairs and Communications. In 2019, we moved an
unmanned agricultural machinery in the field (a farm)under remote monitoring using the fifth-generation
mobile communication system (5G) and in 2020 carried out inter-field movements in which an agricultural robot moves between fields under remote monitoring, which had been considered extremely difficult[6]. This preliminary demonstration of the Remote
World was conducted in Iwamizawa. Regarding thecommunication network used for that remote monitoring, the coverage area is small due to the frequency
12

Feature Articles

Livestock,fisheries, etc.

Agricultural production

Sunlight
NTT
AgriTechnology

Artificial light
NTT WEST
Sensing

Sensing

Environmental
control anddata analysis

Production
and sales

Steel-frame greenhouse
NTT FACILITIESNTT EAST

Sensing

Supply chain

Supply chain

HALEX

Sensing

Weather

Data analysis

NTT InfraNet
Map and topography

NTT DOCOMO
Sensing

Environmental
control anddata analysis

Production
and sales

NTT DOCOMO

Sensing

Construction

Construction

Environmental
control anddata analysis

Open-field cultivation(paddies, uplandfarming, etc.)

Greenhouse farming

Advanced greenhouse farming

From distribution to
consumption, etc.

NTT TechnoCross
SensingWork record

Data analysis

NTT DATA
Agricultural land
management

NTT e-DroneTechnology
Drone

NTT COMWARE
NTT EAST
NTT DOCOMONTT TechnoCross
Sensing
Environmental
control anddata analysis

System for organic farming

NTT DATANTT EAST
NTT DATA CCSNTT DOCOMO
NTT and others
Michibiki smartfarming solution
Data analysis (growthand pest diagnosis, etc.)

NTT NTT EAST
NTT DOCOMO
Remote control ofagricultural robots

NTT EAST
BiostockSensing
Data analysis
Biogas plant

NTT DOCOMONTT COMWARE
NTT EAST
NTT WESTNTT
Supply chain

NTT FIELDTECHNONTT COMWARE
Data analysis(countermeasuresagainst poachingboats)

Food-waste recycling
SDGs

NTT
“Well-being” offood (digitization
and understanding
deliciousness)NTT
NTT WESTNTT DATANTT COMWARE

Soil, biotechnology,
and genes

Fig. 2. Map of food and agricultural solutions (including R&D and field demonstrations in progress).

characteristics of 5G. Consequently, if an agriculturalrobot moves out of the area covered by the network
system, it will not be possible to check the video
while operating the robot from the remote-monitoring center or continue automatic operation.
To solve the above-described problem, we verified
the effectiveness of several technologies, including acooperative infrastructure platform, which is an
IOWN-related technology, for automatically selecting the most-suitable system from various network
systems, such as 5G and broadband wireless access(BWA), in accordance with the operating conditionsof the agricultural robot (Fig. 3).
We have also conducted non-technical studies inconsideration of business operation, such as formulating safety guidelines in collaboration with national
projects and sharing mechanisms for smart agricultural machinery. We plan to implement, at an earlystage, the automation of agriculture centered on agricultural robots and launch the business of undertaking agricultural work.
We plan to enable innovations that will lead to adigital agricultural revolution in the Remote WorldNTT Technical Review

Vol. 19 No. 8 Aug. 2021

we envision. For example, by using IOWN andrelated technologies that enable higher capacity of
networks (more than 100 times current networks),
agricultural cooperatives and contractors of agricultural work will be able to monitor and control a large
number of robots—agricultural machines, drones,
mowers, and harvesters—on wide-area farms frommonitoring centers in remote locations and coordinate those robots. We will also model and systematize
these technologies and expand them globally to contribute to solving the food shortage facing humankind(Fig. 4).
3. Example initiative 2
We are also working to reduce distribution costs,
food loss, and ensure food security by optimizing the
distribution of agricultural products. Currently, about
80% of fruits and vegetables are traded through morethan 1000 wholesale markets throughout Japan, andmost are shipped to markets in big cities such as
Tokyo and Osaka. If too many products are gathered,
the price will drop due to market principles, and13

Feature Articles

Cloud GNSS
Positioning technology

Remote monitoring
Video distribution

Person-detection
processing

Cooperative infrastructure platform (quality-prediction technology for optimal use ofmultiple wireless access networks (Cradio®) and end-to-end overlay network technology)

Carrier 5G/LTE

Alarm

Regional BWA/
private 5G
More accurate positioning throughoptimal selection of satellites

Remotemonitoring

Smooth wide-area autonomous driving
by optimally using multiple networks

Farm roads

Field[Others]
Verification of persondetection technologythat reduces the burden
on the observer

GNSS: global navigation satellite systems
LTE: Long Term Evolution

Fig. 3. Overview of demonstration of Iwamizawa Project.

Fig. 4. Image of future agriculture.

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Vol. 19 No. 8 Aug. 2021

14

Feature Articles

transferring the surplus to other markets will incur
extra costs. There is also a serious shortage of driversof trucks for carrying agricultural products. The
recent increase in individual deliveries through online
shopping and the spread of coronavirus infections areaccelerating this problem. To solve these problems,
we are planning to build a system that uses Digital
Twin Computing, an IOWN-related technology, topredict future supply and demand by using the vast
amount of data collected from the wholesale markets,and on the basis of the predicted information, purchases and sales will be completed in a virtual space
before the agricultural products are brought to thesemarkets. This system will enable the supply side to
supply crops at the right time, place, and quantity, andthe demand side to secure crops at the right time,
place, and quantity. The system will also help solve
social problems through initiatives that take into
account the entire food value chain, such as solving
driver shortages, reducing food loss and transportation costs, and ensuring food security as well as
achieve the SDGs. Marketers, agricultural organizations, and local governments are also becoming moreinterested in this system, and collaborations and partnerships are expanding. This system is expected tolead to a digital agricultural revolution that will bringabout a DX in distribution of agricultural products.
4. Concluding remarks
We believe it is now necessary in Japan to bring
together the wisdom and technology of various fields
in the primary industries, which are indispensable forthe survival of humankind. We need to build a mechanism that accelerates the transformation of existing

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

industries, creates new services, and fundamentallychanges the industrial structure of the entire foodvalue chain by taking both perspectives of agriculture
with producers in mind and food with consumers in
mind. By leveraging the unlimited potential of the
ICT of the NTT Group and R&D capabilities of NTT
laboratories, we will work with various partners toshape the future of food and agriculture. The NTT
Group will continue to be a value partner of choice
for all concerned and contribute to the developmentof primary industries.
References
[1]
[2]

[3]

[4]

[5]

[6]

Activities for Management Strategy of the NTT Group, NTT x Local
Creation, Agriculture, https://www.ntt.co.jp/activity/en/creation/
agriculture/
Y. Takayama, K. Tsuzuki, T. Uekawa, T. Nomura, Y. Maehara, A.
Unami, T. Kawakatsu, H. Kouyama, and N. Iwatani, “Future-oriented
Agriculture—Strawberry Plant Factory Based on Regional Collaboration,” NTT Technical Review, Vol. 19, No. 8, pp. 17–20, Aug. 2021.
h t t p s : / / n t t - r ev i ew. j p / a r c h ive / n t t t e c h n i c a l . p h p ? c o n t e n t s =ntr202108fa2.html
M. Nakayama, K. Miyaoku, and F. Nakanishi, “Local Food Waste
Recycling Solutions for Addressing the Sustainable Development
Goals,” NTT Technical Review, Vol. 19, No. 8, pp. 21–25, Aug. 2021.
h t t p s : / / n t t - r ev i ew. j p / a r c h ive / n t t t e c h n i c a l . p h p ? c o n t e n t s =ntr202108fa3.html
K. Yamamoto, M. Nakashima, Y. Yokoi, and Y. Okabe, “‘Fisheries+d’: NTT DOCOMO’s Solution Co-creation for the Fisheries Industry,” NTT Technical Review, Vol. 19, No. 8, pp. 26–30, Aug. 2021.
h t t p s : / / n t t - r ev i ew. j p / a r c h ive / n t t t e c h n i c a l . p h p ? c o n t e n t s =ntr202108fa4.html
H. Umeshita, S. Uno, Y. Kobayashi, T. Saito, M. Kashima, and M.
Wada, “High-quality, High-yield Organic Farming with BLOFware®.
Doctor,” NTT Technical Review, Vol. 19, No. 8, pp. 31–36, Aug.
2021.
h t t p s : / / n t t - r ev i ew. j p / a r c h ive / n t t t e c h n i c a l . p h p ? c o n t e n t s =ntr202108fa5.html
Joint press release issued by Hokkaido University, Iwamizawa City,
NTT, NTT EAST, and NTT DOCOMO, Nov. 16, 2020 (in Japanese).
https://group.ntt/jp/newsrelease/2020/11/16/201116b.html

15

Feature Articles

Yoshikazu Kusumi

Senior Manager, Strategic Business Creation
Team, Research and Development Planning
Department, NTT.
He received a B.S. and M.S. in nuclear engineering from Osaka University in 1993 and 1995.
He joined NTT in 1995 and was assigned to theLong Distance Communication Business Division. He then worked at the Network Engineering
Center, where he designed a network system forpersonal handyphone systems. He also worked at
NTT Communications in the Carrier Sales Division, where he was in charge of wholesale business for foreign companies and later, planning
global strategies. He is with NTT again, where heis responsible for ICT business creation for the
agricultural industry.

Kanji Yoshitake

Manager, Strategic Business Creation Team,
Research and Development Planning Department, NTT.
After graduating from Tokyo University of Science in 1998, he was assigned to system engineering for public and educational institutions at
NTT EAST. He then was engaged in service
development work for routers, Wi-Fi, etc. He
currently works at NTT and is responsible forcreating an ICT business for the agriculturalindustry.

Takuya Murayama

Manager, Strategic Business Creation Team,
Research and Development Planning Department, NTT.
He received a B.S. and M.S. in applied physics
from Waseda University, Tokyo, in 2005 and2007. He joined NTT in 2007. His research interests include lifelog systems and service design.
He is a member of the Institute of Electronics,
Information and Communication Engineers. He
currently works at NTT and is responsible forcreating an ICT business for the agriculturalindustry.

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Vol. 19 No. 8 Aug. 2021

16

Feature Articles: Initiatives for Smart Agri—Making
Japanese Agriculture a Growing Industry

Future-oriented Agriculture—
Strawberry Plant Factory Based on
Regional Collaboration
Yoshikazu Takayama, Katsuhito Tsuzuki,
Tsukasa Uekawa, Tomoyuki Nomura, Yuriko Maehara,
Akiko Unami, Takashi Kawakatsu, Hiroki Kouyama,
and Naoki Iwatani
Abstract

As a social information and communication technology (ICT) pioneer, NTT WEST is aiming to create
smart communities to solve problems facing local communities and strengthen ties between individuals
and society. Specifically, we are working on “Smart10x” initiatives to solve problems faced by local
communities in ten fields by using the expertise and resources that exist in the community as well as
those of NTT WEST and its group companies. This article introduces the “Collaboration Agreement on
the Promotion of Agriculture and Regional Revitalization Utilizing ICT, Starting from Sakawa Strawberries,” which was announced in April 2021, with regard to our initiatives for plant factories as futureoriented agriculture that is being promoted in the primary-industry sector.
Keywords: food and agriculture business, plant factory, regional revitalization

1. Background of the collaboration agreement
On April 24, 2021, the Sakawa Branch Strawberry
Division of Japan Agricultural Cooperatives (JA)Kochi Prefecture (Sakawa Strawberry Division, hereafter), NTT WEST, the town of Sakawa, and Kochi
Prefecture concluded a collaboration agreement topromote agricultural development and regional revitalization, particularly by leveraging the strawberrycultivation technology of Sakawa Strawberry Division and information and communication technology(ICT) of NTT WEST and its group companies (NTT
WEST Group, hereafter), as a way to explore the possibilities of “plant-based town development” advocated by the town of Sakawa.
In the Sakawa Strawberry Division, farmers are
aging and their number is decreasing. Accordingly,
while working on ways that will allow them to pass
on skills, they aim to increase the number of new
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

farmers and pursue sustainable agriculture by creating an environment that makes it easy for individuals
to take up farming.
To become a social ICT pioneer, NTT WEST istaking the initiative in solving various problems
brought about by changes in the environment surrounding society by using the power of ICT and collaborating with local communities (Fig. 1). As one of
our initiatives, we had been considering the strawberry plant factory business as a means to solve social
problems in the agricultural sector. Accordingly, we
thought it was a good idea to grow Sakawa’s delicious
strawberries, which are highly evaluated by distributors, in a plant factory. Therefore, we consulted with
the Sakawa Strawberry Division, leading to this collaboration.
The town of Sakawa is aiming to attract new farmers to support the Sakawa Strawberry Division andcreate a town in which children can learn about the17

Feature Articles

Smart factory
Smart infrastructureand energy

Smart healthand medical

Smartagriculture

Local
companies,
etc.

Smart learning

Smart
town
NTT WESTSolving local
problems

Expertise andresources thatexist in the region

NTT WESTGroup’s expertiseand resources

Smart life

Smart
food

Smart work
Smart tourism & mobility

Fig. 1. NTT WEST “Smart10x” initiatives.

industries of Sakawa by using ICT in a manner thatthey can nurture their interests in such industries.
Moreover, they want to make effective use of ICT in
the “Sakawa Town, People, Work Creation Comprehensive Strategy” aimed at measures for addressing
population decline, regional revitalization, and establishment of a virtuous cycle.
Against this background, we decided to close a collaboration agreement with the aim of contributing to
the promotion of agriculture and plant-based town
development by using ICT in the production of
Sakawa strawberries. Targeting new agriculture andplant-based town development, NTT WEST will also
explore ways to promote agriculture through digitaltransformation by promoting the use of ICT in agricultural fields and collaboration with plant factories
in the Kansai (west Japan) region through regional
cooperation. Kochi Prefecture is participating in thisagreement to support the collaborative efforts of the
Sakawa Strawberry Division, NTT WEST, and thetown of Sakawa (Figs. 2 and 3).

2. Details of the collaboration
2.1 Specific actions to be taken(1)	Increase the number of new farmers of Sakawa
strawberries•	Dissemination of information on Sakawa strawberries and the town of Sakawa through strawberry plant factories•	Production of strawberries using ICT(2) Promote plant-based town development•	Consideration of the use of strawberries produced at plant factories for sale at roadside stations•	Study of ICT utilization to maximize the attractiveness and profit of roadside stations•	Expanding direct sales and revitalizing local
communities by using closed-type plant-factory
technology (Photos 1 and 2)
2.2 Agreement period
From April 24, 2021 to March 31, 2022.
2.3 Role of each party(1) Sakawa Strawberry Division•	Various activities to increase the number of new

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Feature Articles

Highly rated
Evaluation at strawberrycompetition*

Fruit andvegetablemarketparticipants

Wholesalers

Retailers

Consumers

Reproduced in aplant factory

Sakawa’s strawberries*NTT WEST held a competition to comprehensively
evaluate strawberries in accordance with taste,
appearance, aroma, etc.

Fig. 2. Background and motivation for collaboration with the town of Sakawa.

Terminal control

Data analysis

Light

Photosynthesis

HarvestAir

Water
GrowthAI
Cloud: Control terminal with sensor

Feedback

Fig. 3. Cultivation technology used in a strawberry plant factory.

farmers•	Pursuit of strawberry-cultivation technologies•	Provision of technological expertise on cultivation of Sakawa strawberries(2) NTT WEST Group•	ICT-based support to increase the number of new
farmers•	Regional revitalization through the promotion of
strawberries produced in plant factories•	Studying the development of strawberry-plantNTT Technical Review

Vol. 19 No. 8 Aug. 2021

factory business in Sakawa(3) The town of Sakawa•	Promotion and dissemination of plant-based
town development•	Dissemination of the Sakawa strawberry brand•	Study of agricultural promotion and regional
revitalization using plant factories(4) Kochi Prefecture•	Support for initiatives from production to sales
in line with the intentions of the producing
19Feature Articles

Photo 1. Strawberry cultivation field in Sakawa, Kochi
Prefecture.

region3. Future developments

Photo 2. S
 trawberry plant factory operated by the NTT
WEST Group.

Under this collaboration agreement as a starting
point, we will promote regional revitalization throughcooperation in various fields, including the use of
ICT, with a focus on Sakawa strawberries.

Authors: (top tier from left) Naoki Iwatani, Manager, NTT Business Solutions
Corporation; Akiko Unami, Manager, NTT Business Solutions Corporation; Katsu­
hito Tsuzuki, Director, NTT WEST Corporation; (middle tier from left) Takashi
Kawakatsu, Chief, NTT Business Solutions Corporation; Hiroki Kouyama, NTT
Business Solutions Corporation; Yuriko Maehara, NTT WEST Corporation; (bottom tier from left) Tsukasa Uekawa, Manager, NTT WEST Corporation; Yoshikazu
Takayama, Domainhead, NTT WEST Corporation; Tomoyuki Nomura, Chief, NTT
WEST Corporation

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20

Feature Articles: Initiatives for Smart Agri—Making
Japanese Agriculture a Growing Industry

Local Food Waste Recycling Solutions
for Addressing the Sustainable
Development Goals
Makoto Nakayama, Kento Miyaoku,
and Fumihiro Nakanishi
Abstract

As a social information and communication technology (ICT) pioneer, NTT WEST and its groupcompanies (NTT WEST Group, hereafter) aim to be a corporate group that is well-respected and trusted
by the community by using the power of ICT to address local issues and create a sustainable society.
NTT FIELDTECHNO, an NTT WEST Group company, whose core business is maintenance work in theregional telecommunication business, has enabled digital transformation of the food-recycling businessby using ICT such as the Internet of Things and artificial intelligence. In partnership with Well Create
Co., Ltd., which has excellent technical expertise in composting food residue, in April 2019, we started
providing local food waste recycling solutions that contribute to the popularization of food waste recycling. This article introduces initiatives of NTT FIELDTECHNO concerning food waste recycling toaddress the United Nations’ Sustainable Development Goals.
Keywords: food waste recycling, circular economy, organic agriculture

1. Status of food waste recycling andour solutions
1.1 Local food waste recycling solutions
The cost of introducing food waste recycling
exceeds that of disposing of food residue as waste,
and this has been a major factor preventing the spreadof food waste recycling. To address this issue, theequipment for fermentation and decomposition offood residue provided by our local food waste recycling solutions uses microorganisms, which effectively decompose food residue such as vegetables. It
can decompose and reduce the input food residue intoa primary fermentation product that is five- to tentimes smaller in volume in a short time; consequently,
it makes collection and transportation more efficient,thus reducing costs. We also provide a series of oursolutions as a monthly service (including equipment
rental to customers); therefore, an initial investment
for introducing food waste recycling is not required
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

on the customer’s side, and their monthly food-residue processing costs are significantly reduced(Figs. 1 and 2).
Our local food waste recycling solutions will be
provided by NTT FIELDTECHNO, which provides
on-site telecommunication maintenance services
throughout Japan. In addition to renting and installingthe equipment for food-residue fermentation anddecomposition to customers, the company offers avariety of services, including regular maintenance(Fig. 3).
When introducing these solutions, we want toensure that customers can enjoy the cost benefits;
accordingly, we will (i) provide consulting before
introducing the solution and, if necessary, (ii) carryout tests on decomposition/fermentation of food residue and odors as well as trials using actual equipment.
Cost simulations and tests on food-residue decomposition are provided free of charge, so customers canimplement these solutions without any initial
21

Feature Articles

Food-related businesses
02
03
08

02
03
08

02
03
08

Food-processing plant 01 07

Wholesalers 01 07

08
Cloud system

Supermarket 01 07

04 08

Primary
fermentation
product

Vegetables

Agricultural producer

06

Compost05 08

Recycling center

Tertiary fermentation
product

Secondary fermentation
product

Fig. 1. Overview of our local food waste recycling solutions.

investment and reduce their monthly food-residue
disposal costs. A trial (lasting about three months)
using actual equipment is available for a fee.
1.2 I nformation and communication technology(ICT)-based food waste recycling(1)	Converting abandoned farmland into fields andimproving fertility of farmland
In Japan’s agricultural industry, the expansion ofabandoned farmland, which has doubled in area in thepast 20 years, is a problem. The main cause is theaging of farmers. However, it is also due to the deterioration of soil caused by the use of chemical fertilizers, which makes it difficult to grow crops, making
farming less profitable. The abandoned farmlandsignificantly affects neighboring farmers throughgrowth of weeds and encroachment by pests such as
insects.
To solve this problem of abandoned farmland,
together with the Compost and Soil Research Institute, we are working on using recycled organic compost—made by adding locally available organic
materials (e.g., cow and chicken manure, rice husks,
and rice bran) to food residue generated from ourlocal food waste recycling solutions—and digitizing
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

our knowledge (temperature, humidity, pH adjustment, etc.) concerning such compost. NTT
FIELDTECHNO has developed a system for collecting data on the extremely difficult process of manufacturing high-quality organic compost. The system
uses Internet of Things (IoT) sensors and other technologies to create stable, high-quality compost andpotting soil on the basis of the collected data. Therefore, it supports soil preparation, which is the foundation of agriculture (Fig. 4).
We are currently conducting a joint demonstration
with a large-scale agricultural corporation in Okayama Prefecture regarding a project called “Restoring
Abandoned Farmland and Fertilizing Farmland” byusing high-quality organic compost. We are demonstrating and comparing methods of fertilizing soil ina short period at low cost at a leaf vegetable field bycapturing aerial images with drones and collecting
data on the physics, chemistry, microbial properties,
etc. of soil with IoT sensors.
(2) Organic-farming support project
Our local food waste recycling solutions will also
tackle other issues facing the agricultural industry tocreate a “food-recycling loop.” For example, agriculture relies on intuition and experience, and expertise22

Feature Articles

01

02

Food wholesalers and retailers
generate large amounts of foodresidue (such as vegetables) everyday. Those businesses had to bear
the cost of disposing the waste.

05

03

Food residue is fed into theequipment for fermentation anddecomposition. Food-residue
volume and disposal costs canthus be reduced.

06

The fermentation/decomposition
beds are collected and turned into
fully matured compost throughsecondary and tertiary fermentations at the recycling center, after
which, the fully matured compost
is recycled as soil conditioner.

Food residue is fermented using
microorganisms in about 24 hours.
The water content and temperatureare controlled appropriately, and theresidue becomes a fermentation/
decomposition bed (a primary
fermentation product).

07

The soil conditioner produced at
the recycling center is supplied tocontract farmers, agricultural
cooperatives, and agricultural
corporations for use in the
production of safe and high-quality
vegetables.

The vegetables produced by those
farmers are delivered to food-related
businesses and displayed in stores.
Food waste recycling can thus bepromoted by circulating fresh foodproducts, such as vegetables, in thecommunity in this manner.

04

The fermentation/decomposition
beds collected from food-related
businesses are transported to therecycling center.

08

By using the NTT Group’s IoT
platform, it is possible to monitor theamount of food residue, fermentation status, etc. in real time via theInternet on a smartphone or tablet.

Fig. 2. The process of each solution.

NTT FIELDTECHNO(with Well Create)

Equipment rental
Regular maintenance/breakdown
maintenanceIoT remote monitoring (under
demonstration)

Contract farmers

Compostsales

Food-related businesses
Service provision

Recycling center(with Well Create)

Wholesalers, food processing
and restaurant businesses

Collection of fermentation/
decomposition beds

Fig. 3. Service-provision system.

is passed down through experience and transfer. With
the ongoing aging of farmers and the increase in thenumber of farmers abandoning their farmlands, theNTT Technical Review

Vol. 19 No. 8 Aug. 2021

loss of this expertise has become an urgent issue.
By using ICT, such as sensing and telecommunications that NTT WEST and its group companies (NTT23

Feature Articles

Visualizing compost status
with IoT sensors

Illustration of quality control of organic compost using IoT
Temperature

Unmatured

Medium-matured

Fully matured
Weak odor

60°C

Pathogens are killed
at 60°C or higher.

Lowtemperature

Organic matter
continues todecompose.

40°C
Fully matured at thesame temperature
as outside

Strong odor

Organic compost(food residue +local materials)

High
temperature

Compost supervisor: Rikio Hashimoto,President of Compost and Soil Cultivation
Laboratory (selected as “Master ofAgricultural Technology” by the Ministry ofAgriculture, Forestry and Fisheries)

About 3 months

About 9 months

Time

Fig. 4. Using data to manage the maturation of organic compost.

WEST Group, hereafter) possess, we will promote
not only composting and soil improvement but also
digitalization of farming expertise to support organic
farming. We are in the process of digitizing all processes of organic farming, such as selecting varieties,
raising seedlings, planting, irrigation, and evaluationof nutritional value of crops, for multiple organic
farmers who are growing cherry tomatoes and leaf
vegetables. Through these efforts, we are verifying
improved profitability through labor saving and automation.
2. Future developments
The COVID-19 pandemic has gone on for over a
year and has increased people’s frequency of eating
and cooking at home. Under these circumstances,

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

new food-distribution markets, such as ready-to-eat
meals and home delivery of meal kits, are expanding,and options for selecting food and ingredients are
increasing. Amid such changes in the environment, it
is expected that consumers’ food needs will become
more complex and diverse; as a result, their awarenessof food safety, food loss, and sustainability will further increase.
The NTT WEST Group will build a resource-circulation smart value chain centered on the local foodwaste recycling solutions in light of these changes inmarket needs. In doing so, we want to provide consumers who are health conscious and nature-oriented
with new value of a healthy and prosperous life
within the circle of resource circulation and contribute to creating a sustainable society without food
loss.

24

Feature Articles

Authors: (from left) Fumihiro Nakanishi, Manager, Tokyo Metropolitan Area Sales
Division, NTT FIELDTECHNO CORPORATION; Makoto Nakayama, Deputy
Director, Tokyo Metropolitan Area Sales Division, NTT FIELDTECHNO CORPORATION; Kento Miyaoku, Director, Tokyo Metropolitan Area Sales Division, NTT
FIELDTECHNO CORPORATIONNTT Technical Review

Vol. 19 No. 8 Aug. 2021

25

Feature Articles: Initiatives for Smart Agri—Making
Japanese Agriculture a Growing Industry“Fisheries +d”: NTT DOCOMO’s
Solution Co-creation for the Fisheries
Industry
Keiichi Yamamoto, Masako Nakashima, Yuko Yokoi,
and Yutaka Okabe
Abstract

While there is no end in sight to the decline and depletion of natural fish and shellfish, the global fish
catch is on the rise due to population growth and other factors. The need to reliably nurture marine
resources while protecting the diversity of the oceans from pollution is growing in urgency. Accordingly,
expectations regarding improvement and commercialization of sustainable aquaculture technologies are
increasing. NTT DOCOMO is focusing on the fisheries industry as the main area for industry creation
underpinned by its medium-term strategy through 2020 called “Declaration beyond.” Under this strategy,
we have developed marine-monitoring technology and aquaculture-management solutions that use ICT(information and communication technology) buoys and cloud computing, thus contributing to regional
revitalization in collaboration with partner companies. This article introduces the initiatives of NTT
DOCOMO in the fisheries industry.
Keywords: fisheries, ICT, smart aquaculture

1. “Fisheries +d” initiatives began with support
for post-disaster reconstruction
In April 2017, NTT DOCOMO announced its
medium-term strategy, called “Declaration beyond,”
and has been striving toward transforming itself froma mobile communications company to a “value cocreation company.” We believe that we can create
new business and co-create new social value by combining the strengths of our partners in various fields,such as local governments, other companies, andresearch institutes, with NTT DOCOMO’s customer
base, robust networks, information and communication technology (ICT), and other strengths. We referto these initiatives with the suffix “+d” (plus d), in
which d stands for NTT DOCOMO.
“Fisheries +d” initiatives for solving problems in
the fisheries industry has started with providing
reconstruction support following the 2011 Great East
Japan Earthquake. As part of that reconstruction supNTT Technical Review

Vol. 19 No. 8 Aug. 2021

port, we began exchanges with seaweed and oyster
farmers in the city of Higashi-Matsushima in Miyagi
Prefecture and thought that we want to not only support reconstruction but also create sustainable services that are useful for people engaged in the fisheries industry through NTT DOCOMO’s main business. A service that uses ICT buoys was developed tomeet this goal.
2. ICT buoys for visualizing sea conditions
One day, we heard from an oyster farmer in
Higashi-Matsushima that “The sea conditions havechanged since the earthquake, and our past experience and intuition are no longer valid.” Temperatureand salinity (specific gravity) of the seawater at oyster farms are important factors in understanding sea
conditions, and farmers used to measure them manually whenever they went to the oyster farms. To
address this issue, we developed a service that uses
26

Feature Articles

NTT DOCOMO

Water
temperature

Type-I ICT
buoy

Cloud

Salinity

Chlorophyll

Type-II ICT
buoy

Dissolved
oxygenStationary
type(box type)umi-miru

App

ICT buoys

Fig. 1. Overview of ICT buoy solution.

ICT buoys equipped with sensors for measuring seawater temperature and salinity and communication
modules installed at oyster farms. The sensor data—measured automatically every hour—are sent by themodules to the cloud, from which farmers can viewthe information via the app called “umi-miru” (“viewthe ocean” in English) installed on their smartphones.
Together with our partners ANDEX and Sena andVans Co., Ltd. (S-VANS), we began demonstration
tests of this service in 2016 and launched a commercial service (Fig. 1) in October 2017.
Thanks to the introduction of ICT buoys, farmers
have been able to continuously visualize sea conditions and support their experiences and intuition withdata. Regarding edible-seaweed cultivation, we wereable to confirm the effectiveness of ICT buoys for the“raising seedlings” process. Raising seedlings promotes the growth of seaweed through removing otherseaweeds by exposing the seedlings (cells) of theseaweed attached to the seaweed net to the air. This isa key process that affects the taste, quality, and yieldof seaweed. Seawater temperature and specific gravity had been measured at the seaweed farms before
deciding on the work procedure for the day; however,thanks to the introduction of ICT buoys, past fluctuations in seawater temperature and specific gravity can
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

be understood, so that work for the day can be determined on land. The farmers’ experience thus far has
made it possible to interpret the data and predict the
optimum timing and duration of drying out the seaweed, and “Thanks to ICT buoys, we can now imagine the appearance of seaweed cells on land,” said aseaweed farmer in Higashi-Matsushima.
Information of ICT buoys spread through connections between farmers, and their introduction has
progressed in major seaweed-producing areas such as
Ariake Bay in southwestern Japan. In the 2017 Fisheries White Paper published by the Fisheries Agency,
ICT buoys were mentioned as an example of ICT
utilization in the aquaculture industry. As a result, theintroduction of ICT buoys has expanded to aquaculture sites other than seaweed. For example, three ICT
buoys were installed in Tsushima, Nagasaki Prefecture, for pearl-oyster farming in March 2018
(Photo 1). They were equipped with seawater temperature, chlorophyll concentration, and turbidity
sensors. This case is the first in which chlorophyll
concentration is constantly monitored throughout theyear at a pearl cultivation site. “With the introductionof ICT buoys, we now know the seawater temperatureand chlorophyll concentration every hour, so we canclean and treat Akoya pearl oysters (Japanese pearl
27

Feature Articles

Photo 1. ICT buoy in operation at the Tsushima Pearl Farming Cooperative.

oysters) according to the sea conditions. As a result,
we can produce pearls of higher quality than everbefore,” said Mr. Hidaka, the head of the Tsushima
Pearl Farming Cooperative. Since 2019, ICT buoys
have been added and eleven ICT buoys are currently
in operation at pearl-oyster farms in Nagasaki Prefecture.
Since 2019, we have also been receiving inquiries
about ICT buoys from fish farming businesses concerning amberjack, red sea bream, and salmon.
Regarding fish cultivation, sea conditions, namely,
seawater temperature and dissolved-oxygen concentration, significantly affects the amount of feed intake
and growth of cultured fish species. However, seawater temperature and dissolved-oxygen concentration
are only measured during fish-feeding operations,and in many cases, feeding records are only managed
analogically. When we visited aquaculture sites, wefound that more than 90% of fish-farming companies
are small and medium-sized, and fish-farming management is becoming more difficult due to sluggish
fish prices and soaring feed prices. It is therefore difficult for fish farmers to invest in ICT, so we became
acutely aware that ICT buoys alone cannot solve theproblems facing fisheries sites.
3. From visualizing sea conditions tosolving problems
NTT DOCOMO entered the fisheries industry withthe goal of visualizing sea conditions by using ICT
buoys; however, we have shifted to a policy of listenNTT Technical Review

Vol. 19 No. 8 Aug. 2021

ing to the voices from fishery sites and working with
our partners to provide solutions to the problems that
we hear. In May 2020, we entered into a business alliance with the SABAYA Group (SABAYA Co., Ltd.,SABAR CO., LTD., and FISH BIOTECH Co., Ltd.).
This business alliance aims to create a new market
for safe, secure, and tasty farmed mackerel. In doingso, it hopes to encourage new entrants to the fisheries
industry and contribute to revitalizing local communities and developing Japan’s fisheries industry. As
part of the alliance’s efforts, a demonstration test to
establish a new ICT-based mackerel farming model
was launched in May 2020 at FISH BIOTECH’s
mackerel farm in the town of Kushimoto, Wakayama
Prefecture. NTT DOCOMO has developed and has
been providing an “aquaculture management cloud,”a cloud environment that integrates the managementof ICT buoys (stationary type) and mackerel farming.
We have also conducted various ICT demonstration
tests at the mackerel farming site in Kushimoto,including installation of cameras and other equipment and the use of underwater drones to check fish
behavior and the presence or absence of leftover feedin fish ponds. Through these demonstration tests, we
accumulated knowledge on how to deal with highseawater temperatures, which increases the mortality
risk of mackerel as a result of infectious diseases andchanges in the environment. We also confirmed theeffectiveness of measuring fish length using ultrasonic underwater-visualization technology, improvements to the functions and user interface of the aquaculture management cloud, and the effectiveness of28

Feature Articles

Fish identification using ultrasonic waves

Screenshot of terminal

Fish length is calculated
from the strength of the
response of the identified
fish to ultrasonic waves.

Fig. 2. Illustration of measuring fish length.

the “sea-condition simulation” service that we plan tolaunch.
Fish length measurement and sea-condition simulation using ultrasonic underwater-visualization technology are introduced in the following subsections as
examples of co-creation with a partner.
3.1 M
 easuring fish length using ultrasonic underwater-visualization technology
On March 8, 2021, NTT DOCOMO and AquaFusion Inc. signed a business-alliance agreement toestablish a new aquaculture-management modelthrough development of an ICT service that uses
ultrasonic underwater-visualization technology for
automatically measuring fish length and weight. In
the aquaculture industry, measurements of fish length
and weight are key factors in efficient management offish production. Until now, farmers had taken several
farmed fish out of the fish tank with a scoop net andmeasured them one by one with a measuring instrument. However, physically handling the fish could
kill them, and the growth of the fish extracted as
samples varies, so it is difficult to accurately understand the growth process. Therefore, since October
2020, we have been verifying non-contact measurement of mackerel body length by using AquaFusion’s
ultrasonic underwater-visualization technology during demonstration tests of cultured mackerel with the
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

SABAYA Group. On March 11, 2021, we announced
that we have succeeded in measuring the average
length of mackerel swimming in a fish tank with highaccuracy (Fig. 2). From now onwards, we will verify
the estimation technique of fish weight from fish
length using artificial intelligence (AI).
The ultrasonic underwater-visualization technology automatically analyzes the response of an object toultrasonic waves transmitted at high frequency toidentify a fish. This technology represents the world’s
first use of CDMA (code division multiple access) for
underwater ultrasonic measurement and enables
ultrasonic transmissions of more than 40 times per
second. Featuring resolution 100 times higher thanconventional fish finders, it can identify individual
fish even in densely populated environments such as
fish ponds. The use of ultrasonic waves also makes it
possible to measure fish even at night or when the sea
is turbid, so the technology is independent of themeasurement environment.
Linking fish-length measurement service provided
by AquaFusion with NTT DOCOMO’s aquaculture
management cloud will make it possible to (i) accurately understand the growth process of fish as a function of the aquaculture-management cloud and (ii)provide ICT services for aquaculture with high added
value, such as improving work efficiency and optimizing the amount of feed.
29

Feature Articles

3.2 Sea-condition simulation
Sea-condition simulation is a service that is being
tested in collaboration with Forecast Ocean Plus, Inc.
and ANDEX (our partner in providing ICT buoys).
Forecast Ocean Plus provides the information-consulting business for marine industries and public
institutions and uses various prediction models
resulting from the cutting-edge research of physicaloceanography at the Japan Agency for Marine-Earth
Science and Technology (JAMSTEC). NTT DOCOMO has been collaborating with Forecast Ocean Plusin developing a system that enables safe and efficient
ship operation by equipping ships with terminals thatcan display tidal-current-forecast information provided by Forecast Ocean Plus.
We began considering collaboration in the aquaculture industry in 2018 and developed the “umi-miru”
smartphone app for sea-condition simulation with
ANDEX around the summer of 2019, when the horizontal resolution of the sea-condition prediction
model reached 1 km (Fig. 3). With this app, hourly
forecast for the next three to five days of sea-condition information, i.e., seawater temperature, current
speed, and current direction, predicted by Forecast
Ocean Plus can be displayed in the form of animation. Since 2020, we have been verifying the use of
the umi-miru sea-condition simulation at several
aquaculture sites, including the above-mentioned
mackerel farm in Kushimoto. After sufficient evaluation and verification, we plan to improve the app andcommercialize it. In the bays where many aquaculture sites are located, it is difficult to predict sea conditions due to inflow from rivers, etc. By using seacondition information, such as sea temperature, from
ICT buoys provided by NTT DOCOMO as input
information for Forecast Ocean Plus’s forecastingmodel, it is possible to improve the forecasting accu-

Fig. 3. S creenshot of the umi-miru smartphone app for
sea-condition simulation.

racy of sea conditions in bays.
4. Future developments
The Japanese fisheries industry is facing many
challenges, such as a decreasing fish catches and an
aging population of fishers and farmers. Working
closely with our partners, NTT DOCOMO wants tocontribute to revitalizing local communities anddeveloping the Japanese fisheries industry by providing solutions to these challenges by using our experience and expertise in supporting the reconstruction
from the 2011 Great East Japan Earthquake and in
directly communicating with fishers and farmers.

Authors: (from left) Masako Nakashima, Assistant Manager, Kyushu Regional
Office, NTT DOCOMO, INC.; Keiichi Yamamoto, Manager, ICT for Regional
Revitalization Promotion Office, NTT DOCOMO, INC.; Yutaka Okabe, ICT for
Regional Revitalization Promotion Office, NTT DOCOMO, INC.; and Yuko Yokoi,
Assistant Manager, ICT for Regional Revitalization Promotion Office, NTT
DOCOMO, INC.

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

30

Feature Articles: Initiatives for Smart Agri—Making
Japanese Agriculture a Growing Industry

High-quality, High-yield Organic
Farming with BLOFware®.Doctor
Hirofumi Umeshita, Shintaro Uno, Yutaka Kobayashi,
Takeshi Saito, Masashi Kashima, and Marina Wada
Abstract

Organic farming has been gaining attention as a sustainable agriculture both in Japan and around theworld; however, it faces problems such as inconsistent quality and yield, making stabilized productiondifficult. The organic cultivation theory called the “BLOF® (biological farming) theory” can solve these
problems and achieve stable, high-quality, high-yield production in organic farming. NTT COMWARE
has incorporated the expertise of organic cultivation based on the BLOF theory into its service systemand started to provide a cloud-based farming-support service called “BLOFware®.Doctor.” The service
content and future development of BLOFware.Doctor are introduced in this article.
Keywords: smart agriculture, organic farming, BLOFware®

1. Environment surrounding organic farming
Accompanying the widespread adoption of theUnited Nations’ Sustainable Development Goals,
interest in organic farming as a sustainable agriculture to conserve the global environment has been
growing around the world.
Organic farming is also being actively promoted inJapan, where the Ministry of Agriculture, Forestry
and Fisheries (MAFF) has set a goal of increasing thearea of organic farming to 25% (one million ha) ofJapan’s total farmland by 2050 [1, 2] (Fig. 1). However, the current area of organic farming as a percentage of total farmland is only 0.5% (237,000 ha, as of2018) [3], therefore, increasing it to 25% in about 30
years is a very challenging goal. Organic farming
generally requires more labor than conventional agriculture,*1 and its quality and yield are inconsistent, so
it is difficult to stabilize production. To achieve theabove-mentioned goal, it is important to establish anddisseminate effective technologies to solve these
problems facing organic farming.

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

2. Applying the BLOF® theory to solve theproblems facing organic farming
The solution to the above problems facing organic
farming is the “BLOF® (biological farming) theory,”*2 which is an organic-cultivation theory advocated by Masaaki Koiwai of Japan Bio Farm Co., Ltd.
The BLOF theory enables stable production oforganic crops with high quality and high yield by
scientifically and logically preparing the soil (Fig. 2).
To create optimal soil for growing crops, it is necessary to create ideal conditions with respect to the following three major soil components: (i) amino acids,
which build cells; (ii) minerals, which are essential
for maintaining life; and (iii) medium-matured compost, which promotes root growth.
Plants produce amino acids (organic nitrogen) necessary for growth by synthesizing carbohydrates created through photosynthesis and inorganic nitrogen
absorbed from the roots; however, research has*1 Conventional agriculture: Agriculture that uses chemical fertilizers and pesticides for pest control and weed control.
*2 BLOF® and BLOFware® are registered trademarks of Japan Bio
Farm Co., Ltd. Other company names, product names, and service names mentioned herein may be the trademarks or registeredtrademarks of their respective owners.

31

Feature Articles

The ratio of organic farmingarea to the total farmland:
25% (one million ha)[Announced by MAFF]

Expansion of cultivation thatuses less pesticide/fertilizer by
elucidating and fully using soil
microorganisms

Technological innovation to expand
the area of organic farming

Expansion of supply chain of aneffective biological pesticidethat covers various types of
insects

Pest-control technology thatmakes full use of advanced
physical and biologicalmethods

Pest-control technology thatmakes full use of advanced
physical and biologicalmethods

Diagnostic technology forpotential onset of soil
disease using artificial
intelligence, etc.

Diagnostic technology forpotential onset of soil
disease using artificial
intelligence, etc.

Development of infrastructure
surrounding causeways andcultivated land that enables
automation of weeding

Initiatives andtechnology

Cultivation of varieties
resistant to majordiseases

Development of infrastructure
surrounding causeways andcultivated land that enables
automation of weeding

Establishment of a crop-rotation
system that incorporates
soil-maintenance crops

Establishment of a crop-rotation
system that incorporates
soil-maintenance crops

Making soil by applying
organic matter such as
green manure

Making soil by applying
organic matter such as
green manure

Making soil by applying
organic matter such as
green manure

Control of weeds throughwater management in paddy
fieldsControl of weeds throughwater management in paddy
fieldsControl of weeds throughwater management in paddy
fieldsControl of weeds throughwater management in paddy
fieldsPest-control technology
using indigenous natural
predators and light

Pest-control technology
using indigenous natural
predators and light

Pest-control technology
using indigenous natural
predators and light

Pest-control technology
using indigenous natural
predators and light

Establishment of a crop-rotation
system that incorporates
soil-maintenance crops

Initiatives andtechnology

Initiatives andtechnology

Development of infrastructure
surrounding causeways andcultivated land that enables
automation of weeding

Initiatives andtechnology

Diagnostic technology forpotential onset of soil
disease using artificial
intelligence, etc.

Cultivation of varieties
resistant to majordiseases

Making soil by applying
organic matter such as
green manure

2020

Establishment of a crop-rotation
system that incorporates
soil-maintenance crops

2030

2040

2050

Fig. 1. Efforts to expand the area of organic farming announced by MAFF [2].

shown that amino acids can be absorbed directly
through the roots. The BLOF theory applies theresults of this research and enables the provision ofamino acids as fertilizer to be absorbed directly by theroots to achieve higher quality and higher yields thanordinary crops. Minerals in the soil that have been
consumed by crops in large quantities to promotehigh quality and high yield can be appropriately
replenished through fertilization*3 on the basis of theresults of analyzing the current compositional balance of the soil; as a result, stable production is possible in the following years. By using mediummatured compost, it is possible to create soil with afluffy, clustered structure. This type of soil allows theroots to grow deep into the ground, producing strongcrops that do not attract pests and diseases without theuse of pesticides.
The BLOF theory, which provides solutions to the
problems facing organic farming and helps expand
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

the area of organic farming, is evolving yearly. However, because it requires a high degree of specialized
knowledge and skills to put it into practice, it has notbeen widely used.
3. Cloud-based farming-support service:
BLOFware®.Doctor
In August 2020, through a business alliance withJapan Bio Farm, NTT COMWARE started providing
the cloud-based farming-support service called
BLOFware®.Doctor that incorporates the knowledgeof the BLOF theory. During the development of
BLOFware.Doctor, we adopted an agile methodology and worked with Japan Bio Farm from the concept-making stage. We conducted interviews withexperts in the BLOF theory and farmers about a*3 Fertilization: spreading fertilizer on soil (fields).

32

Feature Articles

Comparison of yields
Carrots

Comparison of taste
Tomatoes

Ordinary spinach(national average fromJanuary to February)

Spinach cultivated on thebasis of the BLOF theory
17.5

227

1991

101

69
8.3

Beforeimplementing
the BLOF theory

After
implementing
the BLOF theory

Beforeimplementing
the BLOF theory

After
implementing
the BLOF theory

3t(return)6t(return)

4

12

99

85
Sugar Antioxidant Vitamin C Nitrate ions*content
content*Origin of the vegetable’s harsh taste
The lower the number, the less harshness, so the taste is better.
Yield: amount of crop harvested
Taste: umami (deliciousness) of food.

Fig. 2. Crops cultivated on the basis of the BLOF® theory.

prototype of BLOFware.Doctor and flexibly reflected the issues and requests we obtained from them inthe specifications of the prototype. In this manner, we
continued improving the prototype. In August 2019,
we conducted demonstration tests on organic farming
based on the BLOF theory by using the prototype of
BLOFware.Doctor in cooperation with farmers andconfirmed that BLOFware.Doctor can contribute toimplementing organic farming based on the BLOF
theory. After incorporating the requests from farmers
concerning operability and functionality received
during the demonstration tests, we launched the service on a full scale in August 2020.
We are collaborating with Japan Bio Farm regarding the provision as well as development of BLOFware.Doctor. By dividing the roles of the two companies according to their strengths, that is, NTT COMWARE took responsibility for construction and provision of the service system, while Japan Bio Farm
took responsibility for provision of expertise andknowledge concerning the BLOF theory and user
guidance, we are able to provide services that focus
on helping farmers. BLOFware.Doctor allows farmers who have never been exposed to the BLOF theory
to easily practice organic farming based on the BLOF
theory on the basis of the following three points.

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

3.1 P
 oint 1: The BLOF theory can be learnt fromthe basics
The first point is that it has a full range of features
to help users learn the basics of the BLOF theory.
BLOFware.Doctor provides a “growing map” that
explains the basics of the BLOF theory in an easy-tounderstand manner with photos (Fig. 3). The map canserve as a textbook of the BLOF theory that summarizes key points concerning work to be done in accordance with the growth stage of each crop, and it canbe used for learning the BLOF theory and as a manual guide for actual farm work.
Japan Bio Farm also holds regular online seminars
limited to users of BLOFware.Doctor. This is a special program that includes lectures on how to use
BLOFware.Doctor and guidance on the agricultural
work needed at that time of the year, so users can
immediately put into practice what they learned in theseminar.
The growing map is available (via the cloud) for
reference any time, and the seminars are archived forreview at any time, so users can learn whenever theylike, such as during their spare time. At organizations
with multiple farmers, such as agricultural corporations, members can learn the same content, even if it
is difficult for everyone to get together at the sametime, which helps to establish a common language.
33

Feature Articles[Recommendation and tips by a farmer
practicing the BLOF theory]
Be careful of [X] when sprinkling
lime and magnesium.
The key to distinguishing between
good and bad fermented
chicken droppings is [X]…

Explain key points inaccordance with thegrowth stage (soil analysis,
fertilizer planning, straw
treatment, raisingseedlings, etc.)

Fig. 3. Screenshot of growing map.

3.2 P
 oint 2: Anyone can easily practice soil analysis and fertilizer planning
The second point is that soil analysis and fertilizer
planning can be easily carried out by anyone. The twomost-important steps in soil preparation, which is thecore of the BLOF theory, are soil analysis, whichanalyzes the balance of soil components in the fieldin question, and fertilizer planning, which calculates
how much fertilizer should be applied to the field. Ifthese steps are not done properly, the effectiveness ofpracticing the BLOF theory will be greatly reduced.
BLOFware.Doctor is linked with the soil-analysis
service provided by Japan Bio Farm. Users collectsoil from their fields and send it to Japan Bio Farm,
who analyze it and send the analysis results back to
the users. The received analysis data can be easily
imported into BLOFware.Doctor, so users can immediately proceed to creating a fertilizer plan.
Although Excel tools are available to assist in fertilizer planning for the BLOF theory, they require complex calculations and adjustments, which is one of thereasons that beginners stumble when practicing the
BLOF theory. In response to the feedback from farmers, BLOFware.Doctor was designed so that anyone
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

can easily create fertilizer plans by using graphs andeasy-to-understand operations. Users can simulate
the optimal amount of fertilizer by simply adjusting
the amount of fertilizer they want to use in accordance with a guidance for optimal balance of soil
components that is automatically displayed on theirscreen (Fig. 4). The calculation and adjustment logic
is all built into the service system, so the user does notneed to be aware of it. By applying fertilizer in accordance with the resulting fertilizer plan, it is possible
to create the optimal soil for growing certain crops
and achieve high-quality, high-yield production.
BLOFware.Doctor incorporates new knowledge on
nitrogen content in the soil, whereas the only previously published information on fertilizer planning
was related to the balance of mineral components. By
simply entering the required information, the system
automatically calculates the optimal amount of nitrogen and the amount of fertilizer needed to achieve it.
BLOFware.Doctor also incorporates a large
amount of information that has never been made public before. For example, BLOFware.Doctor not only
has separate functions for rice, vegetables, and fruit
crops but also incorporates optimized calculation
34

Feature Articles

Soil component

Analysisvalue Simulation (mineral)

Analysis Decrease Increasevalue in value in value

Cation exchange capacity
Electrical conductivity
pH (H2O)
pH (KCI: potassium chloride)
Available phosphate
Exchangeable lime
(CaO: calcium oxide)
Exchangeable magnesium (MgO)
Exchangeable potassium(K2O: potassium oxide)
Boron
Available ironExchangeable manganese
Humus
Salt

Lower limit

Upper limit

Lower limit and upper limit line: Range of
optimum soil-component values inaccordance with the cultivated crops(automatically displayed by the system)
Adjust the amount of fertilizer so that thegraph of each component value
approaches the upper limit line

Fig. 4. Screenshot of fertilizer plan.

logic for each crop, such as carrots, onions, and spinach; in contrast, only common calculation logic for
all crops was previously published. This informationis unique to Japan Bio Farm and has not been published previously. Incorporating this information into
BLOFware.Doctor makes it possible for a wide range
of farmers to use advanced technology based on the
BLOF theory while the core information is kept
secret.

soil analysis and a fertilizer plan for the user’s fields.
Therefore, the user can receive suitable advice basedon his/her specific situation—just like a family doctor.
We have also set up a Facebook page exclusively
for BLOFware.Doctor users as a platform to exchange
information with other practitioners. That page willallow users to interact with each other and accumulate more knowledge.

3.3 P oint 3: Support is available when problems
arise
The third point is that support is available whenever
the user needs it. Although there are about 2000 practitioners of the BLOF theory, they are scatteredthroughout Japan. Consequently, it is often the casethat newcomers to the BLOF theory have no one
around them who practices it or no other practitioners
to turn to for advice when in need. To address thisissue, BLOFware.Doctor provides a support function, called “instructor’s advice,” which allows users
to seek advice from instructors who are experts in the
BLOF theory (Fig. 5). First, the user inputs questions
and photographs of actual crops. The instructor
returns advice based on the questions and photographs as well as information such as the results of

4. Future developments

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Vol. 19 No. 8 Aug. 2021

By providing BLOFware.Doctor featuring the three
key points described above, we will help farmers succeed through the practice of the BLOF theory. Currently, only the rice-paddy version is available, but
the vegetable and fruit-tree versions will be respectively available in the summer and fall of 2021.
We plan to make BLOFware.Doctor even easier touse by incorporating the voices of farmers and thelatest knowledge about the BLOF theory and improving the instructor-advice function with artificial intelligence and chatbots. We also want to develop BLOFware.Doctor into a BLOFware series of services thatprovides comprehensive support for agriculture—from production to sales—to help farmers increase35

Feature Articles

Register questionsin the system

Judging from information,
instructor advises

Soil-analysis results

The cause is thelack of [X].
Try increasing the amountof [X]. For example...

Part of the leaf isblack. Is it somekind of disease?

Resulting fertilizer plan
Photo of crops

Fig. 5. Illustration of usage of “instructor’s advice.”

profits. In the future, we will consider global expansion of BLOFware.Doctor to contribute to solving theworld’s food crisis.
References[1]

Website of MAFF, Strategy for Sustainable Food Systems, MeaDRI,

[2]

[3]

https://www.maff.go.jp/e/policies/env/env_policy/meadri.html
MAFF, “Strategy for Sustainable Food Systems, MeaDRI (Interim
Report),” Mar. 2021 (in Japanese).
https://www.maff.go.jp/j/kanbo/kankyo/seisaku/midori/attach/pdf/
team1-120.pdf
MAFF, “Circumstances Surrounding Organic Farming,” Sept. 2020
(in Japanese).
https://www.maff.go.jp/j/seisan/kankyo/yuuki/attach/pdf/meguji-full.
pdf

Authors: (back row from left) Shintaro Uno, Manager, NTT COMWARE CORPORATION; Yutaka Kobayashi, Chief, NTT COMWARE CORPORATION; Takeshi
Saito, Chief, NTT COMWARE CORPORATION; Marina Wada, Member, NTT
COMWARE CORPORATION; Masashi Kashima, Chief, NTT COMWARE CORPORATION; (front row center) Hirofumi Umeshita, General Manager, NTT COMWARE CORPORATIONNTT Technical Review

Vol. 19 No. 8 Aug. 2021

36

Regular Articles

Multi-radio Proactive Control
Technology (Cradio®): A Natural
Communication Environment where
Users Do Not Need to Be Aware of the
Wireless Network
Motoharu Sasaki, Toshiro Nakahira,Takatsune Moriyama, Tomoaki Ogawa, Yusuke Asai,and Yasushi Takatori
Abstract

To provide a natural communication environment where users do not need to be aware of the wirelessnetwork, we are researching and developing Cradio®—a set of multi-radio proactive control technologies
that combines three advanced and coordinated technology groups: wireless sensing/visualization,
wireless-network-quality prediction/estimation, and wireless-network dynamic control. This article
describes the Cradio technology suite and our vision for the creation of a natural communication
environment by combining these technologies with various social systems.
Keywords: Cradio®, multi-radio proactive control technologies, wireless communication

1. The prospects of wireless networks
1.1 I ncreasing communication volume and diversifying communication requirements
The concept of the Innovative Optical and Wireless
Network (IOWN) has been proposed by NTT as amodel for future implementation of networks [1]. The
role of wireless communication is increasing dramatically in all aspects of our lives due to the growing
volume of smartphone traffic and the development ofInternet of Things (IoT) technology used to connect avariety of diverse objects to the Internet. It is therefore predicted that the volume of wireless communication will continue to increase. According to ITUR*1 Report M.2370, mobile data traffic will reach
5016 EB/month in 2030, about 80 times higher thanin 2020 [2]. In particular, the volume of machine-toNTT Technical Review

Vol. 19 No. 8 Aug. 2021

machine communication, which correlates with IoT,
is expected to increase by about 124 times (622 EB/
month). This shows that in addition to the increase incommunication volume, there will also be greater
diversity in the types of wireless terminals and usage
patterns of wireless communication. Mobile communication will not just be used for smartphones but also
for remotely controlling automated vehicles anddrones and exchanging ultra-high definition video.
This diversification of wireless terminals and usage
patterns means that it is important to provide wirelessnetwork coverage not only in urban areas where thepopulation is concentrated but also in suburban andrural areas. Therefore, we must respond to the*1 ITU-R: The Radiocommunication Sector of the International
Telecommunication Union (ITU).

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increasingly diverse requirements for wireless communication quality suitable for various forms of use.
1.2 D
 iversification and increased frequency ofwireless networks
To address these needs, studies are underway todevelop various wireless communication standards.
For mobile cellular communication, commercial
fifth-generation mobile communication system (5G)
services were launched in 2020, and progress is now
being made in the research and development of 6G
technology [3]. In addition to high-speed and largecapacity communications, low-latency and highly
reliable communications, and multiple connections
that exceed those of 5G, 6G includes new requirements that were not considered in 5G. There are also
growing expectations for the use of private 5G, whichenables the flexible deployment of private 5G systems within the buildings and premises of diverse
entities such as businesses and local government bodies according to the needs of individual regions andindustries [4]. In wireless local area networks(LANs), IEEE*2 802.11be is being standardized as
the successor to the IEEE 802.11ax wireless communication standard, which is the technology behind
Wi-Fi 6. When it finally comes out, IEEE 802.11be
will support not only high-speed transmission with amaximum communication rate of 46 Gbit/s but also
additional features such as multiple access points [5].
Development of the IEEE 802.11ay standard for
WiGig (Wireless Gigabit) networks is also underway
as a successor to IEEE 802.11ad, which uses the
60-GHz band [6]. For low-power wide-area (LPWA)
networks, various demonstration experiments arebeing conducted with the aim of implementing Wi-Fi
HaLowTM (IEEE 802.11ah), which is a wireless communication standard for IoT applications that also
supports video transmission [7].
With developments such as these, the use of diverse
wireless communication standards such as public cellular, private cellular, wireless LAN, and LPWA networks is going to become more widespread. Thesewireless communication standards use a variety of
frequency bands ranging from 1 GHz to several tensof GHz, and studies related to 6G are even considering the use of frequencies above the 100-GHz bandand into the THz band [3]. Although these high-frequency bands support higher communication bandwidths, their coverage areas are smaller due toincreased radio-wave propagation losses. Therefore,
to properly handle user requirements that change
from time to time, from location to location, and fromNTT Technical Review

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one application to the next, it is essential to properly
use complex wireless networks that support a mixtureof different wireless communication standards acrossa wide range of frequency bands with different propagation characteristics.
NTT aims to provide a natural communication
environment where users do not need to be aware of
how they are using wireless networks because they
are always provided with the best possible communication environment to suit their ever-changing needs
and radio-wave conditions in their current location.
As a constituent part of IOWN [1], we are working on
the research and development of Cradio®, a set of
multi-radio proactive control technologies.
2. Cradio® (multi-radio proactive
control technologies)
We designed Cradio to keep up with the constantevolution of user requirements and radio-wave conditions so that a natural communication environment
can be continuously provided without users having to
be aware of how they are using the wireless network.
It is broadly composed of the following three technology groups (Fig. 1).
(1)	Understanding (wireless sensing/visualization): Visualization of real-world conditions
by wireless state measurement/visualization,
wireless sensing, etc.
(2)	Prediction (wireless-network-quality prediction and estimation): Prediction and estimation of constantly changing wireless communication quality(3)	Control (wireless-network dynamic design/
control): Design of physical layouts in accordance with the local environment and requirements, derivation of optimum wireless parameters, dynamic control of network parameters
and resources, etc.
By advancing these three wireless technology
groups and linking them in real time, we aim to keep
abreast of constant changes in radio-propagation conditions and the needs of users to provide a naturalcommunication environment where users do not haveto be aware of how they are using wireless networks.
With these three technology groups, Cradio has
three means of addressing each of the issues that are
liable to make it difficult for users to communicate
comfortably at any time and in any location (Fig. 2).
Wireless sensing/visualization technology addresses*2 IEEE: The Institute of Electrical and Electronics Engineers

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Diverse application systems

Cradio®

...

Constantly changing

Diverse wireless networks

Prediction

Control

Wireless-networkquality predictionand estimation

Wireless-network
dynamic design/
control

Self-employed/Public
Licensed/Unlicensed

Cooperation

Diverseenvironments
Wireless sensing/visualization
Understanding

Diverseterminals

Diverse use cases

Fig. 1. Cradio concept.

Cradio®

Future challenges for wireless networks

Wireless sensing/visualization

Radio environments are becoming more
complex due to the expansion of usage areas
and are becoming harder to understandbecause they are constantly changing.

Wireless-network-quality
prediction and estimation

It is difficult to proactively provide
communication environments adapted to theconstant changes in user needs andpropagation environments or optimal ICT
environments including applications.

Wireless-network
dynamic design/control

It is difficult to provide optimal communication
environments that meet the demands of users
due to increasing complexity in the design andcontrol of a variety of diverse wirelessnetworks.

People are unable
to communicate
with ease anywhere
and at any time.

Fig. 2. How Cradio’s technologies address future challenges in wireless networks.

the increasing complexity of the radio environment
caused by the expansion of usage areas and the continuous fluctuations of these environments that are
making them harder to understand. Wireless-network-quality prediction and estimation addresses thedifficulty of proactively providing communication
environments adapted to constant changes in userneeds and propagation environments and optimal
information and communication technology (ICT)
environments including applications. Wireless-netNTT Technical Review

Vol. 19 No. 8 Aug. 2021

work dynamic design/control addresses the difficultyof providing optimal communication environments
due to increasing complexity in the design and control used in a variety of diverse networks. These three
wireless technology groups are explained below.
2.1 U nderstanding: Wireless sensing/visualization
Wireless sensing/visualization technology (Fig. 3)
collects and analyzes information from various
39Regular Articles

Multidimensional visualization of wireless states

Ascertain wireless status

Frequency,
wireless
communication
systemLocation

Time
Multidimensional visualization of wirelesscommunication-system quality and hidden
margins

Visualization of real-world states

Wireless sensing,wireless positioning, etc.
Wireless environmental
monitoring

Fig. 3. Understanding – Wireless sensing/visualization.

wireless devices in various wireless communication
systems to ascertain and visualize the status of wireless communication systems with regard to multiple
dimensions, including frequency, method, location,and time. This makes it possible to clarify the communication quality of wireless systems, find hidden
margins, and ultimately improve the efficiency ofradio-wave utilization.
By using radio-communication technologies, suchas wireless sensing and wireless positioning, it is possible to ascertain and visualize the real-world conditions around wireless devices. Therefore, it should bepossible to quantify the position and state of everything that affects a wireless network. These technologies create an image of the real world that is important for ensuring the quality of wireless communication. This makes it possible to understand and visualize diverse environmental factors that affect wirelesscommunication quality, including non-communication areas in wireless communication systems. It canalso be expected to create added value as a new social
infrastructure.
With the technology that we have used for ascertaining and visualizing the state of wireless LANs, it
became possible to check the quality of a wireless
NTT Technical Review

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LAN in real time [8]. In addition, wireless-LAN sensing technology [9] makes it possible to ascertain theimpact of the surrounding environment on wirelesscommunication quality and create added value forwireless communication systems. We are currently
working to expand the range of target wireless systems on the basis of these technologies and makefurther enhancements to these technologies.
2.2 P rediction: Wireless-network-quality prediction and estimation
Wireless-network-quality prediction and estimation technology executes deep learning on the basisof information obtained from wireless sensing andvisualization technology to predict and estimate thequality of wireless communication, which changes
from moment to moment in accordance with the surrounding environment and terminal position [10],thereby facilitating proactive optimization on thebasis of future conditions (Fig. 4). The quality ofwireless communication is affected by the radiopropagation environment between transmitters andreceivers and varies in accordance with the usage
conditions (resource availability) of the wirelesscommunication system. Since these conditions
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Cradio®

Learning algorithm

Wireless-quality
prediction engine

Database

Estimated target wireless base station(private 5G, wireless LAN, etc.)

Network

Inquiry(wireless environment
information, terminal
information, location
information)

Predicted quality

Time
Best choice

Terminal

Drone
Smartphone

Robot• Use the best wireless access on basis of predicted quality• Detect anomalies in each wireless accessFig. 4. Prediction – Wireless-network-quality prediction and estimation.

change from time to time, this prediction and estimation of wireless communication quality is not easy to
do. With the above-mentioned wireless sensing andvisualization technology, it is possible to ascertain
and visualize the status of wireless communication in
multiple dimensions on the basis of information collected from various devices and ascertain and visualize the real-world conditions surrounding wirelessdevices that affect the quality of radio communication. As a result, it should be possible to predict andestimate communication-quality parameters for eachlocation, time period, and radio communication
method with unprecedented accuracy. This will makeit possible to make advance network-environment
preparations in accordance with application requirements, avoid deterioration of communication quality
and breaks in communication, and automaticallyselect networks to connect to. Our aim is to provide
proactive communication services that always deliver
high quality of experience and quality of service.
We have conducted demonstration trials to predict
the quality of communication between a cellular sysNTT Technical Review

Vol. 19 No. 8 Aug. 2021

tem and broadband wireless access in the control ofself-driving agricultural machinery, which was able
to execute network switching control to connect to asuitable network while continuing to provide therequired communication quality [10]. We are currently investigating the enhancement of techniques
for predicting and estimating the quality of generalpurpose wireless networks by combining the various
types of information mentioned above.
2.3 C ontrol: Wireless-network dynamic design/
control
In wireless-network dynamic design/control technology, on the basis of communication quality information obtained from wireless-network-quality prediction and estimation, we are carrying out switching/cooperation control of wireless-network dynamic
configuration and switching/cooperation control ofmultiple wireless networks and control/optimization
for the wireless connection of terminals (Fig. 5). As
well as the optimization of various wireless parameters,
this consists of comprehensive wireless-network
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White-box base station(multi-method
support)

Entrance

Dynamic WAN

Multi-wireless network environment(cellular/private 5G/Wi-Fi/LPWA, etc.)

Fig. 5. Control – Wireless-network dynamic design/control.

design optimization and control measures such as the
dynamic configuration of multi-radio networks withwhite-box wireless base stations that support multiple
wireless communication standards, modification of
the physical location and antenna direction of wireless base stations, and dynamic configuration of wide
area network (WAN) entrances to adapt to thesechanges. Dynamic control can be considered not only
for wireless networks but also for radio-propagation
environments using equipment such as intelligent
reflectors. This will make it possible to provide aworld where wireless networks can be dynamically
prepared wherever and whenever they are needed,facilitating a departure from the presumption of preprepared communication environments using conventional fixed wireless base-station locations andspecified wireless communication standards. Using
these technologies, our aim is to proactively and automatically configure optimal wireless networks toaccommodate ever-changing user requirements andradio-wave conditions. This will lead to wireless networks that operate more efficiently and consume lesspower.
On the basis of wireless-resource dynamic control
technology for wireless LANs that we have previously studied [11], we are working on practical technologies for the expansion and technical enhancement of target wireless systems, dynamic control ofbase-station placement (which have hitherto been
fixed) [12], and implementation of distributed intelNTT Technical Review

Vol. 19 No. 8 Aug. 2021

ligent reflectors [13].
3. Cradio’s potential for providing a naturalcommunication environment
With Cradio’s multi-wireless proactive control
technology, it is possible to keep up with the constantchanges of user needs and radio-propagation conditions through the advanced combination of wirelesstechnologies such as the acquisition and visualizationof diverse information in wireless networks, prediction and estimation of wireless-network transmission
quality, and dynamic design and control of wirelessnetworks. Cradio can also collaborate with various
social systems and applications to create a naturalcommunication environment where users do not need
to be aware of the wireless network. By cooperatingwith various application systems outside the wirelesslayer, Cradio optimizes the wireless network inaccordance with the status of applications that are in
use and optimizes applications in accordance with thestatus of the wireless network (Fig. 6).
For example, by cooperating with and using information from social systems such as weather information systems and demographic systems involving
various types of sensors and video information fromcameras, we can expect to improve the accuracy ofquality prediction/estimation and acquisition/visualization of information from wireless networks,
including information about local conditions, such as
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Prediction

Wireless-networkquality predictionand estimation

Cradio®
Understanding
Wireless sensing/visualization

Cooperation

Wireless-network
dynamic design/
control

Control

Fig. 6. Coordination of multi-radio proactive control technology (Cradio) with various applications and social systems.

rainfall, that can affect radio communication (especially at high frequencies), and the state of use ofwireless communication systems (available wirelessresources), and to use this information for the designand control of wireless networks [14]. In the abovementioned example of autonomous vehicles, by using
Cradio to predict and estimate wireless network quality in cooperation with automated driving management systems, it is possible for autonomous vehicles
to select routes and adjust their driving speeds inaccordance with the current quality of wireless communication. Video systems needed for the management of autonomous vehicles should be able to maintain the required video quality by dynamically adjusting the video codec rate. Therefore, all types of systems can be operated in a more advanced and flexible
manner by cooperating with diverse social systems to
obtain input information that can be used by Cradio
and by cooperating so that information obtained with
Cradio can be used outside the radio network layer.
Cradio’s wireless technologies can provide higher
value by coordinating with various systems andapplications. We are currently conducting researchand development aimed at implementing Cradio toprovide wide-ranging value.

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4. Future prospects
We described various components of Cradio andthe natural communication environment that Cradio
can provide through cooperation with diverse systems and applications. With the arrival of IOWN
around 2030, we will continue to promote researchand development aimed at implementing Cradio.
References
[1]
[2]
[3]

[4]

[5]

[6]

IOWN, https://www.rd.ntt/e/iown/
ITU-R Report M.2370, “IMT Traffic Estimates for the Years 2020 to2030,” https://www.itu.int/pub/r-rep-m.2370
NTT DOCOMO, “White Paper on 5G Evolution and 6G (Version3.0),” Feb. 2021, https://www.nttdocomo.co.jp/english/binary/pdf/
corporate/technology/whitepaper_6g/DOCOMO_6G_White_
PaperEN_v3.0.pdf
Telecommunications Bureau, Ministry of Internal Affairs andCommunications, “Initiatives for Widespread Use and Advancementof 5G and Private 5G,” Oct. 2020 (in Japanese), https://www.soumu.
go.jp/main_content/000716749.pdf
Y. Inoue and A. Kishida, “Standardization of Next-generation
Wireless LANs in the IEEE 802.11 Working Group,” NTT Technical
Review, Vol. 19, No. 2, pp. 63–67, Feb. 2021.
https://ntt-review.jp/archive/ntttechnical.php?contents=ntr202102gls.
html
Y. Ghasempour, C. R. C. M. da Silva, C. Cordeiro, and E. W. Knightly,“IEEE 802.11ay: Next-Generation 60 GHz Communication for 100
Gb/s Wi-Fi,” IEEE Communications Magazine, Vol. 55, No. 12, pp.
186–192, Dec. 2017.

43

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[7]
[8]

Wi-Fi HaLow, https://www.wi-fi.org/discover-wi-fi/wi-fi-halow
NTT Access Network Service Systems Laboratories, “Developmentof Wireless Communication Environment Information Platform,”
ANSL R&D Times, Vol. 111, Dec. 2019 (in Japanese), https://www.
rd.ntt/as/times/111/02/top.html[9] T. Murakami, S. Otsuki, T. Hayashi, Y. Takatori, and K. Kitamura,“Wildlife Detection System Using Wireless LAN Signals,” NTT
Technical Review, Vol. 17, No. 6, pp. 45–48, June 2019.
h t t p s : / / n t t - r ev i ew. j p / a r c h ive / n t t t e c h n i c a l . p h p ? c o n t e n t s =ntr201906fa13.html[10] K. Wakao, K. Kawamura, and T. Moriyama, “Quality-prediction
Technology for Optimal Use of Multiple Wireless Access Networks,”
NTT Technology Review, Vol. 18, No. 6, pp. 17–20, 2020.
h t t p s : / / n t t - r ev i ew. j p / a r c h ive / n t t t e c h n i c a l . p h p ? c o n t e n t s =ntr202006fa2.html[11] NTT Access Network Service Systems Laboratories, “Technology

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for Efficiently Providing Optimal Wireless LANs,” ANSL R&D
Times, Vol. 116, Aug. 2020 (in Japanese), https://www.rd.ntt/as/
times/116/04/index.html[12] T. Nakahira, M. Sasaki, A. Hirantha, T. Moriyama, Y. Takatori, D.
Goto, and T. Arai, “Dynamic Control of AP Placement and Radio
Parameters for Improving Throughput in Congested Areas,” 12th
International Conference on Emerging Technologies forCommunications (ICETC 2020), Dec. 2020.
[13] M. Iwabuchi, T. Murakami, R. Ohmiya, T. Ogawa, Y. Takatori, Y.
Kishiyama, and T. Asai, “Intelligent Radio-wave Design: Distributed
Intelligent Reflecting Surface with Direction-based Control for
Millimeter-wave Communications,” ICETC 2020, Dec. 2020.
[14] R. Kudo, K. Takahashi, T. Iwabuchi, R. Omiya, T. Murakami, and T.
Ogawa, “Controlling Wireless Communication Quality by Integrating
Real-world Information and Wireless NW,” IEICE General
Conference, BI-9-2, Mar. 2021 (in Japanese).

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Motoharu Sasaki

Senior Research Engineer, Wireless Access
Systems Project, NTT Access Network Service
Systems Laboratories.
He received a B.E. in engineering and an M.E.
and Ph.D. in information science and electricalengineering from Kyushu University, Fukuoka,
in 2007, 2009, and 2015. In 2009, he joined NTT
Access Network Service Systems Laboratories.
He has been engaged in research on propagation
modeling for various wireless communication
systems; propagation modeling of interference
between mobile terminals for spectrum sharing
wireless access systems, propagation modelingin VHF bands for emergency wireless systems,
and propagation modeling in high frequency
bands for 5G. He received the Young Researcher’s Award and the Best Paper Award from theInstitute of Electronics, Information and Communication Engineers (IEICE) in 2013 and 2014,
respectively. He received the Best Paper Award at
the International Symposium on Antennas andPropagation (ISAP) in 2016 and the Young Engineer Award from the Institute of Electrical andElectronics Engineers (IEEE) Antennas andPropagation Society Japan chapter in 2016. Healso received the Young Researcher Award andthe Excellent Paper Award from IEICE TechnicalCommittee on Antennas and Propagation in 2012
and 2018, respectively. He is a member of IEEE.

Toshiro Nakahira

Research Engineer, NTT Access Network Service Systems Laboratories.
He received a Bachelor of Maritime Safety
from Japan Coast Guard Academy, Hiroshima,
Japan, in 2009 and M.I. in informatics from
Kyoto University in 2012. In 2012, he joined
NTT Network Innovation Laboratories. He is
now working at NTT Access Network Service
Systems Laboratories. He received the Best
Research Award of the fourth basic course workshop of IEICE Communication Quality in 2017
and the Young Engineer Award from IEICE in
2019. He is a member of IEICE.

Takatsune Moriyama

Senior Research Engineer, Supervisor, NTT
Access Network Service Systems Laboratories.
He received a B.E. and M.E. from MuroranInstitute of Technology, Hokkaido, in 1991 and1993. He joined NTT in 1993. From 1999 to June
2019, he worked at NTT Communications,where he was in charge of network service development and operation for corporate customers.
He has been in his current position since July2019.

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

Tomoaki Ogawa

Senior Research Engineer, Supervisor, NTT
Access Network Service Systems Laboratories.
He received a B.E. and M.E. from Keio University, Kanagawa, in 1996 and 1998. He joined
NTT Wireless Systems Laboratories in 1998,
where he was engaged in the research and development of indoor location systems. His mostrecent interest is on the development of 6G wireless network technologies. He is a member of
IEICE.

Yusuke Asai

Senior Research Engineer, Supervisor, NTT
Access Network Service Systems Laboratories.
He received a B.E., M.E., and Ph.D. in electronical engineering from Nagoya University,
Aichi, in 1997, 1999, and 2017. He joined NTT
Network Innovation Laboratories in 1999, where
he has been engaged in the research and development of signal processing and resource-management techniques for broadband wireless LAN
systems. He received the Young Researcher’sAward from IEICE in 2004 and the Certificationof Appreciation for outstanding contributions to
the development of IEEE 802.11ac-2013 fromthe IEEE Standards Association in 2014. He is amember of IEICE and IEEE.

Yasushi Takatori

Executive Manager, Senior Distinguished
Researcher, NTT Access Network Service Systems Laboratories.
He received a B.E. and M.E. in electrical andcommunication engineering from Tohoku University, Miyagi, in 1993 and 1995. He received aPh.D. in wireless communication engineeringfrom Aalborg University, Aalborg, Denmark, in2005. He joined NTT in 1995 and has served asa secretary of IEEE Japan Council Awards Committee and a vice chairman of the Wireless LAN
system development project in the Association ofRadio Industries and Businesses (ARIB). He wasa visiting researcher at the Center for TeleInFrastructure (CTIF), Aalborg University from 2004
to 2005. He served as a co-chair of COEX Adhoc
in IEEE 802.11ac from 2009 to 2010. His current
research interests include future wireless accesssystems for IOWN.
He received the Best Paper Awards from IEICE
in 2011, 2016, and 2020. He was honored with
the IEICE KIYASU Award in 2016. He received
Radio Achievement Award from ARIB in 2020
and the IEEE Standards Association’s Outstanding Contribution Appreciation Award for thedevelopment of IEEE 802.11ac-2013 in 2014. He
is a senior member of IEICE and a member of
IEEE.

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Local Light Injection and Detection
Technology for Optical-fiber
Identification
Hiroyuki Iida, Takui Uematsu, Kazutaka Noto,
Hidenobu Hirota, and Kenji Inoue
Abstract

We developed local light injection and detection technology that enables us to identify the target fiber
below an optical splitter. This technology uses the basic characteristic of optical fibers of an opticalsignal propagating through the optical fiber leaks at fiber bends. This article gives an overview of thistechnology.
Keywords: fiber identification, PON, ONU

1. Cable installation work for open up
fiber-to-the-home services
In 2021, the total number of fiber-to-the-home(FTTH) subscribers reached about 22 million for
NTT EAST and NTT WEST in Japan. FTTH services
have become an indispensable social infrastructure.
For telecommunications carriers to continue to provide optical communication services with high quality and stability to their customers, it will become
increasingly important to maintain the construction
quality of optical fiber networks and improve theefficiency of maintenance operations. The most common construction work in optical fiber networks is toopen the communication lines, which connects the
optical fiber installed from the central office to theoptical network unit (ONU) installed in the customer’s premises. To achieve this connection, the target
fiber must be identified.
2. Problem with conventional
optical-fiber identification
Optical-fiber identification is widely used to specify the target optical fiber at the worksite [1]. Opticalfiber identification is achieved by detecting a test
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

light injected from the appropriate central office andleaks from the bent fiber (Fig. 1). Optical access networks adopt the passive optical network (PON) system, in which one optical fiber is shared by multiple
customers using an optical splitter. Although thisarchitecture has advantageous in cost savings, optical-fiber identification cannot be executed below the
optical splitter. This is because the test light launchedfrom the central office is equally distributed among
all branched fibers below the optical splitter. The
optical fibers below the optical splitter support anenormous number of facilities, and facility management is complicated since it is difficult to identify thetarget fiber. Therefore, we developed technology toovercome this problem.
3. Local light injection and detection technology
The technology we developed consists of matching
convex and concave blocks for bending the opticalfiber and probe fiber with a gradient index (GRIN)
lens (Fig. 2). Optical signals are input and output by
setting the probe fiber in the path of light leaking
from the fiber bend. We call this local light injection
and detection [2]. Conventional optical-fiber identification is limited with regard to performance since it
46

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Optical splitter

Central office

Customer’s premises
ONU

Optical fiber

ONU

Identification
light

OpticalFiber
Identifier

Leakedlight

ONU

Untestable range

Testable range

Fig. 1. Fiber identification in optical access networks.

Local light injection and detection
Behavior of the leaked light and injected lightin an optical fiber

Bent fiber

Concaveblock

Leakedlight

Injectedlight

wi Probth
GR e fib
IN er
len
s

GRIN
lens

wi Probth
GR e fib
IN er
len
s

Opticalfiber

Convexblock

Probe fiber

Fig. 2. Overview of our local light injection and detection technology.

Optical fiber

Optical fiber

Leaked light

Leaked light

Leaked light diffuses widely.

Leaked light is concentrated.

(a) Leaked light in conventional
fiber identification(b) Leaked light in local light injection
and detection

Fig. 3. Contour map of leaked light intensity.

uses a low-speed signal of 270 Hz as the leaked light.
In contrast, our technology can handle high-speed
signals, up to 1 GHz, as the leaked light and can input
optical signals to the bent fiber via the probe fiber.
These unique functions are achieved by optimizing
the input/output efficiency of the light leakage fromNTT Technical Review

Vol. 19 No. 8 Aug. 2021

the bent fiber.
The contour map of leaked light intensity from atypical bent fiber is shown in Fig. 3. In conventional
optical-fiber identification, the leaked light diffusesin the free-air gap (Fig. 3(a)). Our technology generates strong leaked light by imparting the local bend
47Regular Articles

Optical splitter
ONU

Bent fiber
Upstreamlight

Convex block

Frame structure of upstream light
Leaked light

Concave
block Probe

Signalbranchcomponent

Detector
Signal analysis

MAC address display

GE-PON upstream burst signal
Burst

Burst

Burst

Ethernet frame
Destination Source Length
Preambleaddress address /Type

Signalanalysis
component

Unencrypted

Data

FCS

Encrypted Unencrypted

MAC address of an ONU

FCS: frame check sequence
GE-PON: Gigabit Ethernet PON

Fig. 4. Configuration of ONU MAC address capture device.

(1) MAC address of the ONU(2) Authentication status of the ONU

Signalbranchcomponent
Signalanalysis
component(3) Telephone and Internet
utilization status

Fig. 5. Prototype of MAC address capture device and its display screen.

shape precisely designed with a bend radius on the
millimeter order to the optical fiber (Fig. 3(b)). To
receive leaked light with high efficiency, the probe
fiber has a large core diameter and is equipped with a
GRIN lens. Since the parameters of these opticaldevices are optimized for efficient reception of leaked
light, our technology offers a 30-dB improvement in
input/output efficiency compared with the conventional technology.
By drastically improving the efficiency of capturing/injecting leaked light, new applications can be
developed. The following sections introduce specificapplications.
3.1 O ptical-fiber identification below an optical
splitter by media access control address of the
ONU
This section introduces one application of our local
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light injection and detection technology, which monitors upstream signals of the ONU from leaked light.
The upstream signal transmitted from the ONU in acustomer’s premises is received as leaked light(Fig. 4). The media access control (MAC) address of
the ONU is stored as the source address in the ONU
signal frame. The MAC address of the ONU connected to the target optical fiber can be captured byanalyzing the leaked light [3]. Therefore, it is possible
to confirm which ONU the target fiber is connected
to, that is, to identify the optical fiber below an optical
splitter.
The prototype ONU MAC address capture device
and examples of its measurement results are shown in
Fig. 5. The prototype device displays (1) the MAC
address, (2) authentication status, and (3) utilization
status of the ONU. The upstream signal of the ONU
also contains frame information about the authorization48

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Unused fiber

Cut fiber

Unused fiber
Probe pulse

Used fiber
Opticalsplitter

Local light injection/detection

Connector withbuilt in FBG

Bent fiber

Unpowered ONU

Reflected
light

Bent fiber
Probe
fiber

OTDR
OTDR

Fig. 6. Configuration of fiber-termination identification, and prototype of the local light injection and detection device.

and utilization status of the ONU, in addition to the
MAC address of the ONU, which allows (2) and (3)to be displayed. Currently, field engineers have difficulty in checking whether an ONU has been certified
and the status of its service utilization because it isnecessary to confirm certification light emitting
diode of the ONU on/off at a customer’s premises or
carry out a loopback test from the central office. With
our technology, field engineers can check the statusof the ONU in real time at worksites.
3.2 F iber-termination identification by reflection
analysis with optical time domain reflectometry
A second application of our technology is a test
technique to determine whether an unpowered ONU
is connected to the target optical fiber.
When installing optical fiber, field engineers must
check whether the target optical fiber is used fiber orunused fiber. One method determines whether an
optical fiber is used or unused by checking for thepresence or absence of the ONU’s upstream signal
from leaked light. However, this method cannot accurately be used to determine whether the optical fiberis used fiber or unused fiber because it cannot distinguish unused fiber from fiber connected to an unpowered ONU. One solution is to use optical time domainreflectometry (OTDR). However, there is no port at
which the probe pulse from the OTDR can belaunched into the optical fiber.
To solve this problem, we developed a technique todetermine whether an unpowered ONU is connected
to an optical fiber without a test port by applying our
local light injection and detection technology (Fig. 6).
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

This technique enables test measurement by injecting
OTDR probe pulses into the fiber under test througha fiber bend [4]. If the test measurement is to havesufficient accuracy, it is necessary to inject light into
the bent fiber with high efficiency. Since the core
diameter of an optical fiber is about 10 µm, highly
accurate optical arrangements is required. Our technique offers high coupling efficiency, as we optimize
the optical parameters such as beam waist and focal
length of the GRIN lens, and the beam incident angle
to the bent fiber. These characteristics have enabled
high-efficiency light injection from the outside into
the bent fiber.
Measurement results of the map of reflectivity
ratios at R1310 nm/R1550 nm and R1650 nm/R1310 nm areshown in Fig. 7. Here, the reflectivity at x nm wavelength is defined as Rx nm. We measured the fiber
under test with three termination cases: unpowered
ONU, optical connector with built-in fiber Bragg
grating (FBG), and a cut fiber. The measurement
results yielded a map of reflectivity ratios of fiber
termination at multiple wavelengths. As shown in the
figure, the three termination cases occupy different
regions on the map. Therefore, these cases can be
identified by simple threshold determination on themap.
4. Future perspectives
We gave an overview of our local light injection anddetection technology, which inputs and outputs optical signals by subjecting optical fibers to precise
bending, and examined its applications. The upstream
signal monitoring of the ONU and reflected light49

Regular Articles

cal fiber below an optical splitter and whether it isused fiber or unused fiber. Hence, field engineers cancheck the status of optical fibers in real time at theworksite. This technology will drastically improvethe efficiency of construction work and be used commercially as a test tool for the construction and maintenance of optical fiber networks.

9

R1650 nm/R1310 nm (dB)

6

3

0

References
Unpowered ONU
Connector
Cut fiber

−3

[1]
[2]

−6
−4

0

4
8
R1310 nm/R1550 nm (dB)

12

16
[3]

Fig. 7. Example of fiber-termination-identification results.
[4]

analysis of fiber termination, which were introduced
as applications, make it possible to identify the opti-

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

Recommendation ITU-T L. 314: Optical fiber identification for the
maintenance of optical access networks, 2018.
H. Hirota, T. Kawano, M. Shimpo, K. Noto, and T. Manabe, “Optical
Cable Changeover Tool with Light Injection and Detection
Technology,” J. Lightw. Technol., Vol. 34, No. 14, pp. 3379–3388,
July 2016.
H. Hirota, T. Uematsu, H. Iida, and T. Manabe, “Fiber Identification
below an Optical Splitter with ONU Upstream Light Signals,” Proc.
of the International Cable & Connectivity Symposium (IWCS) 2018,
Providence, USA, Oct. 2018.
H. Iida, H. Hirota, T. Uematsu, and N. Ambe, “Novel Fibre
Termination Identification Employing Local Light Injection and
Detection and 1.31/1.55-µm-band Coherent OTDR,” Proc. of theEuropean Conference on Optical Communication (ECOC) 2019,
Dublin, Ireland, Sept. 2019.

50

Regular Articles

Hiroyuki Iida

Research Engineer, Access Network Management Project, NTT Access Network Service
Systems Laboratories.
He received a B.E. in physics from Nihon
University, Tokyo, in 2006 and an M.E. in physics from the University of Tokyo in 2008. He
joined NTT Access Network Service Systems
Laboratories in 2008, where he has been engaged
in research on optical reflectometry and opticalmeasurement. He is a member of the Institute ofElectronics, Information and Communication
Engineers (IEICE) of Japan.

Takui Uematsu

Research Engineer, Access Network Management Project, NTT Access Network Service
Systems Laboratories.
He received a B.S. and M.S. in electronic engineering from Hokkaido University in 2012 and2014. He joined NTT Access Network Service
Systems Laboratories in 2014, where he isengaged in the research and development ofaccess media and equipment maintenance. He isa member of IEICE.

Hidenobu Hirota

Senior Research Engineer, Access Network
Management Project, NTT Access Network Service Systems Laboratories.
He received a B.E., M.E., and Ph.D. in electrical and electronic engineering from the University of Electro-Communications, Tokyo, in 1999,
2001, and 2020. He joined NTT Photonics Laboratories in 2001, where he has been engaged in
the research and development of access media
and equipment maintenance since 2011. He is amember of IEICE.

Kenji Inoue

Senior Research Engineer, Supervisor, AccessNetwork Management Project, NTT AccessNetwork Service Systems Laboratories.
He received a B.E. in electrical engineeringfrom Kyushu University, Fukuoka, in 1995. He
joined NTT Access Network Service Systems
Laboratories in 2005, where he is currently
engaged in research on advanced construction
technology of optical communication facilities.

Kazutaka Noto

Research Engineer, Access Network Management Project, NTT Access Network Service
Systems Laboratories.
He received a B.E. from Miyazaki University
in 2007 and an M.E. from Kyushu University,
Fukuoka, in 2009. He joined NTT Access Network Service Systems Laboratories in 2009 andstarted his research in the field of passive opticalcomponents for optical fiber networks and themaintenance of optical fiber networks. He is amember of IEICE.

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

51

Global Standardization Activities

Standardization Trends in the
Disaggregation Technology of Access
Systems at the Broadband Forum
Kota Asaka
Abstract

Research and development for introducing disaggregation technology into future access systems has
been progressing to flexibly and quickly accommodate various services in such systems and achieve
simple system operations. This article reports on the standardization trends in the disaggregation technology of access systems at the Broadband Forum along with relevant development trends at an open
source software development organization of the Open Networking Foundation.
Keywords: disaggregation, access systems, Broadband Forum

1. Requirements of future access systems
The traffic of a broadband service over opticalaccess systems, e.g., fiber to the home, has been rapidly increasing due to the expansion of remote workand education intended to prevent the novel coronavirus infection from spreading as well as wide dissemination of video streaming services [1]. Current standards of optical access systems have been developed
as specifications with a transmission capacity of 40 or
50 Gbit/s to meet such a rapid and huge demand of
traffic [2, 3]. Future access systems should provide adiverse range of services that have different system
requirements (transmission capacity, latency, reliability, etc.) such as Internet of Things and edge computing, as well as accommodating a huge amount oftraffic.
Given this background, the research and development of disaggregation technology has been progressing. Such technology can reconfigure the functions of an access system by combining general-purpose hardware components (i.e., server and switch)and open source software (OSS) that are loosely
coupled via an open interface. However, a conventional system is achieved by using dedicated hardware equipment and software that are tightly coupled
via a vendor’s proprietary interface [4]. To achieve a
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

disaggregated access system, specifying an open
architecture and interface and developing OSS thatcan be flexibly and quickly replaced in accordancewith system requirements are necessary to ensureinteroperability and promote widespread dissemination.
2. Brief summary of Broadband ForumThe Broadband Forum (BBF) is an industry forum
and has contributed to broadband-access industries
and earned its high reputation for its efforts, especially in developing control/management specifications and interoperability test specifications of accesssystems, which have been published in more than 200
Technical Reports (TRs) [5]. BBF is composed ofmore than 150 companies/organizations, which
include service providers (telecom carriers and multiple service operators), system vendors, ASIC (application specific integrated circuit) vendors, and othersfrom around the world. Telecom service providers
take a leadership role in designating technical topics
and directions that are driving BBF. Each Work Area
in the Technical Committee discusses corresponding
technical specifications on the basis of these topics.
BBF has been intensively engaging in the development of various specifications of access systems with52

Global Standardization Activities

PDP

AAA

R

B

V

Subscriber
sessionmanagement

IP address
assignment/
management

AAA client

QoS function

Routing andforwarding

Network IF

Accessnode

Access IF

Control and management IF

IP/MPLS
A10

IPTV multicast
….

….
BNG
IF: interface

Fig. 1. Functional blocks and interfaces for a conventional BNG.

virtualization/disaggregation technologies, such assoftware-defined networking (SDN) and network
functions virtualization (NFV), and it is recognized
as the most active organization in these topics amongaccess-systems-related standardization organizations
and industry forums. In particular, BBF worked toprovide a diverse range of specifications on the Network Configuration Protocol/Yet Another Next Generation (NETCONF/YANG)*1 model, architecture
and interface of Cloud Central Office (CO)*2, disaggregated dynamic bandwidth-allocation function for
optical access systems [6, 7], and a disaggregatedbroadband network gateway (DBNG). This article
reports on the specifications on a DBNG, which was
finalized in TR in June 2020. It also reports on thespecifications on broadband access abstraction(BAA), which is one of the software components ofCloud CO and abstracts vendor’s proprietary hardware specifications, such as an optical line terminal(OLT), along with relevant OSS development trends
at the Open Networking Foundation (ONF).
3. Specifications of a DBNG
BBF recently specified a DBNG in TR-459 “ConNTT Technical Review

Vol. 19 No. 8 Aug. 2021

trol and User Plane Separation for a disaggregated
BNG” [8]. Figure 1 shows the functional blocks andinterfaces for a conventional BNG based on the information in TR-459. A BNG is an access point andconnected to customer premises equipment at a subscriber’s residence for wireline broadband services. It
aggregates various traffic from access networks andforwards it to designated routes for metro/core networks depending on the service type. In addition tosuch functions, a BNG plays an important role inother functions that support broadband services, i.e.,
authentication, authorization, and accounting (AAA)of subscriber sessions, Internet protocol (IP) address
assignment, and quality of service (QoS) control. A*1 NETCONF/YANG: NETCONF is a configuration protocol of
network equipment and was developed to remotely conduct configuration and management functions in distributed equipmentfrom a centralized SDN controller. The YANG model is a common data-modeling language that abstracts a structure and configuration values of each piece of network equipment. Using
NETCONF and the YANG model makes it possible to achieveinteroperability between network equipment and a controller
from various system vendors.
*2 Cloud CO: Next generation COs (telecom carrier central officesthat contain network equipment) that use SDN/NFV, disaggregation, and cloud technologies.

53

Global Standardization Activities

PDP

AAA

R

B
Control and management IF

Subscriber
sessionmanagement
AAA client
DBNG-CP
to SF(Option)IP address
assignment/
management

DBNG-CPDBNG CP-UP

DBNG-UP

Sessionsteering
function(Option)V

Routing andforwarding

IPTV multicast

Network IF

Accessnode

Access IF

QoS function
IP/MPLS
A10

Fig. 2. Newly defined functional blocks and interfaces for the DBNG in TR-459.

BNG acts as a gateway between an access node andIP/multi-protocol label switching (MPLS). The interfaces between a BNG and each access node and IP/
MPLS are defined as V-IF and A10-IF, respectively.
Although the functional blocks inside a BNG are
configured differently depending on the service to beprovided by telecom carriers, it is composed of several functions. A typical example is shown in Fig. 1:
subscriber session management, IP address assignment/management, AAA client, QoS function, routing and forwarding, and IPTV (television) multicast.
These functions are managed/controlled by the policy
decision point (PDP) and AAA controllers via thecontrol/management interfaces inside the BNG. Theinterfaces between the BNG and each PDP and AAA
are defined as R-IF and B-IF, respectively. Therefore,
functions and external interfaces comprising a BNG
are defined. However, software and hardware comprising a BNG are provided as integrated equipment,
which has different implementation specifications
from vendor to vendor. Therefore, operation of accessnetworks is complicated because BNGs must be controlled/managed at each facility where BNG equipment is installed. There is also an apparent issue thatusage efficiency of resources is low since telecom
carriers are required to increase the number of BNGs
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Vol. 19 No. 8 Aug. 2021

on the basis of the unit of equipment to meet traffic
demand.
To address these issues, BBF defined the DBNG in
TR-459 to newly specify the functionally separated
composition as well as interfaces, as shown in Fig. 2.
This DBNG is achieved by separating various BNG
functions by the functional groups of the DBNGcontrol plane (CP) and DBNG-user plane (UP),which are coupled via the newly created interface of
the DBNG CP-UP. The DBNG-CP is specified forcontrol-signal processing necessary for subscribersession establishment while the DBNG-UP is
designed for transmission/receipt processing of user
data signals. By adopting such a control and user
plane separation (CUPS) configuration, telecom carriers can expect much simpler operation of accessnetworks. This is because they can remotely control/
manage several DBNG-UPs independently located in
multiple facilities from a DBNG-CP at another centralized facility. They can also expect higher usage
efficiency of resources because increasing the number of DBNG-UPs at arbitrary facilities becomes
possible, and the traffic steering function (SF), whichenables traffic assignment to other facilities from theoriginal one, is available as an optional specification.
The interoperability between the DBNG-CP and
54

Global Standardization Activities

DBNG-CPDBNG CP-UP(1)
Mi
NETCONF/YANG

(2)
SCi

(3)
CPR

PFCP

Control signal (DHCP, PPP)
Accessnode

User data signal

IP/MPLS

DBNG-UP
A10

V

Fig. 3. Conceptual diagram of interfaces between DBNG-CP and DBNG-UP.

Table 1. Details of the interfaces between DBNG-CP and DBNG-UP.
No.

FunctionProtocol(1)

Management IF (Mi)Appellation• Pushing of DBNG-UP configurations from the DBNG-CP• Retrieving operational state and notification of alarm
between the DBNG-CP and DBNG-UP

NETCONF/YANG(2)

State control IF (SCi)• Providing traffic forwarding rules to the DBNG-UP• Receiving acknowledgement from the DBNG-UP

PFCP

(3)

Control packet redirection IF (CPR)• Providing a tunnel function for control signals between
the DBNG-CP and DBNG-UP

DHCP, PPP

DBNG-UP can be established among different vendors by specifying the DBNG CP-UP interface.
Figure 3 shows a conceptual diagram of interfaces
between the DBNG-CP and DBNG-UP defined in
TR-459: (1) management interface (Mi), (2) state
control interface (SCi), and (3) control packet redirection (CPR). The details of each interface are given
in Table 1. (1) The Mi is an interface through which
the DBNG-CP pushes configurations (i.e., a routing
protocol setting) to the DBNG-UP. Retrieving theoperation state and notification of alarm between the
DBNG-CP and -UP can be achieved through the Mi,
the protocol of which is specified as NETCONF/
YANG. (2) The SCi is an interface through which the
DBNG-CP provides traffic-forwarding rules to the
DBNG-UP. The DBNG-CP also receives acknowledgement from the DBNG-UP via the interface. The
protocol of the SCi is specified by extending theexisting Packet Forwarding Control Protocol (PFCP),
which had been globally deployed in mobile systems[9]. (3) CPR is an interface used for the control signals (Dynamic Host Configuration Protocol (DHCP),NTT Technical Review

Vol. 19 No. 8 Aug. 2021

Point-to-Point Protocol (PPP), and others), which
tunnel from V-IF (or A10-IF) to the DBNG-CP
through the DBNG-UP. It provides a tunneling function when the DBNG-UP and DBNG-CP are connected via multi-hop networks due to CUPS.
BBF is planning to focus on the promotion andmarketing activities of TR-459 as well as the development of detailed specifications of SF.
4. Specifications of BAA
BAA was specified in TR-384 “Cloud Central
Office Reference Architecture Framework” andTR-413 “SDN Management and Control Interfaces
for Cloud CO Network Functions” [10, 11]. Figure 4
shows a conceptual diagram of BAA based on theinformation of TR-413. In conventional opticalaccess systems, namely the passive optical network(PON), access equipment such as an OLT is implemented tightly coupled with a controller. Therefore,
interoperability cannot be achieved, which results incomplicated operations of access systems. To address55

Global Standardization Activities

SDN controller
M
NB
layer

NB protocol agent
NB abstraction

BAA

BAA
core
layer

PON abstraction function
SB abstraction

SB
layer

Protocol library
OLT A driver

OLT B driver

Device specific IF
OLT A

OLT B

UP (logical switch)

Fig. 4. Conceptual diagram of BAA.

this issue, BAA in Cloud CO was specified as an
abstraction layer so that the SDN controller can control/manage various types of access-equipment hardware from a diverse range of vendors as an abstracted
common logical switch through common commands.
As shown in Fig. 4, BAA consists of a northbound(NB) layer, which functions as a protocol agent, BAA
core layer, which has an abstraction function, andsouthbound (SB) layer, which works as a protocol
library. The BAA core layer and each of the NB andSB layers are connected through NB and SB abstraction interfaces, respectively. BAA is also connected
to an SDN controller via M-IF, and to the UP, such as
OLTs, via device-specific interfaces. By introducing
the above-mentioned configuration, BAA enables
command conversion of control/management signals(commands) from the SDN controller to those for theabstracted logical switch. The converted commands
are transformed to device-specific commands by adriver in the protocol library, then the commands
reach the OLT equipment. Therefore, BAA enables
the SDN controller to configure a flow setting of the
UP and control FCAPS (fault, configuration, accounting, performance, and security) without having totake into account the difference in hardware-vendor
specifications. This enables the establishment ofinteroperability among various vendors, which leads
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Vol. 19 No. 8 Aug. 2021

to simple operation of access systems.
In addition to the development of BAA specifications, BBF is engaged in OSS development to promote it in the near future [12]. Regarding related
trends, ONF, which is an OSS development organization, has been leading the access virtualization project of SEBA (SDN Enabled Broadband Access). In
this project, an access-abstraction technology of virtual OLT hardware abstraction (VOLTHA) had been
proposed and developed in advance of BAA [13].
Although VOLTHA has almost the same functions as
those of BAA, it can be applicable to the OpenFlow
Protocol and whitebox OLTs [14, 15]. VOLTHA wascommercially deployed by Türk Telekom andDeutsch Telekom in 2019 and 2020, respectively, but
it is still being developed at ONF for function
enhancement.
5. Future prospects
As the latest topic in future access systems, thisarticle reported on the standardization trends in the
disaggregation technology of access systems at BBF
along with relevant trends in OSS development at
ONF. Improvement in the technical maturity andfunction enhancement of related standardizations and
OSS can be expected by reflecting the feedback from56

Global Standardization Activities

future discussions at BBF and ONF as well as telecom carriers who have commercially deployed thedisaggregated technology in access systems. NTT
will continue joining the discussion at BBF and ONF
and contributing to global standardization activities
and OSS development by providing requirementsfrom telecom carrier’s point of view.
References
[1]
[2]
[3]

[4]

[5]

Ministry of Internal Affairs and Communications (MIC), “Aggregate
Results of Internet Traffic in Japan (May 2020),” 2020 (in Japanese).
https://www.soumu.go.jp/main_content/000699741.pdf
ITU-T G.989.1: 40-Gigabit-capable passive optical networks (NGPON2): General requirements, https://www.itu.int/rec/T-REC-G.989.1/en
IEEE 802.3ca-2020: IEEE Standard for Ethernet Amendment 9:
Physical Layer Specifications and Management Parameters for 25
Gb/s and 50 Gb/s Passive Optical Networks, https://standards.ieee.
org/standard/802_3ca-2020.html
J. Kani, J. Terada, T. Hatano, S. Y. Kim, K. Asaka, and T. Yamada,“Future Optical Access Network Enabled by Modularization and
Softwarization of Access and Transmission Functions,” J. Opt. Commun. Netw., Vol. 12, No. 9, pp. D48–D56, 2020.
K. Asaka and H. Ujikawa, “Standardization Trends of Virtualized
Access Systems by the Broadband Forum,” NTT Technical Review,Vol. 16, No. 7, pp. 44–49, 2018.
https://www.ntt-review.jp/archive/ntttechnical.php?contents=
ntr201807gls.html[6] BBF TR-402: Functional Model for PON Abstraction Interface,https://www.broadband-forum.org/download/TR-402.pdf[7] BBF-TR-403: PON Abstraction Interface for Time-Critical Applications, https://www.broadband-forum.org/download/TR-403.pdf[8] BBF TR-459: Control and User Plane Separation for a disaggregated
BNG, https://www.broadband-forum.org/download/TR-459.pdf[9] 3GPP TS 29.244: Interface between the Control Plane and the User
Plane nodes, https://portal.3gpp.org/desktopmodules/Specifications/
SpecificationDetails.aspx?specificationId=3111[10] BBF TR-384: Cloud Central Office Reference Architecture Framework, https://www.broadband-forum.org/download/TR-384.pdf[11] TR-413: SDN Management and Control Interfaces for Cloud CO
Network Functions, https://www.broadband-forum.org/download/
TR-413.pdf[12] OB-BAA, GitHub, https://github.com/BroadbandForum/obbaa[13] VOLTHA, ONF, https://opennetworking.org/voltha/[14] Press release issued by BBF, “Broadband Forum and ONF ease thepath to automated and open virtualized access networks,” Oct. 14,
2019.
https://www.broadband-forum.org/2019-10-14-broadband-forumand-onf-ease-the-path-to-automated-and-open-virtualized-accessnetworks[15] VOLTHA-EPON OLT adapter, GitHub, https://github.com/opencord/
voltha-eponolt-adapter

Kota Asaka

Senior Research Engineer, Optical Access
System Project, NTT Access Network Service
Systems Laboratories.
He received a B.S. and M.S. in electrical engineering from Waseda University, Tokyo, in 1996
and 1999, and a Ph.D. in physics from Kitasato
University, Tokyo, in 2008. In 1999, he joined
NTT Photonics Laboratories, where he conducted research on several photonics integrated circuits and low-cost and small optical subassemblies for access networks. He has been with NTT
Access Network Service Systems Laboratories
since 2012, where he is engaged in research anddevelopment of next-generation optical accessnetworks such as NG-PON2 and future accesssystems using SDN/NFV technologies. He has
been participating in the International Telecommunication Union - Telecommunication Standardization Sector (ITU-T), BBF, and ONF. He isa member of the Institute of Electrical and Electronics Engineers (IEEE) Communications
Society and the Institute of Electronics, Information and Communication Engineers (IEICE).

NTT Technical Review

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57

Practical Field Information about
Telecommunication Technologies
Practical Field Information about Telecommunication Technologies

Grounding-system Evaluator for
Preventing Lightening Damage to
Telecommunications Center Buildings
Technical Assistance and Support Center, NTT EAST
Abstract

This article provides information on lightning damage to telecommunications center buildings andintroduces the grounding-system evaluator developed by Technical Assistance and Support Center. The
evaluator supports the investigation of the status of grounding systems, which includes telecommunication, power, and grounding installations. The evaluator also suggests methodologies for improving
grounding systems in preventing telecommunication and power equipment from being damaged bylightning. This is the sixty-fifth article in a series on telecommunication technologies.
Keywords: lightning damage, grounding system, grounding-system evaluator

1. Introduction
When lightning strikes a telecommunications center building or nearby, it can cause damage or malfunction of telecommunication and power equipment. The damage may have a significant impact on
the equipment in such buildings, and it can take along time to restore telecommunication services.
Therefore, it is important to prevent telecommunication and power equipment from being damaged bylightning.
Figure 1 shows the percentage of technical consultations classified by causes and damaged objects
from the EMC Engineering group of Technical Assistance and Support Center (TASC) in fiscal 2019.
Lightning-related technical consultations accounted
for 26% of all consultations, and 30% of those consultations were related to lightning damage to telecommunications center buildings and radio relay
stations. By analyzing the lightning damage in telecommunications center buildings, it was found thatthe damage was mainly caused by imperfections in
the grounding systems, such as lack of wire connecNTT Technical Review

Vol. 19 No. 8 Aug. 2021

tion and isolation.
The most important countermeasure against lightning damage to telecommunications center buildings
is improving the grounding systems. However, toimprove grounding systems, service personnel needto have correct knowledge on the grounding, investigation procedure, and how to solve the problems
which are found in the investigation, such as lack ofwire connection and isolation. To solve these problems, TASC prepared a document for providing“investigation and improvement methodologies andprocedures for grounding systems in telecommunications center buildings.” TASC also developed agrounding-system evaluator that supports the investigation of and improvement in such systems.
This article introduces this evaluator and a fieldcase study.
2. Grounding-system evaluator
The grounding-system evaluator can visualize aconfiguration of the grounding system that includes
the connection between the telecommunication and58

Practical Field Information about Telecommunication Technologies

Noise
29%

Radio
relay
stations 7%

Lightning andovervoltage
26%

Radio
22%

Developed
products
27%

Telecommunications
center buildings
23%

Accessnetworks
20%

Induction
23%

Imperfections in agrounding-system
mainly causes
damages.

Customerpremises23%

Fig. 1. Lightning-related technical consultations

Importing
Equipment
database

Quickly visualize grounding
configuration. Reflects theresults of on-site investigations.

Automatically determines
correctness of wiring.

Fig. 2. Use of grounding-system evaluator.

power equipment and cable. It also points out imperfections in the grounding configuration in accordancewith the above document. Figure 2 illustrates the useof the grounding-system evaluator.
2.1 Configuration-visualization function
The configuration-visualization function is illustrated in Figure 3. The existing data of wiring connection, which are formatted by excel or csv, can beimported from the equipment database. This function
enables users to reduce the time to input the grounding-system configuration and makes it possible toeasily visualize the status/condition of telecommunication facilities, such as equipment, cables, andgrounding cable, in telecommunications center buildings. It is also possible to visualize the results
obtained through on-site investigations via a graphiNTT Technical Review

Vol. 19 No. 8 Aug. 2021

cal user interface (GUI) and reflect them in the above
visualization.
2.2 F unction for automatically determining thestatus of a grounding configuration
The function for automatically determining thestatus of a grounding configuration is illustrated inFig. 4. This function visualizes whether the status of
the grounding configuration is correct. The evaluatorinvestigates the 30 items for ideal grounding systemdescribed in the document of investigation andimprovement procedures and methods written by
TASC. If a fault is found, the evaluator shows thedetails of this fault. This means that users can easilyfind the areas to be improved. Thus, this function is
not only useful for maintaining grounding systems
but also makes design work more efficient.
59

Practical Field Information about Telecommunication Technologies

In addition to data from the equipment
database, the investigation results canbe entered into the configurationvisualization function via the GUI of asurvey tablet.

Reflects the presence orabsence of wiring.

Present

Present

Present

AbsentFig. 3. Configuration-visualization function.

Visualize faults

Display the results
Determine wiring error
Determine
Error code Serial number Error message
1
1
For this equipment rack, theground-cable connection
destination (in the distributionrack) is incorrect.

Fig. 4. Function for automatically determining the status of grounding configuration.

3. Case study of countermeasures TASC
proposed against lightning-damage failure using
the grounding-system evaluator
A case study of a countermeasures proposed by
TASC using the grounding-system evaluator against
lightning damage in a telecommunications centerbuilding is presented in this section.
3.1 Failure status
Due to lightning, the Subscriber Lines Cross-Connect Module (LXM) system failed and many customer services stopped for a considerable time.
Although the system was recovered by restarting the
LXM packages, TASC was asked to investigate thecause of the failure and propose countermeasures toprevent the lightning damage.

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3.2 O
 n-site investigation and simulation using the
grounding-system evaluator
The status of a grounding-system configuration
obtained from the on-site investigation is shown in
Fig. 5, and points to be addressed are listed inTable 1. Figure 6 shows the simulation results of thegrounding-system evaluator, focusing on the fiber
termination module (FTM) on the second floor of the
new building and Figure 7 shows details of wiring
errors. The simulation results show that the wiring
between the FTM and SSF1 (a power supply distributor) is incorrect, and the FTM should be wired toInterface – B (IF-B).
3.3 Estimation of causes
On the basis of the results obtained from the investigation, the estimated invading route of the lightning
surge that caused the failure is shown in Fig. 8 andTable 2. Due to the increase in the ground potential
60Practical Field Information about Telecommunication Technologies[Legend]: Power line cable (G): Grounding: Ground cable: Clock cable: Fault location

Old building 2nd Floor

CSM

New building 2nd Floor
SSF2

Point (2)DSM

: Optical-cable tension member

FR
HO

IF-B

LXM

FR
Point (3)

IF-B

FTM

SSF1
HO
Point (1)

Building grounding
CSM: clock supply module
DSM: dedicated service-handling module

Tension-member grounding

FR: rectifier
HO: a power supply distributor

Fig. 5. On-site investigation of the building and identified configuration points.

Table 1. Wiring status of key points.
Wiring status

Content

Point (1)The optical-cable tension member is connected to SSF-1 via the frame ground (FG) of the FTM.

Point (2)

LXM and CSM/DSM are connected by a clock cable across the building, but IF-C is not inserted.

Point (3)The ground of LXM is connected to another rack (SSF1) instead of the rack receiving power supply (SSF2).

IF-B

FTM
Rectifier

SSF-1

SSF-2

LXM
Pop-up to show incorrect wiringFig. 6. Simulation based on on-site investigation results.

caused by the lightning strike near the telecommunications center building, a potential difference
NTT Technical Review

Vol. 19 No. 8 Aug. 2021

occurred between the building ground and tensionmember ground. Thus, a lightning surge current was61

Practical Field Information about Telecommunication Technologies

Wiring-error determine
Determine

Clear

Setting

Determine Serial
code
numberError message

Details of equipment-rack ground cable
The FG of the 100-VAC distribution frame (2A-0000) is not connected to IF-B.
Details of the FTM ground-cable
Optical fiber of the FTM (2A-0000) is not connected to IF-B.

Fig. 7. Details of wiring errors determined using the grounding-system evaluator.

[Legend]: Power line cable (G): Grounding: Ground cable: Clock cable: Estimated lightning-surge route (1): Fault location: Optical-cable tension member: Estimated lightning-surge route (2)Old building 2F

New building 2F
SSF2

DSM

IF-B

HO
FR

LXM

FR
FTM

IF-B
SSF1

CSM

HO

Cause (2)

Cause (1)Lightning surge
Building grounding

Potential difference occurred
Tension-member grounding

Fig. 8. Estimated lightning-surge route.

Table 2. Estimated lightning-surge route.
Lightning-surge route
Route (1)

Building grounding ⇔ New building IF-B ⇔ SSF2 ⇔ LXM ⇔ SSF1 ⇔ FTM ⇔ TM grounding

Route (2)Building ground ⇔ Old building IF-B ⇔ CSM/DSM ⇔ LXM ⇔ SSF1 ⇔ FTM ⇔ TM grounding

generated and propagated through cables, i.e., thelightning-surge current flowed from the ground cable
into the LXM via the metal cables and flowed out tothe ground cable and clock cable.

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Vol. 19 No. 8 Aug. 2021

3.4 Lightening countermeasures
The countermeasures that were proposed against
the above lightning damage in this case study are
shown schematically in Fig. 9 and described as follows.
Countermeasure (1): To pass the lightning surge
62

Practical Field Information about Telecommunication Technologies[Legend]: Power line cable (G): Grounding×: Ground cable: Removal: Clock cable: New installation

Countermeasure (3): Change New building 2F
connection destination

Old building 2FCountermeasure (2): Insert IF-C

: Optical-cable tension member

SSF2
IF-C

IF-C

DSM

HO

IF-B
FR

IF-B

FTM
SSF1
SF1

CSM

LXM

FR

HO

×
×

Countermeasure (1): Change
connection destination

Building grounding

Tension-member grounding

Fig. 9. The proposed lightning-damage countermeasures.

directly to the optical-cable tension member of the FTM, theground cable between SSF-1
and the FTM should be
removed, and the FTM should
directly connect to IF-B in the
new building.
Countermeasure (2): To pass the lightning surge
flowing into the LXM from theclock cable, two IF-Cs areinserted into the clock cables
crossing the buildings from the
DSM and CSM, and the groundterminal of the IF-Cs should
connect to IF-B in the old building.
Countermeasure (3): To make the SSF-2 and LXM
equipotential, SSF-2 should
connect to the LXM instead of
SSF-1 and LXM.

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

4. Conclusion
This article described the grounding-system evaluator developed by TASC. By conducting a field-survey of lightning damage that occurred at a telecommunications center building, TASC could find thecauses of the failure and proposed countermeasures
to prevent lightning surge. The evaluator can visualize the configuration of a grounding system, which
includes telecommunication equipment, power
equipment, and grounding cables. It can also automatically determine the status of the configuration.
The EMC Engineering group in TASC is continuously engaged in technical support in the field regarding problems caused by lightning, malfunction ofelectromagnetic phenomena, interference of radio
wave, induction from power line, and so on to ensure
reliability of telecommunication services.

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External Awards
The Young Scientists’ Award, the Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology
Winner: Gento Yamahata, NTT Basic Research Laboratories
Date: April 14, 2021
Organization: Ministry of Education, Culture, Sports, Science andTechnology
For his research activities of high-accuracy single-electron control
using silicon quantum dots.
Young Researcher’s Award
Winner: Takayuki Nakamura, NTT Network Service Systems Laboratories
Date: April 16, 2021
Organization: The Institute of Electronics, Information and Communication Engineers (IEICE) Technical Committee on Network
Systems
For “A Study on D-Plane Architecture and Configuration Methodof a Data Network Slice Constituting an E2E Slice.”
Published as: T. Nakamura, T. Narumi, M. Amasaka, and T. Sato, “A
Study on D-Plane Architecture and Configuration Method of a Data
Network Slice Constituting an E2E Slice,” IEICE Tech. Rep., Vol.
121, No. 2. NS2021-12, pp. 65–70, Apr. 2021.
CHI 2021 Honorable Mention Award
Winners: Amanda Baughan, Nigini Oliveira, Tal August, Universityof Washington; Naomi Yamashita, NTT Communication Science
Laboratories; Katharina Reinecke, University of Washington
Date: May 13, 2021
Organization: The Association for Computing Machinery (ACM)
Conference on Human Factors in Computing Systems (CHI 2021)
For “Do Cross-cultural Differences in Visual Attention Patterns
Affect Search Efficiency on Websites?”
Published as: A. Baughan, N. Oliveira, T. August, N. Yamashita, and
K. Reinecke, “Do Cross-cultural Differences in Visual Attention Patterns Affect Search Efficiency on Websites?”, CHI 2021, Virtual
conference, May 2021.
Distinguished Service Award
Winner: Tsuyoshi Joucha, NTT Network Service Systems Laboratories
Date: May 21, 2021
Organization: The Telecommunication Technology Committee(TTC)
For his contribution to standardization activities adapted to thetimes as a member of the planning and strategy committee.
Distinguished Service Award
Winner: Seiichi Sakaya, NTT Network Service Systems Laboratories
Date: May 21, 2021
Organization: TTC

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

For his contribution to developing specifications concerning interconnections to support migration from public switched telephone
networks to Internet protocol networks.
Information and Communication Technology Award, TTC
Chairman’s Prize
Winner: Kensaku Komatsu, NTT Communications Corporation
Date: May 21, 2021
Organization: TTC
For his achievements related to improving domestic technologicalcapabilities by promoting international standardization of WebRTC
and business promotion.
Best Paper Award
Winners: Atsushi Taniguchi, Takeru Inoue, Kohei Mizuno, NTT
Network Innovation Laboratories; Takashi Kurimoto, Atsuko Takefusa, Shigeo Urusidani, National Institute of Informatics
Date: May 21, 2021
Organization: IEICE Technical Committee on Communications
Society
For “Efficient Reliability Evaluation of Multi-domain Networks
with Secure Intra-domain Privacy.”
Published as: A. Taniguchi, T. Inoue, K. Mizuno, T. Kurimoto, A.
Takefusa, and S. Urusidani, “Efficient Reliability Evaluation ofMulti-domain Networks with Secure Intra-domain Privacy,” IEICE
Trans. Commun., Vol. E103-B, No. 4, pp. 440–451, 2020.
Best Paper Award
Winners: Naruto Arai, NTT Space Environment and Energy Laboratories; Ken Okamoto, NTT Information Network Laboratory Group;
Jun Kato, NTT Space Environment and Energy Laboratories; andYoshiharu Akiyama, NTT Advanced Technology Corporation
Date: June 3, 2021
Organization: IEICE
For “Method of Measuring Conducted Noise Voltage with a Floating Measurement System to Ground.”Published as: N. Arai, K. Okamoto, J. Kato, and Y. Akiyama,“Method of Measuring Conducted Noise Voltage with a Floating
Measurement System to Ground,” IEICE Trans. Commun., Vol.
E103-B, No. 9, pp. 903–910, 2020.
Best Paper Award
Winners: Toru Mano, Takeru Inoue, NTT Network Innovation Laboratories; Kimihiro Mizutani, Kindai University; Osamu Akashi,
National Institute of Informatics
Date: June 3, 2021
Organization: IEICE
For “Reducing Dense Virtual Networks for Fast Embedding.”
Published as: T. Mano, T. Inoue, K. Mizutani, and O. Akashi,“Reducing Dense Virtual Networks for Fast Embedding,” IEICE
Trans. Commun., Vol. E103-B, No. 4, pp. 347–362, 2020.

64

Papers Published in Technical Journals andConference Proceedings
Patentability Issues on AI-related Invention in Japan
Y. Nakajima and H. Shiomi
Journal of International Association for the Protection of Intellectual Property of Japan, Vol. 46, No. 2, pp. 71–89, March 2021.
Patent applications for artificial intelligence (AI)-related inventions are swiftly increasing not only in Japan but also in other countries around the world. There is a growing need for patent applications for AI-related inventions, even in industries and sectors thathave not traditionally had much to do with the computer softwarerelated inventions. In light of these circumstances, the Japanese Patent Office is making public and enriching case studies related to therequirements for describing AI-related technologies and determining
inventive step in the Patent-Utility Model Examination Handbook.
This article classifies AI-related inventions into four types according
to their technical features, examines the requirements for novelty,
inventive step, and description of each kind of invention, and points
out the problems that may arise with each class in the future. The
article also aims to highlight the different characteristics of AI-related
inventions from general software-related inventions.

NTT Technical Review

Vol. 19 No. 8 Aug. 2021

Flexible Assimilation of Human’s Target for Versatile
Human-Robot Physical Interaction
A. Takagi, Y. Li, and E. Burdet
IEEE Transactions on Haptics, Vol. 14, No. 2, pp. 421–431, June
2021.
Recent studies on the physical interaction between humans haverevealed their ability to read the partner’s motion plan and use it toimprove one’s own control. Inspired by these results, we develop an
intention assimilation controller (IAC) that enables a contact robot toestimate the human’s virtual target from the interaction force, andcombine it with its own target to plan motion. While the virtual target
depends on the control gains assumed for the human, we show that
this does not affect the stability of the human-robot system, and ournovel scheme covers a continuum of interaction behaviors fromcooperation to competition. Simulations and experiments illustrate
how the IAC can assist the human or compete with them to prevent
collisions.
In this article, we demonstrate the IAC’s advantages over related
methods, such as faster convergence to a target, guidance with lessforce, safer obstacle avoidance, and a wider range of interaction
behaviors.

65