Internet
Infrastructure
Review
Jul.2020

Vol.

47

Periodic Observation Report

Messaging Technology
Focused Research (1)IIJ’s Efforts to Promote LoRaWAN® in
Agricultural IoT
Focused Research (2)COVID-19’s Impact on FLET’S Traffic

Internet Inf rast ruc ture Review
July 2020 Vol.47

Executive Summary ........................ ................................................ 3
1. Periodic Observation Report .......... ................................................ 4
1.1
1.2

Introduction ............................................................................... 4

Sender Authentication Rates ............................................................... 4

1.2.1 Results Based on Emails Received .......... ................................................ 5
1.2.2 Results Based on Domain Names . ......... ................................................ 7
1.2.3 Sender Authentication as a Measure Against Email Spoofing . .............................. 7
1.3
1.4

JPAAWG 2nd General Meeting . ........................................................... 8
Conclusion ................................ ................................................ 9

2. Focused Research (1) ................................................................. 10
2.1
2.2
2.3

Introductions ............................................................................. 10
Testing IoT-based Paddy Field Water Management ........................................ 10
A Single Base Station Can Cover Several km with LoRaWAN® ............................... 11

2.3.1 About LoRaWAN® ........................................................................ 11
2.3.2 Features Compared with Other LPWA Standards .......................................... 122.3.3 Applications Suited to LoRaWAN® . ........ ............................................... 13
2.4

Challenges in Promoting LoRaWAN® for Agricultural IoT ................................... 13

2.4.1 Installing Inexpensive Outdoor Base Stations .............................................. 13
2.4.2 Simple Pre-installation Data Link Tests ..... ............................................... 14
2.5

Solutions to the Issues . ................... ............................................... 14

2.5.1 DIY Solar-powered Base Stations to Expand Installation Options and Cut Installation Costs . ... 14
2.5.2 Simple Data Link Tests via a Wireless Survey Tool . ....................................... 15
2.6

Conclusion ............................................................................... 17

3. Focused Research (2) .................. ............................................... 18
3.1
3.2
3.3

Introduction ............................... ............................................... 18
About the Data ........................................................................... 18

Traffic Condition . ......................... ............................................... 19

3.3.1 FLET’S Traffic (PPPoE) ..................... ............................................... 19
3.3.2 IPv6 IPoE Traffic . ........................................................................ 21
3.4
3.5

2

Discussion . ............................... ............................................... 22
Conclusion ............................................................................... 23© Internet Initiative Japan Inc.

Jul.2020

Vol.

47

Executive Summary

Executive Summary

We touched briefly on COVID-19 at the beginning of the previous IIR issue’s executive summary, and not a day
has passed since that COVID-19 has not been on our minds. Many countries have gone into lockdown as theworld continues working to contain the spread.
The use of information and communication technology (ICT) has come into the limelight under these circumstances. It is playing a major role underpinning our way of life amid the pandemic. ICT provides leisuretime inour homes while we are forced to stay in and stream videos, for instance; it lets people keep on working evenwhile opportunities for interacting with others in person are diminished; it facilitates distance learning for students
unable to physically attend a classroom due to school closures; and it helps to smoothly deliver assistance to people experiencing financial distress. Meanwhile, some issues have been raised, including the question of how weshould approach the balance between individual privacy and the public interest when it comes to, for example,
public institutions using ICT to monitor infected people via devices and surveillance cameras. And as we noted
here in our previous issue, the reliability of the information coursing through the Internet is another issue. People
are working to address these concerns from across many sectors, including government, healthcare, energy,transport, and distribution. The information and communications industry is a key part of the infrastructure that
underpins our society, and we will continue striving to develop technology as we look to play an even greaterrole than ever before.
The IIR introduces the wide range of technology that IIJ researches and develops, comprising periodic observation reports that provide an outline of various data IIJ obtains through the daily operation of services, as well as
focused research examining specific areas of technology.
Chapter 1 is our periodic observation report. These reports cycle through four topics over the course of each year.
In this edition, it is time for messaging technology. IIJ’s email services provide SPF, DKIM, and DMARC senderauthentication when emails are received, and we constantly monitor the authentication results. Our observational
results show that, while use of SPF and DKIM continues to spread, DMARC deployment rates are still low, whichtells us that we need to continue advocating for increased use of DMARC. The report also looks at the use of
sender authentication technology on phishing emails and goes over the JPAAWG 2nd General Meeting.
The focused research report in Chapter 2 discusses IIJ’s use of LoRaWAN® in agricultural IoT. LoRaWAN® is a
type of LPWA (low-power wide-area) wireless network for IoT devices that is gaining attention as it allows people
to build and run networks without having to rely on communications carriers. The report describes the knowledge we gained and challenges we faced through our real-world efforts to install base stations and IoT devices
in paddy fields, and I think you will find it an intriguing read.
The focused research report in Chapter 3 examines the role that information and communications has playedamid the COVID-19 situation. At different times from February onward, people in Japan were asked to observe
restrictions on their activities, which included the government requesting schools be closed, prefectural authorities urging people to stay indoors, and the government declaring a state of emergency. Analyzing changes in
fixed-line broadband traffic patterns around the time each of those requests were made provides insight into how
the requests affected Internet usage. These data will no doubt be a valuable impetus for reaffirming the importance of developing Internet infrastructure.
Through activities such as these, IIJ strives to improve and develop its services on a daily basis while maintaining
the stability of the Internet. We will continue to provide a variety of services and solutions that our customers
can take full advantage of as infrastructure for their corporate activities.

Junichi Shimagami
Mr. Shimagami is a Senior Executive Officer and the CTO of IIJ. His interest in the Internet led to him joining IIJ in
September 1996. After engaging in the design and construction of the A-Bone Asia region network spearheaded by IIJ,
as well as IIJ’s backbone network, he was put in charge of IIJ network services. Since 2015, he has been responsible
for network, cloud, and security technology across the board as CTO. In April 2017, he became chairman of theTelecom Services Association of Japan MVNO Council.

© Internet Initiative Japan Inc.

3

1. Periodic Observation Report

Messaging Technology

1.1 Introduction

measures, however, so using them properly is important to

According to the Council of Anti-Phishing Japan’s reports*1,

ensure effectiveness. Further, some posit that the rise in

the number of phishing cases reported to the council isthese emails reflects the recent social situation, so it may

rising rapidly. April 2020 saw 11,645 cases reported, an

persist for some time yet.

increase of 1,974 vs. the previous month (March 2020) anda hefty 9,257-case year-on-year rise (vs. April 2019). The

In this issue, we report on the prevalence of sender au-

substance of these cases shows a large volume of phish-

thentication technologies (SPF, DKIM, DMARC) that are

ing impersonating major companies that maintain an online

effective against email spoofing. We also discuss how topresence. Indeed, I have also received a number of such

use the results of sender authentication against the type ofemails. The Subject header and the display name and local

phishing emails currently circulating. We also report on thepart of the From header generally look the part, but the

JPAAWG 2nd General Meeting, held last year.

sender domain name is often completely different. And because fraudulent emails impersonating government agencies

1.2 Sender Authentication Rates

may be on the rise, countermeasures should be taken by

It is now 14 years since the first SPF (Sender Policy

both email recipients as well as owners of domains likely to

Framework) specification, RFC 4408*2, was published in

be spoofed.

April 2006. This was later followed by the DKIM specification, which uses digital signatures, and eventually DMARC,

4

As we have repeatedly reported, sender authentication iswhich uses SPF and DKIM authentication results. We reporteffective against phishing and other forms of email spoof-on the current prevalence of these sender authentication

ing. Those who send phishing emails are aware of thesetechnologies.

*1

Council of Anti-Phishing Japan, monthly reports listing (https://www.antiphishing.jp/report/monthly/, in Japanese).

*2

Subsequently revised in April 2014 as RFC 7208.

© Internet Initiative Japan Inc.

Jul.2020

Vol.

47

1. Periodic Observation Report

1.2.1 Results Based on Emails Received

increase in phishing reports, however, implies that spoofed

Given the practical implications, the percentage breakdown

emails are not themselves in decline. That is, spoofed emailsof authentication results for received emails can be con-that are not spoofing as far as SPF is concerned may be on

sidered important from the perspective of studying sender

the rise.

authentication deployment rates. IIJ’s email services provide the ability to perform SPF, DKIM, and DMARC sender

Figure 2 breaks down DKIM authentication results forauthentication upon email receipt. This feature returns aemails received in April 2020. The “none” result accounts“none” result for each method if the received email cannot

for 51.7% (48.3% deployment rate), a 10.5%pt drop frombe authenticated. So the proportion of received emails that

62.2% a year earlier, meaning that the deployment rate in-

do not return “none” can be interpreted as the deployment

creased 10.5%pt. Implementing DKIM as a sender requires

rate for received emails.

some effort as it requires adding a DKIM digital signatureon the sending email server. The current deployment rate is

Figure 1 shows the breakdown of SPF authentication re-by no means adequate, but 13 years since the first DKIM

sults for emails received in April 2020. The “none” result

specification was released in RFC 4871, it has finally spreadaccounts for 12.1%, meaning that the deployment rate wasto around half of all emails received (in terms of emails re-

87.9%. This is a 2.2%pt increase vs. the rate of 85.7%

ceived on IIJ services).

reported a year ago in IIR Vol. 43. The figure for “pass”,
meaning SPF authentication was successful, rose 9%pt

Figure 3 breaks down DMARC authentication resultsfrom 70.1% in April 2019 to 79.1% in April 2020. So thefor emails received in April 2020. The “none” result ac-

proportion of authentication failures (hardfail, softfail, andcounts for 75.4%, indicating a deployment rate of 24.6%,

neutral in the case of SPF) also fell by 6.4%pt, indicating aa 1.5%pt increase vs. a year earlier. This is a very small

rise in emails not spoofing as far as SPF is concerned. The

increase relative to SPF, which in practical terms is now

none

12.1%

permerror

1.0%

neutral0.3%

softfail

5.9%

hardfail

1.6%

pass 79.1%

Figure 1: Breakdown of SPF Authentication Results
pass 20.6%

pass 45.4%

fail 3.9%
permerror 0.1%

none

none

51.7%

75.4%

fail 1.1%
neutral 1.8%

Figure 2: Breakdown of DKIM Authentication Results

Figure 3: Breakdown of DMARC Authentication Results© Internet Initiative Japan Inc.

5

almost fully deployed, and DKIM, which generally entails an

being an extremely low point for DMARC, the graph instead

implementation cost. Deploying DMARC requires either SPF

shows that while there is a gradual increase in sender do-

or DKIM, or both, to be present, but if that requirement ismains supporting DMARC, that growth is very slow.

satisfied, DMARC can be implemented by simply publishinga DMARC record (text resource record) on the DNS, as is

Figure 5 breaks down the TLDs (top level domains) ofdone with SPF. There is no need to look at the sending email

domain names that passed DMARC authentication. The

server’s exit point, so DMARC records should actually bepercentages are not relative to the volume of emails re-easier to configure. We still do not know whether the mea-

ceived; they indicate TLD counts as a proportion of thegre increase in deployment relative to SPF and DKIM reflects

total number of separate DMARC domain names (uniquea simple lack of recognition or administrators being unclear

domain names). The .com TLD had the largest pie piece

about the motivation for publishing a DMARC record. We

at 53.2%. Second was .net with 9.5%, and Japan’s

intend to continue advocating for the broader deployment.jp domain name was third with 6.7%. Among domainof DMARC ahead.

names that passed SPF authentication, .com was again
the most common TLD, so there was no major difference

Figure 4 shows the breakdown of DMARC certification re-in the rankings.

sults over time, from January 2016. Rather than April 2020

(%)
100

75

50
■none
■permerror■temperror
■fail
■pass

25

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Figure 4: Breakdown of DMARC Authentication Results Over Timeothers

19.2%

in

0.8%

co

1.0%

de

1.0%

uk

1.6%

cn

1.6%

org

2.3%

au

3.0%

jp

6.7%

net

9.6%

com 53.2%

Figure 5: TLD Breakdown for DMARC Domain Names

6© Internet Initiative Japan Inc.

(Date)

Jul.2020

Vol.

47

1. Periodic Observation Report

1.2.2 Results Based on Domain Names

on an average of 57.3% of all jp domain names. Our latest

Another view on sender authentication technology is pro-results, for May 2020, show a 7.8%pt increase to 65.1%.

vided by looking at how many records for each senderauthentication technology are registered for registered do-

Figure 6 plots DMARC deployment on jp domain names. Frommain names. To do this, we have to set a scope and obtain

0.57% in March 2018, it rose 0.62%pt to 1.19% in May

all domain names within that scope.

2020. So the rate doubled over roughly two years, but it
was low to begin with and the increase itself was very small

As reported in IIR Vol. 39, we are studying jp domain names

relative to that for SPF, so both readings were very low. By

in collaboration with Japan Registry Services (JPRS), anddomain type, DMARC is currently most prevalent on go.jp

we currently have a joint research agreement with Internet

domains, but only with a 5.4% reading. SPF has 92.4% prev-

Association Japan (IAjapan). I am taking part in the studies

alence on go.jp, so we hope to see similar efforts to drive

as a member of IAJapan.

increasing use of DMARC records on all jp domains.

DKIM needs the DKIM selector name to acquire the digital

1.2.3 Sender Authentication as a Measure Against Emailsignature information (DKIM record), but since the selector

Spoofing

is specified in the email header, the domain name alone isGovernment agencies and so forth are implementing a range

insufficient to determine the DKIM record’s location. It isof measures under the current societal situation, and email

sometimes possible to guess whether a DKIM record has

communications are set to increase as part of that process.

been created , but this is not always accurate. This is why

Online purchasing and the like is also on the rise as people

only study results on the prevalence of SPF and DMARC,

avoid going out. As a reflection of this, fraud via phishingand not DKIM, are published*4. In each case, the proportions

and email spoofing may be on the rise.

*3

are based on domain names that have MX resource records,
enabling us to determine that the domain name is used for

For example, emails impersonating Amazon are frequentemail. There are, of course, ways of configuring SPF andand adopt a number of patterns, but emails from the actual

DMARC records (and, recently, MX resource records too)

Amazon support SPF, DKIM, and DMARC, so sender authen-for non-email domain names, but we’ll cover the details of

tication will tell you if an email is spoofed or not. And thethat another time.

Amazon SPF record ends with “-all”, so an SPF authentication failure always returns the strongest result of “fail”. The

Here, we report on the latest study results for SPF and

DMARC policy is also set to the relatively strong “p=quar-

DMARC. In March 2018, when our study began, SPF wasantine”. So Amazon seems to have actively adopted sender

6■Average■Generaluse■Regional
■lg
■ed
■gr
■ne
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18

(Date)

Figure 6: DMARC Deployment on jp Domain Names*5 Over Time*3

How to Measure Deployment Ratio of Domain Authentications (http://member.wide.ad.jp/wg/antispam/stats/measure.html.en).

*4Anti-spam Measures | Statistical Data (https://www.soumu.go.jp/main_sosiki/joho_tsusin/d_syohi/m_mail.html#toukei, in Japanese).

*5

Regional (newly registered) includes prefectural domain names.

© Internet Initiative Japan Inc.

7

authentication technology and bolstered defences against

Anti-Spam Conference. And as with the 1st GM, IIJ was

email spoofing. A point to note about detecting Amazon

again a platinum sponsor.

spoofing emails is the need to check that the authenticateddomain name is correct. In Japan, Amazon uses the ama-

In light of the 1st GM’s outcomes, the following new ideas

zon.co.jp domain name. Many of the spoofed emails use

were tried at the 2nd GM.

completely unrelated domain names and are set up so as
to pass SPF and DMARC. The Subject header and the dis-

1.Hold meeting over two days

play name in the From header contain the string “Amazon”.

2.Welcome many speakers and attendees from abroad,So ensuring that the authenticated domain name is also
checked is key to avoid being defrauded.

including M3AAWG members
3.Hold training sessions (paid)
4.Conduct Open Round Table discussions

Of the jp domain name types shown in Figure 6, lg.jp, which
is used by local governments and such, has consistently

Open Round Table (ORT) sessions are held at every M3AAWG

had the lowest DMARC deployment rate since our study

General Meeting*6, allowing participants to gather and dis-began. Of course, local governments do not only use lg.jp,

cuss topics of interest to them. ORTs can even be the point

but the deployment rates shown indicate what proportion ofof inception for documents like new technical specifications

domains with MX records have a DMARC record configured,and Best Practices, making them one of the driving forces

and the proportion of those with an SPF record was a highbehind M3AAWG’s activities. JPAAWG set five themes for

80.7%, coming in behind go.jp. So here again, to protect

the sessions, and JPAAWG members served as moderators

against spoofed emails, administrators first of all need to

to facilitate balanced discussion involving all participants.

configure a DMARC record to protect the sender domain

JPAAWG hopes to continue hosting activities like ORTs toin the header. And to determine just how many emails areprovide a forum for discussing issues and thinking about

spoofing the domain, they also need to get set up to re-solutions.

ceive DMARC reports so they can constantly monitor what
is happening.

We wanted to hold the JPAAWG 3rd General Meeting in asimilar format in 2020. Under present circumstances, how-8

1.3 JPAAWG 2nd General Meeting

ever, a large gathering does not look all that viable. We are

The JPAAWG 2nd General Meeting (GM) took place atin the process of considering what sort of format would

Bellesalle Iidabashi First on November 14–15, 2019 (Figure

work, so we will provide notice on the website*7 once a7). As in 2018, it was held in conjunction with IAJapan’s

decision is made.

*6

Messaging, Mobile and Malware Anti-Abuse Working Group (https://www.m3aawg.org).

*7

Japan Anti-Abuse Working Group (JPAAWG) (https://www.jpaawg.org/).

© Internet Initiative Japan Inc.

Jul.2020

Vol.

47

1. Periodic Observation Report

1.4 Conclusion

So in 2020, we had opportunities to present both in Japan

I attended the JANOG45 meeting held in Sapporo over

and abroad, and we were all set to continue communicat-

January 22–24, 2020, and made a presentation in theing our key insights with increased vigor. But the situation“Current State of Phishing and Countermeasures“ session.

took a turn, as you know, and forced a rethink of the for-I went because I felt it was important for a large number

mat in which meetings are held. Yet our work is aimed atof people in the field to be aware that adoption of senderpromoting the proper use of the various tools available onauthentication technologies, DMARC in particular, is low,

the Internet, so even under circumstances such as these, I

as discussed in this report. At the M AAWG 48th Generalthink we should continue working to make communication

Meeting in San Francisco over February 17–20, 2020, we

happen and ensure that those tools are not misused.

3

again held a JPAAWG BoF group meeting, and in a session
titled “State of Messaging Anti-Abuse in Japan”, I presented on JPAAWG’s activities along with other JPAAWG/
M3AAWG members.

Figure 7: Photo taken at the JPAAWG 2nd General Meeting

Shuji Sakuraba
Senior Manager, Application Service Department, Network & Cloud Division, IIJ. Mr. Sakuraba is engaged in the research and developmentof communication systems. He is also involved in various activities in collaboration with related external organizations aimed at bringing
about safe and secure messaging environments. He has been a member of M3AAWG since its establishment. He is the chair of the Japan
Anti-Abuse Working Group (JPAAWG). He is acting chairperson of the Anti-Spam mail Promotion Council (ASPC) and a member of its
administrative group, as well as chief examiner for the Technology Workgroup. He is a visiting researcher at Internet Association Japan andchairman of its Anti-Spam Measures Committee. He is a visiting researcher at JIPDEC.

© Internet Initiative Japan Inc.

9

2. Focused Research (1)IIJ’s Efforts to Promote LoRaWAN® in
Agricultural IoT
2.1 Introductionsin the field, which has involved installing base stations, eval-

IoT initiatives are expanding rapidly across a whole range ofuating data link performance, and the like.

fields. As the use cases multiply in manufacturing, healthto agriculture. Agriculture is a core industry and backbone

2.2 Testing IoT-based Paddy Field Water Managementof the nation, yet it is plagued by issues including serious

With support from the National Agriculture and Food

workforce aging and a lack of successors as well as poor

Research Organization’s special scheme project on vi-

profitability. To address these issues, Japan’s Ministry oftalizing management entities of agriculture, forestry andAgriculture, Forestry and Fisheries has made “smart agricul-

fisheries, IIJ has been developing and testing a low-costture” a keyword and is actively engaged in demonstration

ICT water-management system that facilitates labor saving

testing nationwide.

in the area of paddy field water management. This year,

care, automobiles, and other areas, IIJ has turned its eye

we launched Mizukanri Pack S [Water Management Pack
Against this backdrop, IIJ is looking at whether it can lendS], which packages together the results of these efforts asa hand to ease the burden on Japanese agriculture and help

a set of paddy field sensors that measure water levels andmake it more economically viable. Our track record so far in-temperature, a wireless base station, a smartphone water

cludes developing paddy field sensors that use LoRaWAN®,

management app, and cloud services (Figure 1). The paddy

a new wireless communications technology that IIJ is fo-

field sensors and wireless base station use LoRaWAN® to

cused on.

communicate. A package that automates water management is also available, comprising the Mizukanri Pack S

The biggest issue facing IoT for agriculture is enabling data

paddy field sensors and base station as well as a valve that

communications. Here, we take a deep dive into the know-

automatically controls water volume based on water levels

how we have amassed through experience and trial-and-error

measured by the sensors.

M onitor water level & tem perature remotely from home,
workshop, etc.

IIJ water
management
platformfor paddy fields
Mizukanri app

Sensors collect paddy field
wa te r l eve l / te m p e r a t u r e
data.

LTE

Easily installed in home orworkshop. Listens to multiple
sensors.

LoRaWAN®

Wireless base station(LoRaWAN®)

Figure 1: Mizukanri Pack S Saves Labor in Paddy Field Water Management

10© Internet Initiative Japan Inc.

Paddy fieldsensors

Jul.2020

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47

2. Focused Research (1)IIJ is a communications carrier, so working in an unfamiliar

2.3 A Single Base Station Can Cover Several kmwith LoRaWAN®

area like agricultural IoT and venturing outside of our area

2.3.1 About LoRaWAN®

of expertise to develop new devices like paddy field sensors

LoRaWAN® is a wireless networking specification that uses

was challenging and a constant struggle. We detail thesea spread spectrum modulation technique called LoRa®,

efforts in “The IIJ Stories” .

developed by Semtech. Although LoRa® communication*1

speeds are slower than Wi-Fi and BLE, it can cover an evenIn this report, we focus on the wireless base stations, part of​​wider range than LTE, as illustrated in Figure 2. It also

IIJ’s business domain, and describe efforts to promote use

makes it possible to create low-power devices that canof LoRaWAN® in agricultural IoT. Although it is part of ourcommunicate for several years on battery power alone.

business domain, we were inexperienced in many respects

Mizukanri Pack S paddy field sensors take advantage ofand faced a range of challenges. In particular, we travelledthese characteristics to cover an area of several kilometers

frequently to measure data link status, from Hokkaido inwith a single base station and operate throughout an entire

the north down to Kyushu in the south. Before delving into

growing season on two AA batteries, with no need for thethe knowhow those efforts produced, we first provide somebatteries to be replaced.

background knowledge on LoRaWAN® and how it is distinct
from other LPWA standards.

High

LTE
Wi-Fi
BLE

Mission critical Outdooruse caseHigher Power

Video / Voice
Consumer IoT

Bandwidth

Sensors, Actuators and Tags
Lowest Power and Lowest Cost
Low
Short

Range

Long

Figure 2: LoRa® Relative to Other Standards*1

The IIJ Stories | IoT is changing the future of Japanese agriculture by supporting rice farmer work-style reforms (https://www.iij.ad.jp/interview/03.html, in Japanese).

© Internet Initiative Japan Inc.

11

Some LoRa® wireless networks use proprietary proto-

used within the coverage areas without the need to installcols, but the standard is LoRaWAN®, specified by the

your own base station.

LoRa Alliance®, comprising over 400 member companies
including IIJ. LoRaWAN® certificated devices are intercon-

Sigfox is very inexpensive, with usage fees as low as 100

nectable, opening up a wide range of choice with respect

yen per device per year (depending on the number of de-to sensors and other connected devices from different

vices under contract), and covers 95% of the population as

manufacturers.

of January 2020. In basic terms, it allows for uplink onlywith payloads limited to 12 bytes and the number of mes-

Figure 3 shows the structure of a LoRaWAN® system. The

sages per day limited to 14. Yet it is the leader in Japan indevices communicate via gateways and LoRaWAN®. The

terms of number of devices deployed, with, for example,

gateways connect to a network management server, called

850,000 compatible devices that use these features for tak-a network server, via LTE, Wi-Fi, or wired Ethernet. The

ing gas meter readings already slated for installation.

network server provides management capabilities, including device activation, elimination of duplicate data received

The LTE-M standard is developed by 3GPP, and three mo-from the same device via multiple gateways, control ofbile carriers provide LTE-M services in Japan: NTT Docomo,

communication routes to the application server for eachKDDI, and SoftBank. Using a bandwidth of 1.4MHz allows

data payload, and variable data rate control. The application

bidirectional communication of up to 1Mbps, and it also

server communicates with the network server via a REST

supports FOTA (Firmware Over-The-Air) remote device firm-

API or the like, and stores data received from end-devices,

ware updates. It also supports handover switching of baseprovides application-based visualizations, and controls de-stations when on the move, so it can be used in much thevices according to user command or automatically according

same way as regular LTE. However, if used only on carrier

to preset criteria.

networks, the data charges are 100–150 yen per device up
to 10,000 devices, which is far more expensive than Sigfox.

2.3.2 Features Compared with Other LPWA Standards
LoRaWAN® is a type of LPWA (low-power wide-area) net-

Some carriers provide their own LoRaWAN® base stations

work. These networks are characterized by low powerand base stations shared among users, but generally you

consumption, low bit rates, and wide area coverage. Many

need to install your own base station. Low-price LoRaWAN®

other LPWA wireless networks exist, including Sigfox andgateways are available that are similar to mass-mar-

LTE-M. Communications carriers operate base stations na-

ket LTE-capable IoT gateways, like the Kiwi Technology

tionwide for Sigfox and LTE-M, and the networks can be

TLG3901BLV2 included in Mizukanri Pack S.

Ordinary network server model

Generally built in the cloudDeviceGateway

Application

DeviceNetwork server
DeviceApplication
serverGateway

Application

DeviceFigure 3: Overview of a LoRaWAN®-based System

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2. Focused Research (1)Having to install your own base station puts LoRaWAN®

2.4 Challenges in Promoting LoRaWAN®
for Agricultural IoT

at a disadvantage to Sigfox and LTE-M in terms of equip-

So far we have discussed:

2.3.3 Applications Suited to LoRaWAN®

ment and installation costs. But an advantage is the ability
to add base stations to reach areas not covered by out-

• Features of LoRaWAN® and suitable applications

door base stations, such as basements and inside buildings.

• Advantages of LoRaWAN® in agricultural IoT

And because there are no data charges for communications
between devices and the gateway, the cost benefits are

So what challenges do we face in popularizing LoRaWAN®

considerable if only a few base stations are used to serve a

for agricultural IoT?

large number of devices. LoRaWAN® is particularly suitable
for low-cost applications that involve multiple battery-pow-

2.4.1 Installing Inexpensive Outdoor Base Stations

ered devices installed in large buildings, such as factories,

I was involved mainly in base station design as part of the

shopping centers, and offices.

three-year paddy field water management IoT demonstration
testing project, and based on my experience, the biggest is-With no downlink restrictions, LoRaWAN® is also effective

sues are finding places to install base stations and obtaining

in agricultural IoT, including paddy field water management,a power supply.

when there is a need to control devices like water supply
valves. Ensuring profitability in agricultural IoT can be dif-

The TLG7921M is a waterproof outdoor LoRaWAN® gateway

ficult if expensive devices and services are used, so thewith strong wireless performance, so a single unit can coveradvantages of LoRaWAN® and inexpensive equipment comea wide area if installed in an elevated spot, such as a rooftop

into play here to enable low-cost services even when using

or mountain. But it is more expensive than indoor LoRaWAN®

multiple devices of different types. A range of LoRaWAN®-

gateways, and the cost of installation, including wiring, iscompatible devices from different manufacturers are alreadyalso high, so it is an expensive option unless installed on aavailable for agricultural IoT, including paddy field sensors

decent scale (e.g., rolled out across an entire region).

and water supply valves for paddy field water management,
weather sensors for measuring rainfall and temperature, andKiwi Technology’s TLG3901BLV2 is a very cheap LoRaWAN®

soil sensors for measuring soil temperature and moisture.

gateway included in the Mizukanri Pack S. It is an indoor

These can all be accommodated by a single LoRaWAN®

device intended for installation in homes or offices of ag-

base station. Another advantage is the ability to set up

ricultural businesses, but offices and homes are often far

your own base stations to provide coverage in areas wherefrom the paddy fields where the sensors are installed, andcarrier-operated base stations can struggle, such as moun-the data links can be unstable. Installing them in private

tainous terrain.

homes with a power source near the fields would work, but

Figure 4: Kiwi Technology’s TLG3901BLV2© Internet Initiative Japan Inc.

13

this is not all that realistic since users themselves would

2.5 Solutions to the Issues

have to negotiate with property owners about how much

So far, we have explained that promoting the use of

to pay for the electricity used by the LoRaWAN® gateway

LoRaWAN® for agricultural IoT will be difficult unless weand so forth.

can achieve either of the following:

2.4.2 Simple Pre-installation Data Link Tests• Install inexpensive base stations outdoors

Even if you are able to install inexpensive base stations out-

• Easily assess data link performance before installation

doors, you may need to relocate them or add additional units
if you are unable to easily determine beforehand that they

To solve these issues, our aim was to make the system

can link to devices without any issues.

as DIY-friendly as possible for agricultural businesses. I describe our solutions below.

Several companies offer commercial wireless simulators that
let you enter base station latitude, longitude, and installation
height to simulate data links with peripheral devices. We

2.5.1 DIY Solar-powered Base Stations to Expand Installation
Options and Cut Installation Costs

actually tried one of these, but while the simulator included

If the TLG3901BLV2 indoor LoRaWAN® gateway included in

topographical data, it did not include data on buildings andMizukanri Pack S could be waterproofed and made to run

trees, so we were unable to determine the effect of suchon a cheap solar panel and battery, obviating the need for

objects on data links. When we compared the results of thea power supply, then it could be installed on the edge of

wireless simulator with real-world measurements taken in

paddy fields where it was previously not possible to do so

the vicinity of the paddy field water management IoT test

and thereby provide stable data links. So we decided to makesite, the simulation tended to match the real world in places

available a DIY solar-powered base station package that ag-

with few buildings, but even then, when testing close to

ricultural businesses can easily set up themselves, consistinga building, we found that small changes in device positionof a cheap solar panel and battery and materials readily avail-can greatly affect data transfer success rates. Even if data

able online or at home centers. Agricultural business owners

on buildings and trees is incorporated into the simulator inare used to DIY, with many building their own greenhouses

the future, covering all buildings and trees is likely to be

for instance, and they often have a decent set of tools, so we

difficult, as is keeping the data up to date, so disparities be-believe they will be able to install the DIY solution themselves

tween simulation and real-world testing seem inevitable. In

as long as we provide a clear set of instructions. Finding an

the real-world tests, the data links were also sometimes un-

installation spot along the side of a field should also be easy,stable near busy roads. Assessing such time-based changes

and the cheap price means that the system can easily bein data link status is also likely to be difficult in wirelessrestored if it is, say, damaged by natural events or stolen.

simulators, even in the future.
We expect the package we are putting together to proSo simulation-based pre-installation checks of connectivity

vide a solar-powered base station that runs year rounddo have their limitations, and you need to do real-world tests

at an additional cost of about 70,000 yen on top of theto say anything with certainty. However, there are limits to

TLG3901BLV2. To evaluate the package, we have alreadythe extent to which we, or a contractor, can measure con-obtained materials and built a DIY solar-powered base sta-

nectivity every time a base station or device is installed, andtion ourselves (Figure 5), and I blogged about the process.

this would also be costly.

See my posts for more details*2.

*2

IIJ Engineers Blog, “We set up a solar-powered LoRaWAN® base station for smart agriculture (Parts 1 & 2)” (https://eng-blog.iij.ad.jp/ archives/5567, in Japanese)(https://eng-blog.iij.ad.jp/archives/5599, in Japanese).

14© Internet Initiative Japan Inc.

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2. Focused Research (1)Four of us installed the first solar-powered base station, but

2.The measurement process will take 5 minutes and con-

we believe we need to make improvements as we develop

sist of 30 individual measurements taken at 10-second

the package so that two people or fewer can install it in ashorter amount of time. So we recently arranged to use alocation relatively close to our workplace for a day, and undeterred by rain, ten of us tested out a number of installationintervals.
3.The wireless survey tool will have an LCD screen todisplay measurements in real time.
4.The TLG3901BLV2 will be usable without a SIM.

patterns using various tools and materials. I hope to write
the experience up in a blog post soon. And we look forward

We decided on Requirement 1 to make it easy to conduct

to launching a package that embodies what we learned.

testing anywhere. If we created a smartphone app, users
would need to learn how to operate it, but some agricul-

2.5.2 Simple Data Link Tests via a Wireless Survey Tooltural businesses are not all that familiar with smartphones.

To enable agricultural businesses to easily measure data

Mizukanri Pack S includes a smartphone app, so users needlink performance themselves, we decided to develop ato acquaint themselves with its use once they decide to

wireless survey tool, a device that measures data link per-install the system, but we wanted to make the bar as low

formance. We started out with the following development

as possible in the initial pre-installation survey stage. Making

requirements.

the devices battery powered not only eliminated the need tobe near a power source, it also made it possible to eschew

1.We will not create a smartphone testing app. The
system will consist of only the TLG3901BLV2 and aa power button and have tests start automatically when thebattery is connected.

wireless survey tool. Both will run on a mobile battery
or dry-cell battery.

Figure 5: DIY Solar-powered Base Station© Internet Initiative Japan Inc.

15

Requirement 2 is in line with devices we have used for test-shows the number of successes over the total number ofing so far. Although the LoRaWAN® specification allows fortries (Figure 6). Displaying the test results in real time wasshorter intervals, we selected our interval in light of poten-

also a good idea because the user can disconnect the bat-tial interference in the case of multiple devices using thetery and stop the test if no data is being received at all.

same 920MHz band being nearby as well as the potentiallystrong effect of environmental noise from, for example,

Requirement 4 is there because otherwise, if we were to

moving vehicles.

create several sets of the TLG3901BLV2 and wireless survey tool to lend out to people, we would need the same

We decided on 3 instead of a smartphone app. The wirelessnumber of SIMs. As Figure 3 shows, LoRaWAN® systems

survey tool sends an ACK request via uplink to the Kiwi

normally need to connect to a network server in the cloudTechnology LoRaWAN® gateway. If an ACK is returned,

and thus need a mobile line accessed via a SIM or the like.

it is counted as a success; if no ACK is returned, this is

Fortunately, Kiwi Technology LoRaWAN® gateways fea-a failure. Successes and failures are displayed as 0 and X

ture their own built-in network server. Figure 7 illustrates aon screen. Once the data link test is complete, the screen

LoRaWAN® system using the built-in network server.
The built-in network server enables the gateway alone toprovide almost the same level of functionality as network
servers usually available in the cloud. The gateway can store
data received from devices in internal storage for a period,
allowing for its retrieval externally at any time via a REST
API. You can also request control of devices via the REST
API. When an ACK is received from a device, you can return
an ACK from the unit. This allows for bidirectional communication with devices even if the application server cannot
be reached. The built-in server was originally intended tofacilitate PoC in the absence of a network server contract,
but we were also able to make effective use of this featurein the wireless survey tool.
Figure 8 shows the prototype wireless survey tool that wedeveloped. We have actually already lent it to a number ofpeople to use, and in addition to the expected outcome ofusers being able to perform a preliminary survey of wirelessperformance, some also expressed surprise at the system’s
range: “It picks it up from this far away?!” So the tool also

Figure 6: The Wireless Survey Tool’s LCD Screen

The gateway has a built-in network server feature
DeviceGateway

Network server

Application
server

Application

Gateway

Network server

Application
server

Application

DeviceDeviceDeviceFigure 7: Overview of a LoRaWAN® System Using the Built-in Network Server

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2. Focused Research (1)turns out to be an effective way for people to experienceof the LoRaWAN® gateway by adding SACM zero-config

the long range LoRaWAN® offers before installing a system.

support, for instance.

It is also an effective way of collecting real-world test datafrom a whole range of locations, something we could not do

SACM is a next-generation management system service foralone, so we hope to continue utilizing the wireless survey

routers and IoT gateways, developed by IIJ based on SMF

tool while making additional improvements going forward.

technology, which enables the automatic connection andcentralized management of devices, and offered on an OEM

2.6 Conclusionbasis. With zero-config support, a device will automatically

We have discussed the features and suitable applications

connect to SACM when powered on, acquire its settings,

of LoRaWAN® compared with other LPWA wireless net-and start running. This eliminates any need to operate aworks and the advantages of LoRaWAN® in agricultural

device directly. The user interface allows SACM adminis-

IoT. We also looked at challenges to promoting the use of

trators to centrally configure, monitor, and manage a large

LoRaWAN® in agricultural IoT along with solutions.

number of devices. See our Focused Research report in IIR
Vol. 36 for details of SACM*3.

However, solving the issues we discussed merely means
we have done the minimum groundwork necessary to put

The features we have developed for agricultural IoT and the

Mizukanri Pack S on the market. If sales volumes rise, wesales and operating knowhow we have built will also be

will have to address issues including simplifying pre-ship-

effective in deploying LoRaWAN® solutions for other appli-

ment kitting and making it easy to diagnose the situation

cations. By continuing to develop this technology and buildwhen problems arise after a product is shipped. To that end,a knowledge base, IIJ aims to lower the bar to implementing

IIJ is working with Kiwi Technology to extend the features

LoRaWAN® and see it deployed in a range of different fields.

Figure 8: Wireless Survey Tool Prototype

Moto Onishi
Product Manager, New Business Promotion, IoT Business Division, IIJ
Mr. Onishi joined IIJ in June 2016. He handles project planning for IoT and camera solutions.

*3Internet Infrastructure Review (IIR) Vol.36 (https://www.iij.ad.jp/en/dev/iir/036.html).

© Internet Initiative Japan Inc.

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3. Focused Research (2)COVID-19’s Impact on FLET’S Traffic

3.1 Introduction

staying in, there was a sudden paucity of faces on the

The COVID-19 situation prompted the closure of Japan’s

streets. Trends in FLET’S traffic underwent a clear change

schools nationwide from March, resulting in a sharp rise infrom March 2. Later, on March 25, the Tokyo government

people working remotely from home. The changes in many

began urging people to stay indoors. Japan declared a statepeople’s Internet usage patterns put a strain on individualof emergency covering seven prefectures on April 7, andservices and communication links, and social media wasthis was expanded nationwide on April 16. These events

filled with people observing this phenomenon and express-

greatly altered the societal landscape. Although the number

ing dissatisfaction. Yet there is not much information outof people staying at home has undoubtedly increased, we

there on the macro situation. As such, we report on thehave not seen that large a change in FLET’S traffic volume.

impact on traffic on IIJ’s FLET’S-based services as a bellwether of broadband services used mainly in the home.

3.2 About the Data
The traffic volume data is collected from the interface

COVID-19 began spreading in Japan in mid-February.

counters on routers that accommodate the fiber-optic

Remote work was still experimental at that point, but in lateand ADSL customers on IIJ’s personal and enterprise

February, companies like Dentsu and Shiseido embarked onbroadband services. We use data collected via Sampledlarge-scale remote work programs. Schools closed nation-

NetFlow to study the origin of traffic (sender organiza-

wide on March 2, and that same week, many companies

tions). Further details about the data are available in lastinitiated remote work, and as more and more people began

year’s Broadband Traffic Report*1.

Feb 17 - 23
Feb 24 - Mar 1
Mar 2 - 8
Mar 9 - 15

PPPoE download traffic0

Mar 9 - 15
Mar 16 - 22
Mar 23 - 29
Mar 30 - Apr 5

0

Apr 6 - 12

Apr 6 - 12
Apr 13 - 19
Apr 20 - 26

0

Apr 27 - May 3

Mon

Tue

Wed

Thu

Fri

Sat

Sun

Figure 1: FLET’s Traffic
Download: Feb 17 – Mar 15 (top), Mar 16 – Apr 12 (middle), Apr 13 – May 10 (bottom)*1

18

Kenjiro Cho, Broadband Traffic Report: Moderate Growth in Traffic Volume Ongoing, Internet Infrastructure Review, Vol.44. pp4-9, November 2019.

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3. Focused Research (2)3.3 Traffic Condition

final week from the previous subplot for comparison. The

IIJ’s FLET’S services include IPv6 IPoE in addition to conven-holidays in this period are February 24 (Mon), March 20

tional PPPoE. IIJ’s IPv6 IPoE service uses Internet Multifeed(Fri), April 29 (Wed), May 4 (Mon), May 5 (Tue), and May 6

Co.’s transix service, and the traffic does not pass directly(Wed), and the traffic patterns on these days do differ fromthrough IIJ’s network. The volume of traffic here is currently

other weekdays.

around 20% of that on PPPoE. Congestion on network termination equipment has become a problem with PPPoE in

Downloads usually peak in the evening and fall off sharply

the past few years, and an increasing number of ISPs areafter midnight, with the lowest point coming in the earlyrecently recommending the use of IPoE.

morning. Daytime traffic is high on weekends/holidays.
Upload traffic is almost an order of magnitude smaller thandownload traffic, and there are no clear peaks.

3.3.1 FLET’S Traffic (PPPoE)
Figures 1 and 2 overlay IIJ’s total FLET’S traffic week byweek. This is PPPoE traffic and does not include IPv6 IPoE.

First, we look at download traffic in Figure 1. Comparing the

Figure 1 shows download and Figure 2 upload traffic.

two weeks represented by the red and orange series withthose represented by the aqua and blue series (i.e., before

The chart covers 12 weeks from the week of February 17,

and after March 2) in the top subplot shows that weekday

broken into three four-week subplots. The middle and bot-download traffic increased after March 2. Volumes were still

tom subplots contain five weeks of data as they include thea bit lower than on ordinary weekends. The peak values

Feb 17 - 23
Feb 24 - Mar 1
Mar 2 - 8
Mar 9 - 15

PPPoE upload traffic0

Mar 9 - 15
Mar 16 - 22
Mar 23 - 29
Mar 30 - Apr 5
Apr 6 - 12

0

Apr 6 - 12
Apr 13 - 19
Apr 20 - 26
Apr 27 - May 3

0

May 4 - 10

Mon

Tue

Wed

Thu

Fri

Sat

Sun

Figure 2: FLET’s Traffic
Upload: Feb 17 – Mar 15 (top), Mar 16 – Apr 12 (middle), Apr 13 – May 10 (bottom)© Internet Initiative Japan Inc.

19

also increased just slightly. Not much changes in the middle

together. The dip around lunchtime is probably due to a lull

subplot, but the bottom subplot shows that weekday day-in video conferencing. Through mid-March, upload traffic

time traffic began increasing again in April. The increase in

only increased on weekdays, but thereafter evening andtraffic from early in the morning on March 11 (Wed) is likely

weekend/holiday traffic also rose. We think this is probably

due to the release of the popular video game Call of Duty:

due to an increase in video conferencing for private gather-

Warzone. Microsoft released a monthly update on the sameings, like afterwork drinks, as people became accustomedday, and this also probably contributed.

to the tools. The upload peak value, however, is only about
1/7th the download peak value, so upload traffic certainly

Next, we look at upload traffic in Figure 2. The top subplot

did not rise as much as download traffic.

shows that daytime traffic on weekdays rose slightly throughmid-March, but the increase eased off in the evenings, so it

To determine whether the increase in weekday daytime

is probably related to video conferencing and other remotetraffic was due to specific services, we also looked atwork applications. The middle and bottom subplots show

Sampled NetFlow data. A comparison of the Tokyo areaa progressive rise in weekday daytimes from April, likely adata for February 26 (Wed) and March 4 (Wed) shows anreflection of remote work arrangements gradually coming

overall 1.19-fold increase in download volume. By senderFeb 17 - 23
Feb 24 - Mar 1
Mar 2 - 8
Mar 9 - 15

IPoE download traffic0

Mar 9 - 15
Mar 16 - 22
Mar 23 - 29
Mar 30 - Apr 5

0

Apr 6 - 12

Apr 6 - 12
Apr 13 - 19
Apr 20 - 26
Apr 27 - May 3

0

May 4 - 10

Mon

Tue

Wed

Thu

Fri

Sat

Figure 3: IPv6 IPoE traffic
Download: Feb 17 – Mar 15 (top), Mar 16 – Apr 12 (middle), Apr 13 – May 10 (bottom)

20© Internet Initiative Japan Inc.

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3. Focused Research (2)organization (AS), the data show a decent increase in the

1.32x, and Microsoft 2.40x. This points to growth in full-

proportion of traffic from CDN operators, with the break-length video content, such as movies, and content tied todown among major content providers remaining largely thebusiness applications.

same. Specifically, the figures were Google 1.16x, Amazon
1.16x, Netflix 1.17x, Facebook 1.10x, and Microsoft

3.3.2 IPv6 IPoE Traffic

1.23x. So this was overall growth that was roughly equiv-

The reason PPPoE peak traffic is not rising could be thatalent across different sources of popular content, with no

the FLET’S network is congested, so here we look at IPv6

particular service being a clear standout.

IPoE, which should have ample capacity. Figures 3 and 4
plot IPv6 IPoE traffic volume. The download chart certainly

To examine the changes that followed, we now compare

shows the peaks rising, by a few percent in the top subplot,

February 26 (Wed) and April 22 (Wed). Overall download

barely at all in the middle subplot, and then again by a few

volume was up 1.20 fold, only a slight increase over March

percent in the bottom subplot. And compared with PPPoE,4, but the breakdown among major content providers shifted

weekday daytime traffic is lower relative to its peak. The

a little. Specifically, Google was unchanged at 1.16x, while

increase in weekday daytime upload traffic is also smaller

Amazon had 1.63x, Apple 1.00x, Netflix 1.36x, Facebook

than for PPPoE.

Feb 17 - 23
Feb 24 - Mar 1
Mar 2 - 8
Mar 9 - 15

IPoE upload traffic0

Mar 9 - 15
Mar 16 - 22
Mar 23 - 29
Mar 30 - Apr 5
Apr 6 - 12

0

Apr 6 - 12
Apr 13 - 19
Apr 20 - 26
Apr 27 - May 3

0

May 4 - 10

Mon

Tue

Wed

Thu

Fri

Sat

Sun

Figure 4: IPv6 IPoE traffic
Upload: Feb 17 – Mar 15 (top), Mar 16 – Apr 12 (middle), Apr 13 – May 10 (bottom)© Internet Initiative Japan Inc.

21

3.4 Discussion

peaks should be rising where there is ample capacity, but

We were only able to take observations from IIJ services on

we did not observe any such differences over our observa-

this occasion, which tells us nothing about trends at othertional range.

companies. In mid-April, however, NTT East*2, NTT West*3,
and NTT Communications*4 released data on FLET’S traf-

IPoE peak traffic is increasing, but IPoE traffic depends on thefic volumes. Figure 5 plots the changes in weekday traffic

availability of content over IPv6, so the content breakdown

based on IIJ’s PPPoE data in the same manner as the graphs

differs from that for PPPoE and is not directly compara-published by the NTT companies. The plot shows average

ble. Also, the number of PPPoE contracts has hit a ceiling,

download (DL) and upload (UL) traffic for the weeks ofwhereas the ongoing shift to IPoE to avoid the congestion on

February 25 and April 20. It almost matches the observations

PPPoE means that IPoE contract numbers are also growing. Inof the NTT companies, so we think the same trends basicallyoverall terms, while the growth in IPoE download peak levels

held for FLET’S-based broadband services. We also think theseems to indicate that PPPoE is running out of capacity, thesituation on non-FLET’S networks with sufficient available

potential room for an increase in PPPoE peaks is probably

bandwidth is close to what we observe for our IPoE traffic.

smaller than the amount by which IPoE has increased.

From a macro view, weekday daytime traffic clearly in-Some changes are apparent in March and April too. In

creased after March 2. On weekdays, daily upload traffic

March, it looks like overall Internet usage increased as thewas up about 6% and download traffic about 15%. A 15%

number of people at home during the daytime on week-increase in daily downloads is about the same as the differ-days increased. Then in April, it looks like traffic related toence between weekdays and weekends, but another way

movie streaming and remote work increased as users got

to look at it is that an increase that would normally taketheir systems set up properly and became accustomed to

six months happened in a single day. But the peak values

the tools. As a characteristic effect of remote work, thedid not rise much, so from an ISP perspective, the former

increase in weekday daytime upload traffic is probably dueinterpretation makes sense. The reason the peaks did notmainly to video conferencing. But the volume is not all thatrise much may be due to capacity shortages on the FLET’S

large through the latter half of March, likely because the

network’s PPPoE network termination equipment. There

number of people video conferencing from home was still

may also be congestion at FLET’S network optical splitters

limited. Working efficiently when remoting in requires notor on consumer devices and wiring in apartment buildings.

only a decent home network setup and equipment, includ-

But such problems arise at the individual device level, so theing a PC, but also some level of experience. Companies

traffic

Feb 25-28 DL
Feb 25-28 UL
Apr 20-24 DL
Apr 20-24 UL

0

0

6

12

18

Figure 5: Average Weekday Traffic by Time of Day: February vs. April

22*2

NTT East, “NTT East’s efforts in response to COVID-19” (https://www.ntt-east.co.jp/aboutus/COVID-19.html#traffic, in Japanese).

*3

NTT West, “NTT West: Download traffic across all areas” (https://www.ntt.co.jp/topics/important/covid19_west.html, in Japanese).

*4

NTT Communications, “Internet traffic time series data” (https://www.ntt.com/about-us/covid-19/traffic/, in Japanese).

© Internet Initiative Japan Inc.

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3. Focused Research (2)were apparently experiencing problems on their end, in-Video overwhelms other types of content in terms of sheer

cluding a shortage of VPN licenses and bandwidth. And

volume, however, so usage trends for non-video content

many people were probably not fully set up for video con-are not really evident from the traffic observations because

ferencing when initially trying it out. The breakdown invideo streaming dominates download traffic and video con-

growth by operator shows a uniform rise in traffic from theferencing dominates upload traffic. There are limits to what

major content providers in March, followed by growth for

traffic alone can tell us about trends in Internet usage.

movie content providers and providers of remote work-re-

3.5 Conclusion

lated services in April.

The spread of COVID-19 has fueled a rapid shift toward
It is also clear that traffic falls when the weather is good andremote work. This has revealed problems with individual

rises when it is bad. People are thought to have relaxed andcommunication links and services, yet on a macro level, al-thus ventured out more amid favorable weather over thethough weekday daytime traffic has increased, it has recently

March 20–22 (Fri–Sun) long weekend, and as if to back thissettled at levels within the bounds of existing capacity.

up, traffic was low over that period. Eastern Japan and the
Tohoku region had stormy weather on April 18 (Sat), andRemote work and remote education were rolled out on atraffic increased on this day. Traffic was also on the highhuge scale from March. Until now, remote work had been anside in Kanto on April 13 and 20, perhaps because theseexperimental affair carried out by a select few, but we areconsecutive Mondays were both rainy.

now finding out whether everyone can do it at once. And
although the quality of Internet-based video conferencing,

Growth in broadband traffic was actually accelerating evenremote classes, video streaming, and the like is currently

before COVID-19 spread. Factors potentially behind this in-

sufficient when only some people are engaged, it will takeclude households becoming better equipped to stream video

years to build systems that can cope with large numbers ofas people replaced old PCs ahead of the Windows 7 end-

people all at once. Present circumstances have made clear

of-life and Japan’s consumption tax hike, the progressivethat society as a whole depends on online systems whenintroduction of remote work arrangements as part of work-

push comes to shove. Our hope is that this will provide astyle reforms and efforts to cope with the Olympics, andstrong impetus for reaffirming the importance of developing

increasing interest in video streaming fueled by expectations

Internet infrastructure.

for online streaming of the Olympics and TV broadcasts, 5G
mobile services, and the like.

Kenjiro Cho
Research Director, Research Laboratory, IIJ Innovation Institute Inc.

© Internet Initiative Japan Inc.

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July 2020 Vol.
About Internet Initiative Japan Inc. (IIJ)
IIJ was established in 1992, mainly by a group of engineers who
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to the Internet, under the concept of promoting the widespreaduse of the Internet in Japan.
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Initiative Japan Inc. All rights reserved.
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IIJ-MKTG020-0045

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