Ver. 2.0

July 3rd, 2023

The Fifth Generation Mobile Communications Promotion Forum
Millimeter wave Promotion Ad Hoc

Notices
１．The copyright of this document is owned by the Fifth Generation Mobile
Communications Promotion Forum (5GMF)
２．No part of this document may be published, translated, or reprinted on any
other website in any form or by any means without the prior consent of
5GMF.

Table of contents
Introduction ....................................................................................................................... 4
1

Clarifying the need for millimeter wave ............................................................ 7
1.1

Securing frequency resources for future traffic increases ................................ 7

1.2

Support for future high-speed, large-capacity, low-latency services ............... 9

1.3

Economy, energy efficiency ............................................................................... 10

1.4

Developing new use cases ................................................................................. 10

1.5

A foothold for additional frequency allocations in the future......................... 11

References .................................................................................................................... 12
2

Trends in Japan and overseas .......................................................................... 13
2.1

Overviews of the trends ..................................................................................... 13

2.1.1

Frequency allocation trend ....................................................................... 13

2.1.2

Commencement status of millimeter wave commercial services, etc. ineach country (overview)............................................................................................... 15
2.1.3

Status of millimeter wave terminals........................................................ 17

2.1.4

3GPP standardization trends ................................................................... 18

2.2

Trends in each country (excluding Japan) ....................................................... 19

2.2.1

USA............................................................................................................. 19

2.2.2

Europe ........................................................................................................ 20

2.2.3

China .......................................................................................................... 21

2.2.4

South Korea ............................................................................................... 22

2.2.5

India ........................................................................................................... 22

2.2.6

Australia .................................................................................................... 23

2.2.7

Southeast Asia ........................................................................................... 23

References .................................................................................................................... 24
3

Challenges for widespread use of millimeter wave. ........................................ 25
3.1

Millimeter wave introduction area ................................................................... 25

3.2

Base station equipment for millimeter wave ................................................... 26

3.3

Millimeter wave terminal ................................................................................. 27

3.4

Millimeter wave use cases................................................................................. 27

3.5

Overall issues ..................................................................................................... 28

References .................................................................................................................... 30
4．Millimeter wave technology overview ...................................................................... 31
4.1

Beamforming technology ................................................................................... 31

4.2

MIMO technology............................................................................................... 32

4.2.1

LoS-MIMO ................................................................................................. 33

1

4.2.2Massive-MIMO／Distributed-MIMO ....................................................... 33

4.3

Topology improvement technology ................................................................... 34

4.4

Millimeter wave device technology................................................................... 35

4.5

Infrastructure sharing....................................................................................... 36

4.6

Millimeter wave Carrier Aggregation (CA) ..................................................... 37

4.7

sub6 + millimeter wave Dual Connectivity (DC)............................................. 38

4.8

High-Power UE（HPUE） ................................................................................ 39

References .................................................................................................................... 40
5.1

5G millimeter wave throughput and latency performance measurement (oneto-one communication in an ideal environment) ............................................. 43

5.2

5G millimeter wave indoor environment measurement ................................. 45

5.3

5G millimeter wave outdoor environment measurement ............................... 47

5.4

5G millimeter wave Challenges and Solutions................................................ 52

6

Millimeter wave introduction scenario ............................................................ 56

7

Affinity with local 5G......................................................................................... 59
7.1

What is local 5G? ............................................................................................... 59

7.1.1

Regulation overview .................................................................................. 59

7.1.2

Allocated frequency bands (sub6, millimeter wave) ............................... 59

7.2

Current state of local 5G ................................................................................... 60

7.2.1

Overview (past history to popularization) ............................................... 60

7.2.2

Situation for millimeter wave (actual situation)..................................... 62

7.3

Affinity between millimeter wave and local 5G .............................................. 64

7.3.1

Area scale and radio wave characteristics (good compatibility withmillimeter wave coverage area) .................................................................................. 65
7.3.2

Communication capacity and communication demand (good compatibility

with high speed and large capacity) ........................................................................... 66
7.3.3

Compact system scale (good compatibility with system scale and ultra-

low latency) .................................................................................................................. 68
References .................................................................................................................... 70
8Millimeter wave use case .................................................................................. 71
8.1

eMBB .................................................................................................................. 71

8.1.1

Entertainment ........................................................................................... 71

8.2

FWA .................................................................................................................... 73

8.3

Enterprise networks .......................................................................................... 74

8.3.1

Manufacturing industry............................................................................ 74

8.3.2

Automobiles ............................................................................................... 752

8.3.3

Medical care ............................................................................................... 76

8.3.4

Media .......................................................................................................... 77

8.3.5

Public infrastructure ................................................................................. 77

8.3.6

Agriculture ................................................................................................. 77

References .................................................................................................................... 79
9.1

Terminal ............................................................................................................. 81

9.2

Base station ........................................................................................................ 82

9.3

Antenna device ................................................................................................... 84

9.4

Measurement evaluation equipment................................................................ 85

9.4.1

FR2 terminal performance test ................................................................ 85

9.4.2

FR2 area test ............................................................................................. 85

9.4.3

Radio wave environment monitor ............................................................ 86

9.5
10

Repeater.............................................................................................................. 87
Millimeter wave business outlook .................................................................... 90

10.1 Area development .............................................................................................. 90
10.2 Promoting and supporting 5G/millimeter wave to other industries .............. 90
10.3 Providing a place to promote the spread of millimeter wave ......................... 91
10.3.1For consumer users ................................................................................... 91

10.3.2Millimeter wave lab for consumer services developers .......................... 92

10.3.3

Local 5G developer millimeter wave labs ................................................ 92

10.4 5G wireless human resource development ...................................................... 92
Reference ...................................................................................................................... 93
Conclusion ........................................................................................................................ 94
Appendix (Existing solutions for the spread of millimeter wave List of reference
information links） ............................................................................................................. 95
Terminal solution example ......................................................................................... 95
Examples of base station solutions ............................................................................ 95
Antenna device solution example ............................................................................... 96
Measuring instrument solution example ................................................................... 963

Introduction
In Japan, for the commercialization of 5G, a new frequency band of 3.7 GHz and 4.5
GHz called sub6 was allocated, along with millimeter wave in the 28 GHz band with awide bandwidth of 400 MHz per operator. In addition, the 28 GHz band is also allocatedto local 5G for spot use in limited areas by entities such as local companies and local
governments, along with the 4.7 GHz band. Even in the international standardization of
3GPP, standard specifications supporting millimeter wave was included from the initial
specifications of 5G. However, the commercial deployment of 5G is currently limited to
the 5G refarming of the low- and mid-bands used in 3G and 4G, and the sub6 (in thisdocument, the newly allocated 3.7 GHz and 4.5 GHz bands are defined as sub6 ), and theintroduction of millimeter wave has not progressed sufficiently in terms of area and the
spread of terminals. For the global situation, several countries have allocated millimeterwave in the 26GHz, 28GHz, and 39GHz bands, but commercial deployment focuses on
low-band, mid-band, and sub6, as in Japan, and Countries where millimeter wave
commercial deployment has started are extremely limited.
On the other hand, due to its wide frequency bandwidth, millimeter wave is expected
to play a major role in the creation of new service fields by realizing ultra-high-speed,large-capacity communication, low-delay communication, etc., which are one of thecharacteristics of 5G. Traffic volume continues to increase, and expectations are high for
future traffic accommodation by millimeter wave.
Considering these expectations, we will contribute to industrial use and the resolutionof social issues, promote the spread of millimeter wave as a prerequisite for new 5G/6G
frequency allocation, and promote international initiatives related to millimeter wave inJapan. In January 2023, a millimeter wave promotion ad-hoc was established within 5G
Mobile Promotion Forum (5GMF) for the purpose of demonstrating these purposes. As
one of the major millimeter wave promotion ad-hoc activities, this white paper
summarizes the deployment status, challenges, technologies, use cases, solutions, etc. of
millimeter wave in Japan and overseas. The structure of this white paper and the outlineof each chapter are as follows.
1.

Clarifying the need for millimeter wave
Telecommunications will play an even more important role in developing society
and building a sustainable society in the future, and the utilization of millimeter
wave, which is characterized by high speed, large capacity, and low delay, isextremely important. In this chapter, we discuss the necessity of millimeterwave to secure frequency resources for future traffic increases, support for4

future high-speed, large-capacity, low-delay services, economy, energy efficiency,
development of new use cases, and foothold of additional frequencies allocationin the future. We are trying to clarify from the five viewpoints.
2.

Domestic and international trends
While 5G services are progressing in countries around the world, the use of
millimeter wave remains limited despite progress in frequency allocation. This
chapter summarizes the details of frequency allocation, the status ofcommercialization services, etc., the status of millimeter wave supporting
terminals, and 3GPP standardization trends as trends in millimeter wave inJapan and overseas.

3.

Challenges for widespread use of millimeter wave
Currently, the 5G area is mainly developed around low band, mid band andsub6, and the traffic capacity ratio of millimeter wave is extremely low. This
chapter analyzes the challenges in improving the millimeter wave situationfrom four perspectives: millimeter wave deployment area, millimeter wave
compatible base station equipment, millimeter wave compatible terminals, andmillimeter wave use cases.

4.

Millimeter wave technology overview
This chapter comprehensively covers technologies that are considered to beeffective in resolving the issues of widespread use of millimeter wave as
described in Chapter 3, and technologies related to millimeter wave that havealready been developed or are being considered in standardization such as 3GPP.
are introducing.

5.

Performance evaluation
In order to disseminate millimeter wave, it is important to understand theirhigh-speed, large-capacity and low-delay characteristics quantitatively. In thischapter, specific experimental and measurement results using 5G millimeterwave show that millimeter wave can achieve extremely high throughput anddelay performance in both indoors and outdoors, and also can be fully utilized
in indoors even under non-line-of-sight conditions.

6.

Millimeter wave deployment scenario
Since millimeter wave is high frequency band, it is important to make use of
their characteristics. Since the cell radius becomes relatively small due to thelarge propagation loss, it is effective for use cases in narrow and closed areas.
High-speed, large-capacity capability due to a large frequency bandwidth iseffective in places with heavy traffic and in places where high-speed services are5required. Based on these characteristics, this chapter presents several specificmillimeter wave deployment scenarios.
7.

Affinity with local 5G
With local 5G, it is assumed that many terminals will be used intensively at thesame time in a relatively narrow area, so it can be said that millimeter wavethat can handle ultra-wideband have a very high affinity with local 5G. While
this chapter describes the background and local 5G dissemination status, aswell as the limited use of millimeter wave and their challenges, It is explainedin terms of communication capacity, communication demand, and system scale.

8.

Millimeter wave use case
For the millimeter wave dissemination, it is important to clarify use cases that
can take advantage of the high speed, large capacity, and low latency of
millimeter wave. In this chapter, we divide applications into three categories:"high-capacity high-speed (eMBB) in facilities such as stadiums where people
gather", "FTTH replacement by FWA", and "corporation-dedicated network".
stating the case.

9.

Millimeter wave solutions
In order to promote the millimeter wave dissemination, it is important to beable to procure enough devices and measuring instruments for developing andmanufacturing the equipment that constitutes the network. This chapter
introduces solutions for terminals, base stations, antennas, measuring
instruments, etc. based on actual examples.

10.

Millimeter wave business outlook
The key to future business outlook for millimeter wave is how to convert thisnegative chain reaction, in which millimeter wave network deployment,terminal spread, and service development are slow to progress, into a positive
chain reaction. This chapter summarizes what can be considered as businessand institutional efforts to convert the current situation to a positive chain
reaction. Area expansion, 5G/millimeter wave promotion and support activities
for other industries, provision of a place to promote millimeter wave spread, anddevelopment of 5G wireless human resources are discussed.

As mentioned above, this white paper comprehensively describes the informationnecessary for the millimeter wave dissemination. It is expected that this white paper
will be used to promote the millimeter wave dissemination both in Japan and overseas
and to build an ecosystem.

6

1

Clarifying the need for millimeter wave
By now, there is no doubt that the development of mobile communications from 1G to

5G has played an important role in the development of society. The role ofcommunication will become even more important in building a sustainable society in the
future. In order to respond to this, it is extremely important to utilize millimeter wave,
which is characterized by high speed, large capacity, and low delay. Furthermore, toward
6G in the 2030s, millimeter wave solutions will serve as a basis for studies, and is aprerequisite for consideration of sub-terahertz band utilization. Several aspects of themillimeter wave need are detailed below.
1.1

Securing frequency resources for future traffic increases

Over the past several decades, mobile communication traffic has continued to increase
with the spread of multimedia services and smartphones. Furthermore, with theintroduction of 4G, the demand for not only human communication but also physicalcommunication is increasing due to the dissemination of IoT (Internet of Things). In
addition, in various industries, there is a growing need for converting wired
communication to wireless technology using 5G, and for business efficiency improvement
through communication with the progress of DX. Against this background, mobile
communication traffic has continued to increase, and as shown in Fig. 1-1, traffic has
increased 1.2 times over the past year and 1.8 times over the past three years. These
trends are expected to continue in the future, and there is a possibility that new mobile
communication needs will arise in the future, and further increases in mobile
communication traffic are expected.

7

Fig. 1-1 Changes in mobile communication traffic [1]In response to the increase in traffic due to these factors, it is expected that the current
deployment of 5G, mainly sub6, will increase the capacity, and that the technologicalenhancement of mobile communication systems will increase the communication
capacity. It is considered that only these aspects would not be able to cope with traffic
increase. According to the GSMA report [2], as shown in Fig. 1-2, millimeter wave
frequency resources of 4.5 GHz, 350 MHz, and 150 MHz, respectively, and a total of 5
GHz will be required by 2030 for three types of use cases: eMBB, FWA, and enterprisenetworks. reported as necessary. For these reasons, utilization of millimeter wave
frequency resources is essential.

8Fig. 1-2 Millimeter wave frequency demand forecast up to 2030[2]1.2

Support for future high-speed, large-capacity, low-latency services

Many services and applications have been developed that take advantage of the highspeed, large-capacity and low-latency characteristics of 5G, and further development is
expected. For enterprises, there are many needs such as remote monitoring and remotecontrol, security by AI processing of images, watching over, prediction of failures andfailures, etc., and more advanced services will be developed. In order to support these,
4K and even 8K video quality will be required in the future, and it is considered that acommunication infrastructure which can support such transmission will be required.
Many services and applications utilizing XR devices have already been provided forboth consumer and enterprise use. It is thought that new attractive services andapplications will be created.
Regarding robotics, it is thought that the introduction of robots not only for special
applications in factories, but also in the environment where people live will spread at anaccelerated pace in the future, and services such as monitoring, watching over, andnursing care using robots will be disseminated.
These are only examples, and it is believed that various advanced services andapplications will be developed in the future along with the development of devices. Alongwith this, the need for high-speed, large-capacity and low-delay communication is
expected to increase. Conversely, the provision of high-speed, large-capacity, low-delay
services in the right places will promote the development and spread of these advanced
services and applications.

9

1.3

Economy, energy efficiency

While a rapid increase in communication traffic is expected, it is considered that
intensive traffic will occur in specific places and areas such as stadiums, indoor shopping
malls, train stations, and outdoor places with a high density of people. be. A study [3]shows a case where traffic will increase by 116% from 2021 to 2026 in a specific location,
as shown in Fig. 1-3.
On the other hand, as the implementation cost per unit of data traffic for millimeterwave is declining year by year, the implementation cost for millimeter wave will drop by
75% compared to midband by 2026, and the need for small cells per hot zone will increase.
In 2025, the number is expected to drop by 74% compared to the mid-band, and the power
consumption is expected to be reduced by about 70%. By installing millimeter wave basestations in strategic locations, it is possible to respond to increasing traffic with higheconomic efficiency, thereby reducing the TCO (Total Cost of Ownership) of
telecommunication carriers' 5G communication networks.

Fig. 1-3 Millimeter wave implementation cost and expected power consumption
survey results [3]1.4

Developing new use cases

The high directivity and broadband characteristics of millimeter wave, as well as
operation by beamforming, have the potential to open up new use cases. For example, in
positioning [4-7], where a 5G base station or 5G mobile station transmits and receives areference signal for positioning and determines the position of the mobile station based10

on the propagation delay difference and angle of arrival, etc., millimeter wave can beused. It has been reported that centimeter-level positioning accuracy can be achieved [8].
In the future, we will further develop a sensing function that estimates the position,
shape, and state of any object, not limited to 5G mobile stations, by measuring reflectedradio waves, and joint communication & sensing [9] that fuses 5G data communicationand sensing. Standardization is also envisaged. Joint Communication & Sensing is
expected to create unprecedented new services such as traffic monitoring by 5G networks
[10].
1.5

A foothold for additional frequency allocations in the future

As mentioned above, the use of millimeter wave is expected for various reasons, buteach reason is continuous rather than short-term. Therefore, the currently allocatedfrequencies including the 28 GHz band will not be sufficient in the future, and additionalfrequency resource allocation and utilization will be required even in the 2020s.
Considering expectations for higher speed, larger capacity, and lower latency in the
future, frequency resources with a wide bandwidth to some extent are required, andadditional frequency bands of quasi-millimeter wave and above are expected to be
utilized. In order to utilize these additional frequencies in a timely manner and topromote social development in the future, it is essential to develop solutions and haveoperational skills that will allow the 28 GHz band to be fully utilized from the present
stage.
Studies on 6G towards 2030s are already underway [11-13], but ultra-high-speed,large-capacity 10 to 100 times faster than 5G, ultra-low latency will be required, andfrequencies are sub-bands of several hundred GHz. Even terahertz is being considered.
However, when considering the use of sub-terahertz, the use of millimeter wave is amajor prerequisite, and on the other hand, unless the technology and skills that allow
millimeter wave to be used firmly in 5G are put into practical use at this stage, Terahertz
considerations become meaningless. Conversely, by firmly establishing and operating
millimeter wave solutions at this stage, it is possible to efficiently develop sub-terawave
solutions.
As mentioned above, for the sustainable development of society, it is important toallocate and utilize additional 5G frequencies in the 2020s, and to consider sub-terahertz
for 6G. There is an urgent need to develop solutions, develop use cases, and establish
operational skills for that purpose.

11References[1]

Ministry of Internal Affairs and Communications Information andCommunications Statistics Database
https://www.soumu.go.jp/johotsusintokei/field/data/gt010602.pdf[2] GSMA Vision 2030: mmWave Spectrum Needs, Full Reporthttps://www.gsma.com/spectrum/wp-content/uploads/2022/06/5G-mmWaveSpectrum.pdf[3] Bell Labs Consulting, The business of 5G mmWave, 2022.
[4] 3GPP TR 38.855, v16.0.0, Study on NR positioning support[5] 3GPP RP-190752, New WID: NR Positioning Support, Ericsson[6] 3GPP TR 38.857, v17.0.0, Study on NR positioning enhancements[7] 3GPP RP-210903, Revised WID on NR Positioning Enhancements, Intel Corporation,
CATT
[8]

‘Experimental Investigation of 5G Positioning Performance Using a mmWave
Measurement Setup,’ 2021 International Conference on Indoor Positioning andIndoor Navigation (IPIN), George Yammine, et al.

[9]‘Multibeam Design for Joint Communication and Sensing in 5G New Radio
Networks,’ 2020 IEEE International Conference on Communications (ICC), Carlos
Baquero Barneto, et al.

[10] https://www.ericsson.com/en/blog/2021/10/joint-sensing-and-communication-6g[11] Ministry of Internal Affairs and Communications Promotion Strategy －Beyond
5G Promotion Strategy Roadmap to 6G－
https://www.soumu.go.jp/main_content/000696613.pdf[12] [12] Ministry of Internal Affairs and Communications, “Beyond 5G Promotion
Strategy (Overview), June 2020.
https://www.soumu.go.jp/main_content/000702111.pdf[13] Beyond 5G Promotion Consortium White Paper https://b5g.jp/output/

12

2

Trends in Japan and overseas
There are great expectations for 5G services as a new social infrastructure that willbring significant economic benefits, and services are progressing in countries around theworld. Despite the fact that millimeter wave is necessary to make full use of the true
potential of 5G, its use is limited in all countries except the United States.
Under these circumstances, Japan is the second most commercialized country after
the United States, and the government and industry are discussing how to take theinitiative in the world in the future.
This chapter provides an overview of the trends in Japan and overseas regarding
millimeter wave.
2.1

Overviews of the trends

2.1.1

Frequency allocation trend

In countries around the world, 400MHz to 1000MHz bandwidth is mainly allocated in
the 26/28GHz band for 5G service applications. Millimeter wave frequencies areavailable in 31 countries by December 2022, and frequencies are allocated for commercial
deployment in 18 countries in 2022, and 28 operators (including private network
operators) have started commercialization (Fig. 2-1). In ten countries including Japan,
millimeter wave is allocated not only for public networks but also for private networks(Fig. 2-2). In addition, it is expected that the number of countries and regions where theuse of millimeter wave becomes possible will gradually increase, such as theimplementation of frequency auctions in each country.
WTP (Willingness To Pay) and ARPU (Average Revenue Per User) tend to improve as
millimeter wave use progresses in each country. It has been reported that millimeterwave has not yet become mainstream in the evolution of 5G services [3]. Only 20% of thecarriers that have been allocated millimeter wave have commercialized them, the shareof terminals that support millimeter wave is 10%, and flagship terminals in each country
doesn’t support millimeter wave.
In Japan, in April 2019, sub6 (3.6 GHz to 4.1 GHz, 4.5 GHz to 4.6 GHz) and millimeterwave (27.0 GHz to 28.2 GHz, 29.1 GHz to 29.5 GHz) were assigned to four mobile network
operators as frequencies for 5G.. Also, in December 2019, local 5G was regulated for somefrequencies (28.2 GHz to 28.3 GHz, 100 MHz width), and acceptance of license
applications started at the end of Japanese FY2019. In December 2020, the frequency
for local 5G was extended (4.6 GHz to 4.9 GHz, 28.3 GHz to 29.1 GHz).
Regarding local 5G, its utilization has not progressed as much as had been expectedthough millimeter wave was allocated earlier than sub6. It was assumed that it would13

be operated by the NSA with LTE carriers as anchors, and also mobile operators havenot used millimeter wave at that occasion.
Currently, the Japanese government is considering additional allocations for the 4.9
GHz band (4.9 GHz to 5.0 GHz) / 26 GHz band (26.6 GHz to 27.0 GHz) / 40 GHz band
(39.5 GHz to 43.5 GHz) [4].

Fig. 2-1 5G millimeter wave commercialization and spectrum (as of November 2022)[1]

14

Fig. 2-2 Global millimeter wave spectrum (as of December 2022) [2]
2.1.2

Commencement status of millimeter wave commercial services, etc. in eachcountry (overview)（１）Overall
As of November 2022, full commercial services using millimeter wave are limited to
the United States and Japan. Early stages of commercialization include European
countries/region such as Germany, Italy, Finland and Spain, and Asian such as Australia,
Taiwan, Hong Kong and Singapore.
As mentioned in Chapter 1, millimeter wave can efficiently build networks by taking
advantage of their economic efficiency. It is expected that it will be possible to return theinvestment efficiently [5].

15Fig. 2-3 Examples of economic effects of millimeter wave [5]（２）Japan
In Japan, millimeter wave was assigned to four operators in 2019, and commercial
services have started.
According to the Ministry of Internal Affairs and Communications (MIC), the domestic
population coverage rate of 5G has reached 93.2% as of the end of March 2022[6]. But
the number of 5G base stations is mostly occupied by those base stations of refarming
4G frequencies such as 700MHz, 1.7GHz and 3.4GHz/3.5GHz. Total number of thesebase stations is 44,297 stations (up to 90.7% population coverage). On the other hand,
the total number of sub6 (3.7GHz, 4.0GHz/4.5GHz) base stations is 30,531 (maximum
population coverage is 31.8%), and the total number of 28GHz base stations is 13,218
stations. The contribution to the population coverage rate is 0.0% to 31.8% for 3.7GHz
and 4.0/4.5GHz, and 0.0% for all companies in the millimeter wave band. Regarding 5G
traffic volume, sub6 covers 62.6%, while millimeter wave covers only 0.2% [7]. In thedomestic handset sales market, millimeter wave handsets account for about 5.2%.
Currently, MIC is discussing the future vision of 5G business utilizing high frequency
bands such as millimeter wave and governmental policies to expand 5G business.

16

Fig. 2-4 5G Base Station Development by band [7]2.1.3

Status of millimeter wave terminals（１）Global
As of December 2022, more than 170 models of millimeter wave terminals have beenannounced and released by more than 65 vendors around the world. In addition tosmartphones, various products such as PCs, hotspots and IoT devices, modules, andCPEs are being developed[1]. At this moment, the number of countries and models thathave been released is limited, but it is gradually increasing. In addition, millimeter wave
terminals account for 57.3% of newly shipped terminals in the United States, and aresteadily increasing.

17

Fig. 2-5 Deployment status of millimeter wave terminals [1]（２）Japan
The number of millimeter wave terminals is steadily increasing, with 17 models,
mainly high-end models, to be released in Japan in 2022. On the other hand, the numberof units sold will be just over 1.7 million in 2022, or about 5.2% of the total terminal sales
market[1]. Compared to the U.S., its share of the handset sales market is about 1/10. It
seems that the reason comes from the fact that 1) unlike the United State, terminals
with a high market share do not support millimeter wave and 2) millimeter wave is only
supported by high-end terminals. In the future, it will be a challenge to support
millimeter wave for terminals with a high market share and terminals in a wide priceranges other than high-end terminals.
2.1.4

3GPP standardization trends

3GPP has standardized bands n257, n258, n259, n260, n261, n262 as FR2 bands (24250
MHz – 52600 MHz) since Rel-15. In Rel-17, it was extended to the FR2-2 band (52600
MHz – 71000 MHz) and the band n263 was also standardized.

18

Table. 2-1 millimeter wave bands in 3GPP Release 17
NR BandFrequency

Major regions

Duplexn257

26500 MHz – 29500 MHz

TDD

Japan, Korea

n25824250 MHz – 27500 MHz

TDD

Europe, India, Australia, etc.

n259

39500 MHz – 43500 MHz

TDD

n260

37000 MHz – 40000 MHz

TDD

USA

n261

27500 MHz – 28350 MHz

TDD

USA

n262

47200 MHz – 48200 MHz

TDD

USA

n263

57000 MHz – 71000 MHz

TDD

In addition to mobile terminals such as smartphones, specifications for FWA, in-vehicle,
and high-speed train terminals have been standardized as applications for millimeterwave. The expansion of the maximum continuous bandwidth (from 1.2 GHz to 2.4 GHz)
through carrier aggregation and the addition of specifications for carrier aggregation
between millimeter wave bands have been developed by Rel-17. 3GPP standards arecontinuously being revised in order to further enhance massive-MIMO as introduced in
Chapter 4 and improve the performance of millimeter wave communication.
2.2

Trends in each country (excluding Japan)

2.2.1

USA

In the US, frequencies are assigned to carriers such as AT&T, T-Mobile, and Verizon,
and FWA, hotspot in urban areas and high-traffic areas usage have been expanding. In
addition, when licensing, it is required to achieve at least 40% population coverage in
the area where the license is granted[1].
On the other hand, Verizon is actively using more than 40,000 millimeter wave basestations in more than 1,500 cities across the United States, such as by installing themin bases such as stadiums and stations, as well as in urban areas. It also aims to provide
FWA services (millimeter wave and C-band) to 50 million houses by 2025[1].
As for millimeter wave terminals, as shown in Table. 2-2, the increment is progressing
smoothly. One of the reasons for this is considered that some models of terminals thathave a high market share in the United States have supported millimeter wave since
2020.

19

Table. 2-2 Spread of millimeter wave compatible terminals in the United States(calculated based on IDC)
Year

2019

2020

2021

2022

0.3%

4.3%

43.1%

57.3%

Market share of
millimeter wave
terminals
Along with the mature deployment of infrastructure and the spread of millimeter wave
terminals, the use of millimeter wave has progressed in transportation hubs such as
stadiums, stations, indoor shopping malls, and outdoor crowded places. New use casessuch as watching a game are emerging. It is reported that various viewing methods using
millimeter wave for large-scale sporting events such as American football, Formula 1,
and ice hockey are getting to be popular [3]. In this way, B2B2C business using advanced
networks that actively use millimeter wave is gradually expanding [3].
2.2.2EuropeDeutsche Telekom (Germany), Elisa (Finland), FastWeb (Italy) and TIM (Italy) are in
the early stages of commercialization of millimeter wave. They focus on FWA,
smartphones and industrial applications. A project to build multiple model cities is also
under consideration and underway [1].
In the UK, millimeter wave of 26GHz (24.25GHz-27.5GHz) and 40GHz (40.5GHz43.5GHz) will be allocated to mobile technologies such as 5G, then started public
consultation on the auction (Q2 2024) design and local licensing conditions in March
2023. Local licenses will be granted on a first-come, first-served basis using a Shared
Access licensing framework in key towns and cities (high-density areas) where thegreatest number of millimeter wave deployments is expected. Frequency assignment for
the entire city/town will be held by auction. Also, in low-density areas, where deployment
is expected to be sparse, a shared access licensing framework will be used to grant
millimeter wave local licenses on a first-come, first-served basis [8].
In France, in 2023, as part of the France 2030 policy, the government plans to start a
new call for proposals (assuming investment of more than 750 billion euros by 2025) andprovide support projects [1].
•R&D to accelerate the evolution of 5G and the development of 6G/next-generation
networks•

Developing solutions for communication networks that guarantee a high level of
security and reliability

20

•

Improving the environmental impact of communication networks
In addition, in France, as part of the European 5G-TOURS research project, efforts in

the healthcare field at Rennes University Hospital using the 26 GHz band areprogressing [1].
In Spain, at the MWC venue held in Barcelona at the end of February 2023,
Telefonica’s first millimeter wave commercial base station (manufactured by Ericson)
was installed and used for visitors and millimeter wave related exhibitions. At the
Qualcomm booth, millimeter wave terminals were exhibited and a speed test
demonstration (using Telefonica’s millimeter wave base station) was held. In thisdemonstration, although the results are affected by the communication environment, it
was shown that the speed, etc. did not drop significantly even when there was an obstacle
such as a PC behind the terminals.

MWC 2023

Normal state

Shielded by PC

Millimeter wave base(About 3.0 Gbps

(About 3.0 Gbps

station at the venue

downstream)

downstream)

Fig. 2-6 Millimeter wave related technology exhibition at MWC2023
2.2.3

China

In China, 5G network deployment using sub6 is progressing rapidly, and 2.3 million
base stations have been deployed by December 2022. On the other hand, as of February
2023, no license for millimeter wave has been granted to operators. As a private network
license, in October 2022, the first domestic commercial license (5925MHz-6125MHz,
24.75GHz-25.15 GHz frequency) was granted to COMAC (a Chinese aircraft
manufacturer) [9].
Millimeter wave is expected to supplement the coverage of 5G services and increase21

network capacity, and research and development and testing have been carried out sofar.
In 2019, China standardized specifications through testing of major technologies, andthey put efforts by, completing developments of a test environment for facility testingand performance test system in 2020, SA service testing in 2021, and millimeter wave
testing in 2022 [10].
2.2.4South Korea

In June 2018, Korea Telecom, SK Telecom, and LG Uplus allotted 800MHz frequencies
in the 28GHz band as a result of a frequency auction. An obligation to install 15,000 basestations within three years was imposed.
Although the government continued to encourage investment in the 28Ghz band, each
operator prioritized investment in the 3.5GHz band. LGU+ and KT were suspended
assignment in November 2022 [12] and SKT in May 2023 [13] before the original quota
deadline, November 2023.

However, subway services currently in use of millimeterwave will remain available until the original quota deadline [11].
On January 31, 2023, the South Korean government presented a bill to support theentry of new businesses, consisting of lowering the threshold for market entry, initial
network construction support, and service operation support. It is expected that thefrequency allocation will be announced in the second quarter of 2023, and the selectionof new operators will be made in the fourth quarter[11].
On the other hand, the construction of the government network with 5G and thedevelopment of high-speed networks are being supported by the $300 million Giga-Korea
high-speed project [1].
2.2.5

India

In India, a frequency auction was held in July 2022, with 1GHz width (SA) for RJIO
throughout India, 800MHz width (NSA) for Airtel throughout India, and 400MHz width(SA/NSA (TBD)) for BSNL. Across India, millimeter wave on n258 was assigned with
200-800 MHz band (NSA) to Vodafone being the main market and 400 MHz to Adani
Data Network (5G private network operator) in the main market.
In the first half of 2023, field demonstrations of FWA and mobility use cases will be
conducted, and commercial services will start within one year. [1].

22

2.2.6Australia

Five companies won the spectrum in the Australian Communications and Media
Authority (ACMA) auction of the 26 GHz band. Telstra Corporation Limited 1GHz bandfor most regions, Optus Mobile Pty Ltd 800 MHz band for most regions, Mobile JV Pty
Limited (JV of Vodafone Hutchison Australia and TPG Telecom) 600 MHz band for mostregions, Dense Air Australia Pty Ltd (neutral host operator of the 5G testbed) won
200MHz in a limited area and Pentanet Limited (local ISP in Perth City) won 400MHz
in two areas.
The license won at auction will become effective later this year and will have a 15-year
term until 2036[1].
In Australia, the $28.6 million 5G Innovation Initiative program is funding use casedevelopment and demonstration of the value created by 5G[1].
2.2.7Southeast Asia

In Southeast Asia, Singtel (Singapore), CHT and APT (Taiwan. APT is a millimeterwave private NW operator) in 2020, TRUE and AIS (Thailand), CMHK and HKT (HongKong), Viettel (Vietnam), in 2021 8 companies in 5 countries/regions have started
millimeter wave business.
In addition, including these 8 operators, 16 operators in 5 countries/regions haveacquired millimeter wave frequencies.
Singapore has a $22.5 million grant program to develop new 5G solutions and $50
million in support for the development of cutting-edge communication technologies.
In Taiwan, Advanced Semiconductor Engineering (ASE) is planning to launch a smart
factory business using 5G millimeter wave NR-DC SA [1].

23

References[1] https://www.soumu.go.jp/main_content/000860192.pdf

Qualcomm

Japan,

5G

Business Design WG 2nd meeting Qualcomm materials. (Japanese only)[2] https://www.soumu.go.jp/main_content/000860162.pdf Ericsson Japan, 5G Business
Design WG 2nd meeting Ericsson materials. (Japanese only)[3] GSMA, 5G mmWave Circa 2023- State of the Market and Look back at our
Accomplishments (MWC2023 GSMA Document).
[4] https://www.soumu.go.jp/main_content/000857639.pdf Ministry of Internal Affairs
and Communications, “5G Business Design Working Group” Management Policy.
(Japanese only)[5] Bell Labs Consulting, The business of 5G mmWave.
[6] https://www.soumu.go.jp/menu_news/s-news/01kiban14_02000561.html Ministry ofInternal Affairs and Communications, announcement of 5G development status (endof 2021) (Japanese only)[7] https://www.soumu.go.jp/main_content/000860636.pdf Ministry of Internal Affairs
and Communications, 5G Business Design Working Group (3rd) handout. (Japanese
only)[8] Ofcom, Enabling mmWave spectrum for new uses.
[9] European 5G Observatory, “The Ministry of Industry and Information Technology(MIIT) has granted the license to a domestic aero plane manufacturer.
https://5gobservatory.eu/china-grants-first-5g-private-network-licence/[10] China Academy of Information and Communications Technology (CAICT), Setting
Sail on a New Journey with 5G Commercialization（MWC2023CAICTDocument）.
[11] https://www.soumu.go.jp/main_content/000860119.pdf

Samsung

Networks,

5G

Business Design WG 2nd meeting Samsung materials. (Japanese only)[12] https://www.msit.go.kr/bbs/view.do?bbsSeqNo=94&nttSeqNo=3182564 Ministry of
Science and ICT, Korea[13] https://www.msit.go.kr/bbs/view.do?bbsSeqNo=94&nttSeqNo=3183048 Ministry of
Science and ICT, Korea

24

3

Challenges for widespread use of millimeter wave.
While millimeter wave can be expected to have higher speeds and larger capacities

than sub6 due to their wider bandwidth, currently the 5G area is mainly developedaround low band, mid band, and sub6, and the traffic accommodation ratio of millimeterwave is extremely low. Issues in improving this situation are analyzed from theperspectives of millimeter wave introduction areas, millimeter wave supporting basestation equipment, millimeter wave supporting terminals, and millimeter wave use
cases are described below. Many technologies and solutions have already been
researched, developed, and introduced to address these issues. For more information,please refer to Chapter 4, Overview of Millimeter Wave Technology, and Chapter 9,
Solutions for the Popularization of Millimeter Wave.
3.1

Millimeter wave introduction area

The free space loss for radio wave propagation is given by Equation 1. This means thatthe radio wave propagation loss increases with the power of 2 of the frequency increment.
Propagation loss L=(4πd f/c)² d: distance, f: frequency, c: speed of light (Formula 1）
In addition to free space loss, there is also absorption due to molecular vibration in theair, which varies with frequency, resulting in the loss shown in Fig. 3-1.

Fig. 3-1 Atmospheric and molecular absorption25

In addition, the higher the frequency, the steeper the loss due to shielding, and thereception level greatly decreases in non-line-of-sight (Fig. 3-2).

Fig. 3-2 Example of shielding loss measurement results [1]Due to these radio wave propagation characteristics, the millimeter wave cell radius
is smaller than sub6 when compared at the same effective isotropic radiation power. In
addition, since the shielding loss is steep and large, it is necessary to install the antenna
in a place where the line-of-sight environment can be secured as much as possible. These
are issues for mobile network operators in terms of cost and securing antenna
installation locations, so currently they are mainly introduced from sub6, which is easy
to operate. In order to improve the area of millimeter wave, it is necessary to improve
the performance of antennas based on radio wave propagation characteristics, reduce
the size of antennas, and develop new solutions to relax restrictions on antenna
installation locations.
3.2

Base station equipment for millimeter wave

Millimeter wave is a frequency band that will be newly used for mobile
communications in 5G, and new development is necessary. The degree of penetration islimited compared to sub6, and the economic effect of the scale of wireless devices iscurrently low.
As for the base station antenna, it is easier to implement a small antenna comparedto sub6, and in order to dramatically improve the antenna gain to cope with the increasein propagation loss, it is mainstream to use a super multi-element antenna. In addition,

26

since the loss in the device also increases, implementation using an analog RFIC that
integrates an antenna and an amplifier to minimize loss is usually used. In this way,
millimeter wave base stations have many new points in terms of implementation, andare expected to evolve in the future. For example, the efficiency of a base station
amplifier is about several tens of percent for sub6, while that for millimeter wave is as
low as tens of percent. Currently, the efficiency of the entire system is improved by using
a super-multi-element antenna implementation, and the efficiency of the amplifier itself
will also improve in the future. As for the number of MIMO layers, two layers are themainstream for millimeter wave due to restrictions on equipment size. Also, with respect
to the beamforming function by a massive multi-element antenna, full-digital highperformance has not yet reached commercial implementation from the standpoint ofequipment size, hence hybrid implementation of analog and digital is the mainstream.
The development of these functions is being considered as a possibility of futureenhancement.
3.3

Millimeter wave terminal

As stated in the entire white paper, millimeter wave use cases are not yet sufficient,and in addition, there are currently not enough areas where millimeter wave can be used.
Terminals equipped with millimeter wave are increasing, but the current situation isthat they are still limited to high-end terminals. The cost increase associated withsupporting millimeter wave, such as the development of millimeter wave antennas,
modules, basebands, related SW, etc. mentioned above, leads to a rise in terminal prices,making it difficult to spread to low-end terminals. The current problem is that we havenot been able to find benefits that match this price increase, and end users have not beenable to enjoy it. In addition, the introduction of millimeter wave will increase the numberof parts, which may limit the design of terminals. In the future, the lower cost of
introducing millimeter wave, the miniaturization of antenna modules, etc., and thewider coverage of antenna characteristics will be the keys to the spread of terminals.
In addition, the power efficiency of semiconductor devices such as amplifiers formillimeter wave is still lower than that for microwave, and this is one of the main reasonsfor high power consumption. This also affects battery consumption and heat generation.
It is an issue that greatly affects end-user usability. Resolving these issues is also the
key to the spread of millimeter wave terminals.
3.4

Millimeter wave use cases

Use cases unique to 5G are expanding, such as the need for higher quality video

27

services and remote monitoring and control. However, most of the current use cases arestill at a satisfactory level even with the performance of sub6, and the high-speed andlarge-capacity performance of millimeter wave are not required, which has not led to the
spread of millimeter wave. In the future, it will be necessary to appeal and demonstrate
the effectiveness of millimeter wave to other industries in order to further improve thequality of use cases and to create new use cases that require millimeter wave.
3.5

Overall issues

So far, we have categorized the issues for millimeter wave penetration into millimeterwave introduction areas, millimeter wave compatible base station equipment, millimeterwave implementation terminals, and millimeter wave use cases. In a sense, the current
situation is thought to be creating a negative chain reaction. For example, if there areno use cases that take advantage of the high speed and large capacity unique tomillimeter wave, it is not possible for mobile network operators to anticipate the costeffectiveness of introducing millimeter wave by considering an increase in the numberof users/ARPU. This is one of the reasons why they are reluctant to expand their area.
The reason why the number of terminals supporting millimeter wave is limited is thatthe millimeter wave area is limited. The reason why millimeter wave specific use cases
have not been created is probably that the millimeter wave area is limited and millimeterwave supporting terminals are not widespread. Therefore, for the spread of millimeter
wave, it is necessary to solve all the above three issues and make it a positive chain
reaction(Fig. 3-3).

28

Fig. 3-3 Cross-correlation and positive chain for wide spread of mm-wave
Furthermore, the above-mentioned millimeter wave situation and issues are not only
domestic issues, but global issues. The situation of overseas is even more serious.
Although millimeter wave frequency allocation is gradually spreading overseas, it is still
limited to some countries. Even in countries where millimeter wave frequencies havebeen allocated, they have not been deployed in areas, or have been introduced only in alimited number of areas and for a limited number of applications. There was a case where
the granted license was revoked due to a situation in which the area had not yet been
expanded. For the dissemination of millimeter wave, price reduction, cost reduction, andtechnological innovation by building an ecosystem on a global scale are essential. In the
future, it will be extremely important to share the problems and solutions of millimeterwave with the rest of the world and to build a global ecosystem to disseminate millimeterwave in Japan.

29

References[1] Kazutaka Toyotake, et al., “Human body shielding loss in the terahertz band,”IEICE General Conference, B-1-5, Mar. 202230

4．Millimeter wave technology overview
This chapter provides an overview of the technologies that are considered effective insolving the problems of widespread use of millimeter wave, as described in Chapter 3,
and millimeter wave related technologies that have been specified or are being
considered for specification in standardization such as 3GPP. Fig. 4-1 summarizes the 8
millimeter wave technologies discussed in this chapter and the challenges to be solved.

Millimeter wave carrier
aggregation (CA)Beamforming technology
Large propagation loss,
low amplifier output
and efficiency

Millimeter wave device
technology
Higher the frequency,
lower the amplifier
output and efficiency

MIMO technology
Spatial multiplexing in
propagation condition
such as directivity andshadowing/blocking

Infrastructure sharing

Topology improvement
technology

Equipment andinstallation cost ofbase station due to thesmaller coverage

Coverage/connectivity
reduction in NLOS area

Power consumption ofmobile terminal
handling broadband
signals

sub6 + millimeter wave dual
connectivity (DC)
Unstablecommunication,
non continuous
coverage

High-Power UE
Unbalanced downlink
and uplink coverageFig. 4-1 Millimeter wave technology and challenges to be solved
4.1

Beamforming technology

Beamforming is an essential technology for millimeter wave to solve the problem oflarge propagation loss and lower amplifier output and efficiency. As shown in Fig. 4-2,
by using a multi-element array antenna in the base station, a high array gain can beobtained, which can solve the problem of propagation loss [1]. In addition, by using thesame number of amplifiers as the antenna elements of the multi-element array antenna
or in proportion to the number of elements, the problem of low output and efficiency peramplifier can be overcome. On the other hand, if the array gain is increased by increasing
the number of antenna elements, the beam width becomes narrower. It is required toenable better beam directivity and tracking control. An increase in array gain by a multielement array antenna is effective not only for downlink coverage but also for uplinkcoverage expansion.
Beamforming methods are classified into analog beamforming, digital beamforming,and hybrid beamforming [1]. Due to the need for a large number of antenna elements
and wider bandwidth, analog beamforming is commonly used for millimeter wave. Thisis because high-speed DACs/ADCs that support wideband consume a lot of power31

consumption, so analog beamforming, which requires the least number of DACs/ADCs(the same number as the number of multiplexed signals), is suitable. It is common to use
a VH polarization for multiplexing two transmissions from one antenna panel.
In order to accommodate future traffic increases and further enhance the usefulnessof millimeter wave, it is necessary to increase the multiplexing number of millimeterwave more than two. Using a plurality of antenna panels is one option to increase thenumber of multiplexes, but in this case, the area of the array antenna and the numberof circuits such as amplifiers increase. There is also a method of dividing one antenna
panel and using a plurality of divided small-scale antenna panels, but this method
reduces the array gain. Therefore, by developing a millimeter wave RF chip capable ofmulti-beam multiplexing, which has a function to amplify multiplexed signals together
with a single amplifier, multiplexed signals other than VH polarization can betransmitted from a single antenna panel [2]. In the future, if the power consumption ofhigh-speed DAC/ADC can be reduced, it will be possible to increase the multiplexing
number by applying digital beamforming and hybrid beamforming even to millimeterwave.

Fig. 4-2 Beamforming effect
4.2

MIMO technology

In this section, we introduce solutions for radio wave propagation issues such as
directivity and shadowing/blocking of millimeter wave, and future MIMO-related
technologies that utilize spatial multiplexing.

32

4.2.1LoS-MIMO

Spatial multiplexing of MIMO is realized by forming independent paths on the
propagation channel by signal processing. In a multipath fading environment, thepropagation channel has higher probability to facilitate independent paths. In highfrequency bands such as millimeter wave, where radio waves travel in a straight line
and are less likely to be reflected or diffracted, transmitting and receiving antennas arelikely in a line-of-sight (LoS) environment, and hence the correlation of propagation
channels becomes high. In line-of-sight MIMO (LoS-MIMO), by properly arranging
MIMO antenna elements with respect to transmission and reception distances, it ispossible to reduce the correlation of propagation channels and form multiple
independent paths. In particular, when the element spacing is optimal, communication
using MIMO eigenmode transmission becomes possible [3]. However, since the optimum
element spacing is determined by the transmission/reception distance, the use in fixedcommunication has been conventionally studied. In recent years, it is expected to be usedin mobile communications, and studies are being conducted on LoS-MIMO, which isrobust to fluctuations in transmission and reception distances [4]. These LoS-MIMO
technologies make it easier to use spatial multiplexing even in millimeter wave, making
it possible to improve the frequency utilization efficiency of millimeter wave.
4.2.2

Massive-MIMO／Distributed-MIMO

Millimeter wave has a high directivity, and there is a risk that communication will beinterrupted if radio waves are blocked by obstacles. As a countermeasure, distributed
MIMO(Distributed-MIMO),

which

increases

theprobabilityofline-of-sightcommunication from remote antenna units (RAUs) to user terminals by distributing
many RAUs, is effective, as shown in Fig. 4-3 [5-7]. In particular, the introduction ofwide-area Distributed-MIMO, in which multiple RAUs connected to a central basestation are installed outdoors on utility poles, traffic lights, street lights, etc., and indoors
on walls, ceilings, etc., and these multiple RAUs coordinate with each other is expected[8]. Wide-area Distributed-MIMO enables user terminals to secure line-of-sight paths
with multiple RAUs, thereby enhancing the reliability of millimeter wave
communications. Distributed-MIMO is a technology that maximizes degree of freedom
in spatial domain by securing independent propagation paths by arranging the antenna
elements of an array antenna at a greater distance than the carrier wavelength. There
are two options for Massive-MIMO; one option is to arrange antenna elements with theelement spacing close to about 1/2 wavelength, which has already been adopted inpractical use in the sub6 band, and the aforementioned Distributed-MIMO. The former

33

can generate a steerable plane wave beam, but the degree of spatial domain multiplexing
depends on the number of independent propagation paths. The latter cannot generate asteerable plane wave beam, but likely to have independent paths. However, it has thefeature of maximizing the spatial multiplicity. In 3GPP, Rel-16/17 specifies DistributedMIMO using two transmission and reception points (Multi-TRP: Transmission and
Reception Points) on the base station side for one UE [9].

Fig. 4-3 Channel matrix from transmitters to receiver
4.3

Topology improvement technology

An issue of millimeter wave is coverage/connectivity in areas that has no line-of-sightsfrom the base station. Therefore, installing a relay station or a reflector between the basestation and a user terminal makes it possible to improve the performance in areas thatare out of line-of-sight from the base station. Relay stations are classified into
regenerative relay stations called IAB (Integrated Access and Backhaul) and nonregenerative relay stations such as repeaters. Repeaters requires only power supply
basically and hence are easy to install in both outdoor and indoor without GPS signals.
Further, Repeaters amplify and forward the signal without digital signal processing andtherefore, the delay caused by a Repeater is not high. Since the millimeter wave band
repeater supports beamforming (antenna integrated), the donor-side unit facing the basestation and the service-side unit facing the terminal are separated, and the units areconnected with a single coaxial cable. This enables flexible deployment and area
construction [10].
Recently, methods to control the radio environment dynamically are extensively

34

studied. As shown in Fig. 4-4, these include RIS (Reconfigurable Intelligent Surface),
which controls the position and orientation of relay stations, and the direction ofreflecting waves in arbitrary directions using metasurface reflectors [10, 11]. In addition,some other technologies are also studied such as a technology that bypasses blocking
objects with a dielectric waveguide that enables low-loss transmission compared tocoaxial cables, radiates radio waves from a part of the dielectric waveguide, and freelychanges and moves the radiation position of radio waves. As a result, area creation
technology that can flexibly respond to changes in the radio wave environment, such aschanges in the layout of factories, is being studied [12].

Fig. 4-4 Conceptual diagram of RIS using metasurface technology
4.4

Millimeter wave device technology

Here, we consider device-related technology that solves the problem of low amplifier
output and efficiency in millimeter wave. Fig. 4-5 shows the relationship between
frequency and amplifier output for various device materials. As can be seen from thefigure, the higher the frequency, the lower the output of the amplifier. At highfrequencies above the 28 GHz band, the output of amplifiers made of CMOS or SiGe
drops significantly. By using GaN as a device material, it is possible to increase theoutput even for millimeter wave, but since GaN is more expensive than CMOS, current
millimeter wave base stations use multi-element array antennas and CMOS or SiGe asmaterials. Therefore, if the cost of GaN decreases in the future, it will be possible torealize millimeter wave base stations with various configurations other than multielement array antennas by using high-power amplifiers.
Next, consider the problem that the efficiency of the amplifier decreases as thefrequency increases. In the sub6, DPD (Digital Pre-Distortion) is applied to the Doherty
amplifier, which greatly improves the efficiency of the amplifier. DPD is not used formillimeter wave so far since the requirement for ACLR (Adjacent Channel Leakage

35

Ratio) for millimeter wave is less strict. However, DPD would also be beneficial for
millimeter wave since it can compensate for signal distortion and hence reducing EMV(Error Vector Magnitude), enabling 256QAM transmission, and reducing power backoff
to improve amplifier efficiency. In millimeter wave base stations using multi-element
antennas, it is necessary to get feedback from many amplifiers using many high-speed
ADCs over broadband channel, which increases the circuit complexity and power
consumption of DPDs. Therefore, a technology is being studied to reduce the DPD circuit
complexity by exploiting the relaxed ACLR regulations for millimeter wave to reduce thenumber of high-speed ADCs used for feedback [13].

Amplifier output (W)

1000
100
10

SiC
SiLDMOS
GaAs

1
0.1

GaN

SiGe
CMOS

0.01

1

InP
10

Frequency (GHz)

100

1000

Fig. 4-5 Relationship between frequency and amplifier output
4.5

Infrastructure sharing

Since millimeter wave has relatively smaller coverages, it is necessary to install a large
number of base stations in order to cover a wide area. Therefore, it is an important issue
to keep the equipment cost and installation cost of the base station low. Infrastructure
sharing is considered to be one of the effective means to solve these problems [14]. As
shown in Fig. 4-6, there are various infrastructure sharing methods, which involves
sharing installation locations such as steel towers and antenna facilities, and sharing
base stations. Sharing network facilities of other mobile operators such as roaming and
MVNOs (Mobile Virtual Network Operators), has already been implemented. At low
frequencies such as sub6, many base stations separate the radio unit (amplifier) andantenna via the RF port, so it is relatively easy to share the antenna. On the other hand,since millimeter wave has a large power loss due to transportation from radio unit to36antennas, legacy antenna sharing, which requires a long distance between an amplifier
and an antenna, is not suitable. Especially for outdoor scenarios where coverage is more
important, sharing of base stations or radio units would be suitable for millimeter wave.
Such practical application is being studied [15]. In addition, in high frequency bands
such as millimeter wave, where wide bandwidths can be allocated, a base station
configuration is being studied in which signal processing functions of radio units areconsolidated to a central station using analog RoF (Radio-over-Fiber), and a radio unit
comprising an antenna and an amplifier is shared by a plurality of wireless systems [16].
As a result, it is possible to improve the ease of installation and economic efficiency by
reducing the size and power consumption of distributed radio units.

5G network
structure

Infrastructure Sharing Method
Site sharing

Antenna sharing

RU sharinggNB sharing

Core Network
CU/DU
RU
Antenna
Site
Dedicated equipment

Sharing equipment

Fig. 4-6 Infrastructure sharing methods
4.6

Millimeter wave Carrier Aggregation (CA)In general, communication over millimeter wave uses a wider bandwidth than sub6.
For example, in the 28GHz band available in Japan, 400MHz is allocated per 5G operator,
and up to 900MHz continuous frequency is available for Local 5G. In many cases, rather
than treating such a wideband as a single carrier, a form of carrier aggregation (CA) isapplied, in which multiple carriers with a bandwidth of 100 MHz are aggregated forcommunication with a terminal [9]. CA can flexibly and adaptively change the numberof carriers used for communication. In CA, it is also possible to use different numbers ofcarriers for downlink and uplink (see Fig. 4-7). For example, power consumption of themobile station can be suppressed by controlling the number of carriers based on therequired throughput or the like. Millimeter wave CA has been standardized by 3GPP for
all 5G millimeter wave frequency bands, including the 28 GHz band, and is an essential
technology for millimeter wave operations today.

37Component Carrier

f
gNB

UE

100MHzf

Fig. 4-7 Millimeter wave carrier aggregation (CA)4.7

sub6 + millimeter wave Dual Connectivity (DC)In 5G, the sub6 carrier can be used as an anchor carrier for millimeter wave
communication, and sub6 + millimeter wave dual connectivity (DC), which provides 5G
services through simultaneous communication of sub6 and millimeter wave, can be used
[9, 17]. With sub6+millimeter wave DC, both sub6 and millimeter wave communications
can be used simultaneously, so higher throughput can be achieved than when only
millimeter wave is used. In addition, even in areas where there is no continuous coveragewith millimeter wave or when millimeter wave communications are unstable,
connections can be maintained using the sub6 frequency, reducing the probability ofradio link failures caused by a lack of coverage for millimeter wave. In sub6+millimeterwave DC, use of an LTE carrier as anchor for 5G is called NSA (Non-Standalone), and it
has become an essential technology especially for the initial deployment and early
operation of 5G (see Fig. 4-8). Sub6+ millimeter wave DC (including NSA) has beenstandardized by 3GPP [18] so that it can be implemented in various combinations offrequencies of each country and operator, and is a widely used technology today.

38

Fig. 4-8 Concept of LTE-NR dual connectivity
4.8High-Power UE（HPUE）

For millimeter wave and sub6, maximum outputs at mobile station are defined. In
general, mobile station output power is smaller than the base station output power,
which poses a problem of coverage imbalance between downlink and uplink. To solve
this problem, high-power mobile stations called HPUE (High-Power User Equipment)
have been standardized [19]. Under the control of the base station, HPUE can improve
uplink coverage by increasing power output within a range that does not cause problems.
Several types of HPUE have been standardized for millimeter wave. For example, HPUE
called Power Class 1 is a mobile station specification for fixed radio, and can output a
maximum EIRP of 55 dBm. Millimeter wave HPUE of Power Class 1 has also beencommercialized in the United States.
Base station

Current (antenna power, gain)
Sub6 : 23dBm, 3dBi
mmW : 23dBm, 20dBi** Flexible with EIRP
below 43dBm

UE

UE

Sub6 : 26~29dBm, 3dBi*1
mmW FWA : 35dBm, 20dBi*2*1 Flexible with EIRP below 32dBm*2 Flexible with EIRP below 55dBm
Stable communication is possible
even at the area edge, andthroughput is improved

FWA

At the edge of the area, it is difficult
to reach the base station, reducing
throughput

HPUE (antenna power, gain)

Fig. 4-9 Introduction of HPUE [20]39

References[1] NTT DOCOMO Technical Journal, Vol.17, No.4, PP.29-39, Apr. 2016.
https://www.docomo.ne.jp/english/binary/pdf/corporate/technology/rd/technical_jour
nal/bn/vol17_4/vol17_4_004en.pdf[2] Fujitsu, “RU Technologies,” PP.4, 2023.
https://www.fujitsu.com/global/imagesgig5/RU-Technologies.pdf[3] K. Nishimori, et al., “On the Transmission Method for Short-Range MIMO
Communication,” IEEE Trans. Vehicular Tech., 2011.
[4] M. Palaiologos, M. H. C. Garcia, R. A. Stirling-Gallacher and G. Caire, "Design ofRobust LoS MIMO Systems with UCAs," 2021 IEEE 94th Vehicular Technology
Conference (VTC2021-Fall), Norman, OK, USA, 2021, pp. 1-5.
[5] NTT DOCOMO Technical Journal, Vol.9, No.1, PP.62-66, June 2007.
https://www.docomo.ne.jp/english/binary/pdf/corporate/technology/rd/technical_jour
nal/bn/vol9_1/vol9_1_062en.pdf[6] NEC, “Millimeter-wave distributed-MIMO technique triples the number ofsimultaneous connections and transmission capacity in a real office setting,” Jan.
2021
https://www.nec.com/en/press/202101/global_20210125_01.html[7] KDDI Research Institute, "World's first successful demonstration of wirelessnetwork deployment methodology for Beyond 5G," Oct. 2021.
https://www.kddi-research.jp/english/newsrelease/2021/100701.html[8] NTT/DCOMO/NEC, “World's first successful demonstration of distributed MIMO
that continues wireless connections in the 28 GHz band by eliminating shielding
issues,” Oct. 2022.
https://group.ntt/en/newsrelease/2022/10/31/221031a.html[9] 3GPP TS 38.300, v17.3.0[10] DKK, “Repeater, Metamaterial reflector panels (28GHz),”https://denkikogyo.co.jp/en/elec/product/mobile/l5g/[11] NTT DOCOMO Technical Journal, Vol.23, No.2, PP.14-23, Oct. 2021.
https://www.docomo.ne.jp/english/binary/pdf/corporate/technology/rd/technical_jour
nal/bn/vol23_2/vol23_2_003en.pdf[12] NTT DOCOMO Technical Journal, Vol.23, No.3, PP.5-12, Jan. 2022.
https://www.docomo.ne.jp/english/binary/pdf/corporate/technology/rd/technical_jour
nal/bn/vol23_3/vol23_3_002en.pdf[13] T. Ota, et al., “An Experimental Study on Multibeam Digital Predistorter with
Intercarrier Interference Suppression,” in Proc. IEEE VTC2022-Fall, 2022.

40

[14] TEPCO Power Grid, “Final summary material for public opinion exchange meetingfor future 5G base stations,” Feb. 2022. (Japanese only)
https://www.tepco.co.jp/pg/company/pressinformation/information/2022/pdf/220204a.pdf[15] JTOWER, “JTOWER and Foxconn entered into the agreement to develop a sharedradio unit compatible with 5G millimeter wave,” Apr. 2022.
https://en.jtower.co.jp/en_news/2022/14525/[16] NTT, “Efficiently Accommodating High-frequency-band Wireless Systems by Using
Analog Radio-over-fiber,” Mar. 2020.
https://www.rd.ntt/e/research/JN20200315_h.html[17] NTT DOCOMO Technical Journal, Vol.22, No.2, PP.23-39, Oct. 2020.
https://www.docomo.ne.jp/english/binary/pdf/corporate/technology/rd/technical_jour
nal/bn/vol22_2/vol22_2_004en.pdf[18] 3GPP TS 38.101-3, v17.8.0[19] 3GPP TS 38.101-2, v17.8.0[20] Published report from Telecommunications council of Ministry of Internal Affairs
and Communications (Japanese only)41

5

Performance evaluation

In this chapter, we introduce experimental and measurement results using 5G
millimeter wave. The results demonstrate that millimeter wave can achieve extremely
high throughput and low latency performance and can be utilized in various
environments including non-line-of-sight (NLOS) scenario. A summary of each section is
as follows:-

Section 5.1: Measurement of 5G millimeter wave throughput and latency
performance (one-to-one communication, ideal environment)We measured the throughput and latency of one-to-one communication withvarious receiving power in a line-of-sight (LOS) environment. It was foundthat a throughput of 1 Gbps or more can be obtained and a latency (Ping RTT)of 7 ms or less can be achieved even with a low receiving power with a loworder modulation scheme. This result indicates that 5G millimeter wave issuitable for a wide range of broadband communication and low-latency
services.

-

Section 5.2: 5G millimeter wave indoor environmental measurements


We installed a 5G millimeter wave base station in an actual indoor facility
and measured the throughput at different locations in the facility. It was
found that high throughput is achieved not only in the vicinity of a basestation with a direct path, but also in places where the direct path is blocked
by a pole. This result indicates that 5G millimeter wave can achieve highthroughput over a wide area, even in a real indoor environment where somedegree of blockage and distance between base stations and terminals areunavoidable.

-

Section 5.3: 5G millimeter wave outdoor environment measurement
This section introduces outdoor field measurements, including the results
reported in [2]. Fixed and moving measurements were performed at an areain Tokyo where commercial outdoor base stations are actually deployed. It
was found that each base station can cover a millimeter wave communication
area within a range of about 100m and can achieve higher average throughput
even when moving, compared to sub6. This result shows that 5G millimeterwave can provide high user values even in situations where 5G millimeterwave area coverage is not fully continuous to some extent.

-

Section 5.4: 5G millimeter wave Challenges and Solutions
This section introduces activities and studies to address the 5G millimeterwave challenge, that is to support non-line-of-sight environments [35-39].

42

These include repeaters, RIS, and applications of dielectric waveguides.
5.1

5G millimeter wave throughput and latency performance measurement (one-to-one communication in an ideal environment)
We measured the performance in an ideal one-to-one communication environment
using a commercially available millimeter wave capable terminal and a 5G base stationemulator. Figure 5-1 illustrates the system for the measurement evaluation. The
Keysight E7515B UXM 5G wireless test platform is used as a test platform, and SHARPAQUOS R7 (Qualcomm Snapdragon 8 Gen 1) is used as a terminal for the measurement.
The test platform and the terminal communicate using the LTE anchor of band 1 (2.1
GHz band) and the 5G New Radio (NR) millimeter wave (4 component carriers (CCs)with 100MHz bandwidth on each for a total bandwidth of 400 MHz) of band n257 (28GHz band). The millimeter wave transmitting / receiving antennas of the base stationemulator and the terminal are placed inside of an anechoic chamber, and these are on aline-of-sight at a distance of about 1.5 m. The downlink transmission power from thebase station emulator is adjustable.

Fig. 5-1 Performance evaluation of commercial terminal (provided by Keysight)<Downlink throughput evaluation>
Fig. 5-2 shows the NR physical layer throughput as a function of the downlink powerof the base station emulator for a given modulation and coding scheme (MCS) from256 QAM, 64 QAM, 16 QAM, and QPSK. The throughput does not include thecommunication over anchor LTE band. Throughput exceeding 3 Gbps with 256 QAM wasobserved when the received power (RSRP) was sufficiently higher. Also, we could achieve43almost error free communication if the RSRP is about -80 dBm or higher. Even when the
RSRP is lowered to -110 dBm, it was still possible to communicate at 1 Gbps without
errors using 16 QAM. For millimeter wave, the available bandwidth in Japan is typicallyas wide as 400 MHz for downlink. Therefore, even with low-order modulation, it ispossible to provide high throughput.

Fig. 5-2 5G millimeter wave throughput<5G millimeter wave latency performance>
The NR physical layer throughput and the round-trip delay (Round Trip Time: RTT)
measured using ping packets are plotted in Fig. 5-3. In this experiment, the link
adaptation feature of the base station emulator was enabled so that it automaticallyselects the appropriate MCS index to maintain a 10% block error rate. When lowering
the downlink receiving power, the average throughput gradually decreases from thepeak because the modulation scheme was automatically changed due to thelinkadaptation. As with the results in the previous section, it was possible to maintain
1 Gbps or more at an RSRP range of -110 dBm or higher. The ping RTT is 5.0 to 5.5 ms
with the higher RSRP and 6.5 ms with the lower RSRP. From these results, themillimeter wave systems can achieve low latency communications regardless of
propagation conditions because of the benefits of wide subcarrier spacing and the shorttime length of a slot, as well as short TDD UL-DL switching cycle.

44

Fig. 5-3 5G millimeter wave throughput and round-trip delay
From the results in section 5.1, we can say that millimeter wave systems have acapability to support both low-latency and high-throughput use cases with the devices
that are already available in the market. The measured data also show that it can
provide a stable low-latency performance. These results also suggest that millimeterwave networks can be used for applications that do not require peak throughput
performance but high-reliability and low-latency (quick responsiveness) such as online
gaming.
5.2

5G millimeter wave indoor environment measurement

This section presents the performance evaluation results of 5G millimeter wave
measured in an indoor environment. We installed a 5G millimeter wave base station in
one corner of the 10m x 20m room shown in Fig. 5-4, and measured the downlink
throughput at various locations (points A to F) in the room. 2-layer MIMO and 64QAM
modulation were used in band n257 (28 GHz band) millimeter wave NR carrier (100 MHz
x 4cc totaling 400 MHz), TDD DL:UL ratio = 4:1 and base station transmit power of 32
dBm were assumed. The average throughput was measured over the 5 seconds at eachpoint. The measurement results are follows.
Point A：1666.54Mbps
Point B：1586.91Mbps
Point C：1851.24Mbps
Point D：1842.28Mbps

45

Point E：1602.87Mbps
Point F：1643.85Mbps

Fig. 5-4 Indoor measurement of 5G mm Wave throughput
When there is no blocking or attenuation in the vicinity of the base station (points C/D),
high throughput (over 1.8 Gbps under these measurement conditions/environment) canbe obtained. Points A/B/E/F are far from the base station and there is a pillar near thecenter of the room, so the results at these locations are affected by a certain amount ofblocking and attenuation compared to points C/D. However, it can be confirmed thatthroughput exceeding 1.5 Gbps can still be achieved at all points. This measurement
result shows that high throughput can be obtained over a wide range of locations,
including non-line-of-sight, even in an actual indoor environment where some degree ofblocking and distance between the base station and terminal are unavoidable.
At indoor facilities that have relatively large spaces/areas, such as airports, officebuildings, and shopping malls, LTE/5G or wireless LAN is often deployed using DAS(Distributed Antenna System). The reference [1] provides measurement results showing

46

that installing a 5G millimeter wave base stations alongside such DAS base stations or
wireless LAN access points can cover a wide range of indoor facilities.
As an example, a visualization of the propagation loss (MPL: Maximum path-loss) froma 5G millimeter wave base station when a 5G millimeter wave base station is collocatedwith an indoor DAS base station or wireless LAN access point in an airport concourse isshown in Fig 5-5. Each 5G millimeter wave base station has 128 antenna elements foreach polarization, and can form 16 horizontal beams. It can be confirmed that the MPL
is 115 dB or less in almost the entire area (99.7% of the area). Under the conditions
described in [1], throughput of several Gbps can be obtained in 99.7% of the areas. [1]also shows similar measurements in airport concourses, convention centers, subway
platforms, offices, and shopping stores.
If DAS and wireless LAN have been installed in the facility, it may be difficult toseparately or additionally install a new 5G millimeter wave indoor base stations. [1]reveals that if 5G millimeter wave base stations can be installed alongside an existing
indoor network, it is possible to provide 5G millimeter wave services widely even in largescale facilities.

Fig. 5-5 Installation example of 5G millimeter wave base stations at airports and its
measurement result [1]5.3

5G millimeter wave outdoor environment measurement

In this section, we introduce the results of a 5G millimeter performance measured in
outdoor environment.
5.3.1

Results of uplink throughput measured in outdoor environment

In section 5.3.1, we introduce the results of a 5G millimeter wave performancebenchmark survey [2] conducted in Tokyo by Signals Research Group in April 2022
(English version is available in [3] with registration). In the benchmark survey,

47

commercial smartphones that support 5G millimeter wave are used to communicate withcommercial 5G millimeter wave base stations installed by operators to measure theachievable throughput, RSRP, and SINR. The bandwidths are 400 MHz for the downlink
and 200 MHz for the uplink. With these conditions, the maximum achievable throughput
of 5G millimeter wave is over 2.4 Gbps for the downlink and over 400 Mbps for the uplink(2-layer MIMO and 64QAM, respectively).
<Fixed point measurement>
In the fixed-point throughput measurement near Shimbashi Station, throughput
measurements of over 2 Gbps on the downlink and over 300 Mbps on the uplink wereobserved. At this time, it was confirmed that the distance between the terminal and the
5G millimeter wave base station serving for the terminal was about 115m. This indicatesthat millimeter wave can achieve high throughput even when there is a distance of about
100m.
In practice, throughput varies from place to place. Focusing on the uplink, the resultsof fixed-point measurement of 5G millimeter wave throughput nearby Shimbashi Station
were measured and plotted in Fig. 5-6. Four millimeter wave base stations are deployedin this area. It was confirmed that uplink throughput exceeding 150 Mbps can beachieved over a wide area. In some places with a good communication environment, there
were cases where the uplink throughput exceeded 250 Mbps.

48

Fig. 5-6 Outdoor fixed-point measurement of 5G mm-wave uplink throughput [2]-[3](English version is available in [3] with registration)<Movement measurement>
The average uplink throughput of walking around Tokyo Station was also measured.
In Fig. 5-7, the rightmost graph shows the average throughput when the mobile station's
5G millimeter wave is turned off, and the center shows the average throughput whenthe mobile station's 5G millimeter wave is turned on and is used. Even if the mobile
station's 5G millimeter wave is turned on, millimeter wave communication availability
depends on the quality of 5G millimeter wave and is not always available. Each terminal
experiences a time/location where 5G millimeter wave is available and a time/location
where it is not available. The middle graph shows the average throughput when 5G
millimeter wave is not used all the time. For this, when 5G millimeter wave are turned
off or in sections where 5G millimeter wave communication is not performed,
communication is performed using the 5G sub6 frequency (frequency band n78) instead.

49

Fig. 5-7 5G millimeter wave uplink throughput mobile measurement outdoors [2]-[3](English version is available in [3] with registration)
These results show that 5G millimeter wave can greatly improve uplink moving
average throughput. As mentioned above, the measurement in the middle graph was thecase where 5G millimeter wave is not always available. Even so, it is seen that an
average uplink throughput of three times can be achieved compared to using only the 5G
sub6 frequency band. 5G millimeter wave is sometimes said to be difficult to deploy inareas due to their characteristics of directivity and attenuation, but the results of thismeasurement show that high user benefits can be obtained even in situations where area
coverage is to some extent imperfect. It can be confirmed from the graph on the far leftthat throughput can be further improved if the deployment of 5G millimeter wave
progresses further and communication with 5G millimeter wave becomes possible almost
all the time.
On the other hand, for better connectivity/availability of 5G millimeter wave
communications, it is necessary to cover areas that are out of line of sight from basestations. The next section introduces some such techniques.
5.3.2

Results of downlink throughput and latency measured in outdoor

environment
In section 5.3.2, we introduce results of downlink throughput and latency of the 5G
millimeter wave commercial networks measured in outdoor environment. The

50

performance was measured in Shibuya, Tokyo in November 2022, by using commercial
phones. It was an outdoor walking text to measure the throughput and latency where
Ookla® Speedtest® App [4] is used. The Fig.5-8 and Fig.5-9 show the results ofthroughput and latency measured, in which results of Sub6 and LTE are shown forcomparison.
According to Fig. 5-8, the peak and average millimeter wave DL throughputs are
2Gbps and 1Gbps, and they are approximately 4 times and 10 times higher than Sub6and LTE respectively. And according to Fig. 5-9, the ping latency of millimeter wave isapproximately 15msec, which is 1/3 of Sub6 and LTE.

Fig. 5-8 Outdoor walking measurement of 5G mm-wave downlink throughput

51

Fig. 5-9 Outdoor walking measurement of 5G mm-wave latency
In this measurement the outdoor millimeter wave coverage was also investigated.
Location of each millimeter wave base station was estimated based on the coverage mapsof operators, and the distance, from a base station location to a point where thethroughput and latency are measured, is recorded. As a result, it was confirmed that themillimeter wave coverage is typically at least 100 - 150m and 200 - 250m in dense streets.
5.4

5G millimeter wave Challenges and Solutions

Millimeter wave has similar characteristics to light and have a strong directivity.
Therefore, as understood from the previous section, the issue is how to cover areas thatare non-line of sight from the base station. Although it is conceivable to deploy a large
number of base stations in such an area, it is not economical; more efficient techniques
for establishing an area are required. Therefore, various studies have been conducted toestablish new wireless network topologies using repeaters (or relay stations), reflectors,
and metasurfaces. These technologies are to create new radio propagation paths, or to
avoid blocking objects by high-frequency transmission lines. Such technologies are
expected to extend the millimeter wave coverage to non-line of sight areas [5].
<Repeater>
A Repeater is a wireless device that relays radio waves. By amplifying and forwarding
received signals from the base station that have been weakened by attenuation/shadowing, the coverage can be extended. For example, a Repeater consists of a donor

52unit serving from a base station and a service unit serving to a terminal, and these areconnected by a coaxial cable. An area can be constructed by installing the donor unit in
the direction of the base station and the service unit in the direction in which the area is
to be constructed. A beamforming antenna panel is used for donor and service units,
where the horizontal and vertical beam width and beam direction can be changed
electrically, so that flexible area construction is enabled as needed. It was reported in [67] that a repeater with an output of +37 dBm (5 W) for 4 carriers with a signal bandwidthof 100 MHz (400 MHz bandwidth in total) is developed, where the repeater has a 64element array antenna for beamforming with the 3dB beam width of 15 to 80 degrees
and the beam steering range of ±30 degrees for both horizontal and vertical planes.
<Metamaterial/metasurface application>
For non-line-of-sight areas, adaptive or dynamic control of radio wave propagation
paths according to the surrounding environment is being studied. One of the specifictechnologies for controlling radio wave propagation paths is RIS (Reconfigurable
Intelligent Surface). Metamaterials and metasurfaces are the components used for RIS.
These consist of a large number of elements that scatter electromagnetic waves and aredesigned or controlled such that the scattering characteristics are managed. Since themetasurface can be manufactured in a sheet shape, it can be installed according to theshape of the structure. By controlling the reflected phase distribution via RIS, it ispossible to control the propagation paths of the reflected radio wave, so that the received
power at a target receiving location. In the transparent dynamic metasurface, atransparent glass substrate is placed on a transparent metasurface substrate, and byslightly moving the glass substrate, the mode that passes the incident radio wave, partof the radio wave is transmitted, and part of the radio wave is reflected. It candynamically control 3 patterns: transparent mode, partial transparent mode, and modethat reflects all radio waves. In an experiment, it was observed that a transmittance of 1.4 dB or more in transmission mode and a transmittance of -10 dB or less in reflection
mode [8]. In addition, the transparent metasurface lens has a film shape that can be
attached to the window glass, and can focus radio waves passing through the window
glass to a specific indoor location (hereinafter referred to as the focal point). Therefore,by placing a repeater or reflector at the focal point, it is possible to create an area within
the building. In a demonstration experiment, it was confirmed that the received powerat the focal point was improved by more than 24 dB compared to the case of using normaltransmission glass [8].

53

<Dielectric waveguide application>
It is also necessary to consider the case that the radio shielding object will move. Such
scenario corresponds to, for example, the layout change of the manufacturing equipment
due to the change of the production line. The application of dielectric waveguides is being
studied as a method of quickly and economically providing a line-of-sight communication
environment against these fluctuations in the propagation environment. A dielectric
waveguide is used to bypasses the transmission line for a high frequency band, so thatshielding/blocking objects are avoided and can create coverage for a non-line-of-sightarea. Also, radio waves are radiated from a part of the dielectric waveguide to form acommunication area in the surroundings. So far, two methods of the principle ofradiation of radio waves from waveguides has been studied; bending the waveguide andemitting radio waves from the bent portion and bringing the waveguide into contact withanother dielectric so that the dielectric emits radio waves [9].

54References[1] ‘Mobile mmWave Is Here – and Indoor Deployment Opportunities Abound,’Published by Fierce Wireless, presented by Qualcomm
https://www.qualcomm.com/content/dam/qcomm-martech/dmassets/documents/fierce_ebrief_-_mobile_mmwave_is_here__and_indoor_deployment_opportunities_abound_smaller.pdf[2] 5G mmWave was working well in Tokyo,’ SIGNALS Research Group, June 2022.
https://www.qualcomm.com/content/dam/qcomm-martech/dmassets/documents/SRG-Japan-5G-mmWave-Whitepaper.pdf[3] https://www.qualcomm.com/support/contact/forms/5g-mmwave-performance-intokyo-japan-reg[4] https://www.speedtest.net/apps[5] “5G Sophistication and 6G,” NTT Docomo White Paper, Version 5.0,
https://www.docomo.ne.jp/binary/pdf/corporate/technology/whitepaper_6g/DOCOM
O_6G_White_PaperJP_20221116.pdf[6] Development of 5G RF Repeater, Denko Technical Report, No. 53, 2021
[7] https://denkikogyo.co.jp/elec/product/mobile/l5g/[8] “Research on transparent RIS technology for 5G evolution & 6G, “ NTT DOCOMOTechnical Journal, Vol. 29, No.3, Oct 2021.
[9] “Pinch Antenna - Antenna Application of Dielectric Waveguide,” NTT DOCOMOTechnical Journal, Vol. 29, No.3, Oct 2021.

55

6Millimeter wave introduction scenario
Various frequencies are currently used worldwide in mobile communications. Likewise,a wide range of frequencies from 700MHz to 28GHz is used in Japan. Since radio wave
propagation characteristics and frequency bandwidths differ greatly depending on thefrequency band, mobile network operators use the proper frequency band for the rightplace(Fig. 6-1).

Fig. 6-1 Image of proper use of frequency bands
Specifically, low frequencies below 1 GHz have a small propagation loss but a small
frequency bandwidth, so they are mainly used to cover the service area including
mountainous region (coverage band). Although the higher frequency band, i.e. mid-band
and millimeter wave, has a larger propagation loss, it has a wide frequency bandwidth,
so it is mainly used to provide high-speed, large-capacity services in areas with heavy
traffic (capacity band).
Since millimeter wave is in a particularly high frequency band, it is important to makeuse of their characteristics. Although the cell radius becomes relatively small due to thelarge propagation loss, it is effective for applications in narrow and closed areas, when it
is desired to prevent radio waves from leaking outside the service area as much as
possible by taking advantage of this characteristics. High-speed, large-capacity
capability due to a large frequency bandwidth is effective in places where heavy trafficis generated and high-speed services are required. Based on these characteristics, thefollowing millimeter wave introduction scenarios can be considered(Fig. 6-2).

56

Fig. 6-2 Example of millimeter wave introduction scenarios
1) Hotspots, stadiums, event venues
It is a specific area where many people gather and requires a large communication
capacity. Location-specific high-speed service is also provided. In these introduction
scenarios, flexible operation of millimeter wave that adapts to surrounding traffic,
environment, and behavior, including temporary installation of millimeter wave basestations, is expected.
2) Office, indoor
It is a closed space which covers a specific, relatively small area. By reflecting radio
waves, it is possible to build a good communication environment even in non-line-of-sightconditions. As there is a lot of communication demand, high speed and large capacity are
required.
3) Private NW/Local 5G
It is a closed premises, and it is necessary to minimize the leakage of radio waves
outside the service area as much as possible. A high-speed, large-capacity
communication environment is expected within the service area.
4) Urban sidewalks, roads and intersections
Due to the demand for communication by many people and vehicles, a large
communication capacity is required.

57

5) FWA
There is a high need for FWA, which can easily and inexpensively create a high-speed
home communication environment in a very short period of time as an alternative to
optical fiber lines. Even if optical fiber is widely used, many FWA solutions are being
provided in Japan.
In addition to the above, more millimeter wave introduction scenarios are conceivable.
It is expected that more millimeter wave deployment will be required in accordance withthe future spread of millimeter wave supporting terminals and the provision of services
unique to millimeter wave.

58

7

Affinity with local 5G

7.1

What is local 5G?

7.1.1

Regulation overview

In addition to nationwide 5G services provided by mobile phone operators, local 5G isa 5G wireless system that can be used by various entities such as local companies andmunicipal governments to flexibly build and use networks in their own buildings andpremises. As a system, it was institutionalized in 2019. Like nationwide 5G, local 5G has
the characteristics of ultra-high speed, ultra-low latency, and multiple simultaneousconnections, and its technical specifications are basically the same as those of nationwide
5G.
In 2020, the frequencies were expanded, and sub6 (4.7 GHz band) and additional 28
GHz became available in addition to the initial millimeter wave (28 GHz band). In
addition, "semi-synchronous TDD1)" operation with a ratio of "uplink 1:downlink 1" isalso possible to meet the needs of users who emphasize uplink communication such asvideo transmission.
Taking advantage of these characteristics, in addition to industrial use such as medical
care,

constructionindustry,

agriculture,

manufacturingindustry,logistics,

entertainment, etc., it is expected that Local 5G will be used for various needs, such asutilization related to community development, safety and security, health, welfare,tourism, education, etc. including solving the problems of regional issues.
Local 5G is basically assumed to be used for self-employed purposes. It is also possible
to receive provision as a service from the viewpoint of responding to the diverse needs
closely related to the region, it is also possible to request the construction and operationof networks from local business operators, etc., and use them as telecommunications
services.
7.1.2

Allocated frequency bands (sub6, millimeter wave)

Fig. 7-1 shows the allocated frequency bands for local 5G. In December 2019, local 5G
became available in a part of the 28GHz band (28.2-28.3GHz) by establishing of aregulation related to the Radio Law. In December 2020, the frequency band (4.6-

Quasi-synchronous TDD: It is the method to simplify radio wave interference
coordination for asynchronous operation, only the uplink/downlink slot patterns are
partially changed while matching the slot timing with synchronous TDD fornationwide 5G and local 5G. In local 5G, a regulation was developed in December 2020
for the most popular pattern with a ratio of "1 uplink: 1 downlink" as a "TDD patternwith a high ratio of uplink slots".
159

4.9GHz) and 28 GHz (28.3-29.1GHz) were also allocated.
In the sub6 band (4.6-4.9GHz), 4.6-4.8GHz (200MHz width) is a band shared withpublic service radio, so it is limited to indoor use, and its use is restricted in someareas.
Since the millimeter wave band (28.2-29.1GHz) is a band shared with the Ka-bandsatellite communication system, indoor use is recommended especially for the 28.4529.1GHz (650MHz width). (Because of the possibility of being affected by satellites, it isbasically used indoors, but outdoor use is also possible.)Fig.7-1 Local 5G allocated frequency band
7.2

Current state of local 5G

7.2.1

Overview (past history to popularization)

Local 5G was firstly developed in December 2019, so the first commercial local 5G
license was granted at about the same time as the nationwide 5G service of mobile
network operators was launched in March 2020.
First, the NSA system which an anchor band using BWA private operation
2

is used with combination of the 100MHz width of the millimeter wave band forindoor and outdoor. After 1 year later, from December 2020, the sub6 band which can beused for outdoor operation and millimeter wave band became available. Since then, theSA system, which does not require an LTE anchor band, has been introduced with a
100MHz width of 4.8-4.9GHz.
Fig. 7-2 shows the trend in the number of local 5G licenses. Since December 2020, theintroduction of sub6 base stations has increased rapidly, but the number of millimeterwave base stations has remained unchanged.

BWA private operation: A system for wireless systems that uses the same
frequency band (2575-2595MHz) as regional BWAs and can be developed and operatedusing the 4G/LTE system within their own premises or buildings in the same manner
as local 5G. It was regulated in December 2019 in line with local 5G. In the summer of
2020, the system for 5G-BWA (NR) was developed.
260

On the other hand, the Ministry of Internal Affairs and Communications is aiming topromote the dissemination of local 5G, which has just been regulated. In the three years
from FY2020 to FY2022, we have been conducting technical studies such as transmission,and “development demonstrations for the realization of problem-solving local 5G, etc.” tocreate utilization solutions including use cases. Figure 7-3 shows the transition of local
5G development demonstration. It can be seen that the demonstration experiments
using sub6 accounted for the majority even in the last three years.
In addition, the Ministry of Internal Affairs and Communications established a 5G
investment promotion tax system in August 2020 to promote investment in local 5G, andhas been working to further spread local 5G.
As a result of these various measures and corporate activities, as of the end of August
2022, 102 sub6 operators and 30 millimeter wave operators have obtained local 5G
licenses. However, after about three years, the progress has been limited to a certain
extent.

Fig.7-2 Changes in the number of local 5G licenses [1]61Fig.7-3 Changes in the number of local 5G development demonstrations [1]7.2.2

Situation for millimeter wave (actual situation)

As we are discussing so far, three years have passed since the first system wasestablished, and although local 5G has spread to a certain extent, the number of
deployments is still not sufficient, and most are concentrated on sub6. The current
situation is that the demand for millimeter wave is sluggish.
There are many factors that can affect 5G infrastructure, including low-band, midband, and sub6 infrastructure development in countries around the world, and the lackof millimeter wave development by domestic mobile network operators. Hereafter, wehave sorted out the “factors that hinder the spread of millimeter wave” that can beconsidered as unique issues to local 5G.
[Difficult to build an area]
It has a strong directivity and is difficult to propagate far away due to the influence ofobstructions, etc., it is difficult to construct an area (cell planning) within a building orsite. For example, in the case of an outdoor station, although the coverage area can be
expanded along the path (line of sight) between buildings, it becomes difficult to establish
an area even at a distance of several tens of meters from the base station when in theshade of a building. Also, with indoor stations, it is difficult to create an area for multiple
floors with a single base station, and even on a single floor, it is difficult to create an area
for multiple rooms, excluding rooms near the base station, when creating an area alonga corridor.

62

【The NSA method was the mainstream, complicated, and expensive]
While the SA system is currently the mainstream for sub6 wireless equipment, the NSA
system was the mainstream for millimeter wave, so the system configuration wascomplicated, and in addition to the relatively expensive local 5G equipment, the cost of
4G equipment was also high. (In the future, it is expected that NRDC, which mobile
network carriers are beginning to implement, will also be applied to local 5G).
In addition, 4G that is used as an anchor band in the NSA system includes 1.9 GHz
band TD-LTE (sXGP), private operation BWA, regional BWA, nationwide BWA, andnationwide 4G. However, the NSA operation with private operation BWA is difficult foroutdoor use, especially in urban areas, due to the problem of interference with regional
BWAs that use the same frequency band.
【There are few millimeter wave supporting terminals, and the cost is high]There are few 5G terminals (industrial routers, etc.) that support millimeter wave, andthe price is high. As a result, it is mostly used as a repeater that converts to Wi-Fi, andas a result, cases where the need for local 5G are diminished. Table 7-1 shows the statusof local 5G compatible terminals.
Table 7-1 Status of local 5G compatible terminals (according to March 2023 survey)
Corresponding
Manufacture name.

type

terminal type

frequency
millimeter
wave

sub6

Raku Plus

Mobile router○○

5G dongle

USB dongle－○

K5G-C-100A

mobile router○○

FMP181L

smartphone

○

○

SD01

smartphone

－

○

BZ03

smartphone－○

NEC Magnus
Communications

FG900CS

mobile router

－

○

Nokia

FastMile 5G Gateway 3.2

mobile router－○

Fujisoft+F FS050W

mobile router－○

CompalKyoseraFCNT[After the sub6 regulation establishment, there is a feeling that millimeter wave
deployment will be postponed]
Since December 2020, when the regulation for the sub6 band was established,development manufacturers and vendors have shifted to commercializing sub6, which is63

easier to design areas than millimeter wave, and has a simple SA system configurationand is relatively easy to develop. Therefore, the priority of millimeter wave support has
been lowered.
[Unable to reach a use case that makes use of the ultra-wide band of millimeter wave,
and it is difficult to connect it to business]
There is also a situation where people are leaning toward the use of sub6, and theactual situation is that design considerations are being conducted within the scope ofsub6 performance, without even coming up with the idea of making use of millimeterwave.
As mentioned above, there may be factors preventing the dissemination of local 5G
millimeter wave. On the other hand, for example, sub6, which can be used outdoors, hasa maximum width of 100MHz, so many IoT devices that handle video such as 4K cameras
are being introduced. In that case, millimeter wave, which can secure a 400MHz
bandwidth, will definitely be more advantageous in terms of capacity and operation of asingle base station, but this is also an easy-to-overlook point.
Also, assuming the area that mobile network operators can support, there is an opinion
that it may be possible to share base station facilities from the perspective of suppressing
construction costs and promoting local 5G introduction smoothly., . Sharing of facilities
means that local 5G millimeter band radio waves are also emitted from the 5G basestation of nationwide operators. For example, in regional BWA, the sharing of basestation facilities (borrowing of nationwide BWA base station facilities) is a common
technique in regional BWA area development.
Based on this perspective, as local 5G, which plays a role in the dissemination of 5G
in Japan, we believe that it is necessary to continue to provide and disseminate
information so that all parties concerned can correctly understand the characteristics of
millimeter wave as compared with sub6 and how to use it.
7.3

Affinity between millimeter wave and local 5G

The basic of local 5G utilization is the ability to create spots within one's own building
or premises, and flexibly operate them independently according to diverse needs. Since
it is assumed that many terminals will be used intensively at the same time in a
relatively small area, it can be said that millimeter wave, which can handle ultrawideband, have a very high affinity with local 5G, including the characteristics of radio
waves.

64

Three points regarding affinity will be shown below.
7.3.1

Area scale and radio wave characteristics (good compatibility with millimeterwave coverage area)
It can be said that local 5G, which is used in a limited area, is compatible withmillimeter wave coverage areas.
According to a general interpretation, millimeter wave is weak against shields due to
directivity, and easily affected by rain and snow. In terms of propagation distance, adistance of about 100 to 200m is realistic in an environment with non-line of sight, suchas in a city, and certainly it cannot be said it propagates well.
On the other hand, when we look at the actual use of local 5G, as shown in Fig.7-4, it
is often used in relatively narrow areas. For example, if it is used inside a building(indoor), it is desirable to suppress the leakage of radio waves to the outside, so it isconvenient for millimeter wave that is weak to shielding. Even when using local 5G on
the premises of a business such as a factory, it can be said that millimeter wave is easier
to control than sub6 in order to suppress the leakage of radio waves outside the premises.
In addition, millimeter wave is also suitable for "urban development" initiatives such as
super cities and smart cities, where you want to set up a safe and secure communication
spot in a limited area using smart poles, for example.
With local 5G, everyone can set up their own 5G at their own place, but it is necessary
to take care that leaked radio waves between neighbors do not cause interference witheach other. Sub6 has a longer propagation distance than millimeter wave, but instead,the amount of radio waves that leak out is also greater. Millimeter wave, which has ashorter propagation distance than sub6, can be said to be particularly convenient forhandling in densely populated areas.

Fig.7-4 Image of local 5G, which is expected to be usedin various places such as “in the city” [2]657.3.2

Communication capacity and communication demand (good compatibility

with high speed and large capacity)
Local 5G, which is used in a limited area, can be used by a large number of terminals
in a relatively small space, so it can be said that it is suitable for millimeter wave, which
can easily secure large capacity.
In the millimeter wave band of local 5G, a 900MHz bandwidth is reserved for allocation,and it is possible to operate 400MHz bandwidth like national 5G. Broadband operationis also technically possible.
For example, as shown in Fig. 7-5, when performing real-time video surveillance using
a 4K camera, assuming a transmission rate of about 20 to 25 Mbps for the uplink with
one camera, the operation of 10 cameras will exceed 200 Mbps. It makes difficult to use
other 5G equipment as the 100 MHz bandwidth of sub6 (64 QAM, 2 × 2 MIMO,
synchronous operation) will almost reach the uplink communication capacity., .
On the other hand, if the millimeter wave bandwidth is 400 MHz (64 QAM, 2 x 2 MIMO,
synchronous operation), a communication capacity of about 800 Mbps can be secured in
the uplink, so a 4K camera can be added, or a large number of other 5G devices can bemixed. When it comes to 5G, people tend to focus on the download speed of smartphones,
etc., but local 5G, which is expected to operate with an emphasis on uplinks that
constantly transmit data in real time, such as monitoring the status of facilities andcollecting data, is not limited to downlinks. Uplink communication capacity is also an
important point.

Fig.7-5 Image of video surveillance with a 4K camera on local 5G
In actual camera operation, the required number of cameras will be determined byadjusting the image quality, angle of view, frame rate, transmission rate, compression
method, etc. of the camera considering the transmission capacity that can be achievedby the sub6 5G base station equipment. Advance consideration and design are
assumed. But with millimeter wave, it will be possible to determine the number withflexibly to such ingenuity.

66

In local 5G, "semi-synchronous TDD operation" has been regulated for operations
that emphasize such uplink communication, and in millimeter wave, uplink capacity is
doubled with (uplink 1 : downlink 1 ratio) as compared with synchronous operation(uplink 1: downlink 3 ratio). 3
Local 5G also requires a correct understanding of the usage conditions in the
millimeter wave frequency band (28.2-29.1 GHz). As mentioned above, since the mmwave band is shared with the Ka-band satellite communication system, it is restricted
to install the antennas of local 5G base stations above the horizon. The 250MHz bandof 28.2 to 28.45GHz can be used both indoors and outdoors, but the 650MHz band of
28.45 to 29.1GHz is recommended for indoor use. This is because local 5G base stations
can be affected by earth stations (base stations on the ground) that communicate withsatellites. It does not mean local 5G interferes to the satellite systems. However,
although outdoor use is optional since the presence and degree of influence will change
depending on the operating conditions of the earth station (location, height, antenna
direction, etc.), understanding and caution are required.4
In this way, millimeter wave local 5G, which is capable of ultra-wideband operation,
is not just about fast communication speeds, it is also easy to handle 5G terminals that
require high transmission rates. Since it is easy to handle a wide variety ofsimultaneous connections, it is important to effectively adopt the proper use andcombination of millimeter wave and sub6 according to the required communication
capacity and speed in the local 5G area. It is thought that it will be a point to promote
the utilization of millimeter wave.

In semi-synchronous TDD operation, although the uplink capacity is increased, thedownlink capacity is smaller than that of synchronous operation, so it may not besuitable for downlink-oriented use case. Also, if there are local 5G licensees using thesame frequency for synchronous operation in the vicinity, such as adjacent, there is apossibility that communication failure will occur due to interference. Semi-synchronous
TDD operation must protect the synchronous operation from communication failure, sowhen using semi-synchronous TDD operation outdoors, it is necessary to pay attention
to the impact on other local 5G systems.
4 The joint study of earth station and local 5G is based on the result of studying theimpact on the local 5G base station in the most severe case for the earth station typewith the highest transmission power. In addition, according to the radio wave usage
survey conducted by the Ministry of Internal Affairs and Communications (as of June2020), the " There are 38 radio stations (20 fixed installation type, 18 portable type) of"Earth station". It is operated irregularly from time to time. In addition, the case wherethe "earth station" is installed with an antenna height of 50m, which is particularly
susceptible to interference, is currently limited to one location in Tokyo, and the range
of interference is limited. However, it is necessary to consider the possibility of futurestation placement. [3]367

7.3.3Compact system scale (good compatibility with system scale and ultra-low

latency)
In local 5G, which is used in a limited area, it is easy to integrate the entire system
into a relatively compact size, so it is easy to realize the ultra-low latency that is a featureof 5G, and it can be said that it is suitable for millimeter wave.
The local 5G system, like the national 5G system, consists of 5G core equipment andbase station equipment (RAN). Since the NSA system was the main component for
millimeter wave, the anchor band 4G equipment will also be developed. But as shown in
Fig. 7-6, it is assumed that the company will build its own equipment, including the coreequipment. If so, the facility is considered to be installed within the local 5G service area.
With such a configuration, not only the radio section between the 5G base station andthe terminal, but also the physical proximity between the RAN equipment and the 5G
core equipment will be physically close, enabling data processing within the local 5G
area. It becomes easy to realize low delay.
Also, in the near future, it is possible that the anchor band will be converted to 5G, so
it is expected that sub6 will play a role in local 5G. Regarding the 5G core, two options
can be considered, one is to build it yourself and the other is to use the cloud core. In
either case, ultra-low latency can be expected if data processing can be performed within
the local 5G area.
If the scale of the entire system is within the local 5G area, security measures will beeasier. For example, safe operation can be easily achieved without connection to an
external network such as the Internet, but if you want to use it together with an Internet
connection, only a specific network (a group of terminals) will be blocked from connecting
to the outside. By setting a "closed network", it is possible to flexibly obtain a safe
environment as needed.
A compact system scale is likely to work favorably for the adoption and introduction ofOpen RAN. As a general assumption, it is possible to efficiently combine RAN equipmentfrom multiple vendors that comply with the Open RAN specifications, but in terms ofequipment operation management, it is necessary to manage equipment for each vendor.
In the case of local 5G, which is expected to have a small system configuration, it ispossible to configure the entire system with Open RAN equipment from a single vendor.
These merits and affinities related to system scale are not limited to millimeter wave,
but apply equally to sub6. If amended, the NSA for millimeter wave shown in Fig. 7-6
can shift to the SA if we look further into the future. DC (dual carrier) is also possible bycombining millimeter wave and sub6 to achieve stability during millimeter wave
connections and further increase in capacity and speed. In local 5G DC, it is possible to68use millimeter wave to strengthen and reinforce part of the sub6 area, but from adifferent perspective, ultra-wideband millimeter wave is the main, and sub6 connects
the gaps. By doing so, we can also think of ensuring the convenience and stability ofconnections in the millimeter wave area.

Fig. 7-6 System configuration example for local 5G millimeter wave
Three years have passed since the start of the local 5G system, and although it canbe said that the introduction has progressed to a certain extent, the reality is that it
has not yet been widely deployed. According to the 5G-SDC (5G utilization type social
design promotion consortium) survey "Local 5G market research report (January 17,2023)", the full-scale diffusion period is expected after 2025. [4]
Sub6 is expected to continue to be introduced for the time being, but the bandwidththat can be used outdoors is limited to 100MHz. Shortages can easily be imagined.
Aiming for a future in which the 900MHz bandwidth allocated to millimeter wave iseffectively used in various social activities toward the full-scale spread of local 5G. , It
is necessary for the industry as a whole to prepare early so that it makes easier tointroduce millimeter wave..

69References[1] Ministry of Internal Affairs and Communications, Radio Policy Roundtable in theAge of Digital Transformation, 5G Business Design Working Group (1st Meeting)handout (January 24, 2023)
https://www.soumu.go.jp/main_content/000857640.pdf[2] Ministry of Internal Affairs and Communications, Information and Communications
Council New Generation Mobile Communication System Committee (12th)
Committee Report (Draft) Materials (Local 5G Related) Partially Used (April 12,2019)https://www.soumu.go.jp/main_content/000614449.pdf[3] Ministry of Internal Affairs and Communications, Information and Communications
Council, New Generation Mobile Communication System Committee (18th Meeting)Committee Report (Draft) Materials (Local 5G Related) (July 6, 2020)
https://www.soumu.go.jp/main_content/000697370.pdf[4] 5G utilization type society design promotion consortium (abbreviation: 5G-SDC),
from local 5G related market research report (January 17, 2023)
https://5g-sdc.jp/708Millimeter wave use caseIn the GSMA report, the main use cases for millimeter wave are three categories:"high-capacity high-speed transmission (eMBB) in facilities such as stadiums where
people gather", "FTTH replacement by FWA", and "Enterprise Networks". This chapter
describes use cases and those are divided into three categories.
As described in “Chapter 3 Issues in popularization of millimeter wave”, many current
use cases are satisfied with the performance of sub6. We think that those use cases would
require higher performance with larger capacity and lower delay in the future.
In addition to the cases described here, from the perspective of maximizing theadvantages of 5G in the future, it is expected to create a total use case that combines not
only the use of millimeter wave, but also various elements such as SA, network slicing,
MEC, AI, XR, Metaverse, etc.. At that time, it is also expected to utilize external
resources, including open innovation and M&A of startups.
8.1

eMBB

The use of millimeter wave in areas where people gather, such as sports stadiums,
concert venues, and airports, is expected to provide new value for applications that
require high-speed, large-capacity communications, and to supplement low-band andmid-band capacity. ¥ Examples of millimeter wave use cases for eMBB are described
below.
8.1.1
Entertainment
NFL Finals Exclusive Experience [1][2]Deploying 169 small cells, 4 macro cells, and 24 indoor systems in the stadium and its
surrounding area, it provides an entertainment experience utilizing C-band andmillimeter wave. It provides live and replay video that support up to seven camera angles,
player statistics using AR, and simultaneous experience-type AR games between local
fans using SNS applications.

Fig 8-1 5G millimeter wave small cell installed under the seat of the stadium71Fig 8-2 Live video replay video(5G Ultra Wideband users have more streams to watch)

New watching experience in soccer [3]"5G experience seats" will be installed in the main stand of "Toyota Stadium", utilizing
sub6 and millimeter wave, support information such as the number of shots and passesof each player will be displayed in the AR space through smart glasses and 5G compatible
smartphones installed in each seat. By doing so, we provide new experience value to theaudience.

Fig 8-3 Smart glasses and experience image
Exclusive experience at the theater [4]Installed 32 millimeter wave small cells on the premises of Taiwan's NTCH (National
Concert Hall) to build a private 5G coverage of 14,000 square meters. High-definition
live streaming distribution shot from multiple angles and locations, live video relay to a72

large 4K display installed outdoors, metaverse that reproduces the production of theperformance, immersive/interactive where the audience can interact with the on-site andonline. /Provide a multi-view theater experience.


Individually optimized signage for AR glasses [5]When users wearing AR glasses walk around town, individually optimized
advertisements are displayed on the glasses through image recognition and marker
recognition. The user's hobby and taste information registered in the cloud is matchedwith the content that the store wants to promote, and the corresponding video isdisplayed. Those encourage shop guidance by timely promoting products and gourmetthat users want. Since it requires high-speed, large-capacity communication, it isexpected to be used in millimeter wave in the future.


New information dissemination medium [6]Opened the Metaverse homepage to deliver service information. Visiting users canoperate their own avatars to check service information and the latest news. There is alsoa permanent event space dedicated to holding various events such as music and comedy.
In the event space, multiple users can enjoy live streaming of live music and other eventsat the same time, enabling live experiences with a sense of presence anytime, anywhere.
Since it requires high-speed, large-capacity communication, it is expected to be used inmillimeter wave in the future.

Fig 8-4 Image of Metaverse homepage
8.2

FWA

Economic and rapid deployment is expected by utilizing 5G FWA as an alternative to
FTTH in areas where FTTH is limited. Examples of millimeter wave use cases for FWA
are described below.

73

Provision of FWA in urban areas [7]

Utilizing 3.7GHz, 28GHz, and 39GHz 5G networks that are deployed for mobile use inurban areas, we provide FWA services as an alternative option to FTTH. Efficient
services are provided by utilizing networks already in place for mobile devices.
Provision of FWA in rural areas [8]

We provide FWA using 28GHz and 39GHz to eliminate the digital divide in rural areas.
It provides a communication speed of 300 Mbps (up to 1 Gbps is possible, but considers
the effects of trees and weather), and is estimated to be 40% cheaper than FTTH.

Fig 8-5 Image of provision of FWA
8.3

Enterprise networks

Use cases with large numbers of simultaneous accesses and high UL traffic areassumed in corporate buildings and manufacturing plants. The use of millimeter wave
in such places is expected to enable the simultaneous connection of many devices andthe increase in UL capacity. In addition, by taking advantage of the attenuation causedby shielding, which is a characteristics of millimeter wave, and using millimeter wave,
it is expected to operate closed networks with high confidentiality. Examples of
millimeter wave use cases for Enterprise Networks are described below.
8.3.1
Manufacturing industry

Sharing machine failure points from a remote location [9]When performing machine maintenance work, inexperienced maintenance personnel

could not make correct decisions based on manuals alone, and had to ask for instructions
from experts over the phone, delaying the recovery of the user's machine. Real-timesharing of information on failure points from remote locations through smart glasses has

74

produced significant effects, such as improving the quality of maintenance work andspeeding up the recovery of production at user companies. Since it requires high-speed,large-capacity communication, it is expected to be used in millimeter wave in the future.

Fig 8-6 Image of remote work supportQuality control in flash memory manufacturing factories [10]Deploying 5G millimeter wave solutions with local edge cores in semiconductor fabs.

With high bandwidth up to 2Gbps and ultra-low latency, applications for image-based
quality control such as operation and maintenance using high-resolution immersive
AR/VR glasses and automated visual inspection of chips were demonstrated.
Stable operation and smart factory using 4K video [11]By installing a high-definition ITV camera and a 5G base station to monitor the

production line in the factory and transmitting 4K video shot by the camera via 5G, theaccumulated video and various trends can be synchronized and analyzed. construction.
The video can be checked in real time on a 4K compatible monitor in the control room.
In the future, we aim to make various quality judgments by AI based on video andvarious trends.
8.3.2
Automobiles

Application to autonomous driving [12]A sub6 and millimeter wave 5G environment will be set up on test roads for researchand development of autonomous driving, etc., and by using images and surrounding
information acquired from high-definition in-vehicle cameras and roadside sensors, thevehicle and its surroundings will be understood more efficiently. We verified such asystem. In the future, it is expected to be used in fields such as autonomous driving
where it is necessary to communicate a wide variety of data according to priority.

75

8.3.3

Medical care

Introduction to medical research facilities [13]

By introducing millimeter wave and MEC, real-time data analysis supports decisionmaking, secures dedicated bandwidth to transfer huge data files such as 3D tumor
images, and realizes stable communication with many IoT devices and sensors.
Transmission of high-definition images between hospitals [14]1.

Using the highly secure closed network of MEC, it is possible to transmit datafrom medical equipment and high-definition video from cameras to hospitals inremote locations via high-speed, large-capacity 5G communication. By utilizing
the 5G telemedicine support system, for example, it will be possible to reduce thetravel time of both specialist doctors and patients who had to go to remote areas
for medical treatment, and to receive the same medical care in each region as inurban areas. Since it requires high-speed, large-capacity communication, it isexpected to be used in millimeter wave in the future.

Robot replaces sterilization work [15]A robot equipped with a germicidal lamp replaces the first action of disinfection work

for infectious disease control, which was under pressure on human resources, reduces
the physical and mental burden on medical workers.
In addition, the introduction of robots makes it possible to sterilize the hospital at amore appropriate timing, providing an efficient and less risky medical environment.

Fig 8-7 Image of sterilization work by robot768.3.4

Media

Broadcasting of news and sports by portable high-quality video transmission
equipment [16]It would be possible putting the video transmission device and battery in my rucksack,carrying the camera on shoulder and filmed. The video transmission equipment enables
high-quality video transmission by inserting multiple multi-carrier SIMs, catching
optimal millimeter wave, and bulk transmitting.
8.3.5
Public infrastructure

Patrol inspection and remote work support by drones and robots [17][18]In public infrastructure such as railways, airports, roads, electric power, gas, etc., it isused for patrol inspections by drones and robots, and remote work support by XR devices.
As an individual use case, for example, in railroad radio, priority is given to transmitting
data with high urgency for maintenance using sub6 while the train is running, and inareas such as stations where vehicles are densely packed, millimeter wave are used forlarge capacity transmission. It is expected that there will be needs for utilization suchas updating internal image data when trains stop at stations and updating service
information for passengers (news, weather forecasts, advertisements, etc.).
8.3.6


Agriculture

Approach to smart agriculture [19]The shortage of human resources and the difficulty of successors due to the progressof aging and population decline are major issues facing Japanese agriculture. To address
this issue, efforts are being made to implement smart agriculture using digitaltechnology. For example, using sub6 and millimeter wave, remote control of agricultural
machinery by level 3 automated driving that is "monitored by humans from a remotelocation" and remote sensing using drones to grasp the presence of pests and theappropriate harvest period without going to the site. Proof-of-concept experiments areunderway to prove that this is possible.

77

Fig 8-8 Drone flying over tea plantation

78

References[1] Verizon returns to Super Bowl to spotlight new 5G Internet expansion
https://www.verizon.com/about/news/verizon-super-bowl-new-5g-internetexpansion[2] At Super Bowl LV, 5G Will Change the Game
https://www.pcmag.com/news/at-the-super-bowl-5g-gives-you-7-ways-to-view-theaction[3] "au 5G" conversion of Toyota Stadium from Nagoya Grampus home opening gamehttps://news.kddi.com/kddi/corporate/newsrelease/2020/02/20/4281.html[4] How 5G is transforming live theatre
https://www.gsma.com/5GHub/images/5G-Case-Study-Smart-Theatre-digital.pdf[5] ZEPPELIN formed a business alliance with Dentsu Digital and KDDI. Started
providing AR platform "ARaddin"
https://prtimes.jp/main/html/rd/p/000000010.000036631.html[6] New information dissemination medium "Metaverse homepage" unveiled for the
first time! |SoftBank
https://www.softbank.jp/mobile/info/personal/news/service/20230428a/[7] Verizon expands 5G Home Internet and mobility to more customers | About
Verizonhttps://www.verizon.com/about/news/verizon-expands-5g-home-internet[8] UScellular Fixed Wireless Accesshttps://newsroom.uscellular.com/download/1133910/uscellular5gfixedwirelessaccess.pdf[9] Solutions for the manufacturing industry | docomo 5G | docomo business | NTT
Communications corporate customers
https://www.ntt.com/business/lp/5g/solution/production.htmlhttps://news.gm.com/newsroom.detail.html/Pages/news/us/en/2020/nov/1120-factory0[10] Singtel partners Micron to deploy commercial 5G millimetre wave solution at its
largest facility – a first in Singapore and for the semiconductor manufacturingsector
https://www.singtel.com/about-us/media-centre/news-releases/singtel-partnersmicron-to-deploy-commercial-5g-millimetre-wave[11] JFE Steel and KDDI to bring 5G to steel mills from April
https://news.kddi.com/kddi/corporate/newsrelease/2020/03/17/4319.html[12] DENSO and KDDI Begin Joint Verification Using 5G for Autonomous Driving toRealize a Safe and Secure Mobility Society79https://news.kddi.com/kddi/corporate/newsrelease/2021/03/03/4990.html[13] Private 5G Network from AT&T Now Connecting Researchers and Patients at
Lawrence J. Ellison Institute for Transformative Medicine of USC
https://about.att.com/story/2021/5g_ellison_institute.html[14] Medical Solutions | docomo 5G | docomo Business | NTT Communications
Corporate Customers
https://www.ntt.com/en/lp/5g/solution/medical.html[15] Robotics Solutions | docomo 5G | docomo Business | NTT Communications
Corporate Customers
https://www.ntt.com/en/lp/5g/solution/robot.html[16] LU800 – LiveU
https://www.liveu.tv/products/create/lu800[17] 5G business design WG Document 2-5 (slide 12)https://www.soumu.go.jp/main_content/000860115.pdf[18] Local 5G Realize a prosperous society by accelerating the DX of industries andlocal governments
https://jpn.nec.com/nsp/5g/local5g/index.html[19] Efforts for “smart agriculture” in Kagoshima
https://www.fujitsu.com/jp/innovation/5g/usecase/casestudies/horiguchi/

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9

Existing solutions for millimeter wave dissemination

In order to disseminate millimeter wave, it is important to be able to procure enoughdevices and measuring instruments for developing and manufacturing the equipmentthat constitutes the network. This chapter introduces solutions for terminals, basestations, antennas, measuring instruments, etc. based on actual product examples.
9.1

Terminal

As of December 2022, more than 170 products from more than 65 manufacturers havebeen released that support millimeter wave. As types of terminals, smartphones, PCs,
IoT devices such as IP cameras, mobile wireless LAN routers, modules, CPE (Customer
Premises Equipment), FWA, etc. are already available. At present, most smartphonesthat support millimeter wave are high-end models, but the number of types of terminals
that support millimeter wave is gradually increasing, and it is expected that it will
spread to mid-range models in the future. It is important to use millimeter wave not only
for general users but also for professional use cases. Therefore, some smartphones areequipped with an HDMI terminal as an interface for professionals and support highdefinition video transmission.
Since millimeter wave has very strong directivity, the strength of the radio waves canvary greatly depending on the direction in which the terminal aims. For terminal
reception, devices that dynamically respond to changing reception environments bygrasping and recording the radio wave environment over 360 degrees so that millimeterwave signals can be received from any direction., There is a beam management systemusing AI. There are also devices that perform management, making it possible to respondto changing environments and obstacles. There are also smartphones equipped with anapplication that assists in determining which direction the terminal is facing to receive
millimeter wave more easily.

81Fig. 9-1 Millimeter Wave CPE (by Nokia)

Fig. 9-2 Smartphones that support high-quality video transmission that supports
millimeter wave (by Sony)
9.2

Base station

Due to its radio wave propagation characteristics, millimeter wave requires higheffective isotropic radiated power (EIRP) in order to increase the propagation distance.

82Base stations with 60 dBm or more are already in the market, and downlink speeds of
10 Gbps have been achieved in commercial networks even when they are 10 km awayfrom CPE terminals. Along with the increase in EIRP of base stations, reductions in size,
weight and power consumption are also progressing at the same time. Wider bandwidths
are also being developed to accommodate wider frequency allocations, and it is alreadypossible to procure base stations with a continuous 800MHz bandwidth and noncontinuous 1.4GHz bandwidth (compatible with frequency separation class III) in themarket. In addition, many base stations need to be deployed in order to secure a certain
coverage. As a result, miniaturized base stations can be flexibly installed wherever they
are needed, and will play an important role in millimeter wave deployment. There arealso small base stations that are specialized for easy installation on streetlights. In
addition, millimeter wave has a large shielding loss, and it is generally difficult to
support indoor coverage from base stations installed outdoors, so base stations
specialized for indoor use are also being prepared.
Modem processors for base stations are emerging that have achieved miniaturization,
low cost, and low power consumption through SoC and modularization by diverting thedesign assets of modem RF for mobile stations.
The millimeter wave RU (Radio Unit) that supports ORAN is compact, lightweight,
and consumes low power. The built-in antenna device supports beamforming. Some
products have a dual-band configuration of Sub 6 and millimeter wave. In addition, byintegrating the radio unit (RU) and the control unit (CU/DU), a compact product has
been realized, enabling rapid network construction.

Fig. 9-3 Appearance of millimeter wave RU (by NEC, Fujitsu)

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9.3

Antenna device

The millimeter wave band allocated in Japan is the 28 GHz band, but there are regions
where 26 GHz, 39 GHz, and 41 GHz are available worldwide. There are products that
can handle these frequency bands with a single antenna module, and common devices
equipped with such modules can be used worldwide. There is also an commercialized
antenna module that enables radio wave radiation in two directions with one RFIC byforming an L-shaped multilayer resin board and placing antennas on each of the twoboards facing in different directions. It is expected to realize stable millimeter wave
wireless communication, reduce the number of communication devices, and contributeto thinner terminals and lower manufacturing costs.
A millimeter wave band phased array radio was developed using silicon CMOS
integrated circuit chips that can be mass-produced at low cost, and it is possible to control
the directivity of radio waves with a high degree of accuracy through the compensation
mechanism of phase/amplitude variation of high-frequency signals.

Fig. 9-4 L-shape Antenna Array Integrated Module (by Murata)

Fig. 9-5 In-terminal array of Antenna Array Integrated Module (by Murata)

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Fig. 9-6 Global Millimeter Wave band antenna modules (24 – 29 GHz & 39 – 41 GHz)
(by Qualcomm)9.4

Measurement evaluation equipment

Measurement and evaluation equipment and simulators are necessary whendeveloping RFICs, during evaluating equipment that incorporates RFICs, and when
confirming and verifying the actual performance of operating systems.
FR2 evaluation requires equipment with millimeter wave transmission / receptionfunctions that can support the physical layer between the terminal and the RU (gNB).
Various manufacturers have already prepared their equipment for each measurement
field.
9.4.1

FR2 terminal performance test

RF testing of terminals in FR2 uses over-the-air (OTA) testing because it is challenging
to connect cables and connectors.
Specification TS38.521-2 identifies OTA testing for 3GPP.For this measurement, youneed to use a gNB emulator that generates simulated radio signals from the base station
toward the terminal, a channel model emulator that simulates transmission spacecharacteristics, and a frequency converter from several GHz to FR2. A radio head andan anechoic box are required. In addition, the measurement evaluation in Chapter 5
describes the evaluation of terminal characteristics using this equipment.
9.4.2

FR2 area test

Unlike RFIC and equipment development, mobile network operators and system
integrators need to verify whether terminals operate as expected and are stress-freeunder actual usage conditions. Equipment that can analyze logs of communicationexchanges with base stations during actual operation is necessary. Each company
usually releases products with unique characteristics. There is a tool with dedicatedsoftware on mobile phones that records and analyzes logs in operating conditions. If theterminal used for evaluation supports FR2, it is possible to simultaneously record andanalyze communication logs among anchor LTE, FR1 and FR2 terminals, and basestations, depending on the connection status.

85

Fig. 9-7 FR2 monitor example on smart phone by Keysight Nemo Handy
9.4.3

Radio wave environment monitor

To ensure reliability for system integrators and service providers who deploy basestations for their local 5G service providers, it is important to conduct radio wave
environment surveys before the deployment and during operation. However, with 5G
deployment and operation, the analysis of interference signals becomes more complex.
This is because signals tend to appear in bursts and pulses based on traffic conditions.
As the sweep speed is slow and the dead time is difficult to predict, traditional spectrum
analyzers may not be able to capture everything. The detection may also become difficult
because the carrier signal masks the interfering signal.
A signal analyzer with a real-time spectrum analyzer (RTSA) is effective in solving
these challenges. Real-time spectrum analyzers use snapshot Fast Fourier Transform(FFT) techniques to simultaneously sample, compute, and process data.
Among battery-powered portable products suitable for on-site troubleshooting,products with a real-time bandwidth of 100 MHz or higher are already on the market.

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3GPP-compliant RF analysis tools are used for base station installation, operation andmaintenance, and inspection. A UE simulator that supports millimeter wave is alsoavailable with enabling base station and network testing.

Fig. 9-8 Network Installation and Maintenance Test Tools and Network Performance
Capacity Testers (by VIAVI)
9.5

Repeater

As mentioned in Chapters 4 and 5, one way to expand millimeter wave coverage is toinstall many small cells and repeaters. Small cells are more economical and can increase
capacity than building new towers, but they require backhaul installations, such as fiber,
which is a complex and expensive task. On the other hand, millimeter wave repeaters
are radio wave relay devices, which are simpler to install than small cells, and have theeffect of improving electric field strength and throughput by relaying radio waves toareas where radio waves cannot reach due to shielding materials. The relay method is a
non-regenerative system, and it is amplified and relayed from the base station side
(donor) to the terminal side (service) at 28 GHz without frequency conversion, and canoperate with extremely low latency.
In addition, there are products that have a built-in bidirectional amplifier that
automatically switches transmission and reception by receiving SSB signals periodicallytransmitted from the base station without using GPS. There are also smart repeatersthat are equipped with AI functions and are easy to install and cost-effective, and are
installed in LED street lights in the United States.

87Integrated antenna:•

Configuration with terminal counter antenna on the front side and base station
counter antenna on the back side (18×18×5cm)•

The base station counter antenna is a 32-element array antenna that automaticallysearches for base stations by beamforming
The terminal-to-terminal antenna is configured to be a four-element patch antennathat can radiate at a wide angle•

The main specifications are as follows.
oooSignal bandwidth: 400MHz
Base station counter (uplink) output EIRP): 42dBm/400MHz
Terminal-to-end (downlink) output (EIRP): 30dBm/400MHz
Fig. 9-9 Millimeter Wave Repeater (by DX Antenna)

88

Fig. 9-10 Millimeter wave repeater consisting of two enclosures, a donor unit and aservice unit (by FR-Tech)

89

10

Millimeter wave business outlook

As shown in Chapter 9, solutions such as millimeter wave network equipment,terminals, and measuring devices are in place, and the development of 5G utilizing theseis desired, but the deployment of millimeter wave networks, the spread of terminals, andthe development of services that make full use of their capabilities and characteristics
have been slow. From a situation where a negative chain reaction is occurring, how toconvert these into a positive reaction will be the key to future business outlook. This
chapter summarizes possible efforts to transform into a positive chain reaction.
10.1

Area development

From the viewpoint of millimeter wave utilization, equipment sophistication isimportant, and in order to solve the problems arising from propagation characteristics,
it is required that the introduction of RU (Radio Unit) that can improve thesophistication of beamforming, high efficiency, and low power consumption, and use a
NR-DC (Dual Connectivity) which combines Sub6 and millimeter wave. Currently, themain focus is on the introduction of Sub6, but the introduction of millimeter wave by NRDC is effective in introducing millimeter wave smoothly.
In order to smoothly promote millimeter wave infrastructure development, it isnecessary to promote infrastructure sharing and efficient investment utilizing existing
assets, and to support investment in disadvantaged areas through subsidies and othermeans.
In order to promote the use of millimeter wave, it is necessary to promptly develop
systems to enable the use of repeaters and high-power terminals, andto consider

speeding up and simplifying licensing procedures, such as making base station licenses
eligible for comprehensive licenses. In response to this, the Ministry of Internal Affairs
and Communications has already released a report on the technical conditions ofrepeaters and high-power terminals in June 2023[1], and it is expected that related
regulations will be developed as soon as possible.
In local 5G, since there is a high demand for the introduction of millimeter wave
standalone operation, implementation of standalone operation in millimeter wave iseffective. It is necessary to realize and introduce it to the market. Enhancement of theequipment lineup is also expected.
10.2

Promoting and supporting 5G/millimeter wave to other industries

Although there are many potential needs for 5G/millimeter wave in industries otherthan the mobile communications industry, many companies and organizations are not90

aware of its effectiveness, and even if they are, they are hesitant about how to utilize
and introduce it.
In addition, since many functions and parameters are stipulated as standard
specifications in order to make 5G systems universally available for various applications,special knowledge and skills are required to optimize and operate the system at the timeof introduction and after introduction. It is difficult for companies and organizations inother industries to implement by themselves.
Activities to appeal the effectiveness and use cases of 5G/millimeter wave to people insuch other industries, and support for system introduction will be the first key todissemination. Mobile network operators and local 5G operators are already responding
individually, but in order to promote the spread of 5G/millimeter wave in Japan andoverseas, it is necessary for mobile communications related ministries, companies, andorganizations to cooperate in this activity as a cooperative area.
10.3

Providing a place to promote the spread of millimeter wave

In view of the various factors discussed in this white paper, it is considered thatelements of R&D and service development remain in millimeter wave deployment. Firstof all, it is important to prepare a place where the benefits of millimeter wave can betested and demonstrated. It is important to provide such place to promote open
innovation. It is desirable that companies, organizations, and academia in all industries
can freely participate in these forums without charge and operate them as cooperative
areas. In addition, it is necessary to simplify and speed up licensing procedures.
10.3.1For consumer users

Millimeter wave base stations can be concentrated and deployed in typical places
where millimeter wave is required for consumer users (hot spots, stadiums, event venues,etc.), and high throughput can be maintained even in congested environments. Appeal
the effectiveness and have them experience it. By installing it in a place with high offroad demand, it is possible to recognize the difference between millimeter wave equipped
terminals and non-millimeter wave terminals. In order to extend millimeter wave
coverage at low cost, repeaters can also be utilized. Being able to experience using
smartphones and other devices sold in the market is an important factor. Using such aplace, we will hold events with millimeter wave + use cases and promote that it can beenjoyed on millimeter wave equipped terminals.

9110.3.2

Millimeter wave lab for consumer services developers

We will prepare an experimental environment to lead to the development anddeployment of high-quality services that can make use of millimeter wave such as XR on
the premise of using commercial networks of operators. It is not necessary to deploy inhigh-demand areas, and it is desirable that the conditions of traffic can be managed tosome extent. It differs from the millimeter wave area for general users in that it provides
an experimental environment such as for data acquisition.
10.3.3

Local 5G developer millimeter wave labs

The affinity with local 5G is described in Chapter 7. We prepare a place where you canactually experience use cases that can take advantage of the performance of millimeterwave. In this verification facility, local 5G system providers, OT (Operation Technology)
players and private network users will promote the effectiveness of millimeter wave. It
is also necessary to clarify the difference in characteristics from WiFi.
10.4

5G wireless human resource development

In order to promote the spread of 5G/millimeter wave, it is important to appeal theeffectiveness and support to other industries, but the current issue is the lack of humanresources who can promote it. In order to overcome this issue, it is extremely important
to develop human resources for 5G wireless networks. In addition to human resource
development on the 5G/millimeter wave provider, consideration should also be given tohuman resource development on the user side. In addition, efforts are required to develop
and secure human resources who can connect and combine users, companies,
universities, etc.

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Reference[1] "Technical Conditions for Relay Stations and High-Output Terminals for Expanding
the Use of

5G" among the "Technical Conditions for New Generation Mobile

Communication Systems" - Partial Report from the Information and Communications
Council https://www.soumu.go.jp/menu_news/s-news/01kiban14_02000597.html

93Conclusion
It is clear that the needs for 5G will become more diverse. The demand for higher
performance will increase in order to achieve continuous social development and asustainable society in the future. In order to realize this, the dissemination of millimeter
wave, which is a newly introduced frequency band from 5G, is the key and urgent issue
to bring a clear performance difference from 4G. This white paper, which was developedby millimeter wave promotion ad-hoc established within the 5G Mobile Promotion
Forum (5GMF), comprehensively incorporates the considerations and informationnecessary for the dissemination of millimeter wave. After grasping the current situationand issues such as why millimeter wave is necessary in the first place and why
millimeter wave is not widespread, we included information on technologies, use cases,
deployment scenarios, and available solutions that can address the issues. We also
focused on the affinity between local 5G and millimeter wave, which is expected to be
used in factories and facilities in Japan, and mentioned the synergistic effect ofpromoting their dissemination. We also included recommendations on how to work froma business and institutional perspective in order to promote the spread of millimeter
wave.
Based on this white paper, we, as an ad-hoc group will vigorously promote ourassessments aiming to the dissemination of millimeter wave. We hope that this white
paper will be useful not only for companies and/or organizations involved in 5G and local
5G, but also for people in all industries who are considering improving the efficiency of
their operations and expanding their business through the introduction of 5G. This white
paper also includes information on technologies and solutions that will benefit thedissemination of millimeter wave. Technological enhancement is necessary to improve
the performance of equipment and develop new use cases. Millimeter wave is also an
important frequency resource for 6G, and the lessons and learns obtained frommillimeter wave solutions, implementation and operation will be an important baseline
for frequency development that extends to sub-terahertz. For that reason, we would likethose people who are involved in research and development of future communication
technology in companies and academia to pay attention.
We plan to continue our studies and update the content of the white paper inMillimeter Wave Promotion Ad Hoc. We would appreciate receiving opinions,impressions, requests, and provision of information from those who read this white paper.

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Appendix (Existing solutions for the spread of millimeter wave List ofreference information links）
Terminal solution example
https://www.qualcomm.com/products/technology/modems/snapdragon-x65-5gmodem-rf-system
https://www.qualcomm.com/products/technology/modems/snapdragon-x70-modemrf-system
https://www.qualcomm.com/products/technology/modems/snapdragon-x75-5gmodem-rf-system
https://www.qualcomm.com/products/mobile/snapdragon/smartphones/snapdragon8-series-mobile-platforms/snapdragon-855-mobile-platform
https://www.qualcomm.com/products/mobile/snapdragon/smartphones/snapdragon8-series-mobile-platforms/snapdragon-870-5g-mobile-platform
https://www.qualcomm.com/products/mobile/snapdragon/pcs-andtablets/snapdragon-8-series-mobile-compute-platforms/snapdragon-8cx-gen-2-5gcompute-platform
https://www.qualcomm.com/products/mobile/snapdragon/pcs-andtablets/snapdragon-8-series-mobile-compute-platforms/snapdragon-8cx-gen-3compute-platform
https://www.qualcomm.com/products/technology/modems/snapdragon-x62-5gmodem-rf-system
https://www.nokia.com/networks/technologies/mmwave-fwa/
https://electronics.sony.com/mobile/smartphone/professionalsmartphones/p/xqaq62-b
Examples of base station solutions
https://www.fujitsu.com/global/products/network/solutions/5gran/https://jpn.nec.com/nsp/5g_vision/o-ran.html
https://jpn.nec.com/nsp/5g/local5g/product.html
https://www.nokia.com/networks/mobile-networks/airscale-radio-access/mmwaveradio/
https://www.nokia.com/blog/nokia-fixes-mmwave-wireless-access/https://www.nokia.com/about-us/news/releases/2021/06/08/nokia-qualcomm-anduscellular-hit-extended-range-5g-world-record-over-mmwave/
https://www.nokia.com/about-us/news/releases/2021/10/12/nokia-gives-fixed-95

wireless-access-a-boost-by-enabling-5g-mmwave-indoor-installations/
https://www.nokia.com/about-us/news/releases/2022/06/21/nokia-and-elisa-achieveover-2-gbps-5g-uplink-speeds-on-mmwave-with-qualcomm-solutions/
https://www.nokia.com/about-us/news/releases/2022/10/18/nokia-5g-mmwave-fwatechnology-selected-for-nbn-fixed-wireless-broadband/https://www.nokia.com/about-us/news/releases/2022/10/12/nokia-demonstratesimmersive-stadium-experience-with-5g-private-wireless-at-2022-tissot-uci-trackworld-championships/
https://www.nokia.com/about-us/news/releases/2022/11/15/nokia-and-tpg-telecomset-new-5g-uplink-speed-record-in-australia/
https://www.ericsson.com/en/small-cells/outdoor-coverage
https://www.ericsson.com/en/portfolio/networks/ericsson-radio-system/radio/smallcells/indoor/indoor-air-1279
Antenna device solution example
https://jpn.nec.com/press/201906/20190603_01.html
https://www.qualcomm.com/products/technology/modems/rf/qtm545
Measuring instrument solution example
https://www.viavisolutions.com/en-us/products/oneadvisor-800-wireless-platform
https://www.viavisolutions.com/en-us/products/tm500-network-tester
https://www.viavisolutions.com/en-us/products/tmlite-network-tester#overview
S8711A UXM 5G Test Application | Keysight
Nemo Handy Handheld Measurement Solution | Keysighthttps://www.keysight.com/us/en/cmp/use-case/5g-field-interference-hunting.html

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