Report Issued by the Study Group on the Integration ofSatellite Communications and 5G/Beyond 5G

January 2021
Study Group on the Integration of Satellite Communications and 5G/Beyond 5G
National Institute of Information and Communications Technology (NICT)Contents
Outline of conferences held by the Study Group ......................................................................................... 1
List of Abbreviations ..................................................................................................................................... 2
1.

Introduction........................................................................................................................................... 3

2.

Background behind the integration of satellites and 5G ....................................................................... 5

3.

4.

5.

2.1.

Key 5G technologies ...................................................................................................................... 5

2.2.

Expectations for the integration of satellites and 5G ..................................................................... 7

2.3.

Outline of European projects related to the integration of satellites and 5G ................................ 8

Studying use cases expected for the integration of satellites and 5G ................................................... 9
3.1.

Japan in the age of 5G/Beyond 5G ................................................................................................ 9

3.2.

Investigating use cases in Japan .................................................................................................. 11

3.3.

Summary of use cases.................................................................................................................. 15

Investigating initiatives concerning the integration of satellites and 5G ............................................ 18
4.1.

Effectiveness of the integration of satellites and 5G .................................................................... 18

4.2.

Investigating domestic trials ........................................................................................................ 27

Investigating standardization as it applies to the integration of satellites and 5G ............................. 32
5.1.

State of standardization concerning the integration of satellites and 5G as promoted by the 3GPP
32

5.2.

Investigating in connection with standardization ........................................................................ 35

6.

The concept of communication networks expected in Beyond 5G ..................................................... 37

7.

Conclusion ........................................................................................................................................... 38

Acknowledgements .................................................................................................................................... 41
Reference material ...................................................................................................................................... 42
Appendix: List of Members and Observers................................................................................................. 42※ When citing this document
This document was created at conferences of the Study Group on the Integration of Satellite
Communications and 5G/Beyond 5G as held by the National Institute of Information andCommunications Technology (NICT). This document should be clearly specified as the source whenever
it is cited or referenced.
January 2021
National Institute of Information and Communications Technology (NICT)Outline of conferences held by the Study Group
ConferenceFirst

Date and time, location, attendees
Date and time: August 29, 2019 (Thursday); 14:00 to 16:30

Agenda(1)

Explanation of the main objectives

Location: NICT Otemachi Conference Room (Innovation Center TCR)

being pursued by the Study Group

Attendees: Outside members: 28 individuals from 15 organizations, 4

and a specification of the theme ofindividuals from 2 observer organizations

the first conference(2)Group discussions(3)

Presentation given by andquestioning of each group

SecondDate and time: September 26, 2019 (Thursday); 14:00 to 17:00(1)

Explanation of the main objectives

Location: TKP Tokyo Station Nihonbashi Conference Center (Conference

being pursued by the Study Group

Room 322)

and a specification of the theme of

Attendees: Outside members: 29 individuals from 15 organizations, 2

the second conference

individuals from 2 observer organizations(2)

Introduction of satellite-based 5G
technology(3)Group discussions(4)

Presentation given by andquestioning of each group

Third

Date and time: October 25, 2019 (Friday); 13:30 to 17:00(1) Plenary session

Location: TKP Tokyo Station Nihonbashi Conference Center (Hall 316)

(2) Group discussions

Attendees: Outside members: 29 individuals from 16 organizations, 3(3) Presentation given by andindividuals from 2 observer organizations
Fourthquestioning of each group

Date and time: November 28, 2019 (Thursday); 14:00 to 16:30(1)

Location: TKP Tokyo Station Nihonbashi Conference Center (Hall 316)

the third conference and a

Attendees: Outside members: 28 individuals from 17 organizations, 4

specification of the theme for theindividuals from 2 observer organizations

Fifth

Overview of discussions held up to

fourth conference

Date and time: January 23, 2020 (Thursday); 15:00 to 17:00
Location: NICT Otemachi Conference Room (Innovation Center)
Attendees: Outside members: 29 individuals from 17 organizations, 6
individuals from 2 observer organizations

1(2)

Standardization study(3)

Trial study(4)

Approach to compiling this report(5)

Other matters(1) Checking of the Study Group Report(draft)(2) Other matters

List of Abbreviations

・3GPP：Third Generation Partnership Project・5G：Fifth-generation mobile communication system
・5GPPP：5G Infrastructure Public Private Partnership
・ASIC：Application specific integrated circuit
・ARTES：Advanced Research in Telecommunications Systems
・BER：Bit error rate
・D2D：Device to Device
・DVB-S2X：Digital Video Broadcasting - Second Generation Satellite Extensions
・eMBB：enhanced Mobile Broadband
・ESA：European Space Agency
・EIRP：Equivalent isotropically radiated power
・ETSI：European Telecommunications Standards Institute
・GEO：Geostationary orbit
・gNB：Next-generation Node B
・HAPS：High Altitude Platform Station
・HTS：High throughput satellite
・IoT：Internet of Things
・LAN：Local Area Network
・LEO：Low earth orbit
・MEC：Mobile edge computing
・MEO：Medium earth orbit
・MIMO：Multiple-input and multiple-output
・NFV：Network functions virtualization
・NR：New Radio・NTN：Non-Terrestrial Networks
・QoS：Quality of service
・RAN：Radio Access Network
・SDN：Software-defined networking
・TR：Technical Report
・TS：Technical Specification
・TSG RAN：Technical Specification Group Radio Access Network
・TSG SA：Technical Specification Group Service and System Aspects
・URLLC：Ultra-Reliable and Low Latency Communications
・VM：Virtual Machine
・VNF：Virtual Network Function

2

1.

Introduction
With the impending arrival of the fifth generation of mobile communications (5G), the role to be playedby satellite communications in the context of 5G is drawing attention. In Europe in particular, joint publicprivate projects are actively being implemented, and studies are being carried out on satellite connections
with respect to the standardization of 5G within the 3GPP.
On the other hand, activities for the introduction of 5G in Japan are proceeding at a dynamic pace, but
no studies on the use cases and technologies in which satellite communications have been integrated with
5G to that end have begun (*In response to the recent mention by Ministry of Internal Affairs andCommunications of connections with satellite and HAPS for communication area expansion as a policy of
Beyond 5G on June 2020, the studies have begun in Japan). Satellite communications have traditionallybeen effective for services that take advantage of broad spectrums and multicasting and broadcasting
characteristics, emergency communications employed in the event of a disaster, and broadband services
for moving bodies, such as ships and aircraft. In recent years, we have achieved high-speed, high-capacity
flexible link control and a reduction in the costs of communications and have seen expectations for
improved satellite services rising thanks to high-capacity satellites, such as high-throughput satellites (HTS)
based on the use of multi-beam technology for which empirical testing with Engineering Test Satellite-9
has been planned with mega-constellations comprising a large number of low-orbit satellites described as
being on the cusp of commercial viability.
Under these circumstances, the Basic Space Planning Schedule (revised in fiscal year 2019) clearly statedthat empirical testing tied to 5G, the IoT, and other terrestrial systems would be conducted on Engineering
Test Satellite-9.[1] In addition, the 2019 Workshop on Integrating 5G with Satellite Communications washeld in March 2019 by the NICT with concerned parties from Europe and Japan. The updated status ofproject activities being conducted in Europe for which studies had been carried out in advance (European
projects), along with the fact that integration with satellite communications in the context ofstandardization activities related to 5G was being investigated by the 3GPP, were reported to concerned
parties in Japan. This was followed up by a Conference for the Sharing of Opinions on the Integration ofSatellites and 5G, which was held in May and June 2019. Discussions led to a decision to hold conferencesof the Study Group on the Integration of Satellite Communications and 5G/Beyond 5G, which consists ofdomestic terrestrial and satellite communications providers, manufacturers, potential users, research
institutes, and other parties, and which operates with the objective of engaging in more specific studies of,among other matters, effective use cases facilitated by integrating 5G with satellite communications,necessary technical issues and implementation methods, evaluations and demonstrations, andstandardization with a view to also establishing connections with earlier European projects.
Conferences of the Study Group were held a total of five times by the NICT between August 2019 andFebruary 2020. Effective use cases were studied at the first conference. At the second conference, thetechnologies required for integrating satellites with 5G were introduced, use cases were accordingly divided
into three categories (smart cities, mobility, and emergency disaster response), and system concepts were3

investigated. For the third conference, the effectiveness of systems studied at the second conference, as
well as technical challenges and matters concerning future standardization, were studied. Expected use
cases and matters concerning standardization were examined at the fourth conference, and the results ofthese studies as carried out by the Study Group were summarized at the fifth conference.
The contents of these studies as carried out by the Study Group are hereby presented in this report.

This report has updated several points to reflect changes in circumstances that have occurred since theend of the Study Group.

4

2.

Background behind the integration of satellites and 5G
In this chapter, we will first look at key 5G technologies that European projects seek to incorporate into

the integration of satellites and 5G as a way to provide some context behind the integration of satellite
communications and 5G. Next, we will outline recent changes in terms of circumstances as a way to provide
some context to explain how the integration of satellites and 5G came to be expected. Subsequently, anoutline of European projects will be given to indicate trends in the development of the integration ofsatellite communications with 5G. Finally, network architecture for the integration of satellites and 5G for
which key 5G technologies have been deployed will be mentioned.
2.1.

Key 5G technologies

In this section, key 5G technologies will be discussed. European projects to integrate satellites and 5G
aim to apply the following technologies, which are to be deployed with 5G, to satellites.
 SDN (Software Defined Network)
・Dynamically controls network configuration, functions, performance, and more with software.
・Consolidates functions for controlling network equipment.
・ Enables network operations to be changed by dynamically changing network configurations
according to traffic status and app requests.
・Enables reductions in operating costs and capital investment costs for managing equipment settings.
 NFV (Network Function Virtualization)
・Technology that expands virtualization technology into network infrastructure. Decouples software
functions from dedicated hardware and runs them on general-purpose servers as VNF (virtual
network function) software.
・Launches a VM (virtual machine) and controls network equipment functions to realize network
functions on general-purpose servers with the use of virtualization technology.
・Can expect to improve the flexibility of an entire system, reduce hardware costs, and improve the rateof operation.
 Network slicing
・Technology realized by SDN/NFV as basic elements.
・Technology that multiplexes virtual independent logical networks onto the same physical networkarchitecture.
 Orchestration
・Network services and resources are managed and controlled on an integrated basis and optimized.
・Time spent on processes is shortened by rapidly and flexibly allocating networks and resources.
 Edge computing
・Technology for lower latency, high-volume data processing, and the offloading of terminal loads.
・Elevating the multicasting and broadcasting functions of satellites.

5An outline of network slicing is depicted in Figure 2-1, use cases are shown in Figure 2-2, andimplementation methods are presented in Figure 2-3.[2] The application of these technologies is also
expected to have a significant impact on the integration of satellites and 5G.

Figure 2-1: Outline of network slicing[2]Figure 2-2: Network slicing use cases[2]6Figure 2-3: Methods for implementing network slicing[2]2.2.

Expectations for the integration of satellites and 5G

As presented in Figure 2-4, there are at least three motivations to consider the need for integrating
satellites and 5G. The first is the evolution of satellite communications. In recent years, we have seen lowercost, faster, higher-capacity links being offered as made possible by increasing the frequency utilization
efficiency through the emergence of high-throughput satellites (HTS) outfitted with large numbers ofmulti-beams and the implementation of plans for mega-constellations comprising huge numbers of lowearth orbit (LEO) satellites, and terminals becoming significantly miniaturized and consuming less power.
Next, by deploying the softwarization and virtualization of networks, network slicing, and orchestration
technologies characterizing 5G technology as noted in 2.1 into satellite systems, it is possible to realize theintegration of satellite communications and 5G efficiently.
The last is standardization. The architecture of satellite communications has to date been built
independent of terrestrial systems, and no efforts to standardize connections with terrestrial systems haveever been undertaken. With 5G, however, standardization encompassing non-terrestrial networks (NTN)with the inclusion of satellites has been pursued through the 3GPP, and unprecedented developments canbe seen in this area. Accordingly, progress in terms of the adoption of plug & play features anddevelopment of ASICs can be expected as non-terrestrial networks continue to undergo standardization.
Against this backdrop, groundbreaking improvements to conventional use cases and the creation of use
cases that have never before been seen can be conceivably expected through the integration of satellite7communications and 5G.

Evolution of satellite communications (HTS,
mega-constellations, and more) Significant reduction in line costs
 Faster, higher capacity, lower latency
 Evolution of terminals (e.g., small, lightweight,
inexpensive, and low power consumption)

 Expanding 5G coverage Expanding use into space (satellites, HAPS,UAS, drones, space planes, and more) Expanding the normal use of satellite lines (coexistence with terrestrial systems) Globalization and expanding the use ofsatellite IoT and moving IoT

Deployment of 5G technology in satellite
systems (non-terrestrial systems)
 SDN/NFV Network slicing
 Network orchestration
 Edge computing

 Multi-links and seamless connections among
heterogeneous networks
 Flexible integrated networks, incorporating plugand-play features into satellites
 Reducing equipment costs and operating costs

Standardization
 Standardization of terrestrial and non-terrestrial
systems through the 3GPP/ETSI Systemization for the realization of various use
cases (e.g., in-flight use of smartphones)
 Sharing of frequencies in the context of using the
28 GHz band

Integrated network
based on satellites,
non-terrestrial systems+ 5G
Emergence of
unprecedented use cases
 Smart cities
 Mobility
 Emergency
communications

 Emergence of chipsets for non-terrestrial air
interfaces based on standardization
 Systemization for the realization of various use
cases (e.g., in-flight use of smartphones, unmannedsystems)

Figure 2-4: Motivations for the integration of satellites and 5G
2.3.

Outline of European projects related to the integration of satellites and 5G

In Europe, development programs for the integration of satellites and 5G have been active since around2015. As shown in Figure 2-5, the Horizon 2020 program has been operating SaT5G,[3][4] which waslaunched in 2017 as a large consortium, and the European Space Agency (ESA) promoted SATis5[5] throughthe independent ARTES program. Horizon 2020 also launched a joint EU-South Korean project (5GALLSTAR[6]) in 2018 while a new project (Space 19+[7]) was proposed through the ESAʼs ARTES program in
2019. In these and other ways, initiatives have been ongoing.

EuropeanCommission (EC)

Horizon 2020
(Research andinnovation program)

VITAL project(Feb.2015 30months)

5G-PPP(Research Program)

SaT5G Consortium(June 2017 ~ Nov. 2019)

NetWorld2020(European Technology Platform)
SATCOM WG

5G-VINNI Consortium(July 2018, 36months)

ESA ARTES
Research Program

SATis5 program

Figure 2-5: Activities for the integration of satellites and 5G in Europe83.

Studying use cases expected for the integration of satellites and 5G

3.1.

Japan in the age of 5G/Beyond 5G

In Japan in the age of 5G/Beyond 5G (2020 to 2040), the following circumstances are envisaged, andvarious challenges are expected to arise.
・ Japanʼs population has been declining since it peaked in 2005 and is expected to decline toapproximately 111 million people by 2040 (Figure 3-1).
・Super-aging society (approximately 40% of the population are elderly).
・Changes in social structure.
・More elderly people are living alone or with low levels of income.
・Elderly people account for about half of the consumer market.
・Municipalities and tangible goods are disappearing throughout the country.
・Shortages of retail outlets in rural areas are increasing.
・A shrinking population of productive-age workers is making it harder to maintain productivity.
・At the same time, the need is growing for remote medicine, autonomous driving options, and online
shopping services (home delivery) in areas where conditions are unfavorable.
・Measures to improve productivity are a challenge.
As indicated in Figure 3-2, inhabited areas are projected to become uninhabited over time as outlined
below.
・Approximately 20% of areas currently inhabited by people will become uninhabited by 2050.
・While approximately 50% of the country is currently inhabited, this figure will drop to approximately
40%.

9Figure 3-1: Changes in the aggregate population of Japan (three age brackets)[8]Figure 3-2: Changes in inhabited areas and uninhabited areas[8]

10

3.2.

Investigating use cases in Japan

In investigating use cases for integrating satellites and 5G in Japan, the state of communications basedon an assumption of circumstances described in the preceding section will need to be investigated. In thisconnection, it was decided that the use of the integration of satellites and 5G to address challenges facing
Japan that are slated to emerge by around 2040 would be treated as one of the central themes. In addition,
while various fields might be expected to constitute fields of use cases, it was thought that IoT, smart cities,
transportation infrastructure in the maritime and aviation sectors, and emergency disaster response are
effective use cases.
In this connection, use cases for satellite-based 5G were discussed by the Study Group with a focus on
the following five themes:


Theme 1: Use of satellite-based 5G to address challenges that Japan faces and that will emerge byaround 2040



Theme 2: Use of satellite-based 5G in the age of the Internet of Things (IoT)

Theme 3: Use of satellite-based 5G for realizing smart cities



Theme 4: Use of satellite-based 5G in the maritime and aviation sectors and for transportation
infrastructure

Theme 5: Use of satellite-based 5G in responding to emergency disasters

In investigating use cases, use cases investigated through the earlier 3GPP were referenced. The resultsof investigations carried out through the 3GPP are set forth in Chapter 5 of TR22.822, and various use cases
have been broken down into twelve different use case categories.[9] The relationship between use cases
investigated through the 3GPP and the aforementioned investigative themes for discussion by the Study
Group are presented in Figure 3-3.

11

Use cases in the 3GPP TR22.822
5.1 Roaming between
terrestrial and satellite
networks

System for tracking location andmonitoring information using
terminals attached to shipping
company containers.

5.2 Broadband and multicast
with a satellite overlay

Transmitting TV and digitalcontent through mobile networks.

5.3 Internet of Things with asatellite network

IoT with satellites and terrestrial
coverage (with the assumptionthat satellites belong to LEO
constellations).

Investigative themes for discussion

1. Use of satellite-based 5G toaddress challenges that Japan faces
and that will emerge by around 2040

Satellite use in disasters and other
5.4 Temporary use of a satellite
emergencies. Applicable network
component
slices are available.
5.5 Optimal routing or steeringover a satellite

2. Use of satellite-based 5G in theage of the IoT

Services classified according tolatency requirements when using
satellites.

Seamless connection via satellite
5.6 Satellite transborder service
and terrestrial roaming while oncontinuity
the move.
5.7 Global satellite overlay

3. Use of satellite-based 5G forｓrealizing smart cities

Use of satellite constellations for
global, long-distancetransmissions is effective.

Relay UE allows regular 5G UE to
5.8 Indirect connection throughbe rendered accessible toa 5G satellite access network
satellites.
5.9 5G Fixed backhaul between
NR and the 5G core

5.10 5G Moving Platform
Backhaul

5.11 5G to Premises
5.12 Satellite connection of
remote service center tooffshore wind farm

4. Use of satellites-based 5G in themaritime and aviation sectors andfor transportation infrastructure

Using satellites as a backhaul
between 5G core and NR.
Entertainment, Internet service,and business services provided byrailway companies.
Satellite/terrestrial switching ispossible.
Providing satellite-based
broadcasting/multicasting services
and terrestrial 5G service tovillages in remote areas.

5. Use of satellites-based 5G in
responding to emergency disasters

Satellite-based IoT, high-capacity
data transmission.

Figure 3-3: Relationship between use cases investigated through the 3GPP and the investigative themes
for discussion

The contents of discussions concerning Theme 1, which is a high-level concept, and Themes 2 through5 are presented below.
Theme 1 + Theme 2: Use of satellite-based 5G in the age of the IoT● Summary of discussion contents
・Utilization for IoT.
・Ways of using in uninhabited places will become new ways of using satellites.
・Deploying traffic lights as satellite-based 5G base stations.
・Use cases that leverage the ability of satellites to cover wide areas and broadcast content.
・Satellites as a means of expanding area coverage.
・Data collection through sensor network systems.
・Disseminating satellite communications through the simplification of link-construction methods.

12

・Direct communications with satellites based on the use of mobile terminals.
・Landslide detection using local IoT systems, dam monitoring, and maritime communications.
Theme 1 + Theme 3: Use of satellite-based 5G for realizing smart cities● Summary of discussion contents
・Converting depopulated areas into smart cities.
・Developing communications infrastructure to attract tourists to depopulated areas.
・Providing emergency notifications and medical services to depopulated areas.
・Applying network slicing to emergency links and other links, such as YouTube, when traffic is concentrated
in the event of a disaster.
・High level of point-to-point confidentiality.
・Urban planning based on the use of earth observation image data created in LEO.
・Harnessing satellites and HAPS to cover space that cannot be covered by 5G.
・Use cases in which the advanced security features of 5G have been used (advanced security that is
unsupported by Wi-Fi).
● Specific examples of use cases and services
Security measures for personal information
Medical Monitoring of the Elderly
・Communication links for tourists in depopulated areas
1. Simultaneous multiple-count use at tourist attractions
2. Accommodation facilities in depopulated areas
・Emergency notifications and remote medical services for residents of depopulated areas
1. Security measures applicable to personal information
2. Medical monitoring of elderly persons
・Monitoring of the natural environment
1. Collecting information for predicting natural disasters using distributed installed sensors
2. Providing information on disasters to tourists
・Urban planning in depopulated areas
1. Urban planning that combines positioning and communications
2. Expanding 5G coverage across the sky with satellites and HAPS
● Concerns
・Delays in the adoption of 5G due to insufficient funds available to local governments.
・Poor usability of satellite terminals.
・Not easy to ascertain the radio wave environment as required to expand coverage in areas of the sky bysatellites and HAPS.
Theme 1 + Theme 4: Use of satellite-based 5G in the maritime and aviation sectors and for transportation
infrastructure13

● Summary of discussion contents
・A communications infrastructure to accommodate the distribution of smaller cities is required.
・Satellites are needed for maritime and aviation purposes but the scope of usage can be expected to groweven further in the future as 5G continues to be adopted.
・While satellites are needed as a terrestrial backup option, low latency is an issue.
・Low-orbit satellites and HAPS provide low latency, which means that they can be expected to function
as disaster-resistant base stations.
・Using in order to maintain bus routes in rural areas.
・Remotely carrying out construction in depopulated areas by satellite.
・Broadcasting services through 5G multicasting.
・Satellites should ideally be operated as core infrastructure in accordance with the relevant national policy(and can also be used as infrastructure for autonomous driving).
・Costs of satellite links are high.
・5G base stations reduced through the use of multi-beam satellites.
● Investigating use cases
・It is difficult to currently connect aircraft services. Ship and aircraft services need to accommodate higher
speeds and higher capacities (such as through the application of beamforming).
・Application to flying cars.
・Support for autonomous driving in areas that cannot receive terrestrial coverage.
・Incorporating satellites into a seamless system of logistics by sea, air, and land.
Theme 1 + Theme 5: Use of satellite-based 5G in responding to emergency disasters● Summary of discussion contents
・Expanding 5G coverage.
・Maintaining seamless connections.
・Temporary infrastructure backups.
● Contents of Theme 1 discussions
・Autonomous driving: Effective in rural areas where the population is shrinking.
・Improving end-to-end communications.
・While the population will shrink in the future, there will still be people, which means that the expansionof areas receiving 5G coverage is important; remote medicine will also be required.
・High-functionality at sea.
・Maritime IoT.
・Beyond line-of-sight drone operations by satellite.
・Using satellites for local 5G (such as on construction sites).
・Autonomous robots.
・Support for foreign workers: Using satellites where 5G coverage is not available in areas where thepopulation is declining (such as for the provision of translation services).

14

・Using satellites as backhaul components for terrestrial base stations.
・Using satellites as a maintenance-free option for base stations: The maintenance of base stations imposesa significant burden; satellite backup is an effective option.
・Drones and HAPS as backup options.
・Enhancing communications infrastructure: Effective if flexible coverage and multiple frequencies can beused.
・Wide-area IoT.
・Using satellites for temporary base stations.
・Large-scale agriculture.
● Contents of Theme 5 discussions
・Connecting D2D and smartphone relays to satellites: Satellite costs are an issue.
・Current smartphones can be connected even in the event of a disaster (low speed is acceptable).
・Disaster countermeasures based on the use of IoT terminals.
・Seamless terminals (dual).
・Backup option for remote islands.
・Specially installed public telephones.
・Applications for which terrestrial coverage cannot be provided: resource management, increased capacity,
lower costs.
・Always available earth observations (disaster prediction).
・Using observation satellites in the event of a disaster.
3.3.

Summary of use cases

Since there were differences in levels corresponding to themes discussed in the preceding section, theme
categories were carefully examined, whereupon each theme was reclassified in accordance with thefollowing three categories as presented in Figure 3-4. The correspondence of use cases discussed in thepreceding section and these categories is shown in Table 3-1.
Category A: Smart cities

Category B: Mobility

Category C: Emergency disaster response

15

ThemesUse of satellite-based 5G to address
challenges that Japan faces and that will
emerge by around 2040

Categories

・Contents concerning future depopulation measuresand regional development.

Use of satellite-based 5G in the age of
the IoT

Smart cities

・IoT is classified as a use case in each category becauseof the similarity of its contents to the form of use.

Use of satellite-based 5G for realizing
smart cities

Mobility

・QoL-related contents encompassing future cities and regions.

Use of satellite-based 5G in themaritime and aviation sectors and fortransportation infrastructure

Emergency disaster
response

・Name changed because of contents reflecting a future
expansion of the means and range of mobility.

Use of satellite-based 5G in responding
to emergency disasters
・Independent contents to address challenges arising ina disaster.

Figure 3-4: Reclassifying use case themes

16

Table 3-1: Summary of use cases
Category

Use cases

A: Smart cities

・Various types of data communication services based on the use of satellite terminals installed attraffic lights on roads and 5G terminal base stations.
・High-speed communication links that can be simultaneously used by a large number of people attourist sites.
・Providing 5G service to hotels and other such establishments.
・Providing information for tourists through the monitoring of the natural environment.
・Urban planning that combines LEO satellite images, positioning information, and communications.
・Broadcasting alternatives based on the use of satellite multicasting.
・Autonomous driving (effective in rural areas where the population is shrinking).
・While the population will shrink in the future, there will still be people, which means that the
expansion of areas receiving 5G coverage is important; remote medicine will also be required.
・Autonomous robots.
・Using satellites for local 5G (such as on construction sites).
・Support for foreign workers (such as translation services where 5G coverage is not available in areas
where the population is declining).
・Using satellites for temporary base stations.
・Large-scale agriculture.
・Using satellites as a maintenance-free option for base stations.
・Backup option for remote islands.

B: Mobility

・Collecting monitoring data obtained by various types of equipment on board ships (including engine
system and measurement systems).
・Expanding 5G services to the sky (space) with satellites and HAPS.
・High-speed, higher-capacity, and lower-cost aircraft communications.
・Flying cars.
・Seamless management of logistics in logistics systems at sea and on land, and IoT utilization.
・Autonomous driving.
・Beyond line-of-sight drone operations by satellite.

C: Emergency disaster
response

・Landslides, dam monitoring, and more.
・Collecting and providing information for predicting natural disasters using sensors installed in a
distributed pattern.
・Backhauling with LEO satellites and HAPS in the event of a disaster.
・Connecting D2D smartphone relays to satellites (current smartphones connect directly).
・Observing disaster conditions with the IoT (terrestrial systems cannot be used).
・Always available earth observations (disaster prediction, disaster observation).

17

4.

Investigating initiatives concerning the integration of satellites and 5G
In this chapter, the benefits of the integration of satellites and 5G for users, technologies for the

integration of satellites and 5G as required for realization, the validity of and evaluation items assessed indomestic trials, and the results of investigations into technologies to be confirmed are indicated withrespect to use cases in each category based on discussions related to use cases as mentioned in thepreceding chapter.
4.1.

Effectiveness of the integration of satellites and 5G

We studied a conceptual diagram of systems involved in the integration of satellites and 5G in order torealize use cases in each category, and investigated effectiveness in the event that the integration ofsatellites and 5G is adopted and the technical issues that are relevant for this realization. The results of ourinvestigation are presented below:
Category A: Smart cities

Figure 4-1: Conceptual diagram of systems involved in smart cities● Conceptual diagram of systems: Figure 4-1● Investigating system concepts
・Backhaul uses.
・Where there are no alternative means other than satellites.
・Hypothesizing that the unit price of satellite communications will go down (and that systems based on
the use of large numbers of satellites will also emerge).
18

・Softwarization of networks (networks will be built even with general-purpose components by noncommunication carriers).
・Slicing technology permits the use of multiple satellites (GEO, LEO) according to the application.
● Investigating use case benefits (summary)・Creating spot areas in rural areas and other locations lacking a terrestrial network.
・Ad-hoc network construction in response to demand.
・The maritime use of satellites (unmanned ships, remote islands, uninhabited islands) is effective.
・Unmanned convenience stores (video, sensor data).
・Use with IoT: Monitoring birds and animals with sensors and cameras, accident measures.
・Lower latency in entertainment and financial applications.
・Greater efficiency through MEC processing of satellite image data.
・Remote medicine, operating heavy machinery on a remote basis, agricultural automation.
・Eliminating public and private network congestion through the use of slicing and effectively transmitting
aircraft passenger links and aircraft management links.
● Technical issues
・The 5G core needs to be a protocol that takes latency into account.
・For use cases that require low latency, a connection to LEO is essential and latency parameters fordifferent slices also need to be adjusted.
・Handover control between a satellite system and a terrestrial system is required.
・The interface between satellite terminals and 5G base stations needs to be considered.
・Priority control at the application level is required.
・Using Q/V bands and other high frequencies.
● Effectiveness of adopting satellite-based 5G technologies
Providing 5G services to areas where terrestrial systems have not been adequately developed, such as
remote islands, mountainous areas, and national parks.
● Concerns
・Whether it is acceptable to use general-purpose options for terminals and modems and whether there
are any new research and development elements.
・Whether it is possible to configure parameters applicable to a local 5G base station from a network slicer.
Category B: Mobility

19• The gNB configuration is considered inaccordance with the business model.
Not dependent on the type of mobility• Avoiding interference will improve
the spectrum efficiency.

gNB

f1

f1

f1

f2

f2

f2

f2

fn

fn

fn

fn

・・・

f1

UE

• Assumed to be for directcommunications rather thanfor backhaul use.

UE

UE
gNB

UE

CN

• Local 5G deployment in
the mobility.

Figure 4-2: Conceptual diagram of systems involved in mobility● Conceptual diagram of systems: Figure 4-2● Investigating use case benefits
・Wireless repeaters enable the conversion of in-flight user communications and satellite communications.
・Centralized management of communications (benefit of having network operators).
・Accommodating high-capacity video data and power-saving IoT (load management) with slicing.
・Allocating satellite beams to aircraft through higher satellite capacity and beamforming technology.
・LEO satellites are more advantageous than GEO satellites in terms of spatial separation.
・Beam/satellite switching is possible with handover technology.
・Some applications allow for satellite delays.
● Effectiveness through the adoption of satellite-based 5G technologies(a) QoS・Setting the priority levels for services with network slicing.
・Whether it is possible to share high-value-added, secure communications and general services.
(b) Interference avoidance・Whether it is possible to avoid interference between beams and between beams and terrestrial cells
using 5G technology.
・Whether it is possible to help small antennas, for which side lobe suppression is difficult to achieve, avoid
interference and whether it is possible to efficiently use the 28 GHz band.
・Whether interference-avoidance technology for communicating with terminals in the context of large
numbers of base stations in 5G can be applied to the integration of satellites and 5G.

20

(c) Efficient use of LEO/MEO systems
・Whether satellite-based 5G technologies can be used for the management of resources for an entire LEO
satellite network.
・Network control methods need to be investigated.
● Technical issues and concerns
・Adjacent satellites and adjacent beams will be visible since antennas mounted on mobility systems are
small in size, and off-axis radiation increases.
・Realization of three-dimensional frequency management and seamless movements.
・Total management of terrestrial and satellite systems.
・Narrowing of beam and power saving achieved for earth station antennas.
・Using the Q/V band and other high frequencies.
・Upgrading multi-beam technology.
・Applying massive MIMO technology.
Category C: Emergency disaster response

Figure 4-3: Conceptual diagram of systems involved in emergency disasters● Conceptual diagram of systems: Figure 4-3● System objectives
・Means of communications can be flexibly selected according to the state of the disaster area in the eventof a disaster.
・Ensuring the minimal necessary communications with smartphones that are normally used.
● Investigating use case benefits

21

・Disaster victims and relief organizations for end-user disaster relief and monitoring by local governments.
・Service providers and telecommunications carriers.
(a) Benefits in terms of disaster relief
・Management for discovering victims (detection confirmation, rescue means, transmission, and othermatters).
・Safety confirmation through the use of smartphones.
・Collecting information with drones (aerial photograph, data mule).
・High-definition video (such as 4K) is transmitted through D2D.
・Rapidly transmitting video information from the sky above to emergency headquarters in order to verify
the state of a disaster-affected area.
(b) Methods by which networks are realized in terms of disaster relief
・Networks that can be set up quickly; for example, local 5G (means of communications based on the useof helicopters, HAPS, and other options).
・Using ad hoc networks (using satellite-based 5G).
(c) Benefits in terms of monitoring
・Transmitting video, audio, and data.
・IoT (using sensing devices).
(d) Methods by which networks are realized in terms of monitoring
・Network slicing for each application (satellites, terrestrial systems).
● Issues (overall)・Investigating conditions and issues concerning frequency selection on each path (Figure 4-4, Table 4-1).
・Interference avoidance with terrestrial 5G.
・Network management in 5G cores; seamlessly connecting heterogeneous networks and multiple links.
・Optimal distribution of service areas upon taking coverage provided by smartphone relays, drones, HAPS,
and satellites into account.
・Optimal placement of and function sharing among gNB and edge nodes.

22Figure 4-4: Communication paths
Table 4-1: Issues related to each path
Path

Opposite station

Proposed frequency

IssuesWi-Fi・ For smartphone relay links, there are empiricaltestings conducted by KOZO KEIKAKU ENGINEERING
and NTT DOCOMO.

Smartphones

Mobile basestation2.

Smartphones

Mobile basestation

5G

3.

Smartphones

Drone

5G

1.

・Frequency selection.
・Mobile base stations need to be portable, small, andlightweight to enable them to be easily installed in thefield.
・Selection of frequencies that can be supported withthe omnidirectional antenna of a smartphone.
・The ability of a drone to load(weight and power).

・Can the omnidirectional antennas of smartphones
with the C-band spectrum or lower frequencies
establish the UE-HAPS link ?
・ Can 28 GHz massive MIMO technology be
accommodated on the HAPS side?

4.

Smartphones

HAPS

5G

5.

Mobile basestation

Drone

5G

6.

Drone

HAPS

Ku/Ka

7.

HAPS

Satellite

Ka

8.

Mobile basestationSatellite

Ka

9.

Drone

Satellite

Ka・Frequency selection.
・Ensuring coverage and link capacity through wired
connections.
・Frequency selection.
・Are gNB functions included in HAPS?
・Satellite tracking function for HAPS.

・Frequency selection (trade-off for which weight andpower are taken into account in accordance with thelink design).

The Study Group discussed effectiveness through the integration of satellites and 5G and thetechnologies and issues to be addressed for realization after making assumptions as to who the target end
users and service providers would be in each category. Investigative results are presented in Tables 4-2,
4-3, and 4-4.
23

Table 4-2: End users, service providers, effectiveness, and method of realization (Category A: Smart cities)
End user (service)・Events, temporary use (enable

Service provider
・Government

Effectiveness (benefits)
・Control a larger number of

Method of realization (technologies,
issues)・Efficiently use links by compression

network construction on a

officesterminals (compared totemporary basis)

・Security

existing) and collect data

・Marathons, festivals, etc.

companies

from a large number of・Dam construction

・Localterminals at the same time

MEC/AI on the terminal side

・Meter reading

governments

・Select delay tolerance data

・Technology to seamlessly switch

・Monitoring systems (rural)

・Carriers

・Landslide monitoring・JA (agricultural

・Forestry and agriculture

cooperatives),

・Remote robotic control

fishery cooperatives

using MEC
・Seamless handover
between terrestrial andsatellite systems

・Autonomous driving

・High fish-finding accuracy

・Smart grid・Farming

for each application
・Discard unnecessary data with

between terrestrial and satellite
systems
・Communications protocols: 5Gversion of DVB or other existing
protocols is required
・Definition of satellite-based 5G(delay, speed of communications,error rate)
・What to do about systemization
・Leveling the quality of user links;
quality of service
・Terrestrial station control protocol
・Can switching delay be reduced with
5G?

・Remote healthcare (remote・Hospitals

・High capacity, low latency

surgeries, video transmission)・Can the low latency of terrestrial 5G
be maintained even whencommunicating via satellites?
・Systemization and statutory
revisions are required24

Table 4-3: End users, service providers, effectiveness, and method of realization (Category B: Mobility)
End user (service)

Service provider

Effectiveness (benefits)

Method of realization (technologies, issues)

・Airlines

・Service providers

・Satellite capacity

・Shipping companies

・Shipping companies

・Passengers

・Airlines

・Internet connectivity

・Aircraft manufacturers

・Manufacturers

・Airframe monitoring・ Thinking of objects and individuals as a・Environmental monitoring

single user

(temperature, humidity, other・Network slicing

・Operation control



MIMO



Beamforming (spatial separation)

・Handover technology
・Shipbuilders
・Logistics

meteorological data)



mMTC

(largenumberofconnections)・Container

location・・Space agencies

BeyondeMBB (high capacity)

・Earth station

information

・UAV



line-of-sightTerminating typeWireless repeater type (ships, aircraft)

・Using HAPS

communications

・Realizing low latency

・Networks in space

・Relay satellites

Table 4-4: End users, service providers, effectiveness, and method of realization (Category C: Emergency
disaster response)
End user (service)

Service provider

Effectiveness (benefits)

・Disaster victims

・Telecommunications

・ Management for the discovery of・Rescuecarriers

disaster victims
・Confirming safety through the use oforganizations (disastersmartphones

relief)・ Collecting information using drones

Method of realization (technologies,
issues)・Networks that can be set up quickly;
for example, local 5G (helicopters,
HAPS)
・ Using ad hoc networks (using
satellite-based 5G)(aerial photography, data mule)・Transmitting video (4K) through D2D・Transmitting video information from thesky above to emergency headquarters
to verify the state of a disaster-affectedarea.
・ Local governments

・Telecommunications(monitoring)

carriers

・Video, calls, data, IoT, sensing devices

・ Slicing for each app (satellites,
terrestrial systems)

25

An outline of investigative results is presented below.
・Smart cities
Use cases were investigated on the premise that spots are created in rural areas and other places where
terrestrial networks are lacking. End users (services) included utilization at events; metering; healthmonitoring, agriculture, forestry, and fisheries; smart grids; and remote healthcare. Service providers
included government offices, local governments, and carriers. For effectiveness, improvements in thenumber of simultaneous connections beyond what can be obtained with 4G are expected throughsimultaneous terminal control and data collection. By selecting the data necessary by MEC on the terminal
side, transmission efficiency is expected to increase. If terrestrial and satellite systems can be seamlessly
connected according to the 3GPP protocol, we can also expect to see switching times shrink.
・Mobility
Shipping companies, airlines, passengers, and logistics were identified as end users. Service providers
conceivably consist of communications service providers, shipping companies, airlines, and manufacturers.
Operation control, Internet connectivity, airframe monitoring, environmental monitoring (temperature,humidity, and other meteorological data), and the management of container location information can belisted under effectiveness. Environmental monitoring (temperature, humidity, and other meteorologicaldata) can also be deployed for other uses (for example, environmental monitoring can also be used forroute selection if meteorological information can be obtained from ships). In these cases, each object andindividual can be thought of as a user (terminal), the global movement of which necessitates service
continuity and network slicing (large numbers of simultaneous connections, high speeds, and highcapacities). Earth stations for ships and aircraft conceivably consist of wireless repeater-type stations andterminating-type stations.
・Emergency disaster response
Use cases were investigated upon being broadly divided into two main types: disaster relief andmonitoring. End users for disaster relief consisted of victims and rescue organizations while those formonitoring included local governments. Service providers comprised telecommunications carriers. Listed
for effectiveness were usage to manage the discovery of victims, confirm safety through the use ofsmartphones (through a network combining D2D, drones, HAPS, and satellites), enable the high-capacitytransmission of 4K video through D2D, and transmit video information from the sky above to emergency
headquarters to verify the state of a disaster-affected area. Under methods of realization, it was noted that
networks that could be set up quickly were essential. For example, the connection of local 5G to helicoptersand HAPS was conceivable, as was the use of ad hoc networks based on the use of satellite-based 5G.
Content in terms of monitoring included video, calls, data, and data from IoT sensing devices. It wasthought that network slices could be configured for each app as a method of realization. In this context,
there will be a need to control the speed of communications and delays upon taking networks for bothsatellite and terrestrial systems into account.

26

Also noted was the use of low-latency HAPS as relays for beyond line-of-sight communications with
UAVs, the use of satellites for backhauling purposes, and the use of networks in space by space agencies.

4.2.

Investigating domestic trials

In order to verify the effectiveness of use cases investigated in the preceding section, demonstrations
and evaluations through trials will be required. Thus, we discussed the effectiveness of trials, evaluation
items, and technologies to be checked for each use case that was investigated. As stated in 2.3.2, however,trials and demonstrations based on the use of test beds had already been conducted in Europe. For thisreason, the Study Group proceeded with investigations by also taking differences between overseas needs
and domestic needs into account.
First, a questionnaire survey on trial proposals for the three categories investigated to date wasadministered to the members of the Study Group. Expected use cases for which trials, evaluation items to
be checked, and technologies related to satellite-based 5G were surveyed. The results of this questionnaire
survey are laid out in Tables 4-5 through 4-7 (number of valid responses: 8 institutions). In Category A(smart cities), expectations were shown to be great with respect to unmanned systems, monitoring (video
and data), and local 5G/backhauling (where satellites are used as a local 5G backhaul). The results indicatedthat expectations were great with respect to mobile eMBB, the IoT, drone systems, logistics systems, andbackhauls (satellites and HAPS) in Category B (mobility) and with respect to backhauls (satellites and HAPS),
smartphone integration, and monitoring (video and data) in Category C (emergency disaster response).

Table 4-5: Expected use cases for trials (Category A: Smart cities)
Item

Numberofresponses

Contents

A-1

1

Various types of data communication services based on theuse of satellite terminals installed at traffic lights on roads
and 5G terminal base stations

A-2

1

High-speed communication links that can be
simultaneously used by a large number of people at tourist
sites

A-3

1

Providing 5G service to hotels and other such
establishments

Local 5G, backhaul

A-4

2

Providing information for tourists through the monitoring of
the natural environment

Monitoring (video, data)

A-5

1

Urban planning that combines LEO satellite images,
positioning information, and communications

LEO

A-6

1

Broadcasting alternatives based on the use of satellite
multicastingMulticasting,broadcasting

A-7

0

Autonomous driving (effective in rural areas where thepopulation is shrinking)1

Remote medicine (remote surgeries and video transmission;
expanding 5G areas is necessary even in places where thepopulation is in decline)

A-8

Keyword27

Keyword features

Local 5G
BackhaulMonitoring(video, data)

Unmanned
systemRemote medicine,backhaulA-9

1Autonomous robots, remote robot control

Monitoring, unmannedsystemA-10

4

Satellite use for local 5G (such as on construction sites)

Local 5G, backhaul

A-11

0

Support for foreign workers (such as translation services
where 5G coverage is not available in areas where thepopulation is declining)

A-12

1

Satellite use for temporary base stations (marathons, fairs,
and other events; dam construction)

BackhaulA-13

3

Large-scale agriculture, forestry

Monitoring, unmannedsystemA-14

0

Using satellites as a maintenance-free option for basestations

A-15

3

Backup option for remote islands

Backhaul

A-16

1

Monitoring system (such as monitoring for unmanned
convenience stores)

Monitoring (video, data)

A-17

1

Horse industry

Table 4-6: Expected use cases for trials (Category B: Mobility)
Item

Numberofresponses

B-1

4Collecting monitoring data obtained by various types ofequipment on board ships (including engine system andmeasurement systems)

B-2

4

Transmitting information related to operation control for
ships

B-3

4

High-speed, higher-capacity, lower-cost shipcommunications (such as with respect to Internet
connection)

B-4

3

Collecting monitoring data obtained by various types ofequipment on board aircraft (including engine system andmeasurement systems)

B-5

3

Transmitting information related to operation control for
aircraft

3

High-speed, higher-capacity, lower-cost aircraft
communications (such as with respect to Internet
connections)B-7

2

Expanding 5G service to the sky (space) with satellites and
HAPS

Backhaul (satellites,
HAPS)

B-8

1

Flying cars

Mobile eMBB, IoT

B-9

3

Seamless management of logistics in logistics systems at
sea and on land and IoT utilization (such as with respect tocontainers)

Logistics system, IoT

B-10

1

Autonomous driving

Unmanned system

B-11

2

Beyond line-of-sight drone operations by satellites

B-12

2

On-site monitoring in terms of meteorological and climate
observations (video, data)

B-6

Contents

Keyword28

Mobile eMBB, IoT

Keyword features

Mobile eMBB, IoT

Backhaul(satellites, HAPS)

Monitoring (video, data)

Logistics system

Unmanned
systemTable 4-7: Expected use cases for trials (Category C: Emergency disaster response)
Item

Numberofresponses

C-1

4

Landslides, dam monitoring, and more

C-2

3

Collecting and providing information for predicting natural
disasters using sensors installed in a distributed pattern

Monitoring (video, data)

C-3

4

Backhauling with LEO satellites and HAPS in the event of adisaster

Backhaul (satellites,
HAPS)

C-4

4

Connecting D2D smartphone relays to satellites (current
smartphones connect directly)

C-5

3

Observing disaster conditions with the IoT (terrestrial
systems cannot be used)

C-6

2

Always available earth observations (disaster prediction,
disaster observation)

C-7

4

Observing disaster conditions from the sky (with drones)

C-8

2

Confirming safety with smartphones in the event of adisasterSmartphone integration

C-9

2

Utilizing satellites to find disaster victims

Monitoring (video, data)

Contents

KeywordSmartphone integration

Keyword features

Monitoring(video, data)

Backhaul(satellites, HAPS)

Monitoring (video, data)

Smartphone
integration

In addition, an outline of opinions on expected use cases for trials as obtained from institutions via meansother than the questionnaire survey is as follows:・ Relaying with traffic lights and providing services to users in cars and trains.
・ Local 5G and network slicing.
・ Smartphone relay network in the event of a disaster.
・ In-flight network connection and smartphone relay networks.
・ 5G backhaul and seamless connection switching with terrestrial systems.
・ Local 5G backhaul, IoT in the context of logistics systems, LEO and HAPS.
・ Backhaul.
・ Backhaul, large volume of terminal connections by the IoT.
・ Unmanned monitoring systems, forestry and large-scale agriculture.
・ Network slicing of aircraft airframe control communications and data transmission communications.
・ ICT in the countryside and other local areas (such as for remote medicine and online payments),
autonomous driving.
・ Backhaul and the provision of communications for mobility.
・ Local 5G, mobility communications, IoT monitoring, LEO-based remote operations, dairy farming,and other examples of large-scale agriculture.
・ Collecting information related to operation control for ships, providing communication services
within mobility systems, and sediment sensing using IoT.
・ Use cases with high private-sector demands and disaster monitoring.
・ Local 5G.
A survey on evaluation items to be ideally checked through trials and technologies required for this29

purpose was also conducted by questionnaire. The results of this questionnaire are shown in Table 4-8. As
indicated in this table, characteristic items for the integration of satellites and 5G are enumerated for eachcategory.
・There is a high level of interest in the extent to which seamless connections can be secured by switching
between terrestrial and satellite systems.
・There is also a high level of interest in the effects of network slicing. In particular, the effectiveness andfeasibility of multiple network slices were listed as items subject to evaluation.
・There is a high level of interest in the extent to which QoS can be improved through network orchestration.

30

Table 4-8: Expected use cases and technologies for trials
Use case

Evaluation item response

Smart cities

・Transmission characteristics(information speed, BER
characteristics)
・Simultaneous connectivity
・Latency
・Simultaneous use ofmultiple slices
・Switching between
terrestrial and satellite
systems
・QoS (upper layer quality)・feasibility of linkestablishment
・Quality of video
transmission
・Percentage of national land
covered by satellites

Mobility

Emergency
disaster response

・Transmission characteristics(information speed, BER
characteristics)
・Simultaneous connectivity
・Latency
・Simultaneous use ofmultiple slices
・QoS (upper layer quality)
・Transmission characteristics(information speed, BER
characteristics)
・Simultaneous connectivity
・Latency
・Simultaneous use ofmultiple slices
・QoS (upper layer quality)
・Call-loss ratio
・Video transmission quality(including drones)

Response summary concerning
key technologies required for the
integration of satellites and 5G

Evaluation item (responsesummary)

・Optimal control by network
slicing/NFV・Simultaneous operations of・ Transmission(information

characteristics
speed,

BER

multiple slices
・Access control
・Integrated operations ofcharacteristics)
・Simultaneous connectivity

satellites/terrestrial systems

・Latency(orchestration)

・ Simultaneous use of multiple

・Interference avoidance・Local 5G

slices・ Switching between terrestrial

・5G IoT・Connecting with LEO

and satellite systems
・QoS (upper layer quality)

・User terminals, low power・Link establishability

consumption

・Quality of video transmission

・Video transmission

・ Video・Remote control

transmission

quality(including drones)
・ Percentage of national land
covered by satellites

・Real-time control (low latency)
・Utilizing the Q/V band (highfrequencies)
・High-capacity transmission
・Upgrading multi-beams

31

5.

Investigating standardization as it applies to the integration of satellites and 5G

5.1.

State of standardization concerning the integration of satellites and 5G as promoted by the 3GPP

An investigation into standardization concerning the integration of satellites and 5G as promoted by the
3GPP began in March 2017 for non-terrestrial networks (NTN) and has been carried out for TSG RAN and
TSG SA within the framework of investigations carried out by the 3GPP as shown in Figure 5-1. This
investigation has thus far yielded documents as indicated in Table 5-1. Plans for NTN-related releases as
formulated by the 3GPP are outlined in Figure 5-2. Specifications for the integration of satellites and 5G
are contained in a plan to be completed for Release 17, which is scheduled for release in 2022.

Figure 5-1: Framework of investigations by the 3GPP[10]Table 5-1: Documents related to the integration of satellites and 5G maintained by the 3GPP
Item
3GPP Activities
in TSG RAN

3GPP Activities
in TSG SA

Standard

Contents

TR 38.913

Study on Scenarios and Requirements for Next Generation Access Technologies

TR 38.811

Study on New Radio (NR) to support non-terrestrial networks

TR 38.821

Solutions for NR to support non-terrestrial networks (NTN)

TS 22.261

Service requirements for the 5G system

TR 22.822

Study on using Satellite Access in 5G

TR 23.737

Study on architecture aspects for using satellite access in 5G

TR 28.808

Study on management and orchestration aspects with integrated satellite components
in a 5G network32

TSG RAN：Technical Specification Group Radio Access Network
TSG SA：Technical Specification Group Service and System Aspects
TR：Technical Report、TS：Technical Specification

Figure 5-2: Release plans related to the integration of satellites and 5G in the 3GPP (produced based on[11])
Technical items to be considered for non-terrestrial networks (NTN) in discussions related to 5G NR
specifications as held by the 3GPP are presented in Table 5-2.[12]Table 5-2: Impact in terms of changes to 5G NR specifications that need to be taken into account in NTNs
(areas subject to technical investigations)[9]NTN attribute

Altitude: HighImpactAffected specifications

Technical orientation

HARQ

Feedback

Adaptive control at the

Changing the method ofTransmission delay:

physical layer (MCS,

adaptive control

Large

power, etc.)
Waiting time at the

Revising the timer value

upper layer
Movement of base

Cell pattern fluctuations

Handover, paging

33

Revising sequencesstation (in the case ofFluctuations in

LEO)

transmission delay

Timing advance

Revising sequences andfrequency values
Appropriately selecting

Initial synchronizationinterval)

Doppler fluctuations
Time density of DMRS
Difference in
Cell: Wide areatransmission delay
values in cells: Large

Propagation loss: Largeparameters (sub-carrier

Nonlinear distortions inparameters (density)

Random access

Doppler compensation

Timing advanceDelay compensation

PAPR

transponders

Appropriately selecting

PAPR suppression
technology

Excerpted from 3GPP document TR 38.811

34

5.2.

Investigating in connection with standardization

In accordance with the trend towards standardization as discussed in the preceding section, the Study
Group investigated items for which standardization was believed to be needed as the use of satellite
communications in conjunction with 5G undergoes future growth in Japan. Items for which it is believedthat standardization will be needed in each category are indicated in Table 5-3. These items have beenbroadly divided into items related to standardization for the integration of satellites and 5G by the 3GPP
and items to be standardized in the field of applications.
Table 5-3: Proposed standardization items related to the integration of satellites and 5G
Category

Smart cities

Mobility

Emergency disaster
response

Proposed standardization item

Classification

・Quantitative definition of satellite-based 5G (such as in terms of speed in Mbps,
delay in ms, and number of connections)

Satellite-based 5G
standardization

・Provisions governing quality of communications and satellite quality for eachapplication

Satellite-based 5G
standardization

・Communication protocols on a layer-by-layer basis (satellite-based 5G version
corresponding to DVB-S2X)

Satellite-based 5G
standardization

・ Protocol for ascertaining user state (user terminal), protocol by which theforegoing is controlled (base station)

Satellite-based 5G
standardization

・Seamless switching between satellites and terrestrial systems; network slicing
methodSatellite-based 5G
standardization

・Reducing equipment and development costs by standardizing satellite-based 5G
chips

Satellite-based 5G
standardization

・Developing laws for remote medicine

Application
standardization

・What kind of network slicing architecture should be built (divided according towhat standard)? (Examples: Divide according to the form of use by the network
provider, such as mMTC or eMBB. Divide according to the effectiveness andbenefits of each use case.)

Satellite-based 5G
standardization

・How to sort out issues, such as the interference caused by placing base stationsin the air and installing repeaters in moving bodies (such as aircraft) (from thestandpoint of developing the law rather than standardization).

Application
standardization

・Scheduling in terms of data transmission

Satellite-based 5G
standardization

・Standardization as concerns roaming procedures

Satellite-based 5G
standardization

・Standardization of and adoption of an API (application programming interface) fordata required in the event of a disaster

Application
standardization

・Power saving for IoT sensor systems (such as for EIRP, frame configuration, andintermittent transmission and reception)

Application
standardization

・Detailed information pertaining to disaster information (specific items concerning
victim location information and detailed requirements with respect to thecontents thereof)

Application
standardization

35

An outline of the results of investigations for each category is presented below.
・ Smart cities
Even as investigations are being conducted by the 3GPP, there is a question as to whether a definitionof satellite-based 5G (such as in terms of delay, speed, and error rate) is also necessary in Japan.
Moreover, standard specifications governing communication methods (such as with respect to frame
configuration), parameter provisions governing seamless connections, and provisions governing
service quality to ensure the quality of end-to-end communications on a per-user basis shall be
stipulated. Ascertainment of the state of user terminals and the management of networks based on
this information will also be required. For remote medicine, whether low latency for terrestrial 5G canbe maintained with satellites is an issue. It is conceivable that systemization and statutory revisions
will be required.
・ Mobility
Standardization is required for different types of use cases, such as operation control and Internet
connectivity. Given considerations with respect to frequency sharing and radio interference, statutory
revisions will be needed if repeaters are to be installed in moving bodies.
・ Emergency disaster responseStandardization required for disaster response include the unification of data required in the event of
a disaster, scheduling in data transmission, standardization of roaming, provision of IoT sensor power,
and provision of detailed information on disaster information. Satellite-based 5G integration is also
effective in collecting large amounts of data using mMTC.
Some items corresponding to standardization as concerns the integration of satellites and 5G as
described above are also included in the contents currently being promoted for non-terrestrial network
systems in Release 17 through the 3GPP. In the future, it will be necessary to focus on 3GPP trends, as wellas the study contents that are effective for domestic use. In addition to the standardization of theaforementioned communication protocols, discussions concerning standardization required to use satellite
frequencies with 5G technology will also be required. For example, if you will be using 5G standards foraircraft communications based on the use of the Ku and Ka bands, you will need to request frequencies byentering background technology into ITU-R SG5. If you will be using 5G with a different application, an
entry into ITU-R SG4 will need to be made.

36

6.

The concept of communication networks expected in Beyond 5G
In investigating future communication networks including satellite communications in light of theeffectiveness of the integration of satellites and 5G as discussed by the Study Group and the required
technologies involved, it is conceivable that communications networks in Beyond 5G will be premised ona network that is connected from space to the ground on a multilayered basis. A conceptual diagram ofthis system is presented in Figure 6-1 (In this report, the network to be realized by around 2040 as a
successor to 5G is defined as Beyond 5G). Research and development work with a view to realizing thisnetwork will need to be undertaken.

Figure 6-1: Concept of communication networks in Beyond 5G

37

7.

Conclusion
Conferences of the Study Group were held for the purpose of specifically investigating the effective use

cases made possible by the integration of satellite communications and 5G, the required technical issues
and methods of realization, evaluations and demonstrations, and standardization with a focus on the rolesof satellite communications in 5G and in light of activities being carried out through European projects andthe state of progress being made for standardization by the 3GPP. Key results are summarized below:
・ The integration of satellites and 5G aims to expand terrestrial 5G technology to encompass nonterrestrial networks inclusive of satellite communications. Key technologies for this purpose consist of
SDN/NFV, network slicing, network management, edge computing, and other network technologies
in the context of 5G. Activities related to the integration of satellites and 5G have been preceded byvarious projects, including SAT5G and SATis5 in Europe, and standardization through the 3GPP isprogressing.
・ Three motivations that speak to the necessity of adopting the integration of satellites and 5G can beconsidered. First, there is the evolution of satellite communications in recent years. The emergence of
HTS and mega-constellation plans based on groups of LEO satellites will accommodate higher speeds
and higher capacities at low cost, while terminals that are significantly miniaturized and can operate
at lower power consumption levels are getting much closer to terrestrial systems than before. Second,
there is the possibility of being able to efficiently realize the integration of satellites and 5G throughthe deployment of network technologies characterizing 5G technology in satellite systems. Third, while
the architecture for conventional satellite communications had been built independently of terrestrial
systems, standardization has been promoted for non-terrestrial systems, inclusive of satellites, for the
first time with 5G by the 3GPP. This is expected to lead to progress in terms of the promotion of plugand-play features and development of ASICs as non-terrestrial systems undergo standardization.
Against this backdrop, we can expect to see unprecedented use cases and groundbreaking
improvements to conventional use cases generated through the integration of satellites and 5G.
・ In investigating effective use cases in Japan, an investigation based on social conditions, such as
domestic demographics during the 5G/Beyond 5G era (2020-2040), is important for establishingcontext. A conceptual investigation of systems that are effective for use case categories consisting ofsmart cities, mobility, and emergency disaster response, as well as the effectiveness of technologies
necessary for the foregoing, was checked.
Smart cities: Use cases are premised on the creation of spots in rural areas and other places where
terrestrial networks are lacking. End users (services) included utilization at events; metering; healthmonitoring; agriculture, forestry, and fisheries; smart grids; and remote healthcare. Service
providers included government offices, local governments, and carriers. For the effectiveness of
the use of satellite-based 5G, improvements in the number of simultaneous connections beyond
what can be obtained with 4G are expected through simultaneous control and data collection.

38

We expect to see more effects in terms of the collection of large amounts of data with IoT than interms of high-speed communications. By selecting data necessary by MEC on the terminal side,transmission efficiency is expected to increase. If terrestrial and satellite systems can be seamlessly
connected according to the 3GPP protocol, we can also expect to see switching times shrink.
Mobility: End users consisted of shipping companies, airlines, passengers, and logistics. Service
providers consisted of communications service providers, shipping companies, airlines, andmanufacturers. Operation control, Internet connectivity, airframe monitoring, environmental
monitoring, and the management of container location information are included under theeffectiveness of the use of satellite-based 5G. In these cases, each object and individual can bethought of as a user (terminal), the global movement of which necessitates service continuity andnetwork slicing (large numbers of simultaneous connections, high speeds, and large capacities).
Earth stations for ships and aircraft conceivably consist of wireless repeater-type stations andterminating-type stations. The use of low-latency HAPS as relay points for beyond line-of-sightcommunications with UAVs, the use of satellites as backhaul components, and the use of networks
in space are also possible.

Emergency disaster response: Use cases can be broadly divided into two main types: disaster relief
and monitoring. End users for disaster relief consisted of victims and rescue organizations while
those

for

monitoring

included

local

governments.

Serviceproviders

comprised

telecommunications carriers. Listed for effectiveness were usage to manage the discovery ofvictims, confirm safety through the use of smartphones (through a network combining D2D,
drones, HAPS, and satellites), enable the high-capacity transmission of 4K video through D2D, andtransmit video information from the sky above to emergency headquarters to verify the state ofa disaster-affected area. Under the methods of realization, it was noted that networks that could
be set up quickly were essential. For example, the connection of local 5G to helicopters and HAPS
was conceivable, as was the use of ad hoc networks based on the use of satellite-based 5G.
Content in terms of monitoring included video, calls, data, and data from IoT sensing devices. It
was thought that network slices could be configured for each app as a method of realization. In
this context, there will be a need to control the speed of communications and delays upon taking
networks for both satellite and terrestrial systems into account.
・ For trials in Japan, the effectiveness of trials can be expected, especially in connection with unmannedsystems, monitoring (video and data), mobile eMBB, IoT, logistics systems, local 5G and backhaul, andsmartphone integration.
・ With respect to standardization, the integration of satellites and 5G is being studied primarily in thediscussion of non-terrestrial networks through the 3GPP, and specifications are slated for completion
with Release 17. Items for which standardization is conceivably necessary are broadly divided into
items related to the standardization of the integration of satellites and 5G through the 3GPP and items

39

to be standardized in the field of applications. In addition to focusing on 3GPP trends in the future, wewill need to investigate content that is effective for domestic use. As well as the standardization ofcommunication protocols, discussions concerning the standardization required to use satellite
frequencies with 5G technology will also be required.
・ Future communication networks including satellite communications were investigated in light of theeffectiveness of the integration of satellites and 5G as discussed by the Study Group and therequired technologies involved. It is conceivable that communications networks in Beyond 5G,
defined as a network to be realized by around 2040 as a successor to 5G, will be premised on a
network that is connected from space to the ground on a multilayered basis. Research anddevelopment work with a view to realizing this communication network will need to be undertaken.

40

Acknowledgements
In holding conferences of the Study Group, we invited a wide range of organizations related to theintegration of satellites and 5G, including domestic satellite operators, terrestrial mobile carriers, satelliterelated manufacturers, universities, survey and research institutes, and standardization bodies, toparticipate and were able to promote the effective exchange of opinions in a way that would lead tofuture initiatives. At the same time, community formation was spurred in a way that was effective forpromoting initiatives for the integration of satellites and 5G in Japan. NICT wishes to express theappreciation to all of the members and observers who participated in this process.

41

Reference material[1] Basic Space Planning Schedule (revised in fiscal year 2019) (in Japanese, December 13, 2019)[2] Akihiro Nakao (University of Tokyo), The Importance of the Integration of 5G and Satellite
Communications, 2nd Conference, Study Group on the Integration of Satellite Communications and5G/Beyond 5G (in Japanese, September 26, 2019)[3] Kumar Singarajah, Role of Satellite Systems in the Future 5G Ecosystem, September 18-19, 2017[4] SaT5G project：https://www.sat5g-project.eu/[5] SATis5 Demonstrator for Satellite-Terrestrial Integration in the 5G Context：
https://artes.esa.int/projects/satis5-0[6] 5G ALLSTAR: https://5g-allstar.eu/news/[7] Space19+: https://artes.esa.int/news/artes-40-–-new-proposal-new-marketplace[8] Long-Term Outlook Committee, Policy Subcommittee of the National Land Council: Interim summaryof Long-Term National Land Outlook (in Japanese, February 21, 2011)[9] 3GPP TR22.822 V16.0.0 (2018-06) Technical Specification Group Services and System Aspects; Studyon using Satellite Access in 5G; Stage 1 (Release 16)[10]

Adrian Scrase, 3GPP Overview: The Standardization Ecosystem for Global Mobile Systems, 3GPP
Summit CEATEC, October 17, 2018[11]

3GPP: https://www.3gpp.org/[12]

Takayuki Sotoyama (Panasonic): NTN (Non-Terrestrial Networks) in the 3GPP Standardization Trends,
4th Conference, Study Group on the Integration of Satellite Communications and 5G/Beyond 5G (inJapanese, November 28, 2019)

Appendix: List of Members and Observers
Internal Member: National Institute of Information and Communications Technology (NICT)
External Members: SKY Perfect JSAT Corporation, Nippon Telegraph and Telephone Corporation (NTT), NTT
DOCOMO, INC., KDDI CORPORATION, SoftBank Corp., Panasonic Corporation, Mitsubishi Electric
Corporation, NEC Corporation, NEC Space Technologies, Ltd., Japan Radio Co., Ltd. (JRC), Japan Aerospace
Exploration Agency (JAXA), The University of Tokyo, Waseda University, Tohoku University, Mitsubishi
Research Institute, Inc. (MRI), KOZO KEIKAKU ENGINEERING Inc., Rakuten Mobile, Inc.
Observers: Association of Radio Industries and Businesses (ARIB), Ministry of Internal Affairs andCommunications (MIC)42