위성통신시스템 6g : capacity enhancement with satellite...

<한국통신학회 추계종합학술발표회 튜토리얼>

위성통신 시스템

6G : Capacity Enhancement with Satellite Communications

2018. 11. 17

김경록, 이동구, 김재현

[email protected]

Wireless Internet aNd Network Engineering Research Lab.

http://winner.ajou.ac.kr

Department of Electrical and Computer Engineering

Ajou University, Korea

http://winner.ajou.ac.kr/

Contents

위성통신의 역사

위성의 궤도 및 스펙트럼

위성시스템

상용 통신위성

3GPP TR 38.811 NR to support NTN

Satellites of Future (SoF)

1

2

3

4

5

6

2

위성의 역사 : Important Milestones (before 1950)

Putting the concepts together

1600: Tycho Brache’s experimental observations on planetary motion.

1609-1619: Kepler’s laws on planetary motion

1926: First liquid propellant rocket launched by R.H. Goddard in the US.

1927: First transatlantic radio link communication

1942: First successful launch of a V-2 rocket in Germany.

1945: Arthur Clarke publishes his ideas on geostationary satellites for worldwide communications (GEO concept).

V2 Rocket

3

위성의 역사 : Important Milestones (1950’s)

Putting the pieces together

1956: Trans-Atlantic cable opened (about 12 telephone channels – operator).

1957: First man-made satellite launched by former USSR (Sputnik, LEO).

1958: First US satellite launched (Explorer 1) First voice communication established via satellite(SCORE)

Sputnik Explorer

4


First satellite communications

1960: First passive communication satellite launched into space (Large balloons, Echo I and II).

1962: First non-government active communication satellite launched Telstar I (television pictures, telephone calls, fax)

1963: First satellite launched into geostationary orbit Syncom 1 (comms. failed).

1964: International Telecomm. Satellite Organization (INTELSAT) created.

1965 First communications satellite launched into geostationary orbit for commercial use Early Bird (re-named INTELSAT 1)

Echo1 Telsat 1 Intelsat 1

5

위성의 역사 : Important Milestones (1970’s 1980’s)

GEO applications development 1972: First domestic satellite system operational (Canada). INTERSPUTNIK founded.

1975: First successful direct broadcast experiment (one year duration; USA-India).

1977: A plan for direct-to-home satellite broadcasting assigned by the ITU in regions 1 and 3 (most of the world except the Americas).

1979: International Maritime Satellite Organization (Inmarsat) established.

(The name was changed to “International Mobile Satellite Organization” when it began to provide services to aircraft and portable users, but the acronym "Inmarsat" was kept)

GEO applications expanded 1981: First reusable launch vehicle flight.

1982: International maritime communications made operational.

1983: ITU direct broadcast plan extended to region 2.

1984: First direct-to-home broadcast system operational (Japan).

1987: Successful trials of land-mobile communications (Inmarsat).

1989-90: Global mobile communication service extended to land mobile and aeronautical use (Inmarsat : http://www.inmarsat.com

6

http://www.inmarsat.com/


1990-95: Several organizations propose the use of non-geostationary (NGSO) satellite

systems for mobile communications.

Continuing growth of VSATs around the world.

Spectrum allocation for non-GEO systems.

Continuing growth of direct broadcast systems. DirectTV created

1990: 우주 왕복선 디스커버리호 발사

1994: GPS 서비스 시작

1997: 탐사선 Path Finder 화성에 착륙

Launch of first batch of LEO for hand-held terminals (Iridium: http://www.iridium.com/ )

Voice service telephone-sized desktop and paging service pocket size mobile terminals launched (Inmarsat).

1998: 국제 우주 정거장 건설 시작

1999: Globalstar Initiates Service.

<Iridium >

<Iridium handset> 7

http://www.iridium.com/

위성의 역사 : Important Milestones (2000’s 2010’s~)

2000’s유럽연합, 중국, 일본, 인도 등이 신흥 우주기술 강국으로 등장

2003: 적외선 망원경 스피처와 갤렉스 우주 망원경 발사

중국이 세계에서 3번째로 유인우주선 발사

2004: 쌍둥이 화성 탐사로봇 스피릿, 오퍼튜니티 발사

2006: 명왕성 탐사선 뉴호라이즌호 발사

2007: 화성 탐사선 피닉스호 발사

일본이 아시아 최초 달 탐사 위성인 ‘가구야’ 위성 발사 성공

2011: NASA 수성탐사선 메신저호 수성궤도 진입, NASA 우주왕복선 아틀란티스 종료

2012: 화성탐사선 큐리오시티 화성 착륙.

2014: ESA 혜성탐사선 로제타 혜성 궤도 진입 성공. 최초로 혜성의 클로즈업 이미지 제공.

2014: ESA 혜성탐사선 로제타가 탐사로봇 파일리 투하.

2016: 인류 최초의 혜성 탐사선 로제타 임무 종료

2018. 5. 5 : NASA의 화성 지질 탐사선 인사이트 발사 성공

2018년 11월 26일 화성에 도착, 탐사 예정

2018. 8. 11 : 태양의 외부 코로나를 조사하기 위해 계획된 NASA의 무인탐사선 파커솔라 발사예정

8

<Insight (NASA)>

위성의 역사 : Important Milestones (국내)

1990’s 1992년 8월 11일 : 한국 최초 인공위성 우리별 1호 (KITSAT-1) 발사

1993년 6월 4일 : 과학로켓 1호 (KSR-1) 발사

1993년 9월 26일 : 우리별 2호 (KITSAT-2) 발사

1995년 8월 5일 : 무궁화 1호 (KOREASAT-1, 통신위성)

1996년 1월 14일 : 무궁화 2호 (KOREASAT-2, 통신위성) 발사

1997년 7월 9일 : 과학로켓 2호 (KSR-2) 발사

1999년 5월 26일 : 우리별 3호 (KITSAT-3) 발사

1996년 우주개발중장기기본계획 수립에 의해 개발된 첫번째 인공위성

독자설계로 개발된 우리나라 최초의 고유모델 위성


1999년 12월 21일 : 아리랑 1호 (KOMSAT-1, 다목적실용위성) 발사

9


[1] https://ko.wikipedia.org/wiki 10

2000’s 2002년 11월 28일 : 한국 최초로 개발된 액체추진 과학로켓(KSR-3) 발사

2003년 9월 27일 : 과학기술위성 1호 (STSAT-1) 발사

2006년 7월 28일 : 아리랑 2호 (KOMSAT-2, 다목적실용위성) 발사


최초의 민군 복합위성

2008년 4월 8일 : 국내최초 우주인 탄생

2009년 6월 30일 : 나로우주센터 준공

2009년 8월 25일 : 한국 최초 우주발사체 나로호(KSLV-I) 발사(실패)

과학기술위성 2A호 탑재

2010년 6월 10일 : 나로호(KSLV-I) 2차 발사(실패)

과학기술위성 2B호 탑재

2010년 6월 27일 : 천리안 위성 (COMS, 통신해양기상위성) 발사

2010년 12월 30일 : 올레 1호 (무궁화 6호, KOREASAT-6) 발사

KT의 통신위성, 고화질(HD), 3차원(3D), 고품질 위성방송 서비스 제공

2010’s 2012년 5월 18일 : 아리랑 3호 (KOMPSAT-3, 다목적실용위성) 발사

2013년 1월 30일 : 나로호 (KSLV-I) 3차 발사성공

나로과학위성 탑재

2013년 8월 22일 : 아리랑 5호 (KOMPSAT-5, 다목적실용위성) 발사

2013년 11월 21일 : 과학기술위성 3호 (STSAT-3) 발사

2015년 3월 26일 : 아리랑 3A (KOMPSAT-3A) 발사

전자광학카메라, 적외선 센서

2017년 5월 5일 : 무궁화 7호 (KOREASAT-7) 발사

2017년 10월 30일 : 무궁화 5A호 (KOREASAT 5A) 발사

11



향후 발사계획 2020년 다목적실용위성 아리랑6호 발사예정

영상레이더(SAR)로 지상 관측

2018년 12월 정지궤도복합위성 2A, 정지궤도복합위성 2B 발사예정<우리별 1, 2, 3호 >

<아리랑 1호>

<아리랑 5호>

12


과기정통부 우주개발 시행계획

13



위성시스템

상용 통신위성



1

2

3

4

5

6

14

위성의 궤도 : Kinematics & Newton’s Law

Law of Universal Gravity

a : acceleration due to gravity

r : radius from center of earth

μ : universal gravitational constant G multiplied by the mass of the earth ME

μ : Kepler’s constant = 3.9861352 x105 km3/s2

G : 6.672 x 10-11 Nm2/kg2 or 6.672 x 10-20 km3/kg∙s2 in the older units

2

EGMF ma m

r

2 2

EGMa

r r

15


Balancing the Forces

Centripetal force(Inward force: 구심력) is equal to Centrifugal force(Outward force:원심력)

Second order differential equation with six unknowns (위치, 방향 vector)

The orbital elements

2

3 2

EM m dG m

r dt

r rF

2

2 30

d

dt r

r r

ˆ ˆ, : unit vector rr r r

원심력 구심력

16


Conversion (polar coordinate system)

ˆ cos ,sin

ˆ sin ,cos

r

θ

2 2

ˆ, cos ,sin

ˆˆ, cos ,sin sin ,cos

ˆ ˆˆ ˆ ˆ, 2 2

x y r r

x y r r r r

x y r r r r r r r r

r r

r r θ

r r θ θ r r

2ˆ

mm

r

r r 2

2ˆˆ ˆ2

mm r r r r

r

r θ r

2

2

2 0r r

r rr

미분

ˆˆ ˆ ˆˆ ˆ,d d

dt dt

r θr θ θ r

17


Derivation of Kepler’s Law

Second order differential equation is re-defined into polar coordinates

Solving the two differential equations leads to six constants (the orbital constants) which define the orbit, and three laws of orbits (Kepler’s Laws of Planetary Motion)

Johaness Kepler (1571 - 1630) a German Astronomer and Scientist

2

2r r

r

2 0r r

18

위성의 궤도 : Kepler’s Law

First Law (타원궤도의 법칙)

Orbit is an ellipse with the larger body (earth) at

one focus

Second Law (면적속도 일정의 법칙)

The satellite sweeps out equal arcs (area) in equal

time

NOTE: for an ellipse, this means that the orbital

velocity varies around the orbit

Third Law (주기의 법칙)

The square of the period of revolution(T) equals a

CONSTANT the THIRD POWER of SEMI-MAJOR

AXIS(a) of the ellipse 2 3T a

0

01 cos( )

pr

e

22 34

T a

19

위성의 궤도 : 6 parameters determining orbit orientation

- Ω: longitude of the ascending node

on the equatorial plane

- i: inclination of the orbital plane

with respect to the equatorial plane

- γ: argument of the perigee at the

ascending node

- tp : time of passage at the perigee

(reference initial time)

- a: semi‐major axis of the ellipse

- e: orbit eccentricity

𝑒 = 1 −𝑏

𝑎

2

20

위성의 궤도 : Main Orbit Type

LEO 500 -1000 km

GEO 36,000 km

MEO 5,000 – 15,000 km

Orbit Type Height Period

LEO-Low Earth Orbit 500 ~1000km 90~120 min.

MEO-Medium Earth Orbit 5,000~15,000km Approx. 6 hour

GEO-Geostationary Orbit Approx. 36,000km Approx. 24 hour 21

위성의 궤도 : GEO – Geostationary Orbit

Characteristic In the equatorial planeOrbital Period = 23 h 56 m 4.091s = 1 sidereal day Satellite appears to be stationary over any point on equator:

Earth Rotates at same speed as Satellite Radius of Orbit r = Orbital Height + Radius of Earth Avg. Radius of Earth = 6378.14 Km

3~4 Satellites can cover the earth (90/120° apart)

*1 sidereal day(항성시) is defined as one complete rotation relative to the fixed stars

22

위성의 궤도 : NGEO – Non-Geostationary orbit

Characteristic Orbit should avoid Van Allen radiation belts:

• Region of charged particles that can cause damage to satellite

Occur at • ~2000-4000 km and • ~13000-25000 km

Van Allen belt

23

위성의 궤도 : LEO – Low Earth Orbit

Characteristic

Circular or inclined orbit with < 1400 km altitude

Satellite travels across sky from horizon to horizon in 5 - 15 minutes => needs handoff

Large constellation of satellites is needed for continuous communication (66 satellites needed to cover earth)

Requires complex architecture

Requires tracking at ground

• Earth stations must track satellite

24

위성의 궤도 : MEO – Medium Earth Orbit

Characteristic

MEO systems operate similarly to LEO systems. In MEO systems

however, hand-over is less frequent, and propagation delay and free space loss are greater.

MEO requires relatively few satellites in two to three orbital planes to achieve global coverage.

Examples

• Inmarsat-P (10 satellites in 2 inclined planes at 10,355 km)

• Odyssey (12 satellites in 3 inclined planes, also at 10,355 km).

GPS satellites (MEO application)

Broadcast pulse trains with very accurate time signals

A receiver able to “see” four GPS satellites can calculate

its position within 30 m anywhere in world

24 satellites in clusters of four, 12 hour orbital period

25

위성의 궤도 : HEO- Highly Elliptical Orbits

Characteristic HEOs (i = 63.4°) are suitable to provide coverage at high latitudes (including

North Pole in the northern hemisphere)

Depending on selected orbit (e.g. Molniya, Tundra, etc.) two or three satellites are sufficient for continuous time coverage of the service area.

All traffic must be periodically transferred from the “setting” satellite to the “rising” satellite (Satellite Handover)

26

위성의 궤도 : Sun-synchronous Orbit (Special type)

Characteristics

A satellite in Sun-synchronous orbit crosses the equator and each latitude at the same time each day

Sun-synchronous orbit is advantageous for an Earth observation satellite, since it provides constant lighting conditions

Be useful for search and rescue

27

위성의 궤도 : Coverage vs. Altitude

El

Satellite Altitude (km)

28

위성의 궤도 : LEO, MEO and GEO Orbit Periods

Satellite system Orbital Height(km) Orbital

Velocity(km/s)

Orbital Period

INTELSAT (GEO) 35,786.43 3.0747 23h 56min 4.091s

ICO-Global(MEO) 10,255 4.8954 5h 55min 48.4s

Skybridge (LEO) 1,469 7.1272 1h 55min 17.8s

Iridium (LEO) 780 7.4624 1h 40min 27s

0.0

5.0

10.0

15.0

20.0

25.0

30.0

0 5000 10000 15000 20000 25000 30000 35000 40000

Altitude [km]

Ho

urs

MEO

GEO

LEO

29

위성의 궤도 : Minimum Delay for two hops

0.0

50.0

100.0

150.0

200.0

250.0

300.0

0 5000 10000 15000 20000 25000 30000 35000 40000

Altitude [km]

De

lay [

ms

]

MEO

GEO

LEO

30

위성의 궤도 : Orbit Perturbations

Effects of a nonspherical earth

In Kepler’s third law, the earth is assumed spherical earth of uniform mass

it is known that the earth is not perfectly spherical, there being an equatorial bulge and a flattening at the poles, a shape described as an oblate spheroid.

Oblate spheroid

3ona

2

1

1.52 2

2

1

1 1.5sin1

1

66,063.1704km

o

K in n

a e

K

31

위성의 궤도 : Orbit Perturbations

Atmospheric drag

For near-earth satellites, below about 1000 km, the effects of atmospheric drag are significant.

Because the drag is greatest at the perigee, the drag acts to reduce the velocity at this point, with the result that the satellite does not reach the same apogee height on successive revolutions.

2/3

00

0 0 0

na a

n n t t

32

위성의 스펙트럼 : Commonly Used Bands

AM HF VHF UHF L S C X KuKa V Q

1 10 100 1

MHz GHz

Terrestrial Bands

Space Bands

Shared (Terrestrial and Space)

SHF

0.1 10010

AM 535 to 1735 kHz

HF band 3 to 30MHz

VHF band 30 to 300MHz

UHF band 0.3 to 3GHz

L band 1 to 2 GHz

S band 2 to 4 GHz

C band 4 to 8 GHz

X band 8 to 12 GHz

Ku band 10.95-14.5 GHz

Ka band 26.5 to 40 GHz

Q band 30 to 50 GHz

V band 50 to 75 GHz

VQ

33

위성의 스펙트럼 : 통신용 주파수 대역

Frequency Bandwidth Mission Satellite

UHF 240~400 MHz 500KHz Military FLASAT, LEASAT

L 1.5~1.6GHz 47MHz Commercial MARISAT, IRIDIUM

C 6(UL)/4(DL)GHz 80MHz Commercial INTELSAT, DOMSAT

X 8/7GHz 500MHz Military DSCS, NATO

X 10GHz 500MHz Commercial IMPACT (Japan)

Ku 14/11GHz 500MHz Commercial INTELSAT, DOMSAT

Ka 30/20GHz 2.5GHz Commercial JCS, INMARSAT-5 F1~ F5, IRIDIUM

Ka 30/20GHz 1.0GHz Military DSCS IV

Q 43.5~47GHz 2.0GHz Military MILSTAR, SKYNET IV

V 59~64GHz 5.0GHz Military MILSTAR (ISL: Inter Satellite Link )

34

위성의 스펙트럼 : Earth’s Atmosphere

대류권

성층권

중간권

열권

외기권

35

위성의 스펙트럼 : Space-Earth Frequency Usability

Atmospheric attenuation effects

Atmospheric attenuation effects for Space-to-Earth as a function of frequency (clear air conditions).

(a) Oxygen; (b) Water vapor. [Source: ITU © 1988]

Resonance frequencies

below 100GHz:

• 22.2GHz (H20)

• 53.5-65.2 GHz (Oxygen)

36

위성의 스펙트럼 :

Atmospheric attenuation

Example: satellite systems at 4-6 GHz

elevation of the satellite

5° 10° 20° 30° 40° 50°

Attenuation of

the signal in %

10

20

30

40

50

rain absorption

fog absorption

atmospheric

absorption

e

37



위성시스템

상용 통신위성



1

2

3

4

5

6

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위성시스템 : Satellite System Elements 1/4

Satellite System Elements

Space Segment

Satellite

TT&C Ground Station

Ground Segment

Earth

Stations

Coverage Region

SCC

39


Space segment : Satellite lifetime

Satellite Launching Phase

Transfer Orbit Phase

Deployment

Operation

TT&C - Tracking Telemetry and Command Station

• Establishes a control and monitoring link with satellite

• Tracks orbit distortions and allows correction planning

SSC - Satellite Control Center

• Provides link signal monitoring for Link Maintenance and Interference monitoring.

Retirement Phase

40


Satellite Subsystems

Attitude and Orbital Control System (AOCS)

Orbit insertion (launch phase)

Orbit maintenance

Fine pointing

Telemetry Tracking and Command (TT&C)

More usually TTC&M - Telemetry, Tracking, Command, and Monitoring

Power System

Solar cell & battery

Communications System

Antennas

41


Ground Segment

Earth Station = Satellite Communication Station (air, ground or sea, fixed or mobile)

FSS – Fixed Satellite Service MSS – Mobile Satellite Service

42

위성시스템 : AOCS-Orbit insertion

Direct injection in orbit

Satellites is directly injected up to 200km altitude by rocket or space shuttle

it is not economical in terms of launch vehicle power to perform directly injection (orbital altitude > 200km)

• Hohmann transfer orbit

<Rocket> <Space shuttle> 43

위성시스템 : AOCS-Orbit insertion

Hohmann transfer orbit

Launching sequence

1. direct injection in LEO

2. perigee Kick motor

• Transfer orbit

3. apogee kick motor

• Target orbit

Perigee kick motor

Apogee kick motor

LEOTransfer orbit

Target orbit

44

Power system Solar cell

Primary electrical power for operating the electronic equipment in satellite

Type• Cylinder panel (DC power 940W)

• Rectangular solar sail (DC power 2~6kW)

Battery

During eclipse, power is provided by long-life batteries

Type• Ni-Cd (nickel-cadmium)

• Ni-H2 (nickel-hydrogen)» Offer significant improvement in Power-

weight ratio compared to Ni-Cd

• Lithium Based Battery Technology» Future

<Cylinder panel> <Rectangular solar sail>

< Nickel-hydrogen > < Lithium Based Battery >

45

위성시스템 : Power System


Solar Cell Efficiency

Early silicon solar cell

~ 10% efficiency

2wiTHI-ETA3-ID(AZUR)

Early 2000

~17% efficiency

Multi-junction solar cell

2000 ~

3G Triple Junction SC

2010 ~

Ga in P, Ga in As, Ge

~ 30% efficiency

46


Eclipse in GEO

The earth will eclipse a GEO satellite twice a year, during the spring and autumnal equinoxes (during 72min.)

To maintain service during an eclipse, storage batteries must be provided

Spring and autumnal equinoxes : 춘분점 및 추분점, 낮과 밤의 길이가 같음

MAX. = 72min

47

Reception:

+ Rx Antenna gain

- Reception Losses

(cables & connectors)

+ Noise Temperature Contribution

위성시스템 : Link Power Budget

Transmission:

+ HPA Power

- Transmission Losses

(cables & connectors)

+ Tx Antenna Gain

Space Channel

- Tx Antenna Pointing Loss

- Free Space Loss

- Atmospheric Loss

(gaseous, clouds, rain)

- Rx Antenna Pointing Loss

Received power (Pr) La = Losses due to attenuation in atmosphere

Lta = Losses associated with transmitting antenna

Lra = Losses associates with receiving antenna

Lpol = Losses due to polarization mismatch

Lother = (any other known loss - as much detail as available)

Lr = additional Losses at receiver (after receiving antenna

Lp = Free Space Loss

Pt = power into antenna

Gt, Gr = Tx, Rx antenna gain

rotherpolrataapt

rtout

rotherpolrataap

r

rotherpolrataap

rttr

LLLLLLLL

GGP

LLLLLLL

GEIRP

LLLLLLL

GGPP

x

48

위성시스템 : Link Power Budget Example

Parameter Value Totals Units Parameter Value Totals Units

Frequency 11.75 GHz

Transmitter Receive Antenna

Transmitter Power 40.00 dBm Radome Loss 0.50 dB

Modulation Loss 3.00 dB Diameter 1.5 m

Transmission Line Loss 0.75 dB Aperture Efficiency 0.6 none

Transmitted Power 36.25 dBm Gain 43.10 dBi

Polarization Loss 0.20 dB

Transmit Antenna Effective RX Ant. Gain 42.40 dB

Diameter 0.5 m

Aperture Efficiency 0.55 none Received Power -98.54 dBm

Transmit Antenna Gain 33.18 dBi

Slant Path Summary

Satellite Altitude 35,786 km Transmitted Power 36.25 dBm

Elevation Angle 14.5 degrees Transmit Anntenna Gain 33.18 dBi

Slant Range 41,602 km EIRP 69.43 dBmi

Free-space Path Loss 206.22 dB Path Loss 210.37 dB

Gaseous Loss 0.65 dB Effective RX Antenna Gain 42.4 dBi

Rain Loss (allocated) 3.50 dB Received Power -98.54 dBm

Path Loss 210.37 dB

49

위성시스템 : Separating Signals

Division of Up and Downlink

Up and Down:

FDD (Frequency Division Duplexing)

• f1 = Uplink

• f2 = Downlink

TDD (Time Division Duplexing)

• t1=Up, t2=Down, t3=Up, t4=Down,….

Polarization

• V & H linear polarization

• RH & LH circular polarizations

t

f

Uplink

Downlink

t

fU

plin

k

Dow

nlin

k

Uplin

k

Dow

nlin

k

<FDD>

<TDD>

50

위성시스템 : Separating Signals - polarization

Linear Polarization (horizontal or vertical): the two orthogonal components

of the electric field are in phase

The direction of the line in the plane depends on the relative amplitudes of the two components.

Circular Polarization: The two components are exactly

90º out of phase and have exactly the same amplitude.

Elliptical Polarization:All other cases.

Linear Polarization Circular Polarization Elliptical Polarization

51

위성시스템 : Separating Signals - polarization

<Vertical Linear Polarization> <Horizontal Linear Polarization>

<Right-handed/clockwise Circular Polarization><A Left-handed/counter-clockwise

Circular Polarization>

52

위성시스템 : Satellite Antenna

Satellite Antenna

53

위성시스템 : MAC Protocols

Multiple Access

FDMA (Frequency Division Multiple Access)

assigns each transmitter its own carrier frequency

• f1 = User 1; f2 = User 2; f3 = User 3, …

TDMA (Time Division Multiple Access)

each transmitter is given its own time slot

• t1=User_1, t2=User_2, t3=User_3, t4 = User_1, ...

CDMA (Code Division Multiple Access)

each transmitter transmits simultaneously and at the same frequency and each transmission is modulated by its own pseudo randomly coded bit stream

• Code 1 = User 1; Code 2 = User 2; Code 3 = User 3

MF-TDMA (Multi Frequency-TDMA)

Multiple FDMA with different bandwidth based on Channel characteristics

Dynamic TDMA in a frequency band

54


TDMA (INTELSAT/EUTELSAT)

The earth stations transmit one after another bursts of carrier with duration TB.

Bursts are inserted within a periodic time structure of duration TF, called a frame

Frame structure

55


TDMA (MUX/DEMUX) : Synch issues

TX RX 56


MF- TDMA Frames

The hub measures the signal-to-interference ratio (SIR) from each terminal through the return link and determines whether each terminal is faded or not.

The hub allocated clear-sky frame or rain-fade frame from these measurements

Timeslots

Common Signaling Channel• Slotted ALOHA, the frequency range of a terminal is

transmitted in this slot

Acquisition : Coarse timing synchronization

Synchronization : Precise timing synchronization

Traffic : Terminals send its data in these slots

Resource Allocation

Terminals in need of capacity send capacity request (CR) messages to a scheduler in hub

The scheduler collects CR messages during a superframe, generates a terminal burst time plan (TBTP) table, and send it to terminals

Upon receiving the TBTP table, each terminal reads the TBTP table to know what timeslots are assigned.

Time

Frequency

Superframe …

Time

Frequency

Frame

FrameFrameFrame

Tsf

Wsf

Wcsf

Wrsf

Tcf

Trf

Time

CSC

ACQ

SYNC

TRF

TRF

…TRF

Frequency

Clear-sky frame

Rain-fade frame

• CSC : Common Signal Channel

• ACQ : Acquisition

• SYNC : Synchronization

• TRF : Traffic 57

anchorstation main

hub

in theaterhub

위성시스템 : 위성망 토폴로지

Star 형 Mesh 형 Tree 형

58

위성시스템 : Satellite Routing

Key Elements of Iridium Communication System

[2] “Manual for ICAO aeronautical mobile satellite (route) services Part-2 IRIDIUM,” draft v4.0, ICAO, Mar. 2007. [3] Iridium-NEXT, “http://spaceflight101.com/spacecraft/iridium-next/” 59


Routing Scheme

GSO Routing

no ISL

LEO Routing

movement between the LEO satellite and the Earth -> a satellite has a very short visible period to motionless users on the ground.

Dynamic Topology: Support to inter-satellite handover, inter-beam handover.

Availability of ISL form a mesh network topology in the sky. Intra-plane and Inter-plane ISL may be supported.

60


Routing Scheme : Dynamic topology

The ISLs in the constellation form a mesh network topology

Each satellite is typically able to set up 4–8 ISLs

There are two types of ISLs:

• Intra-plane ISLs connecting adjacent satellites in the same orbit

• Inter-plane ISLs connecting neighboring satellites in adjoining orbits.

» some inter-plane ISLs may be temporarily switched off

» Fortunately, although the constellation topology changes frequently, it is highly periodic and predictable

61

Routing Scheme : Dynamic routing

Routing mechanisms popular in the Internet are not directly applicable

frequent topological changes in satellite constellation

large overhead and oscillation

Discrete-Time Dynamic Virtual Topology Routing (DT-DVTR)

full use of the periodic nature of satellite constellation and works completely offline

Virtual Node (VN)

hide the topology changes from the routing protocols

62



Routing Scheme : DT-DVTR It divides the system period into a set of time

intervals so that the topology changes only at the beginning of each time interval

In each interval, the routing problem is a static topology routing problem

A number of consecutive routing tables are then stored onboard and retrieved when the topology changes online computational complexity

• large storage requirement on the satellites

optimization procedure can be used to choose the best path or a small set of paths

Although it can significantly reduce the storage size, some links may become congested while others are underutilized

[4] Werner, M.; , "A dynamic routing concept for ATM-based satellite personal communication networks," Selected Areas in Communications, IEEE Journal on ,

vol.15, no.8, pp.1636-1648, Oct 199763


Routing Scheme : Virtual NodeA virtual topology is Superimposed on the

physical topology of the satellite constellation

Even as satellites are moving across the sky, the virtual topology remains unchanged In a certain period, a VN is represented by a

certain physical satellite

As this satellite disappears, the VN is represented by the next satellite passing overhead

Each VN keeps state information Routing tables

Information of users within the VN’s coverage

The state information is also transferred from the first satellite to the second.

A routing decision is made on the virtual topology

64

위성시스템 : GNSS Applications (case study)

Navigation systems for AL-FEC mechanism

Purpose

A Transmission Control Scheme aided by navigation systems to enhance the resource efficiency in the AL-FEC mechanism

[8] K. H. Lee, J. H. Kim, “Efficient AL-FEC Mechanism Aided by Navigation Systems for SOTM systems,” IEEE Trans. Wirel. Communi., vol. 15, no. 10 pp. 6651-6661, oct. 2016

※ AL-FEC (Application Layer Forward Error Correction)※ SOTM (Satellite on the Move), PEP (Performance Enhancing Proxy)

<System Model>

<System architecture with navigation systems>

65

위성시스템 : GNSS Applications (case study)

Navigation systems for AL-FEC mechanism

Performance Evaluation

[8] K. H. Lee, J. H. Kim, “Efficient AL-FEC Mechanism Aided by Navigation Systems for SOTM systems,” IEEE Trans. Wirel. Communi., vol. 15, no. 10 pp. 6651-6661, oct. 2016

<Packet delivery ratio in UDP with and without prop. AL-FEC mechanism>

66

위성시스템 : LTE + Satellite (example)

Real Scenarios tested

Scenario 1: Compact EPC at VSAT side

[10] G. M. Mattos, “Challenges and opportunities on testing LTE backhaul via satellite,” International Workshop on Challenges and Trends on BroadbandWireless Mobile Access networks – Beyond LTE-A, Dec. 2014. 67


Real Scenarios tested

Scenario 2: Compact EPC at HUB side


Measurements

Performance improvement with compact EPC at VSAT side vs. at Hub side

5% for throughput download

36% for throughput upload

8% for RTT measured at VSAT side

3% for RTT measured at HUB side



Results

Good user experience for voice service for both uplink and downlink

Best MOS 4.4 measured with PESQ tool and EPC at VSAT side

Optimized LTE integration with satellite backhaul resulting mean RTT less than 650 ms as expected

Sustainable download and upload data rates (average 50%, peak 80%) compatible with satellite shared channel capacity (Maximum: 8 Mbps download and 1 Mbps upload)

LTE plus satellite system architecture integration evaluation (compact centralized/decentralized EPC)

[10] G. M. Mattos, “Challenges and opportunities on testing LTE backhaul via satellite,” International Workshop on Challenges and Trends on BroadbandWireless Mobile Access networks – Beyond LTE-A, Dec. 2014.

※ PESQ (Perceptual evaluation of speech quality)

70




위성시스템

상용 통신위성



1

2

3

4

5

6

71

상용 통신위성 : Intelsat (International Telecommunication Satellite Organization)

<Intelsat 39>

Nation International

Type / Application Communication

Operator Intelsat

Contractors Space Systems/Loral (SS/L)

Equipment C- and Ku-band transponders

Configuration SSL-1300

Propulsion R-4D-11, 4 x SPT-100 plasma thrusters

Power 2 deployable solar arrays, batteries

Lifetime +15 years

Mass -

Orbit GEO

Launch time ’17.09 (Intersat 37e)

Transponder(transmitter – responder)

: receives signals over a range of uplink frequencies, amplifies them, and re-transmits them 72

상용 통신위성 : Inmarsat (the International Maritime Satellite Organization)

<Inmarsat-5 F4>

Nation International

Type / Application Communication (Global Express)

Operator Inmarsat

Contractors Boeing

Equipment 89 Ka-Band spot beams ,6 steerable spot beams

72 transponders

Configuration Spacebus-4000B2

Propulsion Xeon ion propulsion system (XIPS)

Power 2 deployable solar arrays (wing span : 40.6m)

Batteries

Lifetime 15 years

Mass ~ 6100 kg

Orbit GEO

Launch time ’17.05

73

상용 통신위성 : Inmarsat Global Xpress 1/3

74


75


76

상용 통신위성 : Thuraya

<Thuraya 3>

Nation United Arab Emirates


Operator Thuraya Satellite Telecommunications Co.

Contractors Boeing

Equipment L-Band 128 active elements

C-Band 2 active (2 spare)

12.25 m X 16m mesh reflector

128- element diple L band feed array

1.27 m round dual-pole reflector for C-band

communications

Configuration BBS-GEM (Geomobile)

Propulsion R-4D

Power 2 deployable solar arrays (40.4m)

, batteries

Lifetime 12 years

Mass 5250 kg

Orbit GEO

Launch time ’08.01.15 77

상용 통신위성 : Iridium (저궤도 위성)

<Iridium-NEXT>

Nation USA

Type / Application Communication, traffic monitoring

Operator Iridium Communications Inc.

Contractors Thales Alenia Space (prime), Orbital

(integration)

Equipment L-band payload, Ka-band cross-links, Ka-

band downlinks, ADS-B payload, AIS

payload (0n 58 satellites)

Configuration ELiTeBus-1000

Propulsion -

Power 2 deployable solar arrays, batteries

Lifetime 10 years (design), 15 years (planned)

Mass 860 kg

Orbit 780 km x 780 km 86.4º

Launch time ’17.01.15

78

상용 통신위성 : Globalstar (저궤도 위성)

<Globalstar – 2 >

Nation USA


Operator Globalstar

Contractors Alcatel Alenia Space

Equipment 16 C-to-S-band transponders, 16 L-to-C-

band transponders

Configuration ELiTeBus-1000

Propulsion -

Power 2 deployable solar arrays, 2.4 kW (bol), 1.7

kW (eol), batteries

Lifetime 15 years

Mass 700 kg

Orbit 1410 km x 1410 km

Launch time ’13.02.06

79



위성시스템

상용 통신위성



1

2

3

4

5

6

80

5G standardization roadmap (NTN)

81[11] Intergation of non-terreistrial solutions in the 5G standardisation roadmap, “https://artes.esa.int/news/integration-non-terrestrial-solutions-5g-standardisation-roadmap”

Universal terrestrial radio access architecture and interface protocols specification

Interface architectures, protocols, and resource control

Interface Physical layer

Overview the Non-Terrestrial Networks in 5G System

Objective

To study channel models, to define the deployment scenarios as well as the related system parameters and to identify and assess potential key impact areas on the NR

In a second phase, solutions for the identified key impact on RAN protocols/architecture will be evaluated and defined

82

Overview the Non-Terrestrial Networks in 5G System

83[11] Intergation of non-terreistrial solutions in the 5G standardisation roadmap, “https://artes.esa.int/news/integration-non-terrestrial-solutions-5g-standardisation-roadmap”

Roles for Non-Terrestrial Networks in 5G system

Expect

Upgrade the performance of limited terrestrial networks

Un-served areas that cannot be covered by terrestrial 5G network

• Isolated/remote areas, on board aircrafts or vessels

Underserved areas

• Sub-urban/rural areas

Reinforce the 5G service reliability

Providing service continuity

• M2M/IoT devices or for passengers on board moving platforms (e.g. passenger vehicles-aircraft, ships, high speed trains, bus)

Ensuring service availability

• Critical communications, future railway/maritime/aeronautical communications

Enable 5G network scalability

Providing efficient multicast/broadcast resources

• Data delivery towards the network edges or even user terminal

84

5G Use Cases wherein Non-Terrestrial Network components have a role

5G use cases for Satellite access networks

85

5G service enabler

5G Usecase

5G Use case description Satellite service3GPP

References

eMBB

Multi

connectivity

• Users in underserved areas are connected to the 5G

network via multiple network technologies and benefit

from 50Mbps+

• Delay sensitive traffic may be routed over short

latency links while less delay sensitive traffic can be

routed over the long latency links

• Broadband connectivity to cells or

relay node in underserved areas in

combination with terrestrial

wireless/cellular or wire line access

featuring limited user throughput

TS 22.261

TR 22.863

TR 22.864

Fixed cell

connectivity

• Users in isolated villages or industry premises

access 5G services and benefit from 50 Mbps+

• Broadband connectivity between the

core network and the cells in un-

served areas (isolated areas)

TR 22.863

Mobile cell

connectivity

• Passengers on board vessels or aircrafts access 5G

services and benefit from 50 Mbps+.


core network and the cells on

board a moving platform (e.g.

aircraft or vessels)

TS 22.261

TR 22.863

Network

resilience

• Some critical network links requires high availability

which can be achieved through the aggregation of two

or several network connections in parallel

• The intent is to prevent complete network connection

outage

• Secondary/backup connection

(although potentially limited in

capability compared to the primary

network connection)

TR 22.863

※ eMBB (enhanced Mobile Broadband)



86

5G service enabler

5G Usecase


References

eMBB

Trunking

• A network operator may want to deploy or restore 5G

service in an isolated area (not connected to public

data network)

• A network operator may want to interconnect various

5G local access network islands not otherwise

connected

• Broadcast channel to support

Multicast delivery to 5G network

edges

TR 22.863

Edge

network

Delivery

• Media and entertainment content updates are

transmitted in multicast mode to a RAN equipment at

the network edge where it may be stored in a local

cache or further distributed to the User Equipment.

• The intent is to offload popular content from the mobile

network infrastructure (especially at backhaul level).

• Broadband connectivity combined

with terrestrial cellular access to

connect a cell/group of cells or relay

node(s) on board moving platforms.

TS 22.261

TR 22.864

Mobile cell

hybrid

connectivity

• Passengers on board public transport vehicles

access reliable 5G services. They are served by a

base station which is connected by a hybrid

cellular/satellite connection. The cellular connectivity

may be intermittent and/or support limited user

throughput

• Broadcast/Multicast service to access

points in homes or on board

moving platforms

TS 22.261

TR 22.862

TR 22.863




87

5G service enabler

5G Usecase


References

eMBB

Direct to

Node

broadcast

• TV or multimedia service delivery to home premises or

on board a moving platform

• Broadcast/Multicast service to access

points in homes or on board moving

platforms

TS 22.261

TR 22.864

Direct to

mobile

broadcast

• Public safety authorities want to be able to

instantaneously alert/warn the public (or specific

subsets thereof) of catastrophic events and provide

guidance to them during the disaster relief while the

terrestrial network might be down

• Automotive industry players, are interested to provide

instantaneously Firmware/Software Over The Air

services (FOTA/SOTA) to their customers wherever

they are. This will include information updates such as

map information including points of interest (POI), real-

time traffic, weather, and early warning parking availability,

infotainment, etc

• Media and entertainment industry can provide

entertainment services in vehicles

• Broadcast/Multicast service directly to

User Equipment whether handheld

or vehicle mounted

TS 22.261

TR 22.862

TR 22.864




88

5G service enabler

5G Usecase


References

eMBB

Wide area

public

safety

• Emergency responders can exchange messaging and

voice services in outdoor conditions anywhere they

are and achieve continuity of service whatever mobility

scenarios.

• Access to User Equipment (handset

or vehicle mounted)

TS 22.261

TR 22.862

Local area

public

safety

• Emergency responders can set up a tactical cell

wherever they need to operate. This cell can be

connected to the 5G system via satellite to exchange data,

voice and video based services between the public safety

users within a tactical cell or with the remote coordination

centre


core network and the tactical cells

TS 22.261

TR 22.862




89

5G service enabler

5G Usecase


References

mMTC

Wide area

IoT service

• Global continuity of service for telematic applications

based on a group of sensors/actuators (IoT devices,

battery activated or not) scattered over or moving

around a wide area and reporting information to or

controlled by a central server

- Automotive and road transport

- Energy

- Transport

- Agriculture

• Connectivity between IoT devices

(battery activated sensors/actuators or

not) and spaceborne platform.

• Continuity of service across

spaceborne platforms and terrestrial

base stations is needed.

TS 22.261

TR 22.861

TR 22.862

TR 22.864

Local area

IoT

services

• Group of sensors that collect local information,

connect to each other and report to a central point.

The central point may also command a set of actuators

to take local actions such as on-off activities or far more

complex actions

• The sensors/actuators served by a local area network

may be located in a smart grid sub-system (Advanced

Metering) or on board a moving platform (e.g. container

on board a vessel, a truck or a train)

• Connectivity between mobile core

network and base station serving IoT

devices in a cell or a group of cells.

TS 22.261

TR 22.863

※ mMTC (massive Machine Type Communication)


5G use cases for Aerial access networks

90

5G service enabler

5G Usecase


References

eMBB

Hot spot

on

demand

• Users in un/underserved areas (big events) are

connected to the 5G network and benefit from 50

Mbps+

• Broadband connectivity to cells or

relay node in un/underserved areas.

TS 22.261

TR 22.863

Regional

area

public

safety

• Emergency responders can exchange messaging,

voice and video services in indoor/outdoor conditions

anywhere they are and whatever mobility scenarios

• Access to User Equipment (handset

or vehicle mounted).

• Adhoc connectivity between two cells

TS 22.261

TR 22.862

Fixed

cell

Connectivity

• Users in isolated villages or industry premises

(Mining, off shore platform) access 5G services and

benefit from 50 Mbps+.


core network and the cells in un-

served areas (isolated areas).

TS 22.261

TR 22.863


NTN channel model features per deployment scenarios

91

Deployment-D1 Deployment-D2 Deployment-D3 Deployment-D4 Deployment-D5

Platform orbit and altitudeGEO

at 35786 km

GEO

at 35786 km

Non-GEO down

to 600 km

Non-GEO down

to 600 km

HAPS between

8 km and 50 km

Carrier Frequency on the link

between Air / space-borne

platform and UE

Around 20 GHz

for DL Around 2 GHz

for both DL and UL (

S band)

Around 2 GHz

for both DL and

UL (S band)

Around 20 GHz for

DL

Below 6 GHz

Around 30 GHz

for UL

(Ka band)

Around 30 GHz for

UL

(Ka band)

Maximum Channel Bandwidth

(DL + UL)Up to 2 * 800 MHz

Up to 2 * 20

MHzUp to 2 * 20MHz Up to 2 * 800 MHz

Up to 2 * 80

MHz

Channel model calibration

92

Deployment-D1 Deployment-D2 Deployment-D3 Deployment-D4 Deployment-D5

UE type

Handheld, nomadic,

fixed, moving platform mounte

d

Handheld, moving

platform mounted

Handheld, moving

platform mounted

Handheld, nomadic,

fixed, moving platform mount

ed

Handheld, moving

platform mounted

Doppler cause Mainly UE mobilityMainly UE

mobility

UE + satellite

mobilityUE + satellite mobility

UE + HAPS

mobility

O2I penetration loss No No No No Possible

Atmospheric

absorptionMandatory Negligible Negligible Mandatory Negligible

Rain attenuationRain and cloud attenuation ar

e not neededNegligible Negligible

Rain and cloud attenuation ar

e not neededNegligible

Cloud attenuationRain and cloud attenuation ar

e not neededNegligible Negligible

Rain and cloud attenuation ar

e not neededNegligible

Scintillation Tropospheric Ionospheric Ionospheric Tropospheric Negligible

Fast fading models

(system level)Flat fading

Flat fading or

frequency selective

fading

Flat fading or frequency

selective fadingFlat fading

Frequency selective

fading

O2I: Outdoor to Indoor

Channel model calibration

NTN channel model features per deployment scenarios

Satellite and aerial access network architecture principles

Possible satellite and aerial access network architectures

Satellite access network & without ISL & above 6 GHz

Satellite access network & with ISL & above 6 GHz

93

PublicData

network

Very Small

Aperture TerminalGateway

Service link Feeder link

Corenetwork

Spaceborne

Plateform

PublicData

network

Very Small

Aperture Terminal GatewaySpaceborne

Platform

Service

linkFeeder

link

CorenetworkInter

Satellite

link

Spaceborne

Platform

ISL : Inter Satellite Link



Satellite access network & below 6 GHz & with terrestrial access network

94



Satellite access network & below 6 GHz & without terrestrial access network

Aerial access network & with IAL & above 6 GHz

95

Handheld

or IoT device GatewaySpaceborne

Plateform


PublicData

network

Corenetwork

PublicData

network

Very Small

Aperture Terminal GatewayAirborne

Platform

Service

linkFeeder

link

CorenetworkInter

Aerial link

Airborne

Platform

IAL : Inter Aerial Link



Aerial access network & without IAL & below 6 GHz

Aerial access network & with IAL & below 6 GHz

96IAL : Inter Aerial Link

Handheld or IoT deviceGateway

Airborne

Platform


PublicData

network

Corenetwork

Handheld

or IoT device

PublicData

network

GatewayAirborne

Platform

Service

linkFeeder

link

CorenetworkInter

Aerial link

Airborne

Platform

Doppler and Propagation delay characterization

Doppler shift/variation

Doppler shift

Shift of the signal frequency due to the motion of the receiver, the transmitter or both

Doppler variation rate

During time, the Doppler shift is evolving

The Doppler shift and Doppler variation depend on the relative speed of the space/airborne platforms, the speed of the UE, and the carrier frequency

Doppler shift formula

∆𝐹 = 𝐹0 × 𝑉 × cos 𝜃 /𝑐

97

V

Angle θ

Doppler (Non GEO Sat – 2GHz)

2 GHz 600km 2 GHz 1500km

2 GHz 10000km98

Doppler and Propagation delay characterization

Differential propagation delay

99

<UE>

[Differential propagation delay]NR vs NTN

<Cell Edge UE> <Cell Center UE>

[Differential propagation delay] cell center vs cell edge

<gNB>

Potential key impact areas on NR to support NTN

Non Terrestrial Network Design Constraints(Differences between NTN and NR)

Propagation

Multi path delay, Doppler

GSO: up to 272.4ms

NGSO: up to 14.2ms

HAPS: less than 1.6ms

Frequency plan and channel bandwidth

S band (2~4 GHz, 2×15 MHz), Ka band(26.5~40 GHz, 2×800 MHz)

Cell pattern generation

Larger cell, Moving cell(NGSO, HAPS)

Propagation Delay(cell Edge) >>> Propagation Delay(cell center)

100NGSO: Non-Geostationary Satellite OrbitHAPS: High-altitude Platform Station

Non Terrestrial Network Design Constraints

Mobility of the infrastructure’s transmission equipment

Cellular network usually fixed base stations (gNB)

NTN moving base stations higher Doppler effect(HAPS, NGSO)

LEO in S band (2GHz) ±48kHz Doppler shift

LEO in Ka band (20GHz) ±480kHz Doppler shift

LEO in Ka band (30GHz) ±720kHz Doppler shift

pre/post compensated




Service continunity between land-based 5G access and non-terrestrial based access networks

Support both non-transparent air/spaceborne (on-board processing) and bent-pipearchitectures

Handover preparation and HO failure/RLF handling

Time synchronization

Measurement object coordination

Lossless handover support

Specifics related to intra-Non Terrestrial network mobility, as well as between Non-Terrestrial and Cellular networks




Radio resource management adapted to network topology

Access control

• Cellular gNB(Xn interface) closed to the UE response time

• Satellite system satellite base station, gateway, hub level response time pre-grants, Semi Persistent Scheduling (SPS), grant free access scheme

Terminal mobility

Support very high speed UEs (최대 1000km/h)




104



위성시스템

상용 통신위성



1

2

3

4

5

6

105

SoF : Current Trends in Satellite Communications 1/3

전세계 우주개발 경쟁

최근 수년간 중국의 성장이 전통 우주개발의 강국이던 러시아를 앞질러 가고 있으며, 미국이 그 밖의 지역들의 위성발사 합과 비슷한 숫자의 인공위성을 발사하고 있음

<국가별, 응용분야별인공위성발사기록>106


국가별 우주개발 투자

2017년 예산을 기준으로 전세계의

국가들이 우주개발에 투자한 총 예산

44 B USD (약 47조원)

한국은 NASA, ESA, …, 인도 다음인

세계 10위로 643 M USD (6850억원)

예산을 투자

<국가별공공우주개발예산>107

세계 10위


전세계 우주개발 트렌드

소형 민간 기업 주도

전체 우주산업 시장규모의 약 77%

비용 저렴한 SmallSat, CubeSat

상용 위성 개발비의 1/100 이하

108

<실시간지표면 열, 온도측정서비스 – Koolock社 ><실시간날씨변화 분석서비스 – Orbital Micro Systems社>

SoF : ESA Copernicus program 1/4

109[12] https://www.sinergise.com/en/news/sentinel-hub-powering-copernicus-data-and-information-access-services

<Copernicus DIAS [12]>

<Copernicus programs>


110

111


112


[13] https://youtu.be/W3fv7TUmqf8

What is the SENTINEL mission ?

113

Recap of Falcon 9 launch and landing by SpaceX

발사체 시스템 재사용으로 위성 발사 비용 감소

SoF : Reusable Rocket Development

[14] https://www.youtube.com/watch?v=ANv5UfZsvZQ

통신분야의 위성군 프로젝트

Micro Sat, Nano Sat, Cube Sat 등 기술발전과, 통신/관측의 융합 서비스가 가능성에서 주목을 받으며, 현재 다양한 형태의 중궤도 및 저궤도 위성통신 시스템 제안

브로드밴드 시스템

• OneWeb,Starlink,

• Leosat,O3b, mPower

• ISIS, AISTECH,

• Planet Labs

그 밖의 시스템

• Sprie

114

SoF : Small Satellite of Future 1/4


지구 관측 위성 투자/개발 현황

100’s EO SATs to be launches by Private sector By 2025

CompanyRaised

($M)

Current/Planned

# of SATs

Resolution

(2/5m)

Full Constellation

Deployment

Hera systems 4.2 0/48 0.25/1 2020

Planet Labs 18.3 150/200 (June,’18) 3/5 2018

BlackSky Global 53.5 0/60 1 2019

OmniEarth 10.3 0/18 2/5 2019

Planetary Resources 22.5 0/10 10 2020+

AxelSpace 15 0/50 2.5 2020+

IceEys 2.8 0/40 - 2020

Terra BellaSold to

Planet 2/15 0.9/2 2018

Airbus+ Bill Gate +Soft

Bank? 0/500

115


Planet Labs

PlanetScope data reveals development of a plantation in the Brazilian [15]

116[15] https://storage.googleapis.com/planet-videos/mato-grosso-plantation.mp4


117

Planet Labs

Detect changes in infrastructure [16]

North Korea’s Chemical Material Institute manufactures materials used in development of ballistic-missile warheads.

[16] https://www.planet.com/markets/defense-and-intelligence/

US Retail TrafficWorld Oil Storage

Index

Global Water

ReservesPoverty Mapping Agriculture

118

SoF : Satellite Information Convergence Service

US Retail Traffic

119


120

World Oil Storage

Index


121

Global Water

Reserves


Poverty Mapping

122


123

Agriculture

SoF : Small Satellite of Future

Conclusions



위성시스템

상용 통신위성



124

References

[1] https://ko.wikipedia.org/wiki[2] “Manual for ICAO aeronautical mobile satellite (route) services Part-2 IRIDIUM,” draft v4.0, ICAO, Mar. 2007. [3] Iridium-NEXT, http://spaceflight101.com/spacecraft/iridium-next/[4] Werner, M.; , "A dynamic routing concept for ATM-based satellite personal communication networks," ,

IEEE Journal on Selected Areas in Communications, vol.15, no.8, pp.1636-1648, Oct 1997[5] Timing & Synchronization, https://www.gsa.europa.eu/sites/default/files/GNSS_timing.pdf[6] CDM-625 IEEE 1588v2 Precision Time Protocol performance, http://www.comtechefdata.com/files/WP-CDM-

625-IEEE-1588v2-PTP-Performance.pdf[7] 3GPP TS 36.355, v.10.0.0, Rel. 10, “LTE; Evolved Universal Terrestrial Radio Access (E-UTRA)” LTE Positioning

Protocol (LPP), Jan, 2011. [8] K. H. Lee, J. H. Kim, “Efficient AL-FEC Mechanism Aided by Navigation Systems for SOTM systems,” IEEE

Trans. Wirel. Communi., vol. 15, no. 10 pp. 6651-6661, oct. 2016[9] A. Donner, J. A. Saleemi, and J. M. Chaves,”TETRA backhauling via satellite: improving call setup times and

saving bandwidth,” Journal of Computer Networks and Communications vol. 2014, pp. 1 – 16, Oct. 2014.[10] G. M. Mattos, “Challenges and opportunities on testing LTE backhaul via satellite,” International Workshop on Challenges

and Trends on Broadband Wireless Mobile Access networks – Beyond LTE-A, Dec. 2014. [11] Intergation of non-terreistrial solutions in the 5G standardisation roadmap[12] https://www.sinergise.com/en/news/sentinel-hub-powering-copernicus-data-and-information-access-services[13] https://youtu.be/W3fv7TUmqf8[14] https://www.youtube.com/watch?v=ANv5UfZsvZQ[15] https://storage.googleapis.com/planet-videos/mato-grosso-plantation.mp4[16] https://www.planet.com/markets/defense-and-intelligence/

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http://www.comtechefdata.com/files/WP-CDM-

Thank you !

Q & A

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위성통신시스템 6g : capacity enhancement with satellite...

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