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The 20th AIAA 12-15, May, 2002

THE WIDEBAND INTERNETWORKING ENGINEERING TEST AND DEMONSTRATION

SATELLITE (WINDS) SYSTEM

Ryouichi Kuramasu, Tsunehiko Araki, Masaaki Shimada, Eiichi Tomita,

Tetsuo Satoh, Tomonori Kuroda, Masanobu Yajima, Tsuyoshi Maeda, Tatsuya Mukai,

National Space Development Agency of Japan (NASDA)

Naoto Kadowaki, Masahiro Nakao

Communications Research Laboratory (CRL)

2-1-1 Sengen, Tsukuba-shi, Ibaraki 305-8505, Japan

e-mail: mukai.tatsuya@nasda.go.jp

Abstract

The Wideband InterNetworking engineering

test and Demonstration Satellite (It is abbreviated

to WINDS.) Program (The former tentative

program name: The Ultra-High-Data-Rate

Internet Test Satellite Program) is planned as the

joint-development project of National Space

Development Agency of Japan (NASDA) and

Communications Research Laboratory (CRL).

Phase A study of this program was started by

NASDA last year and is still continuing. The

WINDS network experiment system is planned to

demonstrate the high data rate internet multicast

experiment and other communication experiments,

using newly key technology such as Ka band

satellite antenna with rain attenuation

compensation function, Ka band scanning spot

beam antenna, high throughput on-board switch

and so on.

This paper describes the concept and outline of

the WINDS network experiment system.

1. Outline of program

(a) e-Japan Strategy

The Japanese government is carrying out IT

Policy as “e-Japan Strategy”. It is insisted to make

Japan the world’s most advanced IT nation within

five years through preparation of high-speed

Internet network. The WINDS is considered as

one future technology to be developed in order to

construct the wireless fixed international network

based on “e-Japan Strategy”.

(b) i-Space program

The WINDS program is positioned as the main

project of i-Space program [1] in the basic strategy

of space development in Japan.

This Program is NASDA’s integrated program

based on the newly subject for “Constructing

space infrastructure for realizing the

Ultra-High-Data-Rate Internet Society”

cooperatively pursued by the NASDA under the

Ministry of Education, Culture, Sports, Science

and Technology (MEXT) and CRL under the

Ministry of Public Management, Home Affairs,

Posts and Telecommunications (MPHPT).

(c) Objectives of program

From the “e-Japan strategy” of government and

the basic strategy of space development in Japan,

this WINDS program has mainly two objectives.

(1) Development of this satellite communication

network experiment system aiming at the

future space communication infrastructure to

overcome digital divide and contribute to the

Copyright © 2002 by American Institute of Aeronautics and Astronautics All rights reserved.

20th AIAA International Communication Satellite Systems Conference and Exhibit12-15 May 2002, Montreal, Quebec, Canada

AIAA 2002-2044

Copyright © 2002 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

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advanced information communication

network society.

(2) Demonstration of the utilization for high data

rate satellite communication system in

advanced information infrastructure by using

this satellite communication network

experiment system.

(d) Promotion of Satellite Communications

Experiment

CRL and NASDA consider it also important to

explore new and attractive application

experiments by promoting the utilization of

satellite missions.

As results of promotion of satellite utilization

activity, CRL and NASDA will demonstrate the

new satellite use, which will increase the demand

for satellite utilization with joint experiment body.

The examples of such demonstration will be the

follows.

(1) High-data-rate satellite multicasting to realize

100Mbps-class data distribution.

(2) Utilization of high-data-rate satellite

communications in the field of tele-education

and tele-medicine

(3) Utilization of satellite communications for

disaster and environment monitoring.

(4) Other differential satellite utilization making

most of satellite features

2. The WINDS network experiment system

(a) Outline

The WINDS network experiment system is

total experimental network system constructed

with the experimental communications satellite

named WINDS, the ground experimental

terminals and tracking control system.

The WINDS is designed based on the study [2]

by CRL together with NASDA.

This satellite has an ability as a fiber-like Gbps

connection and the 155Mbps ATM-based

multimedia access by small ground terminals

throughout the Asia-Pacific area.

Even though the high-speed terrestrial lines

such as optical fiber networks are being laid, the

satellite communication system can be utilized as

a complementary system together with ground

infrastructure. The satellite multicasting function

(one to N communication) is one of its significant

features making use of its wide area coverage and

simultaneity.

(b) Network configuration

From the above promotion of satellite

utilization, network configuration to be

constructed was considered as follows.

(1) Non-symmetrical communication with

on-board switch

(2) Symmetrical communication with on-board

switch

(3) Bent-pipe communication

(c) Mission Payload configuration

To realize high data rate communication in

widely Asia pacific area, 2types of satellite

antenna are demanded. Fixed antennas named

Multi-beam antenna (MBA) provide high EIRP

and G/T performance for higher data rate

transmission. Scanning spot beam antennas

named Active phased array antenna (APAA)

provide widely cover area. The WINDS coverage

areas are shown in Figure1.From the network

configuration, the WINDS has both bent pipe

transponder and regenerative ATM baseband SW.

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The Outline of Mission payload configuration

is shown in Figure 2, and the Specification of

communication links is shown in Table 1.

Figure 1.

Coverage Areas (tentative)

APAA beams(example)

Fixed Beams allocation area

APAA beams(example)

Fixed Beams allocation area

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Figure 2.

Outline of Mission Payload Configuration (tentative)

Table 1. Specification of communication links (tentative)

Non-symmetrical or Symmetrical

communication with on-board switch

Bent-pipe communication

Data Relay Regenerative (ATM baseband SW) Bent Pipe

Frequency U/L: 28GHz band D/L: 18GHz band

Antenna Beams Fixed beams (MBA) for Japan and prospective cities in Asia region

Scanning Spot beams (APAA) for the other area

Data Rate U/L: 1.5,6,51,155Mbps

D/L: 155Mbps

1.2Gbps(622Mbps�2),

622Mbps

Satellite EIRP >70dBW (maximum EIRP for a Fixed Beam)

>55dBW (total EIRP of APAA)

Satellite G/T >21dB/K (for Fixed Beam)

>11dB/K (for APAA)

Link Availability >99.5% (in Japan, Target)

>98% (in Asia-Pacific Region, Target)

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(d) Key technology to be developed

The following shows the significant matters in

connection to the development of the WINDS

network experiment system.

(1) Ka-band satellite antenna with rain attenuation

compensation function

The rain attenuation of Ka-band is

significantly large, but it is needed to use

Ka-band in order to realize the newly

broadband fixed satellite communications.

Therefore, the effective rain attenuation

compensation technology in Ka-band is needed.

NASDA will try to realize the development of

the Multi-beam antenna (MBA) with multi-port

amplifier (MPA) using TWTA.

(2) Ka-band scanning spot beam antenna

Scanning spot beam antenna is one solution

to provide experiment opportunity in remote

areas of Asia-Pacific region and the Ka-band

active phased array antennas (APAA) will be

developed as this scanning spot beam antenna.

(3) High throughput ATM baseband switch

155Mbps ATM baseband switch is under

development by CRL for better connectivity.

(4) Small-sized ground terminals

Small-sized ground terminals such as very

small aperture terminal (VSAT (about

1.2m-2.4m)) and Ultra small aperture terminal

(USAT) (about 0.45m) with ATM function are

also needed.

(e) Satellite System

The WINDS is designed by considering about

the launch by H-IIA rocket.

The current main specifications of satellite

system are shown in Table2, and Satellite

configuration is shown in Figure3.

Table 2. The main specifications of satellite system

Launch Date 2005

Orbit GEO (143, 146 or 154.5deg.E)

Mass. 4900 kg on GEO

2450 kg (DRY)

Generated Power 7kW (EOL)

Attitude Control 3 axis Stabilization

Figure 3.

Satellite Configuration (tentative)

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3. Conclusion

The WINDS is demanded to start the

experiment by FY2005 on “e-Japan strategy” and

its development is going on aiming at the launch

for FY2005.

Some engineering model about each

development element and test is scheduled on this

phase.

References

[1] IAF-00-U.3.03

“NASDA’s Activities and roles in promoting

satellite utilization experiments”

[2] AIAA2000-1138

“advanced Ka-band satellite

communications mission”

[3] IAF-01-M.2.a.05

THE ULTRA-HIGH-DATA-RATE INTERNET

TEST SATELLITE PROGRAM