Transcript New Technology & AMSAT Dr. Tom Clark, K3IO (ex W3IWI) _____________________________________________________ ARRL TTF Forum Dayton, Ohio May 17,2008 Standing in for Bob McGwier, N4HY May 17, 2008 K3IO: ARRL TTF.

New Technology
& AMSAT
Dr. Tom Clark, K3IO
(ex W3IWI)
_____________________________________________________
ARRL TTF Forum
Dayton, Ohio
May 17,2008
Standing in for Bob McGwier, N4HY
May 17, 2008
K3IO: ARRL TTF Forum
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Some Mandatory Things needed for amateur
radio to have a significant presence in space
 Launch Opportunities
 Space used to have a significant R&D presence, but it has
become a commercial commodity
 Money

There ain’t no such thing as a Free Launch
 Enthusiasm
 from the “tekkie” volunteers, satellite users, ARRL, IARU,
ITU, Governments, sponsors, etc
 Suitable frequencies for the radios to use
 LEO favors the use of VHF, UHF and low microwave
o 144-146, 435-438, 1260-1270 MHz
 HEO favors the use of microwaves
 Advancing the S.O.T.A. in technology
 Justify amateur radio’s existence (“inventions”, EMCOM, etc)
 Keep the “tekkies” excited
May 17, 2008
K3IO: ARRL TTF Forum
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Low Earth Orbit (LEO) Satellites:
 Launches used to be “free” when NASA launched
R&D missions – cost is now ~$20k/kg.
 Well suited to simple VHF/UHF links that use
existing radio resources.
 FM/FM repeaters and some Linear Transponders
 ~$50k University programs – especially Cubesats
 AX.25 data telemetry – not many transponders
 Not strong on Amateur Radio, but they need mentors!
 ARISS Program
 Strong on Crew Participation in Educational Programs
 Conventional radios favoring VHF/UHF
 Suitsat – “Gee Whiz” educational and PR
Programs
May 17, 2008
 Suitsat-2 will use interesting SDX technology
K3IO: ARRL TTF Forum
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High Earth Orbit (HEO) Satellites:
 Offers Global-.scale communications. AMSAT has a goal
of 24/7 communications.
 Future “Phase-3” launches are problematic
 Very few launch opportunities & they are quite expen$ive (> $1-2M each)
 Elliptical orbits require us to be real “Rocket Scientists” with kick motors
and complex attitude control.
 AMSAT-DL is building Phase-3E and AMSAT-NA is supporting them.
 AMSAT has EAGLE in its plans – HEO in elliptical orbit
and with kick motors and significant new capabilities (ACP)
 Then, about a year ago, we became aware that there is a
significant possibility for adding an amateur piggyback
payload on commercial Geostationary (GEO) Satellites.
No kick motors are required ! The ride is their responsibility.
They supply significant quantities of power – like HUNDREDS of watts
They supply attitude control, with earth pointing at accuracies ~ 1°
It appears that this is a “renewable resource” with multiple launches
possible (if we don’t blow it!)
 But the commercial launch opportunity implies $IGNIFICANT CO$T$




NEEDLESS TO SAY, WE REALLY LIKE THIS OPTION ! !
May 17, 2008
K3IO: ARRL TTF Forum
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AMSAT-NA’s HEO FUTURE:
A Heavy Emphasis on Microwaves
United States Microwave Allocations
Amateur Service in the USA
The Amateur-Satellite Service
Band
(MHz)
Bandwidth
(MHz)
Band
(MHz)
Bandwidth
(MHz)
23 cm: 1240-1300
60
Lu=1260-1270 
10
13 cm: 2300-2310
13 cm: 2390-2450
10
60
S1=2400-2450
50
9 cm: 3300-3500
200
S2=3400-3410 ☼
10
5 cm: 5650-5925
275
Cu=5650-5670 
Cd=5830-5850 
20
20
3 cm: 10000-10500
500
X=10450-10500
50
1.3 cm: 24000-24250
250
K=24000-24050
50
 means Earth-to-Space (uplink) direction only
 means Space-to-Earth (downlink) direction only
☼ the 9 cm satellite band is only available in regions 2 & 3
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Some GEO Thoughts
 The possibility of a GEO launch (with no kick
motors and a lot of watts!) has caused us to put
many EAGLE developments on the back burner:




Mechanical Structure » provided by them
Thermal Control » provided by them
Power System » hundreds of watts provided by them
Adaptive Phased Array » fixed (e.g. dish) antenna(s)
 It’s a couple of years before we could launch,
and a GEO satellite should live ≈ 15 years.
 Therefore, we must forecast the state of “amateur” technology
in the 2015-2020 era.
 How best can amateur radio use a 24/7 stable
“ionosphere”?
 Advancing the state-of-the-art in communications technology?
 Public Service (especially emergency communications)?
 Fun, ???
May 17, 2008
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The stable, 24/7 nature of GEO requires that
we re-examine “optimum” communication links.
 Uplinks are “many users-to-one satellite”, while downlinks
are “one-to-many” » asymmetric comm links.
 On uplink, the user’s signal suffers a 1/R² loss in SNR,
and the downlink also suffers a 1/R² loss.
 With a linear transponder, this leads to a net 1/R4 SNR loss.
 If the signal has FEC & is demodulated at the satellite, and then
re-modulated with “fresh” FEC, then the SNR loss is only 1/R².
 The system design needs to optimize the spacecraft and
the user at the same time.
 Amateurs will need new equipment.
 The TAPR “kit” model (followed by commercial licenses, a la
theTNC-2) seems appropriate. The joint TAPR/AMSAT HPSDR
sponsorship is a start.
 Uplink probably FDMA at C-band=5.7 GHz
 Wideband “Broadcast” Downlink at S2=3.4 GHz
May 17, 2008
K3IO: ARRL TTF Forum
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Typical GEO User “Classes”
A. There will undoubtedly be conventional linear
(SDX) transponders to serve legacy users:

VHF (=145 MHz), UHF(=435 MHz), L (=1.26 GHz) & S1 (=2.4 GHz)
B. There will be a low-speed text message capability with small, hand-held user terminals.


Much like “SMS” or “Twitter” messaging
This should prove invaluable for first-responder Emergency
Communications !
C. For stations with ~1m dish antennas, there will
be multiple channels


Operations much like “Echolink” or “D-Star”
Perfect for casual QSOs,roundtables, nets, etc.
D. With a somewhat larger dish & TX, the user
can have wideband (~¼-½ Mb/sec) data access.

May 17, 2008
Class C-users should be able to copy Class-D wideband data.
K3IO: ARRL TTF Forum
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AMSAT calls this development program
ACP = Advanced Communications Payload
 ACP was discussed at this morning’s AMSAT
Forum:
 Matt Ettus (N2MJI) discussed his thoughts on ACT system
architecture
 Michelle Thompson (W5NYV) discussed plans for user terminal
design and an ACT on-the-air demo in the San Diego area:
May 17, 2008
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The San Diego Demo
 Has a primary goal of demonstrating multiplatform Interoperability
 Since 9/11 & Katrina, Homeland Security has spent billions
in an attempt to provide interop, but have hit roadblocks
from entrenched commercial interests.
 We think the amateurs, employing “open source” concepts,
can show the way. The scheme involves TCP/IP as the lowlevel interface.
 We hope to get H.S. to provide $ignificant $upport to
make the GEO mission a real possibility.
Interested in GEO & ACP?
Stop by the AMSAT booth this weekend and chat with Matt,
Michele & me, or visit http://www.amsat.org/namaste/ to
see/hear Michele presentation
May 17, 2008
73 de Tom Clark, K3IO
mailto: [email protected]
K3IO: ARRL TTF Forum
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Backup Slides
 Comments on each of the microwave bands
 Extracted (enedited) from a 2006 presentation
May 17, 2008
K3IO: ARRL TTF Forum
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Some Things to Note #1
 Galileo’s E6 signal (similar to GPS’s L2 signal at
1226 MHz) overlays the 1260-1270 MHz
satellite (uplink only) subband.
 Chinese and Japanese also plan their own GNSS
systems with additional signals in 1200-1300
MHz band
 The 23 cm band faces an imminent threat from
the European Galileo GNSS, plus similar Chinese
and Japanese programs on the books.
 Galileo + GPS + other GNSS are becoming
“Safety of Life” services (like navigating civilian
aircraft) and our priority is low.
 See article by Peter Blair, G3LTF for a summary
of the problem:
http://www.southgatearc.org/articles/galileo.htm
May 17, 2008
K3IO: ARRL TTF Forum
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Some Things to Note #2
 The 13 cm band has become a SEWER with all
the ISM & Part 15 and unlicensed users (WiFi,
cordless phones, Bluetooth, Microwave Ovens)
all over the world.
 But S-band with AO-40 proved to be a very
popular DOWNLINK.
 We need UPLINKS to stake a claim on our
rights to this spectrum.
May 17, 2008
K3IO: ARRL TTF Forum
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Some Things to Note #3
 The 9 cm band (3400-3410 MHz) has
not figured in a lot of planning for
amateur satellites because it is
(currently) only available in ITU Regions
2&3 (Americas, Oceania, Asia).
 However many European countries (OH*,
OZ,G,DL,OK,ON,PA,LA,9A and ???)
have 9 cm (3400-3410 MHz) allocations
for terrestrial applications) ( * Note: OH only
3400-3408)
 Some of us are now seriously advocating
the use of this band to the benefit of
the countries that
CAN
use it.
May 17, 2008
K3IO: ARRL
TTF Forum
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Some Things to Note #3
cont’d 1
 The IARU says about 9 cm:
 The Amateur-Satellite Service seeks to retain its bidirectional (Earth-to-space and space-to-Earth)
allocation of the band 3400-3410 MHz in Regions 2
and 3, and to expand this allocation to Region 1.
 CEPT DSI Phase I established an Amateur Service
secondary allocation at 3400-3500 MHz. In addition,
the following footnote was adopted by the CEPT:
EU17: In the sub-bands 3400-3410 MHz, 5660-5670 MHz,
10.36-10.37 GHz and 10.45-10.46 GHz the amateur service
operates on a secondary basis. In making assignments to
other services, CEPT administrations are requested
wherever possible to maintain these sub-bands in such a way
as to facilitate the reception of amateur emissions with
minimal power flux densities.
In effect, EU17 encourages administrations to afford some
consideration to amateur weak-signal operations in the band
sub-band 3400-3410 MHz, among others.
There is a major effort by the telecommunications industry to
promote the band 3400-3650 MHz for fixed wireless
access (FWA) applications, which could affect amateur uses
of the band. Radiolocation interests oppose FWA
applications of this band.
May 17, 2008
K3IO: ARRL TTF Forum
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Some Things to Note #3
cont’d 2
 If we go ahead and use 9cm for downlink, then amateurs would still be able to
listen, even from Region 1, even without a
rules change.
 Commercial VSAT users use 3400 as
uplink, while Fixed Satellite Service has it
downlink.
 Some nice brand new ~50w PA’s are now
available (PyroJoe on EBay & K5VH) for
$150. They look good enough to fly!
 [political sarcasm removed for public
consumption]
May 17, 2008
K3IO: ARRL TTF Forum
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Which Brings us to C-Band
120
130
140
WiFi Channel ##
150
160
170
180
1.3
1.25
SAT
UP
SAT
DOWN
Weak
Signal
P3E
Terrestrial Amateur
1.2
Pre-2004
802.11a WiFi
USA
Intelligent
Transportation
1.15
New WRC-03 WiFi
European Hiperlan (Indoor only, 200 mw max)
1.1
WECA WiFi Adopted by FCC 2004
Fixed Satellite (Earth to Space) & Radionavigation
1.05
1
5600
May 17, 2008
5650
5700
5750
5800
K3IO: ARRL TTF Forum
Frequency
5850
MHz
1
5900
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So S-band is a sewer –How about WiFi @ C-Band?
 We are fortunate that the WiFi & Part 15
activity overlays the C-band UPLINK.
 Ground-based uplink signals might even help
move them to the other end of the band.
 In my CC-Rider printed paper, you will see the
numbers behind my estimate that:
If every person in US & Canada has a WiFi
xmitter on the air for 16 hours a day (i.e. 217
million xmtrs are on the air at any given time),
If they uniformly occupy all 550 MHz allocated
to the unlicensed services,
Then they would only add ~57K to the system
temperature at the spacecraft.
May 17, 2008
K3IO: ARRL TTF Forum
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And Even Higher?
 My gut feeling is that 10,24, 47 +++ GHz are
great for experiments (like beacons), but the
user community is not yet ready for them on an
operational basis.
 Rejoinders? Comments?
73 de K3IO
May 17, 2008
K3IO: ARRL TTF Forum
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Mandatory References:
 A fantastic resource with all the relevant ITU
material and footnotes is maintained by DL4TA:
http://www.kloth.net/radio/freq-itu.php
 G3LTF’s Galileo article is at
http://www.southgatearc.org/articles/galile
o.htm
 Get the pointers from Jan for
http://www.iaru.org
May 17, 2008
K3IO: ARRL TTF Forum
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