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Giuseppe Giuseppe CodispotiCodispotiTelecommunication and Telecommunication and IntegratedIntegrated ApplicationApplication UnitUnit
ItalianItalian SpaceSpace AgencyAgency
Involvement of Digital Divide affected countries in Q/V Involvement of Digital Divide affected countries in Q/V
Band experimentation and useBand experimentation and use
Vienna, Feb. 19Vienna, Feb. 19thth, 2013, 2013
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Italy, through its national body the Italian Space Agency, ASI, has proposed to use the experimental Q/V band frequency system,part of the payload on-board Alphasat satellite scheduled for launch on July 2013. The Q/V payload has been developed by ESA based on an Italian proposal and funded by ASI
On board segment
Ka/Q/V bands payload, TDP5, on board AlphasatESA/INMARSAT satellite, consists of 3 40/50 GHztelecom beams and 2 propagation beacons at Kaand Q bands
On Ground Segment
Three main ground stations at Tito, Spino d’Adda (Italy) and Graz (Austria) for both propagation and telecommunication experimentation and a series ofground stations for propagation only research.
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Fixed Beams
-3 -2.5 -2 -1.5 -1 -0.5 0
Az [deg]
5
5.5
6
6.5
7
7.5
8
El [d
eg]
RF 48G
Space Engineering S.p.A.
IT1 Beam Measured Gain @ 48 GHz
-3 -2.5 -2 -1.5 -1 -0.5 0
Az [deg]
5
5.5
6
6.5
7
7.5
8
El [d
eg]
RF 48G
Space Engineering S.p.A.
IT2 Beam Measured Gain @ 48 GHz
-3 -2.5 -2 -1.5 -1 -0.5 0
Az [deg]
5
5.5
6
6.5
7
7.5
8
El [d
eg]
RF 48G
Space Engineering S.p.A.
EU1 Beam Measured Gain @ 48 GHz
Up-link (V-Band) Beam Contourover Tito, Italy
Up-link (V-Band) Beam Contourover Spino d’Adda, Italy
Up-link (V-Band) Beam Contourover Graz, Austria
40/50 GHz telecom fixed beams over Tito and Spino d’Adda, Italy, and Graz, Austria
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Open beams
40 GHz (Q-Band) Open Beacon Coverage 20 GHz (Ka-Band) Open Beacon Coverage
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Why to experiment the use of higher frequency band?
“ . . These bands are essentially undeveloped and available for use in a broad range of new products
and services, including high-speed, point-to-point
wireless local area networks and broadband Internet access. Highly directional, 'pencil-beam' signal
characteristics permit systems in these bands to be engineered in close proximity to one another without
causing interference”
Federal Communications Commission (FCC) of the
U.S.A.
TLC systems at Q/V bands
• Larger bandwidth
• Smaller antenna for fixed gain
• Higher gain for fixed antenna
• Enhanced directivity for spot beams systems
• Increase of atmospheric impairments
• Research activities needed
• Different design approach:
– FMT
– Lower QoS
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Advantages & today limitations
Distribution of Attenuation at Q Band (ITALSAT Measurements at Spino d’Adda)
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0 5 10 15 20 25 3010
-2
10-1
100
101
102
total attenuation at 39.6 GHz (dB)
tim
e p
erc
enta
ge (
%)
19941995199619971998199920001994-2000
Gas and clouds up to 3 dB
Transition from stratiform to convective rain (for Site Diversity)
Inter-annual
variability15 dB at 99.9 % avail.
Atmospheric Propagation
• Impairments
– Gas
• Oxygen
• Water vapour
– Clouds
– Rain
– Turbulence
• Effects
– Absorption
– Scattering
– Attenuation
– Scintillation
– Depolarization
3 4 5 6 7 8 9 10 11 12-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
UTC Time (h)
Sig
nal le
vel a
t 18.7
GH
z (
dB
)
Italsat experiment at Spino d'Adda (elev. 37.8 deg.) - 08.07.1996
3 4 5 6 7 8 9 10 11 12-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
UTC Time (h)
Sig
nal le
vel a
t 18.7
GH
z (
dB
)
Italsat experiment at Spino d'Adda (elev. 37.8 deg.) - 08.07.1996
3 4 5 6 7 8 9 10 11 12-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
UTC Time (h)
Sig
nal le
vel a
t 18.7
GH
z (
dB
)
Italsat experiment at Spino d'Adda (elev. 37.8 deg.) - 08.07.1996
Gas
absorption
Cloud
absorption
Rain
attenuation
Scintillation
Prediction in the Q/V band
• Gas and clouds models:
– satisfactory accuracy (versus radiosoundings)
– Few beacon measurements
• Rain attenuation, depolarization and scintillation
models: needed much further research efforts
• Urgent need of appropriate satellite long-term propagation campaign in Q/V band:
– Attenuation at multiple frequencies and sites
– Depolarization and scintillation measurements
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Aldo Paraboni Alphasat Experiment
• Long-term scientific objectives
– New data to design future Fade Mitigation Technique, FMT, systems such as:
• On-board antenna reconfigurability
• Variable power partitioning among beams
• Adaptive Code Modulation, ACM
• Up- and down-link power control
• …
– First and second order statistics of propagation impairments
– Coordination of measurements from European Earth terminals
– Plan for a synergic use of Weather Forecast (ECMWF) and of Earth Observation products (MSG, TRMM, Cloudsat, etc.)
– Concurrent communication and propagation measurements
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Past European Beacon Experiment (ITU-R database)
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Network of Alpahasat Propagation Terminals
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Large GS,
TLC and Propagation
Large GS TLC
Small Prop Terminal
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Potential involvement of other Nations
40 GHz (Q-Band) Beacon Coverage 20 GHz (Ka-Band) Beacon Coverage
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• Data of propagation characterization coming from
other countries are needed in order to prepare the use of Q/V band frequencies for coming application.
• Cost of the investment to join the experiment is
extremely low when compared with the possible
benefits.
• The advantage gained is not only for the scientific
community but has mainly to be viewed as an general opportunity for technological improvement.
• The use of the proposed frequency bands in areas other
than those already involved will allow the use of new
technologies for countries where a fast telecommunication development is needed. Larger
bandwidth availability will help to spread fast telecom services channels such as voice, television, internet etc.
