1. Proposal for methodology to estimate spectrum requirements
for AMS(R)S satellite systems
under AI 1.7 (WRC-11)
Presentation at the
ACP/WGF 19th meeting Sep 2008
Tony Azzarelli
(European Space Agency)

2. WP4C Work: Methodology 1. ACP/WGF 2. ITU-R WP4C
Aviation requirements inputs
Satellite Technology inputs
Total Bandwidth Requirement
Methodology to derive Spectrum
Requirements for WRC-11 AI 1.7
RIT(t), MIT

3. Aviation Communication Needs
1.a) Simulation Approach
e.g. COCR
RIT(t;s)
MIT = max { RIT(t;s) }

4. Aviation Communication Needs
time
Amount of data
in one flight
flight path / phases
cruise
departure
arrival
at airport
begin
end
airport
Flight Phases
Communications

5. Aviation Communication Needs
SIMULATION
Chart thanks to CNES

6. Aviation Communication Needs
Aggregate Throughput
R1(t;s)
R2(t;s)
RIT(t; S) =
= S(i = 1 .. n) Ri(t; S)
= R n(t; S)
R (Mbps)
n(t;S) number of transmitting a/c
Ri(t;s)
RN(t;s)
Maximum RIT (MIT)

7. Use of SPOT BEAMS WGF output / WP4C input Spot beam area (s)
Aviation Area (S)
RIT(t; S)
Airspace Unit (DS)
RIT(t; DS)
Spot beam area (s)
RIT(t; s) =SRIT(t, DS)
Use of
SPOT BEAMS

8. WGF output / WP4C input PIAC r = average(t) { R(t) }
1.b) PIAC Approach
e.g. COCR
PIAC
r = average(t) { R(t) }

9. Aviation Communication Needs
WGF output / WP4C input
Output
Aviation Communication Needs

10. 1. Output of the Simulation Approach
WGF output / WP4C input
1. Output of the Simulation Approach
RIT(t; s) = Si=1 .. n Ri(t;s) = R · n(t;s) where: n(t;s) = number of transmit a/c at t
MITSIM(s) = max(t) { RIT(t;s) } = R max{ n(t;s) } = R n(s)
MIT(s)= R n(s) t0

11. 2. Output of the PIAC Approach MITPIAC(s) = PIAC(s) * r(s)
WGF output / WP4C input
2. Output of the PIAC Approach
MITPIAC(s) = PIAC(s) * r(s)
where: PIAC(s) = N(s) maximum instantaneous a/c count in the region
And: r(s) = average{ R }, average data rate per flight.
The two approaches are the same because MITSIM = MITPIAC, i.e.:
MITSIM = R n(s) = Si=1..n R(to; s)
= PIAC (1/PIAC) Si=1..n R
= PIAC (1/PIAC) Si=1..PIAC R pi(to;s)
= PIAC average(i) { Ri } = PIAC mean(t) { R(t) } (ergodic)
= MITPIAC
One would use one approach or the other depending on the tools available
to calculate the aviation throughput and also depending if the satellite
has or not spot beams.

12. These outputs will be provided to WP4C for Calculating Bandwidth for
WGF output / WP4C input
These outputs will be provided to WP4C for
Calculating Bandwidth for
AMS(R)S Services under WI 1.7

13. 2. ITU-R WP4C Methodology WP4C Work: Methodology Satellite Aviation
characteristics
Aviation
comms needs

14. WP4C Work: Methodology
Detailed Methodology

15. WP4C Work: Methodology
Step 1: beam structure
MIT(s i)
MIT(S)

16. WP4C Work: Methodology Step 2: Bandwidth Calculation
per beam or cluster of beams

17. g2 , due to satellite access method (e.g. CDMA)
WP4C Work: Methodology
Framing overhead at different protocol layers
Step 2
a = 1 + a 1 + a 2
Signalling overhead 1. 2.
b = b · h · d F S 3.
g = g1 g2 D B
g1 =D/B
g2 , due to satellite access method (e.g. CDMA)

18. Non-Uniform Throughput
WP4C Work: Methodology
BR(s1)
Aviation region
Step 3
m > 3/11
Non-Uniform Throughput
m = 3/11
BRSS= (3/11) BR(s)

19. WP4C Work: Methodology RIT BRSS = m Ss BR(s) MIT (s)
required bandwidth
RIT
BRSS = m Ss BR(s)
= m Ss ab g MIT(s)
= ab g m Ss MIT(s)
MIT (s)
T(s) = a MIT
RS(s) = b T
BR(s) = g RS
BRSS = m BR

20. Thank you for your attention!
Comments are welcome!