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Proposal for methodologyto estimate spectrum requirements

for AMS(R)S satellite systemsunder AI 1.7 (WRC-11)

Presentation at theACP/WGF 19th meeting 15-19 Sep 2008

Tony Azzarelli(European Space Agency)

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WP4C Work: Methodology

Aviation requirements

inputs

Satellite Technology inputs

Total Bandwidth Requirement

Methodology to derive Spectrum

Requirements for WRC-11 AI 1.7

RIT(t), MIT

2. ITU-R WP4C1. ACP/WGF

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Aviation Communication Needs

1.a) Simulation Approach

RIT(t;s)

MIT = max { RIT(t;s) }

e.g. COCR

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Aviation Communication Needs

•time

Amount of data

in one flight

flight path / phases

•cruise

•departure

•arrival

•at airport

•begin •end

airport •departure cruise arrival airport

•at airport

Flight Phases

Communications

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Aviation Communication Needs

Chart thanks to CNES

SIMULATION

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Aviation Communication Needs

RIT(t; S) =

(i = 1 .. n) Ri(t; S)

= R n(t; S)

R (Mbps)n(t;S) number of transmitting a/c Maximum RIT (MIT)

R1(t;s)

R2(t;s)

Ri(t;s)

RN(t;s)

Aggregate Throughput

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WGF output / WP4C input

Aviation Area (S)

RIT(t; S)

Airspace Unit (S)

RIT(t; S)

Spot beam area ()

RIT(t; ) =RIT(t, S)

Use of

SPOT BEAMS

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WGF output / WP4C input

1.b) PIAC Approach

• PIAC

• r = average(t) { R(t) }

e.g. COCR

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WGF output / WP4C input

Output

Aviation Communication Needs

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WGF output / WP4C input

1. Output of the Simulation Approach

•RIT(t; s) = i=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

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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) = i=1..n R(to; s)

= PIAC (1/PIAC) i=1..n R

= PIAC (1/PIAC) i=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 availableto calculate the aviation throughput and also depending if the satellite has or not spot beams.

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WGF output / WP4C input

These outputs will be provided to WP4C for

Calculating Bandwidth for

AMS(R)S Services under WI 1.7

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WP4C Work: Methodology

2. ITU-R WP4C MethodologySatellite

characteristicsAviation

comms needs

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WP4C Work: Methodology

Detailed Methodology

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WP4C Work: Methodology

Step 1: beam structure

MIT(i)

MIT(S)

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WP4C Work: Methodology

Step 2:

Bandwidth Calculation

per beam or cluster of beams

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WP4C Work: Methodology

Step 2

= 1 + 1 + 2

Framing overhead at different protocol layers

Signalling overhead1.

encoding modulation raw spectrum

Rj-1

signal domain

Rj

Filtering

BBw

data domain

data2.

= b · ·

3. = 1 2

=/B

due to satellite access method (e.g. CDMA)

F S

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WP4C Work: Methodology

Step 3

BR(1)

Aviation region

= 3/11

BRSS= (3/11) BR()

> 3/11

Non-Uniform Throughput

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WP4C Work: Methodology

BRSS = BR()

= MIT()

= MIT()

RIT

MIT ()

T() = MIT

RS() = T

BR() = RS

BRSS = BR

required bandwidth

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Comments are welcome!

Thank you for your attention!