background : why additional am(r)s spectrum capacity ?

1ICAO ACP WGF10/WP3

MONTREAL AUG 2003

SPECTRUM REQUIREMENTS

FOR FUTURE AERONAUTICAL MOBILE (ROUTE) SYSTEM - AM (R )S

( Presented by Christian Pelmoine /Dale Stacey, Eurocontrol SMG)

2ICAO ACP WGF10/WP3

MONTREAL AUG 2003

BACKGROUND : WHY ADDITIONAL AM(R)S SPECTRUM CAPACITY ?

• Congestion in existing VHF comm band

• The Problem is here already but is predicted to be critical around 2012-1015, despite enhanced VHF technologies

• Cater for new technologies and applications (when defined). High speed data, security, video, 3D awareness etc..

• Provide convergence of data, IT and communication systems within Aviation

• Natural progression of the research and trials work being done at Eurocontrol for a 3G system.

• Less tangible phenomena of demand follows supply in next generation technology deployment (as seen with the mobile phone and internet application explosions)

3ICAO ACP WGF10/WP3

MONTREAL AUG 2003

BACKGROUND: MISSION REQUIREMENT FOR FUTURE AM(R)S

• Support voice and data

• Initially Commercial aviation, finally General aviation

• Finally in all controlled airspace: airport, TMA and en-route. A phased rollout would be anticipated targeting ‘hot spot’ congested core Europe first.

• Provision for new applications : high speed data

• Reliable and secure transmission link

4ICAO ACP WGF10/WP3

MONTREAL AUG 2003

THE SPECTRUM CAPACITY STUDY

Realised by a leading Aviation ATS provider (DFS) with support of recognised 3G Telecomms company (LS TELECOM)

Re-use previous traffic capacity study, including Eurocontrol/ DGAC Macondo, STATFOR.

3 steps:

– Estimate the traffic throughput

– Define a reusable model to translate traffic throughput into spectrum bandwidth

– Investigate the sensitivity of BW requirements with selected parameters

5ICAO ACP WGF10/WP3

MONTREAL AUG 2003

MAIN ASSUMPTIONS

• Use the most spectrally efficient technology adapted to the Aviation mobile scenario

• Technology based on the trials (CDMA) being undertaken by Eurocontrol

• Dimensioned for the long term (2029 traffic estimate)

• Dimensioned on busiest European sectors

6ICAO ACP WGF10/WP3

MONTREAL AUG 2003

DFS and LS TELECOM STUDY PRESENTATION

7ICAO ACP WGF10/WP3

MONTREAL AUG 2003

Future AM(R)S spectrum requirements

To Dimension a future system (the three C’s)

• Capacity (max data throughput per given area/vol)

• Coverage (% of total coverage area)

• Cwality (Quality, Grade of Service)

8ICAO ACP WGF10/WP3

MONTREAL AUG 2003

Capacity

New system must cater for;-

CAPACITY

• At least a threefold increase in the number of voice channels

• High Speed Data services (greater than the existing VDL modes)

• Provisions for Video and Security requirements

• New technologies and applications (freeroutes, 4D, greater pilot awareness etc)

• less tangible phenomena of demand follows supply in next generation technology deployment (as seen with the mobile phone and internet application explosions)

• Other ?

9ICAO ACP WGF10/WP3

MONTREAL AUG 2003

Coverage Targets

• Assumption is this should be as per the existing VHF comm coverage or better ( a phased rollout would be anticipated targeting ‘hot spot’ congested core Europe first.)

Quality Targets

• The grade of service as it manifests itself in Availability, BER, Blocking probability etc should be comparable or better than that realised in the existing systems.

10ICAO ACP WGF10/WP3

MONTREAL AUG 2003

Consider Busiest sector in Europe ?

• Paris TMA was chosen as existing traffic results were most readily available• Study will be rerun using London TMA for a benchmark and control.


MONTREAL AUG 2003

Future AM(R)S spectrum requirements

• Consider the busiest hour for this sector

Peak Instantaneous Aircraft Count PIAC2000=34.16 (Analogous to cell subscriber density)

• Consider how this traffic will grow over the next 29 years (time to realise system and lifetime of system nominally 29 years)

PIAC2029=34.16 x G(Growth factor)= 104.9

(growth 3.94% per year from STATFOR, G=(1+0.0394)^29 )

NOTE

It is worth stressing that the aircraft density concept is important here. Ignore the controversial operational concept of fitting 105 movements in a TMA.


MONTREAL AUG 2003

Breakdown of assumed throughput per Service

(BASEBAND) Throughput all

a/c in kBit/s

Fixed channel rate

in kBit/s

Required number of channels

Voice DL 870,41 20 44 (43,52)

UL 870,41 20 44 (43.52)

Data+Security DL 809,17 64 13 (12,64)

UL 3,14 64 1 (0,05)

Commercial Data

DL 197,60 64 4 (3,09)

UL 197,60 64 4 (3,09)

Video DL 768,00 384 2

UL 0 384 0

Sum over all Servicesfor average calculation

DL 3974,7

UL 2409,5

37,89

105 (104,9)

105 (104,9)

22,97

Average data rate

in kBit/s8,29

8,29

20,4

12,8

1,88

1,88

7,32

0

37,89

22,97


MONTREAL AUG 2003

requiredo

bto

requiredo

b

n

er

c

n

n

eru

b

1

)1()1(

c Power of wanted signal u Number of user in the cell Factor for adjacent cell interference

r Data rate of the signal before spreading

ton Power spectral density of thermal noise

requiredo

b

n

e Figure of merit for demodulator

SIMPLIFIED MODEL


MONTREAL AUG 2003

Calculation of RF Bandwidth Requirements

Required Bandwidth

MHz

EUROCONTROL

Channels

3,84 Mchips

1,2288 Mchips

UL DL UL DL UL DL UL DL

Voice 2,45 2,46 2,48 2,49 5 5 5 5

Data & Security

3,81 6,15 0,44 2,23 5 10 1,25 2,5

DataCommercial

0,55 0,55 0,44 0,45 5 5 1,25 1,25

Video

0 2,17 0 5,12 0 10 0 2,5

Sum

6,81 11,33 3,36 10,29 15 30 7,5 11,25

Sum incl.Overhead

8,51 14,17 4,2 12,86 15 30 7,5 11,25

EUROCONTROL average

8,65 14,64


MONTREAL AUG 2003

Provisional Results of Bandwidth Calculation

Bandwidth requirements in MHz

0

5

10

15

20

25

30

Uplink

Downlink

Note granularity of W CDMA system is the dominating feature.


MONTREAL AUG 2003

OPTIONS

OPTION A OPTION B OPTION C

Proposed System Extrapolation ofbands usingexistingtechnology

W-CDMA(5 MHzchannels)

IS-95(1.25MHzchannels)

Additional Spectrumrequired for 2029 toaccommodate existingServices growth only

> 38 MHz 10 MHz 7.5 MHz

Additional Spectrumrequired for newservices

Cannot readilybeaccommodated

35 MHz 11 MHz


MONTREAL AUG 2003

0

5

10

15

20

25

30

10 30 50 70 90

cell radius in km

ban

dw

idth

in M

Hz

Msingle (r =20kBit/s)

Msingle (r' =31,56kBit/s)

Msingle (r =384kBit/s)

Msingle(r =20kBit/s) +Msingle(r =384kBit/s)

Bandwidth requirement vs. cell radius Sensitivities


MONTREAL AUG 2003

Bandwidth requirement vs. maximum transmit power

0

5

10

15

20

25

30

35

40

-4 -2 0 2 4 6 8 10 12

transmitter power in dBW

ban

dw

idth

in M

Hz

r = 20 kbit/s

r = 384 kbit/s

r = 31,56 kbit/s


MONTREAL AUG 2003

Impact of adjacent cell factor

0

2

4

6

8

10

12

14

16

18

20

0 0,2 0,4 0,6 0,8 1

adjacent cell factor

ban

dw

idth

in M

Hz

10 km

15 km

35 km

50 km

75 km


MONTREAL AUG 2003

Impact of transmit frequency

1,5

1,7

1,9

2,1

2,3

2,5

2,7

2,9

3,1

3,3

3,5

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

frequency in MHz

ban

dw

idth

in M

Hz

r =20kbit/s

r =384kbit/s


MONTREAL AUG 2003

Conclusions to date

• Provisional indications show between 18.75 MHz and 45 MHz of spectrum will be required by 2029

– The lower granularity IS-95 protocol would appear more suitable to the Aviation Scenario

– This calculation is provisional giving us a methodology and order of magnitude only

– This calculation is only valid for the deployment of wideband CDMA type technology for a very specific scenario (fixed cell radius, freq etc)

• Spectral efficiency of new technology is at least 4 times better than existing technology

• Sensitivity analysis presents some interesting conclusions on parameters for optimising system


MONTREAL AUG 2003

NEXT STEPS

• Still some work required on spectrum capacity assessment

– Review the com traffic estimate with the greater aviation community, in particular for the newest applications,

– further alignment of the study model to the ITU mobile model which is likely to increase required RF spectrum

• Build a political case to present information to CEPT and ultimately ITU, to enable spectrum allocation at WRC 2007

• Support the feasibility (including flight trials) activity, selection of technology and candidate RF band(s).

Lobby for global support within Europe and beyond


MONTREAL AUG 2003

background : why additional am(r)s spectrum capacity ?

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