AMCP WGW/WP21

AERONAUTICAL MOBILE COMMUNICATIONS PANEL (AMCP)

Working Group of the Whole

Montreal, Canada

21-24 May 2002

Agenda Item 4 e)

Feasibility of finding UAT frequencies in the ARNS-Band 960-1215 MHz within the Core Area of Europe

Prepared by Joachim Wollweber, DFS Deutsche Flugsicherung GmbH;

Dr. Armin Schlereth, DFS Deutsche Flugsicherung GmbH;

Summary:

This working paper provides a short documentation on the various items that need to be considered before a candidate frequency for allocation of new ARNS installation like UAT within the band 960 – 1215 MHz can be identified. Focus has been taken on specific needs to be dealt with in the Core Area of Europe. There are several reasons for the encountered frequency congestion:

- Large number of (military-) systems and equipment already in operation,

- High RF-load created by other systems (e.g. 1030/1090 MHz),

- Various other (military) systems that are planned for operation.

It could be summarized, that even if the interference compatibility criteria between existing primary ARNS-systems can be met, no frequency allocation for UAT above 973 MHz will be possible for the foreseeable future.

It is further recommended, that for the proposed UAT-system none of currently (and proposed) operational DME-channels shall be used.

A detailed feasibility study has to be conducted, that includes all systems and requirements for the protection of ARNS-services in the Core Area of Europe. Results of this study are a prerequisite before the system-specification and frequency allocation for UAT can be decided on.

Development of ICAO SARPs for UAT is only justified, when the worldwide implementation of such a system is possible, which includes the worldwide allocation of an appropriate frequency channel. In addition the added value compared to the already standardized systems Mode S Extended Squitter and VDL Mode 4 has to be proven.

Reference Papers:

[1]RTCA Special Committee 186, Working Group 5, ADSB UAT MOPS, Meeting #5, 19-22 June 2001, Lexigton, MA, Results on the utilization of the frequencies 978 and 979MHz in Europe, prepared by N.Fistas, A.Antorino and G.Gulean EUROCONTROL

[2]GLOBAL NAVIGATION SATELLITE SYSTEMS PANEL (GNSSP), Working Group B, (29.May-9.June.2000, Seattle), Agenda Item 1: Possible lack of available spectrum for the allocation of VHF NABS in the ARNS-VHF Frequency Band in the area between of the states BEL/D/F/HOL/LUX in Europe, Presented by W.Bellen, Prepared by J.Wollweber

[3]TLAT-Report-Appendix D, System description for the Universal Access Transceiver, Chris Moody, Revised Version March 2001

1.Introduction

ICAO AMCP Working Group C is currently discussing the possible standardization of UAT as a third system to provide ADS-B services. In the past a lot of efforts have been taken to standardize the other two ADS-B systems Mode S Extended Squitter and VDL Mode 4. In that context one major issue was identified to allow introduction of these technologies, which is the availability of interference limited spectrum. Therefore this paper discusses the availability of spectrum for UAT, to provide a profound basis for a decision on how to proceed further. Only in case spectrum is available to allow introduction of UAT on a worldwide basis efforts should be taken to develop ICAO SARPs. Further on the expected added value through introduction of a third ADS-B system like UAT has to be proven first.

2.Current Situation

In figure 1 a scenario is outlined, which includes the systems to be taken into account, when discussing the possible introduction of a new system into the band 960 – 1215 MHz.


Figure 1: Scenario to provide an overview on systems involved in the band 960 – 1215 MHz

Eurocontrol already did an investigation of the European situation regarding the candidate channels at 978 of 979 MHz [1] for UAT, which have been discussed within RTCA SC 186 Working Group 5. This investigation showed that none of these channels could be made available through channel re-allocation within the area of Benelux States and Germany, because no alternative frequency for existing and operationally used installations could be identified. It should be noted, that not all currently registered assignments were outlined in the report [1], meaning that situation is even worse. Attachment A gives an updated overview of assignments of channels 17X (978 MHz) and 18X (979 MHz) in Europe. Further on investigation in this report [1] didn’t include actual frequency planning requirements for UAT signals in case they would include more adjacent channel protection than a DME-channel.

Regarding the whole band 960 -1215 MHz in some areas of core Europe states (Benelux states, Germany) have already encountered frequency congestion, meaning that no frequency could be identified for a new service.

In general it could be stated, that the larger the Designated Operational Coverage (DOC) the fewer installations can be place on a frequency. Otherwise interference free operation between “Aeronautical Radio Navigation and Surveillance” installations could no longer be fulfilled. The required frequency protection criteria include a large number of other constraints, which have to be taken into account:

-Co-channel protection between DME using Same-Pulse-Code (SPC) and Different-Pulse-Code (DPC) for the interrogation- and reply-frequency,

-Adjacent channel protection between DME for the interrogation- and reply-frequency,

-Sufficient protection between the two primary ARNS-services DME and SSR/ACAS for their interrogation- and reply-frequencies,

-Protection against interference on image frequencies (DME separation 63 MHz, SSR/ACAS 60 MHz),

-Frequency paired ARNS installations operating in the VHF-band 108-117,975 MHz (ILS, VOR, GBAS)

-Other non ICAO compatible military systems that may operate on Non Interference Base (NIB) in some states in the band 960 – 1215 MHz like

  • A/A-, S/S-, MM- and ICAO-non compliant TACAN use,
  • JTIDS/MIDS,
  • RSBN4,
  • Various IFF-modi and systems ETCAS 6.04(A) and 7.0

In summary it should be made clear that channels 17X and 18X are not available in the Core Area of Europe for the foreseeable future due to the constraints outlined above.

The following section proposes a possible solution for the introduction of UAT in the band 960 – 1215 MHz.

3.Proposed Solution

In this section first a general discussion of possible changes in the band 960 -1215 MHz will be made to improve availability of DME- channels before a recommendation on how to introduce UAT is outlined.

A number of DME-channels defined in ANNEX 10 are not available to provide sufficient protection between SSR- and ACAS-signals and DME/TACAN-signals. New DME-channels can only be made available in the band 960-1215 MHz either due to introduction of new interrogation modes and channel allocations for DME or due to successful review of frequency separation requirements of Annex 10 between DME/TACAN and SSR/ACAS.


Figure 2: Proposal to allow for introduction of UAT in the band 960 – 1215 MHz

A proposal for re-organisation of the band 960 – 1215 MHz is outlined in figure 2. As a prerequisite a symmetrical protection mask for SSR is assumed. This means that for 1030 MHz a bandwidth of 12 MHz is assumed and for 1090 MHz a bandwidth of 6 MHz is proposed. This would allow reducing the number of non-occupied DME-channels due to protection of SSR from 65 to 53. But this needs further discussion in the appropriate frequency planning body.

More details on how the band 960 – 1215 MHz is used are outlined in the figure of attachment B, which will not be discussed in this paper but should serve as background information.

Regarding the possible implementation of UAT only the lower part from 960 to 973 MHz could be used due to the constraints outlined above. This would only conflict with some of military used systems like Mobile Maritime TACAN or RSBN, which are on one side locally restricted or planned to be put out of service anyway.

In order to be able to finally decide on the possible usage of the lower part of the band 960 – 1215 MHz for UAT implementation detailed protection criteria have to be developed as well.

4.Recommendation

In order to expedite the process for a decision whether ICAO SARPs shall be developed for UAT, the following issues are recommended:

A detailed feasibility study has to be conducted, that includes consideration of all systems and requirements for the protection of ARNS-services in the Core Area of Europe as outlined in this report. This is a prerequisite, in order to allow for a selection of the appropriate frequency channel for UAT to guarantee a worldwide implementation of such a system.

The proposed UAT-system shall not be allocated to any of the currently (and proposed) operational DME-channels. In case this would happen, introduction of UAT in some of the Core European states will not be possible within the foreseeable future.

Even in case interference compatibility criteria to existing primary ARNS-system can be met no frequency allocation above 973 MHz will be possible in Core Area of Europe.

Evaluation to clarify that capacity of UAT is sufficient for 2015+.

Clarification of added value provided by UAT compared to Mode S Extended Squitter and VDL Mode 4. Only in case added value could be identified development of ICAO SARPs is desirable.

It is recommended that AMCP-WGW takes into account information provided in this working paper, when deciding on a possible standardisation of UAT as a third ADS-B medium.

1

Attachment A: Channel allocation of 17x and 18x in Europe

Country / Location / Sys1 / Rwy
-Des / Sys2 / Sys3 / Freq.1 / Chn.2
DME- / PC / Chn.3
MLS / Id / Lat / e/w / Long / TRD
[100'] / Range1
[NM] / FL1
[100'] / Range2
[NM] / FL2
[°] / Range3
[NM] / FL3
[100']
D / Ahlhorn / TAC / 17 / x / AHL / 5253 / e / 0814 / 40 / 250
D / Furstenfeldbruck / TAC / 17 / x / FFB / 4813 / e / 1109 / 50SA,40 / 250
E / Albacete / TAC / 17 / x / 3857 / w / 0152 / 200 / 600
F / Metz/Frescaty / TAC / 17 / x / MET / 4904 / e / 0608 / 40 / 250
GRC / Dekelia/Tatoi / VOR / DME / 108,000 / 17 / x / DTA / 3806 / e / 2346 / 40 / 250 / 40 / 250
NOR / Svalbard / DME / 17 / x / ISD / 7804 / e / 1336 / 25 / 100
TUR / Usak / VOR / DME / 108,000 / 17 / x / USK / 3841 / e / 2928 / 80 / 250
CZE / Kunovice / DME / MLS / 18 / x / 500 / 4902 / e / 1727 / 23 / 100 / 23 / 100
D / All Germany / TAC / 18 / x / 100 / 100
D / Bruggen / DME / MLS / 18 / x / 500 / 5113 / e / 0608 / 23 / 100 / 23 / 100
D / Geilenkirchen / TAC / 18 / x / GIX / 5058 / e / 0603 / 80 / 500
E / Mahon/Menorca / 01 / DME / MLS / 18 / x / 500 / 3951 / e / 0413 / 190 / 23 / 100 / 23 / 100
F / Cognac/Chat.Bernar / DME / MLS / 18 / x / 500 / 4539 / w / 0020 / 23 / 100 / 23 / 100
F / Grenoble/St-Geoirs / 09 / DME / MLS / 18 / x / 500 / 4522 / e / 0521 / 270 / 23 / 100 / 23 / 100
F / Lorient / DME / MLS / 18 / x / 500 / 4745 / w / 0328 / 23 / 100 / 23 / 100
FIN / Rovaniemi / 21 / DME / MLS / 18 / x / 500 / 6633 / e / 2549 / 37 / 23 / 100 / 23 / 100
G / Belfast City / ILS / 04 / DME / 108,100 / 18 / x / 5437 / w / 0532 / 215 / 25 / 62,5 / 25 / 100
G / Belfast City / ILS / 22 / DME / 108,100 / 18 / x / 5437 / w / 0532 / 35 / 25 / 62,5 / 25 / 100
G / Benbecula / ILS / 06 / DME / 108,100 / 18 / x / BCL / 5729 / w / 0723 / 235 / 25 / 62,5 / 25 / 100
G / Benbecula / ILS / 24 / DME / 108,100 / 18 / x / BUC / 5729 / w / 0723 / 55 / 25 / 62,5 / 25 / 100
G / Dundee / ILS / 10 / DME / 108,100 / 18 / x / IDDE / 5627 / w / 0301 / 270 / 25 / 62,5 / 15 / 50
G / Dundee / ILS / 28 / DME / 108,100 / 18 / x / 5627 / w / 0301 / 100 / 25 / 62,5 / 25 / 100
GIB / Gibraltar / DME / MLS / 18 / x / 500 / 3609 / w / 0521 / 23 / 100 / 23 / 100
GRC / Andravida / DME / MLS / 18 / x / 500 / 3756 / e / 2117 / 23 / 100 / 23 / 100
GRC / Chania/Souda / 11 / DME / MLS / 18 / x / 500 / 3531 / e / 2411 / 290 / 23 / 100 / 23 / 100
GRC / Kavala/Chrisoupoli / DME / MLS / 18 / x / 500 / 4055 / e / 2437 / 23 / 100 / 23 / 100
HRV / Osijek/Osijek / 29 / DME / MLS / 18 / x / 500 / 4528 / e / 1848 / 111 / 23 / 100 / 23 / 100
HRV / Rijeka / 14 / DME / MLS / 18 / x / 500 / 4512 / e / 1435 / 324 / 23 / 100 / 23 / 100
I / Lamezia/Terme / 28 / DME / MLS / 18 / x / 500 / 3854 / e / 1614 / 98 / 23 / 100 / 23 / 100
I / Palermo/Punta Rais / 25 / DME / MLS / 18 / x / 500 / 3810 / e / 1305 / 67 / 23 / 100 / 23 / 100
I / Roma/Fiumicino / 16 / DME / MLS / 18 / x / 500 / 4151 / e / 1216 / 344 / 23 / 100 / 23 / 100
I / Verona/Villafranca / 05 / DME / MLS / 18 / x / 500 / 4524 / e / 1054 / 227 / 23 / 100 / 23 / 100
JOR / Amman/Queen Alia / DME / MLS / 18 / x / 500 / 3143 / e / 3602 / 23 / 100 / 23 / 100
LBY / Tripoli/Intl / DME / MLS / 18 / x / 500 / 3239 / e / 1309 / 23 / 100 / 23 / 100
MLT / Malta/Luqa / 32 / DME / MLS / 18 / x / 500 / 3551 / e / 1428 / 135 / 23 / 100 / 23 / 100
NOR / Bardufoss / DME / MLS / 18 / x / 500 / 6903 / e / 1833 / 23 / 100 / 23 / 100
NOR / Haugesund/Karmoy / 14 / DME / MLS / 18 / x / 500 / 5920 / e / 0513 / 314,3 / 23 / 100 / 23 / 100
NOR / Honningsvaag / ILS / DME / 108,100 / 18 / x / HV / 7101 / e / 2558 / 25 / 62,5 / 25 / 100
NOR / Kristiansund/Kvern / DME / MLS / 18 / x / 500 / 6307 / e / 0751 / 23 / 100 / 23 / 100
NOR / Sogndal / ILS / 24 / DME / 108,100 / 18 / x / SG / 6110 / e / 0709 / 60 / 25 / 62,5 / 25 / 100
POL / Rzeszow/Jasionka / 27 / DME / MLS / 18 / x / 500 / 5007 / e / 2203 / 91 / 23 / 100 / 23 / 100
POR / Lisboa / 03 / DME / MLS / 18 / x / 500 / 3846 / w / 0909 / 203 / 23 / 100 / 23 / 100
S / Gallivare / ILS / 30 / DME / 108,100 / 18 / x / NG / 6707 / e / 2048 / 117,93 / 25 / 62,5 / 25 / 100
S / Goteborg/Save / ILS / 19 / DME / 108,100 / 18 / x / GP / 5746 / e / 1152 / 5 / 25 / 62,5 / 25 / 100
S / Linkoping/Saab / DME / MLS / 18 / x / 500 / 5825 / e / 1540 / 23 / 100 / 23 / 100
S / Mora/Siljan / DME / MLS / 18 / x / 500 / 6057 / e / 1431 / 23 / 100 / 23 / 100
S / Skelleftea / DME / MLS / 18 / x / 500 / 6438 / e / 2104 / 23 / 100 / 23 / 100
TUN / Tozeur/Nefta / DME / MLS / 18 / x / 500 / 3356 / e / 0806 / 23 / 100 / 23 / 100
TUR / Diyarbakir / DME / MLS / 18 / x / 500 / 3752 / e / 4012 / 23 / 100 / 23 / 100
TUR / Istanbul/Ataturk / ILS / 36 / DME / 108,100 / 18 / x / IES / 4100 / e / 2849 / 179 / 25 / 62,5 / 25 / 100
Pristina / DME / MLS / 18 / x / 500 / 4234 / e / 2102 / 23 / 100 / 23 / 100

Attachment B: Usage of the band 960 – 1215 MHz

950 / 960 / 970 / 980 / 990 / 1000 / 1010 / 1020 / 1030 / 1040 / 1050 / 1060 / 1070 / 1080 / 1090 / 1100 / 1110 / 1120 / 1130 / 1140 / 1150 / 1160 / 1170 / 1180 / 1190 / 1200 / 1210
 /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  / 
Int. / 1030 / Reply / 1090 /

f Transponder

A/

/ A  /  A/ / A / Mode 3 / A/C / f 3MHz / IFF M1-4 / 3 MHz

G/

/ A  /  A / / G / ACAS Mode S / f 1MHz / IFF M4/S / 0,5MHz
G/ / /G  /  G/ / G
M3A/C /

-50dB

/

-47dB

/

-43dB

/

-38dB

/

-31dB

/ -19dB / -15 / -11 / -6 / 0 / dB / -6 / -11 / -15 / -19dB /  of Int+Reply / -20dB / -3dB / 0 / -3dB / -20dB / -40dB / -60dB
M S, ACAS /

-50dB

/

-47dB

/

-43dB

/

-38dB

/

-31dB

/ -19dB / -15 / -11 / -6 / 0 / dB / -6 / -11 / -15 / -19dB /  of Int+Reply / -20dB / -3dB / 0 / -3dB / -20dB / -40dB / -60dB
IFF M1-4 /

-60

/

-50

/

-47

/

-43

/

-38

/

-31

/ 0dB /  of Int+Reply / -20 / -3 / 0 / dB / -3 / -20 / -40 / -60 / -70
IFF M4,S /

-50

/

-47

/

-43

/

-38

/

-31

/ -19 / -15 / -11 / -6 / 0 / dB / -6 / -11 / -15 / -19 /  of Int+Reply / -20 / -3 / 0 / dB / -3 / -20 / -40 / -60 / -70
IFF M5 /

-50

/

-35

/

-17

/

0

/ dB /  of Int+Reply / -20 / -3 / 0 / dB / -3 / -20 / -40 / -55
ASMGCS /

-50

/

-47

/

-43

/

-38

/

-31

/ -19 / -15 / -11 / -6 / 0 / dB / -6 / -11 / -15 / -19 /  of Int+Reply / -20 / -3 / 0 / -3 / -20 / -40 / -60
Int. / DME /

TAC

/ AN
x-chn. /  /  /  / 17 /  /  /  /  / 60 /  /  / 70 /  /  /  /  /  /  / 126
y-chn. /  /  /  / 17 /  /  /  /  / 60 /  /  /  /  / 80 /  /  /  /  / 123 / 126
w-chn. / 18  /  /  /  / 56
z-chn. / 17  /  /  /  / 56 / 80 /  /  /  /  / 119

A/A-

/
TACA
/ N (/-Tr / ansp.) /  /  /  /  /  /  /  /  /  /  /  /  /  /  /  / 126

Reply

/ DME /

TAC

/ AN / 126
x-chn. /
1 
/

/

/ 17 /  /  /  /  /
64 
/  /  /  /  /  /  / 
y-chn. / 64 /  / 80  /  /  /  /  /  /  /  /  /  /  /  /  / 63
w-chn. / 18 /  /  /  /  / 56
z-chn. / 80  /  /  / 80  /  /  /  /  / 119

L5

/

L5

UAT

/ UAT

A/A-, S/S

/
TACA
/ N (/-Tr / ansp.) / 64x /  /  /  /  /  / 125 /  /  /  /  /  / 63

MM-

/
1 
/

 16

/ 64y /  /  / 79y / 125 /  /  / 16y

JTIDS

/MIDS / -23 / 
 / 
 / 
 / 
 / -23 / -60 / -60 / -23 /  / 
 / -23 / -60 / -60 / -23 / 
 / 
 / 
 / 
 / 
 / 
 / 
 / 
 / 
 / 
 / -23
mil. /

RSBN

/  /  / 

GSM

/ 

PSR

/  / 

If-SAT-TV

/
A/A /  / Air to / Air / Primary user / Arial /

Sys

/ tems: / DME / +comp. / TACAN /

SSR

/

=IFF

/

A, C, S

A/G /  / Air to / Gnd / others uses / Times new Roman / TACAN / noncomp / A/A,MM /

ACAS

/

=TCAS

/ II V.7
G/A /  / Gnd to / Air / restricted use, NIB / RSBN / -2007 /

IFF

/

M4

/

other

G/G /  / Gnd to / Gnd. / no clearanc or/radiation / no /radiation / JTIDS/ / MIDS / ETCAS
Cable / in + on / non ra / diating / Spectral mask / 0dBCarrier / Polygone / ASMGCS

1