ACP WGC6/WP32
Future communication systems, spectrum availability
(Presented by the Secretary)
The attached draft paper on future comms systems, spectrum availability and a first cut at an internal
aviation document to track progress on compatability and spectrum avialability issues for comment was
developed by Dale Stacey and John Mettrop in response to the action taken at the WGF/10 meeting
(August 2003). It was originally proposed that the paper be submitted to the next ITU 8B meeting
(November 2003) via the UK. The Appendix a was not intended for submission.
1
ITU – 8B/WP ???
November 2003
Future Communications System, Spectrum Availability
UK, EUROCONTROL (PLUS OTHERS)
SUMMARY
This paper investigates the work required to identify and support the case for the assignment of additional
spectrum to the Aeronautical Mobile (R) Service including the deliverables that the ITU and States are
likely to expect aviation to produce.
2
SCOPE
This paper investigates the work required to investigate the spectrum requirements for a future
Aeronautical Mobile (R) system in accordance with satisfying resolution [COM 7/6]
“consideration of the frequency range between 108 MHz and 6 GHz for new aeronautical
applications”
INTRODUCTION
Within Europe and the United States of America, 25 kHz VHF communications capacity has
reached saturation. This has led to a number of measures being taken to alleviate the problem
such as the implementation of 8.33 kHz channel spacing in Europe and the planned introduction
of VDL Mode 3 in the USA. With the predicted growth in demand for communications services it
is anticipated that the current measures being implemented are unlikely to provide sufficient
capacity to meet demand beyond 2020.
In addition to this new applications are expected to be deployed within Aviation that are
potentially highly data intensive, this will require significantly increased datacomm abilities.
A number of studies have been carried out by Eurocontrol and ICAO to look at new technologies
or opportunities to expand the existing VHF 118-137 MHz legacy systems and provide for new
services/applications. Theoretically, new systems will offer increased spectral efficiency over the
legacy technology so longer term this is considered the only way to satisfy Aviation growing
demand and change of applications.
In order to address the perceived shortage of aeronautical communications capacity beyond
2020 and in the light of the Eurocontrol/ICAO studies, CEPT on behalf of Europe input a
proposal into the recent World Radio Conference for an agenda item to be included in the next
World Radio Conference to identify and allocate new Aeronautical Mobile (R) spectrum. This
proposal gained sufficient support and has now been included on the provisional agenda for
WRC-07 with an associated resolution detailing the order of priority for investigating current
allocations for their suitability for accommodating a new Aeronautical Mobile (R) allocation.
Having achieved the inclusion of an item on the agenda of WRC-07 to identify suitable spectrum
for a new Aeronautical Mobile (R) service, aviation now has to carry out the work to ensure a
successful outcome to the agenda item in 2007.
DISCUSSION
An agenda item for WRC 2007 has been included to consider new allocations for AM(R)S as
detailed in resolution com7/7. Therefore Aviation has the chance to identify spectrum that can be
used to support the implementation of future air-ground communication system(s). This
spectrum allocation should be of a global basis so that eventually the opportunity exists to
rationalise ATC air-ground communication systems within agreed timescales.
Since the amount of work required will be substantial it is vital that a task list, work programme
and deliverables are agreed at an early stage to ensure that the work is focused and the effort
3
required optimised. This paper therefore proposes a number of tasks that will have to be carried
out and a number of deliverables that will have to be submitted to the ITU process.
TASK LIST
Identification of Suitable Aviation Spectrum
For each band that aviation has access to between 108 MHz and 6 GHz a study needs to be
carried out to identify: which systems are either currently or expected to operate within the band; (alignment
with the medium and long term Aviation Strategy)
 The number and location of all current assignments;
 Predicted change in the number of assignments including introduction or
decommissioning of any systems;
 Any transition timescales;
 Quantity of spectrum available and associated timescales;
 Planning constraints to be placed on the new system.
Identification of Spectral Requirements for a New System
Aviation has to produce a study predicting the likely communications traffic requirement for the
foreseeable future and then based on a given technology the spectral capacity required to
support that traffic level (note: the ITU have produced a number of recommendations, especially
from the mobile phone industry, on predicting the spectrum requirements for a new system).
Aviation has split this task into two parts, namely; Identification of the scenario (here a number of different operating scenarios are possible),
Aviation is trying to define the user requirements for each of these and rationalise on a
scenario.
 Building of a model. This is to transpose the baseband user requirements into RF
Spectrum bandwidth (MHz). This model could be based on a number of technologies (eg.
TDMA, CDMA, ANLE, RLAN, satcomms or hybrids of these)
Once these tasks are complete, an assessment can be made as to if this requirement can be
accommodated in existing Aviation utilised bands.
Identification of Spectrum Outside of Aviation
Should there be insufficient spare spectrum identified within the existing aviation bands to meet
the predicted demand from the new aeronautical communications systems then work will have to
commence on sharing with other non-aeronautical services.
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DELIVERABLES
In order to convince the ITU and States that a new allocation to Aeronautical Mobile (R) service
is required of the size and spectral location identified by the study work carried out within
aviation the following deliverables will have to be produced:





Scenario study and ratification (Study into the quantity of spectrum required to support a
new communication system)
Definition of a model
Timescales for transition, expected spectrum release and timescales for that release
Study into the current and expected use of each existing aeronautical band and the
spectrum capacity required
Study into the suitability of non-aeronautical spectrum for a new aeronautical
communications system (if necessary)
Proposed location of the new assignment to the Aeronautical Mobile (R) service
For each deliverable the ITU will expect a full justification for the statements made including
supporting data.
TIMESCALES
The flow chart shown in appendix 1 show the required study plan at a high level between now
and the close of CPM (expected autumn 2006).
At this point a decision is needed as to whether the existing aviation utilised spectrum can
support a new system or whether additional spectrum will be required.
PROPOSED ACTION BY ITU
To endorse the proposed deliverables and timescales.
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APPENDIX 1PROPOSED TIMESCALES
Regional Preparation
ITU Process
AMRS STUDY PLAN
CEPT
CPG
APT
2003
CITEL
Define Scope
Arab
group
WRC 2003
new agenda item
initiated
Af rican
Russian
Group
Federation
Group
CPM
Build
Aviation
scenario
and
rqments
Build
and
develop
models
Review
candidate
bands
SG 8B
CEPT
CPG
CEPT
CPG
Develop
inter system
compatibility
criteria for
all bands
Assess
feasibility
in each
band
CEPT
CPG
CEPT
CPG
Can
requirement
be satisfied by
current aviation
spectrum
N
Y
CEPT
CPG
Refine required
outcomes
CEPT
CPG
APT
APT
APT
APT
APT
APT
2004
CITEL
CITEL
APT
Arab
group
Af rican
Russian
Group
Federation
Group
Af rican
Russian
Group
Federation
Group
SG 8B
SG 8B
2005
CITEL
CITEL
Arab
group
Arab
group
Af rican
Russian
Group
Federation
Group
Af rican
Russian
Group
Federation
Group
SG 8B
SG 8B
2006
CITEL
CITEL
look to extend
agenda item
CEPT
CPG
Arab
group
Arab
group
Arab
group
Af rican
Russian
Group
Federation
Group
SG 8B
CPM
Af rican
Russian
Group
Federation
Group
SG 8B
2007
CITEL
Arab
group
Af rican
Russian
Group
Federation
Group
SG 8B
WRC 2007
SG 8B
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APPENDIX 1 (NOT MADE AVIALABLE FORMALLY TO CEPT/ITU AT THE MOMENT)
2. Candidate Aviation utilised Bands
The AMCP WGF meeting 8 in April 2002 proposed an initial list of candidate bands. 2 It
is proposed to review this in the light of WRC03 outcomes and to agree on a short list
(for example 2 or 3 preferred candidate bands) as the basis for where initial compatibility
studies should be performed.
BASED ON TABLE OF AMCP CANDIDATE BANDS (extracted from *2)
AVIATION BANDS
Frequency
(MHz)
74.8 – 75.2
Primary
Allocation
Bandwidth
Available
Marker
beacons
Navigation
(VOR and ILS)
0.4 MHz
138 - 144
AM(OR)S
Military
6 MHz
328 - 335
Navigation
(ILS
Glide
slope)
7 MHz
960 - 1215
DME / SSR
275 MHz
1215 - 1350
Primary Radar
135 MHz
1545 - 1555
and 1646.5 –
1656.5
2700 – 2900
AMS( R)S and
mob satellite
10 +
MHz
Primary Radar
200 MHz
4200 – 4400
5030 - 5150
Air altimeter
MLS
200 MHZ
160 MHz
5150 - 5250
MLS
100 MHz
108 - 118
10 MHz
10
Status/Comment
Appropriate only for legacy system extension. Not suitable for
a new system
Potential option subject to negotiation with Aeronautical
Navigation, minimal equipment adaptation required makes it
attractive. VOR use is expected to reduce from 2010. GBAS
and GRAS requirements will be added to this band. Band
partitioning between ARNS and AM(R)S or generic allocation,
maybe possible, but will need studies and ITU agreement
Lack of an operational ‘party line’ with incompatible civil
avionics would require further study. Most appropriate for
extension of legacy system.
Potential option subject to negotiation with Aeronautical
Navigation. Band partitioning between ARNS and AM(R)S, or
generic allocation, maybe possible, but will need studies and
ITU agreement
960-977 MHz currently not used for ICAO standard systems.
The US forsee installing UAT in this band. This band will
continue to be heavily used by DME in Europe with
introduction of RNSS and GNSS.
Compatibility with primary radar systems (mainly en-route)
should be demonstrated.
These bands are saturated and are currently shared although
AMS(R)S has priority under pre emption. Unlikely that a
terrestrial AMRS system could co exist.
Compatibility with primary radar systems (mainly airport) is
difficult. Use of primary radar for airport is not foreseen to
decrease in Europe
Compatibility has to be assessed.
Better option in this band is above 5090 MHz co sharing with
MLS primary. This band is suitable for short range
communications as demonstrated by EUROCONTROL 3G
trials. Sharing criteria with MLS has to be defined.
Potential option but unlikely for safety-of-life service
NON AVIATION BANDS
To be further identified and discussed.
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3. COMPATIBILITY ANALYSIS
There are basically two scenarios to be considered.
3.1 Exclusivity
This is where the new system is installed in one of the candidate bands and has
exclusive use of the band. Under this scenario a migration plan would be required to
phase out the use of an ‘old’ Aviation system
This is the easiest scenario to accommodate technically but politically maybe
significantly more challenging depending on the system considered.
3.2 Band Sharing
This is where the new system is proposed to slot in with existing Aviation (and
sometimes other systems
3.3 Criteria.
The first step will be to define criteria. This needs to be;





Intra system criteria
Inter aviation system criteria
New system and non aviation system criteria.
Limits for co and adjacent channels
Limits for spurious and out of band
Inter band criteria.
Some of this information exists today in ICAO Annex 10, but much of it will need to be
developed.
4. Programme for study and testing.
A proposal is to consider the required study completion date and work back.
Considering that Aviation needs completion on this agenda item for WRC 2007 and it is
highly likely additional non aviation spectrum may be sought. A decision milestone is
needed to define whether the existing aviation spectrum is sufficient or new spectrum
will be required. It is proposed this milestone should be at the mid point between now
and WRC 2007. I.e. sometime in 2005.
A high level programme is proposed;TO BE DEFINED
TICK BOX
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Freq
(MHz)
Primary
Allocation
BW
Available
Compatability
criteria
completed
NOT
REQUIRED
Exclusive
allocation
feasible
NO
Shared
allocation of
band feasible
NO
74.8 –
75.2
Marker
beacons
0.4 MHz
108 118
Navigation
(VOR and
ILS)
AM(OR)S
Military
10 MHz
Y/N
Y/N
To be defined
6 MHz
Y/N
Navigation
(VOR and
ILS)
DME/SSR
7 MHz
Y/N
275 MHz
Y/N
1215 1350
Primary
radar
135 MHz
Y/N
1545 1555
and
1646.
5–
1656.
5
2700
–
2900
4200
–
4400
5030 5150
AMS( R)S
and
mob
satellite
10 + 10
MHz
Y/N
Y/N
To be
defined
Y/N
To be
defined
Y/N
To be
defined
Y/N
To be
defined
Y/N
To be
defined
Y/N
To be
defined
Primary
Radar
200 MHz
Y/N
Y/N
To be defined
Air
altimeter
200 MHZ
Y/N
MLS
160 MHz
Y/N
5150 5250
ARNS
100 MHz
Y/N
Y/N
To be
defined
Y/N
To be
defined
Y/N
To be
defined
Y/N
To be
defined
138 144
328 335
960 1215
9
Y/N
To be defined
Y/N
To be defined
Y/N
To be defined
Y/N
To be defined
Y/N
To be defined
Y/N
To be defined
Y/N
To be defined
Y/N
To be defined
Ranking
Study
Priority
Comments
Insufficient
bandwidth for
a
future
wideband
system