frequency clearance agreement -...

Frequency Clearance Agreement

13/09/2010 Slide No.1


13/09/2010 Slide No.2

JTIDS/MIDS Frequency Clearance

Agreement(FCA)Management

Al Gore


13/09/2010 Slide No.3

Scope of Presentation

Why FCAs are required

Typical restrictions to JTIDS/MIDS

FCA Mitigation

Meetings and working groups

Future threats


13/09/2010 Slide No.4

Why are FCAs required?


13/09/2010 Slide No.5

Why are JTIDS/MIDS FCAs required?

• Operates in 960-1215 MHz band (UHF)

• Issue – allocated and protected to ARNS:

• DMEs

• SSR

• Satellite Navigation (GNSS)

• Issue – Link 16 operates on non/tolerable interference basis

• Requires evidence of tolerable co-existance

• FCA records operating restrictions


13/09/2010 Slide No.6

JTIDS / MIDSCARRIERS



UA

T GP

S L

5

Galil

eo E

5A

QZ

SS

SB

AS

CO

MP

AS

S

Galil

eo E

5B

GL

ON

AS

S L

3

Mode S

ES

Proposed New Systems:

ADS-B

1090 MHz

GPS L5, Galileo E5A, QZSS, SBAS (WAAS,

EGNOS, GAGAN, MSAS): 1176.45 12 MHz978 MHz

GLONASS L3: 1198.55 – 1204.88 MHzGalileo E5B: 1207-10 MHz to 1207+4 MHzCOMPASS: 1195 – 1215MHz

LINK 16 FREQUENCY SHARING960 - 1215 MHz Band

JTIDS / MIDSFREQUENCIES

EVERY3 MHz

14 5 32

1030 1090

1215960

Allocated to the Aeronautical Radionavigation Service

Allocated to the RNSS

1164TACAN / DME

CHANNELS

EVERY 1 MHz

ATCRBS

MODE S

IFF

TCAS

Proposed AM(R)S*

*US FAA Proposal for AM(R)S at the WRC 03; Mode S ES = Mode Select Extended Squitter

•RNSS = Radionavigation Satellite Service; AM(R)S = Aeronautical Mobile Route Service

AM(R)S

960 MHz 1024 MHz

Global Navigation

Satellite Systems


13/09/2010 Slide No.7

Why are JTIDS/MIDS FCAs required?

• MIDS uses 51 frequencies in the UHF band 960-1215 MHz

• DME, IFF and TACAN also operate with these frequencies

• A possibility exists of interference to these systems from JTID/MIDS transmissions

• Civil Aviation Authorities agencies have therefore imposed restrictions on the use of MIDS during peacetime

• Gain authorised use of the band


13/09/2010 Slide No.8

FCA Document

• Legal document• FCAs are not static documents• Contain operating restrictions• Supporting evidence

• Safety cases• CFCC

• FCA management essential

• CAAs may monitor JTIDS/MIDS operations• FCA Education required:

• User• Technicians• Managers• New users


13/09/2010 Slide No.9

FCA Document (2)

• CAA perspective:

• Protect Civilian air traffic

• Military

• Gain best possible use

• Looking to increase peacetime training capability

• Train as you fight


13/09/2010 Slide No.10

JTIDS/MIDS Interference potential


13/09/2010 Slide No.11

Interference potential

• JTIDS/MIDS transmissions potentially affects DME reply efficiency

• Interference may be caused by transmissions above a certain pulse density

• Three factors affect – proximity to the transmitter, TSDF and number of transmitters in an area

• Any operating modes involving simultaneous transmissions may be prohibited

• FCAs define the total number of emissions that can be generated by JTIDS/MIDS platforms in a geographical area

• The number of emissions originating from a single platform is also a factor


13/09/2010 Slide No.12

Pulse Density

• MIDS Pulse Density = how many MIDS transmissions occur in a particular local area

• Complex issue - affected by several factors including:• Number of active JUs

• Message packing level being used-̶ Standard, Packed 2 or Packed 4

• Type of Time Slot Access being used̶ Dedicated or Contention Access


13/09/2010 Slide No.13

Time Slot Duty Factor (TSDF)

• To measure approximate Pulse Density we calculate a value known as:

TIME SLOT DUTY FACTOR (TSDF)

TSDF = Maximum % of Time Slots used in the Net

• Calculation assumes that each Time Slot is only used by a single JU - may not always be the case!

• Based on Time Slots within a single 12 second Frame

• Total allocation of 1536 Time Slots per frame = 100% TSDF

Maximum % of a Frame allocated to a single JU


13/09/2010 Slide No.14

Time Slot Duty Factor

• TSDF may refer to:

• Maximum allowed in a network

• An individual Platform

• Geographical Area

• May be:

• Potential – As allocated in the design

• Actual – That currently being utilised


13/09/2010 Slide No.15

Other factor

• Terminal power

• Variable power = variable interference threat


13/09/2010 Slide No.16

Typical FCA restrictions


13/09/2010 Slide No.17

Typical Restrictions

• Restrictions vary in different countries

• Time Slot Re-use – No Time Slot may be used by more than one terminal at any one time, except:• Network Entry (IEM)

• RTT

• MIDS Voice

• Users allocated the same Time Slot must be separated by at least xx nm

• Terminal EIRP – No High Power (Class 2H terminal)


13/09/2010 Slide No.18


• Multiple Networks/Separation:

• To ensure no transmissions are made in the same TS, users within xx nm are to be synchronised

• When users are not synchronised a minimum separation of xx nm must be maintained


13/09/2010 Slide No.19


• Packing Levels –

• Pulse density may be restricted

• Maximum packing level may be Standard DP and P2SP

• P2DP and P4 may not be allowed


13/09/2010 Slide No.20

Operating Restrictions – Surface Platforms

• A Surface Platform may not transmit when:

• Within 3 nm of DME

• Within 1 nm from SSR equipment

• Within protected airspace

3nm1nm


13/09/2010 Slide No.21

Operating Restrictions – Airborne Transmissions

Air Platform Separation from Civil/Military

Aircraft

• Military ac may not transmit within specified distances from civil ac

• Airborne platforms will also cease transmissions within 2 nm of DME:


13/09/2010 Slide No.22

FCA Mitigation


13/09/2010 Slide No.23

FCA Mitigation

• Gain best possible operating restrictions• Evidence gathering• Bench testing of DME/NAV Aids

• USA• UK• GER• FRA

• Live environment testing (UK)• IPF features in terminal

• Full• Exercise• Combat

• Mitigation recorded in FCAs/Safety Cases etc


13/09/2010 Slide No.24

Network Monitoring

• Dynamic

• Allows real time monitoring and recording of MIDS/JTIDS activities

• NM take action

• Non real time management

• Paper based

• Provides record


13/09/2010 Slide No.25

International Working Groups


13/09/2010 Slide No.26

International FCA Working Groups

• Working groups exist to support:

• FCA testing

• CFCC

• Drive for CFC

• Sharing of information

• Mitigation to MIDS/JTIDS FCAs

• Cross border emission coordination

• Multi National Working Group (MNWG)

• European JTIDS/MIDS Cross border Coordination (EJCC)

• Pacific JTIDS/MIDS Cross border Coordination (PJCC)


13/09/2010 Slide No.27

MNWG (1)

• Exist to support:

• FCA testing

• Drive for CFC

• Sharing of information

• Investigating threats to MIDS/JTIDS FCAs

• Meetings – Once a year

• Attended by Technical/Operators

• Sub groups

• EJCC

• PJCC

• GNSS sub working group


13/09/2010 Slide No.28

MNWG (2)

• Products:

• CFCC

• MNWG Note book –

• 30 National FCAs

• Starchart

• POCs

• Sharing of test information

• Next meetings

• 2011 (May or June TBC) Luxembourg

• 2012 Switzerland (date venue TBC)

• Contact:

• Rose Ricketts rose.ricketts@navy .mil


13/09/2010 Slide No.29

EJCC (1)

• Started 2003

• Deal with European Cross border emissions issue

• Forum for guest forces procedures

• Common training issues

• Products• EJCC Cross Border SOPs

• Guest forces discussions

• Deconfliction server

• Operational Liaison

• Chair• Maj Xavier Belles (BEL)

• Co-Chair Lene Jensen (DEN)


13/09/2010 Slide No.30

EJCC (2)

• Military/Government reps• Operational/Technical

• Held once year

• Next meeting• 8-11 Nov 2010

• Karup Airbase Denmark

• Contacts/Further information:• Xavier Belles – [email protected]

• Lene Jensen – [email protected]

• Erik Caers - [email protected]

mailto:[email protected]

mailto:[email protected]


13/09/2010 Slide No.31


13/09/2010 Slide No.32

Threats to MIDS/JTIDS FCAs


13/09/2010 Slide No.33




UA

T GP

S L

5

Galil

eo E

5A

QZ

SS

SB

AS

CO

MP

AS

S

Galil

eo E

5B

GL

ON

AS

S L

3

Mode S

ES

Proposed New Systems:

ADS-B

1090 MHz

GPS L5, Galileo E5A, QZSS, SBAS (WAAS,

EGNOS, GAGAN, MSAS): 1176.45 12 MHz978 MHz

GLONASS L3: 1198.55 – 1204.88 MHzGalileo E5B: 1207-10 MHz to 1207+4 MHzCOMPASS: 1195 – 1215MHz

LINK 16 FREQUENCY SHARING960 - 1215 MHz Band

JTIDS / MIDSFREQUENCIES

EVERY3 MHz

14 5 32

1030 1090

1215960

Allocated to the Aeronautical Radionavigation Service

Allocated to the RNSS

1164TACAN / DME

CHANNELS

EVERY 1 MHz

ATCRBS

MODE S

IFF

TCAS

Proposed AM(R)S*

*US FAA Proposal for AM(R)S at the WRC 03; Mode S ES = Mode Select Extended Squitter

•RNSS = Radionavigation Satellite Service; AM(R)S = Aeronautical Mobile Route Service

AM(R)S

960 MHz 1024 MHz

Global Navigation

Satellite Systems


13/09/2010 Slide No.34

Threats

• Number of threats:• Frequency re-mapping?

• UAT

• GNSS/Satilite Navigation systems

• Single European Sky (SES)

• Civilian DL?

• Other new systems

• MNWG/EJCC working to understand and provide mitigation

• Drive to world common FCA?


13/09/2010 Slide No.35

Summary

MIDS/JTIDS not allocated to 960-1215 MHz band

FCAs are imposed by Civil Aviation Authorities to ensure non interference between MIDS and navigational systems

FCAs define restrictions on MIDS usage in peacetimeRequire through life management

Testing used to prove tolerable interference

Restrictions in place in peacetime

FCA restrictions continually under scrutiny

International working groups tackling issues

Threats to band = threats to FCA = threats to JTIDS /MIDS operations


13/09/2010 Slide No.36

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