PJCC 2012 26 July 2012 Honolulu

1. Link 16 Joint Tactical Information Distribution SystemMultifunctional Information Distribution System(JTIDS / MIDS)Spectrum Issues Tutorial Information PJCC 2012 26 July 2012 Honolulu This information is furnished upon the condition that it or knowledge of its possession will not be released to any nation outside of those participating in the JTIDS/MIDS Multi-National Working Group (MNWG) without specific authority of and benefit to a MNWG member; that individual or corporate rights originating in the information whether patented or not, will be respected and; that the information will be provided the same degree of security afforded to the providing MNWGs member government organization. This brief is presented on behalf of the US MNWG Head of Delegation.

2. Tutorial Information Agenda 1. Introduction Opening Remarks 2. Background Link 16 Description Frequency Spectrum Implications 3. Link 16 Compatibility in the Frequency Band Link 16 Waveform Design Considerations Link 16 and Aviation Systems Analyses and Test Programmes 4.MNWGCommon Frequency Clearance Criteria 5. US Frequency Remapping Capability • Link 16 Terminal EMC Protection Features • Acronyms

3. Background Link 16 Description and Frequency Band Implications

4. Background • Link 16 Description • Link 16 JTIDS/MIDS System Description and Functions • Equipment/Terminals • Example Platforms • Time Slot Duty Factor • The 960-1215 MHz Frequency Band Spectrum Implications • National Frequency Clearance Agreements • Frequency Sharing 960 – 1215 MHz Band • Surveillance, Navigational Aides and Other Aviation Systems

5. Link 16 JTIDS/MIDS System Description MIDS JTIDS • International Cooperation • Joint & Allied Interoperability • Open Architecture • State of the Art Technology • Acquisition Reform • Secure and Jam-Resistant Communications, Navigation and Identification System • Tactical Digital Data and Voice • Low Probability of Exploitation • User Identification • Relative Navigation • Inherent Relay Capability • Other Characteristics • Frequency Hopping over 51 different carrier frequencies • Utilizes Hybrid Direct Sequence and Frequency Hopping Spread Spectrum signals • Data Rates: 28.8 - 119.0 Kbps (error correction); ET proposes 1 Mbps • Omnidirectional broadcast • High Capacity • US DOD Primary data link • Many US allies also utilize Link 16 • Nodeless • Frequency: 960-1215 MHz • Time Division Multiple Access (TDMA) • Multiple Voice Channels • Situational Awareness

6. CLASS 2H USN SHIPS 1 kW 840 LBS. Link 16 EQUIPMENT/Terminals* CLASS 1 CLASS 2 HIGH POWER CLASS 2M RT DPG AMPLIFIER GROUP 1.56 CU. FT 1981 U.S. ARMY 1.35 CU. FT 1.25 CU. FT 200 WATTS 1040 WATTS 200 WATTS 180 LBS. 90 LBS. The Future CLASS 2H (SHIP/GROUND/AIR) MIDS LVT1 1990 JSF SCWDL SDB U.S. AND EUROPEAN AMF JTRS AIRCRAFT 0.6 CU. FT 200 WATTS USAF MIDS LVT3 40 – 80 Watts 64 LBS. STT MIDS - JTR UK AN/URC-138 Army MIDS LVT2 200 Watts MIDS On Ship USN Ships 1 KW F22 ICNIA *Not to Scale

7. Example Link-16 PlatformsPresent and Future B2 B1 EUROFIGHTER (Typhoon) USN EA-6B Mirage F-16 USN SH-60 F22 UCAV USAF F-15 COMPASS CALL/ SENIOR SCOUT F-35 USAF E-3 UK TORNADO F-18 US NAVY CARRIER Link-16 US NAVY CG US NAVY E-2C RIVET JOINT/ COMBAT SENT NATO E-3 USMC JTIDS MODULE ASOC NATO CRC UK E-3 USAF JTIDSMODULE FR E-3 USAF CRC US ARMYFAAD MDA CORPS SAM USAF JOINT STARS MDA PATRIOT USAFAOC MDA THAAD USMC TAOM MIDS is the Third Generation Link-16 Terminal JTIDS - First and Second Generation Link-16 Terminals

8. Link 16 System Architecture Antijam Flexible High Capacity Secure Extended LOS Link 16 Transmit capacity varies from unit to unit. More turns means more capacity.

9. Time Division Multiple Access

10. JTIDS / MIDS TDMA ARCHITECTURE • 12 SECONDS PER FRAME • 1536 TIME SLOTS/FRAME (EACH NET) • 127 NETS • TERMINAL RESTRICTED TO ONE NET EACH TIME SLOT • IN A TIME SLOT TERMINAL CAN TRANSMIT OR RECEIVE - NOT BOTH 126 NETS 0 7 6 5 4 1 2 3 TIME SLOTS 7.8125 ms TIME SLOT PROP- AGATION SYNC JITTER MESSAGE

11. TIME SLOT / SIGNAL STRUCTURE JTIDS PULSE 6.4 sec 5 BITS ENCODED IN 32 CHIPS

12. TRANSMISSION PULSE ENLARGED DETAIL • 6.4 μs PULSE • CONTAINS 5 BITS OF DATA • CPSM 5 BITS YIELDING 32 CHIPS PER PULSE _ + - - + + + + 25 CHIPS = 5 BITS 10 20 1 2 3 30 32 200 nsec 6.4 use 1206 MHz Hops on 51 Different FREQUENCIES 969 MHz TIME

13. JTIDS Single Carrier Spectrum

14. Dedicated Access • Most access assignments are dedicated. • With dedicated access, a single user transmits data, all other users receive the data.

15. Multi-net • Multi-netting involves mutually exclusive groups performing differentfunctions using the same time slots (but with different hopping patterns). • Decision to use multi-net made during the initial network design build. Multi-net is not an operator selectable feature. 1 0

16. FTR TO FTR AIC DOWN AIC UP VOICE VOICE ­ NET n ­ ­ ­ FTR TO FTR NET 2 AIC UP AIC DOWN VOICE VOICE NET MGMT FTR TO FTR WEAPONS CONTROL AIC DOWN VOICE VOICE NET 1 C2 PPLI AIC UP EW C2 STATUS NET ENTRY RTT FTR PPLI NON C2 PPLI SURVEILLANCE VOICE NET 0 VOICE 0 64 1536 160 256 848 976 1088 768 1312 16 32 784 816 STACKED NETWORK • MULTIPLE DATA & VOICE CIRCUITS • 128 STACKED NETS – 118 KBS / NET – INDEPENDENT PRESETS FOR EACH FUNCTION – > 2 MBS SIMULTANEOUS (FREQ ASSIGNMENT LIMITS) • SURVEILLANCE – AUTOMATIC CAPACITY REALLOCATION – SIMULTANEOUS MULTIPLE RELAYS – 500 TRACKS @ 12 SEC UPDATE – VARIABLE UPDATE RATES • OTHER SIMULTANEOUS FUNCTIONS – TWO 16 KBS VOICE – AIR INTERCEPT CONTROL – FIGHTER-TO-FIGHTER – RELNAV / PPLI – C2 STATUS, WEAPONS CONTROL, EW & NET MANAGEMENT 0

17. CONTENTION • Transmitters use the same time slots. • Separate ‘protocol” used to minimize message “conflicts” • push-to-talk • over subscribed pool • operational control • Receivers hear only the closest transmitter.

18. JTIDS / MIDS Time Slot Duty Factor 200 nmi (300% TSDF) • Time Slot Duty Factor (TSDF) • Defined as the total percentage of JTIDS/MIDS transmission pulses over a 12 second period (out of 396,288 pulses total) within a specific geographic area. • Factor is derived from total number of possible pulses in a time slot (72, 258, or 444) times the number of time slots where JTIDS/MIDS terminals can possibly transmit in the 12 second period (frame). • Two numbers are typically used. The first number is the TSDF for the entire exercise within the geographic area, while the second number is the TSDF of the highest TSDF JTIDS / MIDS platform. • Geographic area is a radius around each platform • 100/50 nomenclature represents: • 100% TSDF in the exercise or in a geographic area • 50% TSDF for the highest TSDF platform • A third number is also sometimes used to represent the TSDF in a second tier geographic area. For example, 100/50/(300) represents: • 100% TSDF in the exercise or in a geographic area of 100 NM • 50% TSDF for the highest TSDF platform • 300% between 100 NM and 200 NM (50% TSDF ) 100 NM (100% TSDF)

19. The 960 - 1215 MHz Frequency BandSpectrum Implications • Internationally allocated (protected) world wide for the Aeronautical Radionavigation Service (ARNS) from 960-1215 MHz • Allocation to the Radionavigation Satellite Service (RNSS) from 1164 -1215 MHz • Allocation to the Aeronautical Mobile (Route) Service [AMR(S)] from 960-1164 MHz • Band usually administered by civil aviation agencies worldwide • JTIDS/MIDS operates in the band as a guest • Non harmful interference basis to the primary ARNS systems • ITU Radio Regulation RR-4.4* • Special national frequency clearance agreements • To date there are 32 different nations • JTIDS/MIDS designed to be compatible with existing ARNS systems • More than twenty year interagency (civil and military) electromagnetic compatibility test program • New aviation systems being implemented and others being explored for this band * ITU Radio Regulation RR-4.4 permits state operation of radio stations on a non-interference basis without protection.

20. Why an FCA? • Link 16 non-interference basis world wide • Not in accordance with table of allocations • ITU Radio Regulation RR-4.4 • Need special agreement with civil aviation authorities to operate Link 16 • Frequency Clearance Agreement • Design characteristics • Operational restrictions • Coordination to meet requirements

21. National Link 16 Frequency Clearance Agreements

22. Index: EGNOS: European Geostationary Navigation Overlay Service; GAGAN: GPS Aided GEO Augmented Navigation; GLONASS: Global Navigation Satellite System; IRNSS: India Regional Satellite System; MSAS: MTSAT Satellite Based Augmentation System; QZSS: Quasi-Zenith Satellite System; NigComSAT: Nigerian Communications Satellite

23. Link 16 Carrier Frequencies

24. Composite Spectrum of the JTIDS Carriers

25. L-Band Surveillance, Navigational Aides and ARNS / Aviation Systems • TACAN/DME Interrogator • SSR Transponder Reply 1090 MHz: ID and Altitude Interrogation 1030 MHz Reply: For TOA and Dx Calculation Interrogation ACAS Collision Avoidance ADS-B (UAT or 1090 ES) AM(R)S Air to Air* AM(R)S A/G FL and RL* Unmanned Aircraft Systems (UAS) CNPC* MLAT / HMU / WAM* • TACAN/Distance Measuring Equipment • DME/N associated with VOR and ILS • DME/P associated with VOR and MLS • TACAN range and bearing • Secondary Surveillance Radar • (SSR) Beacon Interrogator • Mode S Sensor, ATCRBS or IFF * Possible Future Capability

26. 4 R GNSS Example: GPS and Augmentation Systems GPS Satellites WAAS GEO Satellite* GPS Satellites GPS L1 & L5 Non-Precision Landing Wide Area Reference Station (WRS) WRS Differential GPS WAAS L1 & L5 CAT I Precision Landing GPS Master Control Station 4 L LAAS L1 & L5 CAT II/III Precision Landing * Other GEO augmentation satellites include EGNOS, MSAS, GAGAN

27. TACAN/DME Frequency Plan National Allotment Channels 962-977 MHz (1X – 16X) used for Military Shipboard and Land TACAN Ground Beacons Tx

28. TACAN / DMEINFORMATION • General Information • The Tactical Air Navigation (TACAN) system provides slant range and bearing information to pilots • The Distance Measuring Equipment (DME) system provides only slant range • Both systems consist of airborne interrogators and ground –based transponders (beacons) • Used for an aircraft to determine position relative to fixed locations (Beacons) • Two modes (x and y) of operation available • Measurement Information • Range from beacon derived by subtracting the specified beacon reply delay time from the round – trip propagation time • Bearing from beacon derived by detecting amplitude modulation on reply pulse train and comparing it to reference bursts

29. TACAN/DME Operation • DME frequencies • Spaced in 1 MHz increments throughout the 962 to 1213 MHz band. • Interrogation frequencies (on which aircraft transmit) are contained within the band 1025 to 1150 MHz • Reply frequencies from the beacon are on paired channels in either 63 MHz below or above the corresponding interrogation frequency. • Operation • The DME interrogator obtains a distance measurement by transmitting a pulse pair and waiting for a reply pulse pair from the beacon. • The two pulses in the pair are separated by either • 12 us for X mode interrogations and replies or • 36 us for the Y mode interrogator and 30 us for Y mode replies. • The beacon replies after a predetermined delay from the time of receipt of the interrogation. Based on the propagation delay, the aircraft interrogator equipment calculates the (slant range) distance from the transponder to its current location. • A DME ground-based transponder serves all aircraft within a designated radius of coverage (typically between 100 and 300 nautical miles)

30. Time TACAN/DMECompatibility Implications TACAN/DME Operates on fixed frequenciesin the same frequency band as Link-16 TACAN/DME communicates using pulse-pairs with a fixed spacing Airborne TACAN / DME Interrogators If the system detects two pulses with the proper spacing (within the receiver decoder window) and within the expected signal level range, it declares a valid decode Ground-Based TACAN / DME Beacons

31. SSR Description • Provides Air Traffic Control facilities with aircraft location and identification information • Consists of ground beacon interrogators and airborne transponders • Several SSR interrogation modes are available • Examples include: • Air Traffic Control Radar Beacon System (ATCRBS) • Mode Select (Mode S) • Identification Friend or Foe (IFF) • Link 16 does not transmit carriers in the 1030 MHz or 1090 MHz SSR bands

32. SSR Interrogator Description • Transmits interrogations at a fixed rate at 1030 MHz • Has rotating directional antenna with narrow horizontal beamwidth and fan shaped vertical beamwidth • Receives aircraft transponder replies on 1090 MHz • Determines azimuth, range and identification of aircraft • Determines altitude on altimeter equipped aircraft • Uses pulse position modulation

33. SSR Transponder Description • Receives interrogations at 1030 MHz • Has omnidirectional antenna • Provides identification (Mode 3/A) and altitude level (Mode C) depending on interrogation mode • Transmits replies on 1090 MHz • Uses pulse position modulation

34. Link 16 Compatibilityin theFrequency Band

35. Link 16 Compatibility in the Frequency Band • Link 16 Frequency Band Selection • Waveform Design Considerations • Test Program Summaries • Link 16 Operational Controls for EMC • Common Frequency Clearance Criteria • Compatibility with New Aviation Systems Planned To Opereate in the Frequency Band • Link 16 Terminal EMC Features

36. Frequency Band Selection • Design requirements • Omnidirectional broadcast • Frequency has to be less than 2500 MHz • High jamming resistance requires at least 200 MHz bandwidth • frequency has to be ≥ 400 MHz • Candidate bands with these systems were rejected due to EMC considerations • Pulsed radars • Television • Satellite downlink • Microwave relay • Radio astronomy

37. Frequency Band Selection( Continued ) • CANDIDATE FREQUENCY BANDS

38. Frequency Band Selection( Continued ) • Candidate bands were examined with respect to • EMC • International usage • Available bandwidth • It was concluded that the 960 – 1215 MHz  band was  the best choice

39. Waveform Design • From beginning of design, EMC with ATC systems was considered • Over 100 waveforms investigated for compatibility • Eventually chose one to US FAA and DOD satisfaction • Compatibility with TACAN/DME and SSR / ATCRBS / IFF / TCAS • Was a multiagency effort in the US • NTIA • FAA • DOD • RTCA • ARINC • FCC • MITRE • ECAC/JSC

40. Compatibility withTACAN/DME and SSR Receivers • TACAN / DME solution • Minimize the number of decodes • A 6.4 microsecond pulse width chosen to prevent single pulse decodes • Adjacent JTIDS / MIDS pulses transmitted uniformly over the band • Psuedo randomly • Frequencies of adjacent pulses at least 30 MHz apart • Minimize the number of pulses received • Waveform has maximum aggregate RF duty cycle of 21 % (TSDF = 100%) • ( 258 Pulses / Time Slot X 128 Time Slots / Sec X 6.4 microseconds) • Because of fast spectrum roll off, only 7 out of 51 frequencies will typically be detected at foreground levels which reduces effective RF duty cycle To 2.9% ( 7 / 51 X 21 ) • SSR solution • JTIDS pulses eliminated by two large spectrum notches • 45 MHz around 1030 MHz • 48 MHz around 1090 MHz • Pulse spectrum controlled down to -60 dBc at 15 MHz away

41. Compatibility Design Objectives TACAN / DME Beacons • Minimize the number of decodes and pulses detected • Decodes can reduce traffic handling capability to less than 100 aircraft • 27 Decodes = 1 % reduction • Single pulses interrupt receiver processing and reduce reply efficiency • Requirement = 70 % Detected Capability Link 16 Ground Site TACAN/DME Beacon Want Pr <= -33 dBm

42. Compatibility Design Objectives TACAN / DME Interrogators • Minimize the number of decodes and pulses detected • Decodes can capture automatic gain control • Equipment can tolerate at least 200 decodes / sec at power levels 8 dB above the desired level • Single pulses can interrupt receiver processing and potentially reduce reply efficiency • Requirement is to tolerate 6000 pulses / sec at power levels 30 dB above desired level 1000 ft

43. Compatibility Design ObjectivesSecondary Surveillance RADAR Receiver • SSR Ground Interrogators • IFF, ATCRBS or Mode S Sensors • Minimize the number of pulses detected • Single pulses can interrupt receiver processing and potentially cause reduction in reply efficiency • Reduction must be minimized • SSR ATC is the most important safety of flight requirement Link 16 Ground Site SSR ATCRBS Ground Interrogator Want Pr < = -20 dBm

44. JTIDS Single Carrier Spectrum

45. Composite Spectrum of the JTIDS Carriers

46. ENLARGED DETAIL 25 CHIPS = 5 BITS • 6.4 microsecond pulse • Contains 5 bits of data • CCSK encoding of 5 bits, yielding 32 chips per pulse • CPSM modulation using the 32 chips _ _ + + + + - - - - + + + + 1 1 2 2 1 1 3 3 0 0 0 0 0 0 200 ns 2 2 6.4 3 3 nsec 3 3 2 2 usec 1206 MHz Hops on 51 Different FREQUENCIES 969 MHz Time (t) Frequency Hopping

47. Test Program Summary

48. Test Program Summary(Continued)

49. Test Program Summary(Continued)

50. 100/50 TSDF US EMC Test Program • As part of the spectrum support efforts for JTIDS, an EMC Test Program was performed where JTIDS was tested against ATC systems operating in the frequency band to ensure EMC • TACAN/DME/N Interrogators • TACAN/DME/N Beacons • DME/P Interrogators • DME/P Beacon • ATCRBS Interrogators • Mode S Sensor • ATCRBS and Mode S transponders • TCAS (analysis was performed based on Mode S transponder test data) • Resulted in CFCC being granted in 2004