Trends in Aeronautical Flight Test Telemetry

1. The International Consortium for Telemetry Spectrum Trends in Aeronautical Flight Test Telemetry Timothy Chalfant & Gerhard Mayer Edwards AFB ICTS International Seminar AeroIndia 2009 Bangalore Approved for Public Release Case AFFTC-08334 Distribution A: Distribution is unlimited

2. Agenda • General Trends (G. Mayer) • The Spectrum Problem • The Role of the ICTS • WRC´07 Resolutions 2. Future Trends in FT Telemetry (T.Chalfant) • Flight Test Telemetry in C –Band • Network Topologies • Telemetry Standards 3. Summary and Conclusions

3. General Trends in flight test telemetry • More measured parameters per mission e.g. 3000 (AB 300), >30 000 (AB 380) • Higher amplitude & time resolution 8b & 10us (1970), 32b & 100 ns (2008) • From PCM to packetized transmission protocol overhead ! • Leading to increased data rates 100 kbps (1970) , 40 Mbps (2008) • More frequency spectrum required !

4. Flight tests in civil aviationincrease of measured parameters

5. The spectrum problem • Spectrum allocated for flight testing (1400 to 2450 MHz) has been outstripped by an exponential growth in required measurements and data rates • The existing telemetry bands are increasingly affected by encroachment from commercial interests and have been reduced internationally • Interference from unlicenced wireless devices has impacted the use of the remaining spectrum

6. Telemetry Spectrum -demand increasing but supply decreasing

7. International Consortium for Telemetry Spectrum To Ensure the Future Availability of Electromagnetic Spectrum for Telemetering The ICTS is an international advocacy group of telemetry practitioners committed to promoting the benefits of electromagnetic spectrum for telemetering applications.

8. ICTS • Is a sponsored group of the International Foundation for Telemetering (IFT) – a not-for-profit organisation that hosts the annual Int. Telemetering Conference. • Comprises membership from Government, Industry, and Academia across the ITU regions • Is organised (mirroring the three ITU regions) for a regional co-ordination and communication/ networking (mainly using e-communication methods) • Under the rules of its IFT charter, the ICTS has no“official position” on spectrum requirements in the context of the WRC

9. Main Objectives In this endeavor, the main objectives of the ICTS are: • Create a forum for information exchange on potential telemetry spectrum issues, • inform national, regional, and international spectrum managers of the importance of telemetry to their economy and security and • inform and inviteopen participation in the group to all telemetrypractitioners; including government; industry, academia, etc. and share information on the use, research, and development of new technologies for improving the use of telemetry spectrum.

10. Situation just before WRC 2007 • 5 additional bands for AMT were under study of AI 1.5 (4.4 to 6.7GHz). All bands are considered to have other users (existing occupants). • The CPM was the primary decision basis for delegates, commenting on advantages / disadvantages, on basis of compatibility and technical studies discussed at the WP8B. • ICTS information booth during the WRC 2007, to show the importance of AI 1.5 to the delegates and decision makers of ALL nations.

11. REGION 1 Europe Africa NOT ALLOCATED Except in Algeria, Saudi Arabia, Bahrain, Egypt, United Arab Emirates, Jordan, Kuwait, Lebanon, Morocco, Oman, Qatar, Syrian Arab Republic, Sudan, Tunisia NOT ALLOCATED REGION 2 America Except Brasil, ,Cuba, French overseas deptmts NOT ALLOCATED Except Brazil, Cuba, French overseas depts, Guatemala, Paraguay, Uruguay, Venezuela Brasil REGION 3 Asia&Pac NOT ALLOCATED NOT ALLOCATED NOT ALLOCATED Australia 5030 MHz 5091 MHz 4400 MHz 5150 MHz 5925 MHz 4940 MHz 5250 MHz 6700 MHz Documents : 305 (COM 4), 335 (Plenary) ; 336 (Plenary) Documents : 305 (COM 4), 335 (Plenary) ; 336 (Plenary) Documents : 305 (COM 4),

12. 2. Future Trends in Flight Test Telemetry • C-Band Telemetry Operation • Network Topologies • Telemetry Standards

13. Flight Test Telemetry in C-Band • Link budget comparing C- to S-Band fc= 5170 MHz, λC = 5,8 cm; fS = 2320 MHz, λS = 13 cm free space attenuation increase, Δα ~ (λS/λC)² -7dB gnd antenna* gain can compensate, GR~(λC/λS)² +7dB aperture angle of gnd antenna,* ~ λC/λSβc = 0,45 x βs flight antenna, wide area coverage identical gain 0dB • Influence weather & environment additional Atmospheric loss in wet regions (40° lat.) -3dB less gnd reflections expected at low elevation angles higher “roughness” of terrain, proportional λs/λc, generates diffuse refraction patterns instead reflections. * same effective antenna area for C-and S-Band assumed

14. CTEIP topics related to C-band Implementation • Multi-mode, multi-band transmitters & control interfaces • TM receiver changes required • Multi-carrier, single-carrier waveforms • Implementation of FEC and LDPC • TM platform integration issues with C-band • Integration into spectrum management systems • Ob & Gnd multiband antennae systems • Using & adaption existing tracking algorithms

15. iNET multi-band gnd receiving antenna concept

16. Immediate Development & Testing Efforts • C-Band Hardware airborne FM/PCM transmitters available IRIG 106 Standard multimode transmitters in developmt Retrofit gnd antennae, down convert signals US DoD project already supported initial flight trials • Operational Aspects Tracking systems & algorithms need up front evaluation Initial flight trials show no channel anomalies

17. Preserve existing TM link for safety of life / flight Make Bi-directional wireless network connection to TAs: Dynamic bandwidth (spectrum) sharing based upon priority and quality of service Improved transmission quality (error free delivery) Access to data recorded on TA storage device Ability to change configuration of TA instrumentation Flight Simulators Network Telemetry Topology The iNET Project Goals Illustration • Telemetry Network System (TmNS) Encompasses: • Vehicle Network (vNET) (Test Article, TA) • RF Network (rfNET) • Ground Network [Interface only (gNET)] • Serial Streaming Telemetry (SST) Link Courtesy US DoD/CTEIP iNET Program Office

18. Routers Network Data Acquisition Unit Network Solid State Recorder Crypto Device Aircraft Antenna Ground Antenna Network Transceiver Flight Simulators Ground Network iNETProject Description TmNS Encompasses: Telemetry Network System • iNET Deliverables: • TmNS • Network Manager • Spectrum Manager • Architecture • Standards Vehicle Data Acquisition Network Range Network Interface Vehicle Data Acquisition Network Dedicated Legacy TM Link Dedicated Legacy TM Link RF Network Vehicle Data Acquisition Network Dedicated Legacy TM Link Modified TM Processing Apps Routers Network Instrumentation carts Courtesy US DoD/CTEIP iNET Program Office

19. iNET Technical Parameters (notional) Courtesy US DoD/CTEIP iNET Program Office

20. Telemetry Standards • European Telemetry Standards Committee • Europe (and others) • www.aktm.org/etsc • Telemetry Standards Coordinating Council • Chartered by the Int’l Foundation for Telemetering • www.telemetry.org • Range Commanders Council (US DOD) • Aka Inter-Range Instrumentation Group (IRIG) • Stds made available to ETSC and TSCC

21. RCC Telemetry Standards • New Standards • Planned Releases • New TM Bands • TM Networks (IRIG-106 Vol 2) • IRIG-106 (Telemetry Standards) Recent Releases • release every 2 years • New Modulation (SOQPSK) • New Digital Recorder formats (Ch-10) • Updates to TM Attributes Standard • Stds for expression of Measurement Uncertainty • On-Board Networks • CPM/Advance Modulation

22. Summary • The 2007 WRC succeeded in securing additional radio spectrum resources for aeronautical telemetry. An immediate use must be initiated! • The new “WRC-bands” will allow the implication of wide band TM links into flight test missions. In Region 3 (Asia & Pacific) up to 59 MHz of usable bandwidth will be allocable. • Components & systems for either new state-of-the art equipment or for upgrade of existing systems are already in work. Tracking systems & algorithms need an up front evaluation. • The Indian FT community needs to occupy the bands or they will lose access to critical spectrum. Commercial interests are hunting to catch more spectrum !!

23. Conclusions • Test ranges involved in international T & E missions should utilize telemetering capabilities in the new bands as soon as possible, especially the global harmonized part from 5091 to 5150 MHz. • Indian goverment was supporting AI 1.5 in the WRC-07 process in a very cooperative way. • Therefore India Industry and government (HAL, DRDO, etc) is encouraged to take the next consequent step, to implement the C-band telemetry capability in their test ranges in these bands.

24. Further information ICTS Web site: www.telemetryspectrum.org IFT Web site: www.telemetry .org ITU Web site: www.itu.int/ITU-R/ ERO web site: www.ero.dk

25. Questions? Telemetry engineers do it with frequency! Are you getting enough?