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A Study of Future Communications Concepts and Technologies for the National Airspace System–Part I
Ms. Denise S. Ponchak and Mr. Rafael D. Apaza NASA Glenn Research Center
Cleveland, OH, USA [email protected] [email protected]
Mr. Brian Haynes
Xcelar Hopkins, MN, USA
Mr. Joel M. Wichgers
Rockwell Collins Cedar Rapids, IA, USA
Mr. Aloke Roy Honeywell International, Inc.
Columbia, MD, USA [email protected]
Abstract— The National Aviation and Space Administration (NASA) Glenn Research Center (GRC) is investigating current and anticipated wireless communications concepts and technologies that the National Airspace System (NAS) may need in the next 50 years. NASA has awarded three NASA Research Announcements (NAR) studies with the objective to determine the most promising candidate technologies for air-to-air and air-to-ground data exchange and analyze their suitability in a post-NextGen NAS environment. This paper will present progress made in the studies and describe the communications challenges and opportunities that have been identified during the studies’ first phase.
TABLE OF CONTENTS
1. INTRODUCTION……………………………….…..ERROR! BOOKMARK NOT DEFINED. 2. HONEYWELL…………….......................................2 3. ROCKWELL COLLINS……….……........................4 4. XCELAR…………………………………………..4 5. CONCLUSIONS……………..........................……..6 ACKNOWLEDGEMENT…………………………8
1. INTRODUCTION
NASA’s NextGen Concepts and Technology Development (CTD) Project integrates solutions for a safe, efficient and high-capacity airspace system through joint research efforts and partnerships with other government agencies. The CTD Project is one of two within NASA’s Airspace Systems Program and is managed by the NASA Ames Research Center. Research within the CTD Project is in support the 2011 NASA Strategic Plan Sub-Goal 4.1: Develop innovative solutions and advanced technologies, through a balanced research portfolio, to improve current and future air transportation. The focus of
CTD is on developing capabilities in traffic flow management, dynamic airspace configuration, separation assurance, super density operations, and airport surface operations. Important to its research is the development of human/automation information requirements and decision-making guidelines for human-human and human-machine airportal decision-making. Airborne separation, oceanic in-trail climb/descent and interval management applications depend on location and intent information of surrounding aircraft. ADS-B has been proposed to provide the information exchange, but other candidates such as satellite-based receivers, broadband or airborne internet, and cellular communications are possible candidate’s. For further information, the CTD project plan can be found at: http://www.aeronautics.nasa.gov/pdf/ctd_project_plan_2011_508.pdf
In the Spring of 2012, NASA Ames Research Center issued an amendment (CTD1 Subtopic 3) entitled: “Technology Candidates for Air-to-Air and Air-to-Ground Data Exchange” calling for proposals to NASA Research Announcement (NRA) “Research Opportunities in Aeronautics”, NNH11ZEA001N. Future applications such as airborne separation, oceanic in-trail climb/descent and interval management depend on the location and intent information of the surrounding aircraft with respect to an aircraft. Presently, Automatic Dependent Surveillance Broadcast (ADS-B) technology has been proposed to receive that information. However, satellite-based receivers, broadband or airborne internet, and cellular communications have also been proposed as possible candidates. The purpose of this solicitation was to identify the air-to-air and air-to-ground communication methods for NextGen and beyond NextGen operations. The specific goals are as follows:
1. Identify existing or emerging technology candidates (and their integration), including but not limited to ADS-B, suitable for air-to-air and air-to-ground communications over a NAS modernization horizon of 50 years.
https://ntrs.nasa.gov/search.jsp?R=20140010819 2018-08-19T13:27:39+00:00Z
2. Quantify the functional attributes and characteristics of each candidate, including (but not limited to) communications range, bandwidth, latency, integrity, reliability, and security.
3. Map the technology candidates to specific air traffic management applications where they will be most beneficial and cost effective.
4. Identify the infrastructure and architecture needs of the potential technologies for air-to-air and air-to-ground exchange.
5. Identify rough magnitude cost estimates, or relative cost comparisons, and any technological characteristics such as bandwidth, and reliability.
6. Provide assessment of how these technologies could be used for air traffic management applications including but not limited to airborne separation and interval management.
7. Identify vulnerabilities and security issues and mitigation of any proposed concepts.
The proposer was asked to identify current and future technologies that would be useful for air-to air and air-to-ground information exchange related to air traffic management applications. This was an exploratory NRA subtopic and there was flexibility for the proposer to select an appropriate approach. The anticipated duration was 24 months from the date of the award. The expected outcomes, deliverables, and, schedule were defined as follows:
1. A report describing technology candidates (and their integration) that will allow air-to-air and air-to-ground data exchange. Describe strengths and weaknesses of each. The report should include but not be limited to how the ADS-B could be made more cost effective. (Q3)
2. A report documenting infrastructure and architectural needs of these identified technology candidates. (Q4)
3. A report describing comparison of multiple alternatives and/or their integration based on costs, bandwidth, safety, reliability and security to support air-to-air and air-to-ground communications appropriate for future air traffic management operations. (Q5)
4. A report describing alternative technologies, their integration, dependencies on infrastructure and their potential use for air traffic management applications including but not limited to airborne separation and interval management. (Q7)
5. A detailed description of most promising technology alternative(s). (Q8)
The proposals were due on April 3rd, 2012. NASA Glenn Research Center led the evaluation of submitted proposals. In September 2012, three contract awards were made. They were: A Study of NAS Data Exchange Environment through 2060 (Honeywell, Columbia, MD, Aloke Roy/PI); NASA Com50 (Rockwell Collins, Cedar Rapids, IA, Joel Wichgers/PI); and, Technology Candidates for Air-to-Air nd Air-to-Ground Data Exchange (Agile Defense LLC, Hopkins, MN, Brian
Hayes/PI). These three studies all began in October 2012 and have a 24 month duration. This paper provides a summary of approximately the first six months of effort for each study.
2. HONEYWELL
BACKGROUND Honeywell has been studying communication technologies
suitable to support future Air Traffic Management needs in the 2060 time frame. The study was sponsored under NASA’s Next Generation (NextGen) Concepts and Technology Development (CTD1) project, sub-topic area-3: Candidates for Air-to-Air and Air-to-Ground Data Exchange. This section summarizes Honeywell’s initial findings to characterize candidate technologies for “Beyond NextGen” communications.
HONEYWELL TECHNICAL APPROACH The technical approach started with the characterization of
existing, upcoming and embryonic communication technology candidates. These technologies were identified by literature survey of public domain information, including standards, specifications, research papers and reports published at various forums around the World. Through the course of the project, increasingly fine filters were applied through objective, criteria-based analyses and assessments. For example, a filter eliminated candidates that do not meet basic ATM needs and criteria. Those criteria were derived from ICAO Global Navigation Plan and Communications Operating Concepts and Requirements (COCR), which was jointly defined by Eurocontrol and the United States Federal Aviation Administration (FAA). Successive filters examined architectural impacts and costs to ascertain the best value alternatives from the initial set of technology candidates. This report summarizes the findings of Honeywell after the candidate technology characterization. Subsequent publications will report the results of architectural, cost and operational analyses.
COMMUNICATION ENVIRONMENT IN 2060 NextGen represents a paradigm shift from rules-based to performance-based operations in the NAS, and data exchanges are a key enabler to achieve reduced aircraft separation and efficient movements in a more dense and dynamic airspace environment. As needs for situational awareness, airspace avoidance, and weather avoidance information increase with more complex and dynamic operations, advanced communication technologies coupled with innovative and cost-effective applications of existing technologies will be necessary to meet the required performance objectives. Communication beyond NextGen is expected to be multi-faceted whereby airborne platforms maintain multiple communication channels simultaneously with other terrestrial and airborne platforms to meet the availability, integrity and continuity of service requirements for autonomous operations.
CANDIDATE TECHNOLOGY ANALYSIS
Current Technologies Current communication technologies for aviation include
dedicated HF, narrow-band VHF systems; shared low-speed satellite systems such as INMERSAT Classic and IRIDIUM; and IEEE 802.11 wireless systems operating on shared Industrial, Scientific and Medical radio spectrum. These legacy systems will not meet the stringent performance requirements of the ATM systems Beyond NextGen.
Emerging Technologies
The US and Europe defined the Future Communications Infrastructure (FCI) for safety critical communications in the 2020 timeframe and beyond. The FCI identified AeroMACS (Aeronautical Mobile Airport Communications System) based on the IEEE 802.16 standard for airport terminal area, L-band systems for terrestrial enroute and next generation satellite systems for oceanic, remote and polar regions.
In addition to the above, some emerging commercial technologies targeting passenger communications are also under various stages of development. These technologies include 4G/5G cellular, Swift Broadband, IRIDIUM Next, Ka/Ku band SATCOM, and other commercial satellite based technologies. Some of these technologies, for example 4G/5G cellular and Ka/Ku band SATCOM, will evolve with the commercial market and will continue to serve the future needs. Some others, such as L-band and VHF may remain in place to satisfy very specialized aviation environments and services.
Embryonic Technologies Free space optical (FSO) communication is the most
notable embryonic technology to consider for the aviation environment. X-Ray is an extension of the FSO. However, X-Ray communications requires very high power and therefore mostly effective indoors over short ranges.
It is anticipated that the dominant challenges of FSO, which are atmospheric attenuation and signal acquisition and maintenance from high-speed, mobile platforms will be mostly mitigated over the next fifty years. Therefore, FSO will be a viable technology candidate for Beyond NextGen aviation while X-Ray may still be limited to indoor usage where high-power radiation may not be required.
Evaluation Criteria The communication performance requirements for the technology elements were derived from the Future Radio System (FRS) in the Communications Operating Concept and Requirements (COCR) document. Specifically, the COCR Phase 2 worst case loads in 2030 were used as the initial values and they were escalated at an annual rate of 2.5% over 30 years to derive the loads for year 2060 timeframe. Subsequently, those loads were used as basis for establishing the evaluation criteria for latency, continuity, integrity and availability.
Technology Characterization The technology candidates were assessed by comparing
their performance against the needs of various aeronautical services. A weighted score card was developed that normalized the performance of the technologies in various airspaces to meet the critical needs defined under the evaluation criteria. Then a final score for each technology was obtained by summing its weighted scores and then the technology candidates were ranked based on their final scores.
For the purpose of this analysis, some of the critical NextGen ATM applications involving Trajectory Based Operations, Separation Assurance procedures including Interval Management, In-Trial Procedures, Crossing and Passing, Continuous Descent Approach, FIS services and SWIM applications are considered and the results are extrapolated for the overall requirement.
Figure 1 and Figure 2 show the ranking of the technology candidates to meet the critical air-to-air and air-to-ground ATM applications respectively. From pure technology perspective, it can be observed that broadband VHF clearly outranks all other technologies to support air-to-air surveillance services. On the other hand, multiple technologies will be suitable for the air-to-ground environment and a hybrid technology solution may be desired to cover all the services in all applicable airspaces.
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APTTMA
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Figure 1. Technology capability scores for Air-to-Air Networking
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APT
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Figure 2. Technology capability scores for Air
Ground Datalink
B-VHF
B-VHF
CONCLUSIONS & RECOMMENDATIONS There are several good technology candidates to support
air/ground services for transition through NextGen and several great choices in the year 2060 time frame. In the near term, AeroMACS is the clear winner for the APT region. L-DACS and ANTARES are preferred alternatives for TMA, and ENR, while ANTARES would be the choice for the ORP region. These near-term technology solutions present better options for NextGen ATM because they have been designed to support high-reliability, safety services. As the demand for higher volume data transfer grows over the time horizon, cellular 4G/5G+ technologies will be the preferred technology candidates for APT, TMA, and ENR regions. Similarly, Ku-band satellite technologies may become better options for high-throughput data services beyond NextGen. FSO technology offers very high throughput, low latency and inherent communication security. The reliability and availability of FSO will be lower than other technologies in the APT and TMA regions due to atmospheric attenuations and other potential health hazards.
NEXT STEPS
The communication architectures for the leading technology candidates will be developed in the next step to further analyze their potential for ATM over the next fifty years. The architectures may include a specific technology, such as L-DACS, or it could be a hybrid consisting of two technologies, such as FSO and cellular.
A cost tradeoff analysis will be performed after a set of architecture alternatives have been identified to evaluate the relative cost impact for the aeronautical industry to migrate to the chosen architecture. The cost estimates will be a high level, relative approximation and will factor in the ramifications of shared versus dedicated infrastructure development.
In Phase-II of the NASA CTD1 contract, a simulation model will be developed to assess the performance of the proposed technology architecture against the projected performance requirements and utilize existing NASA traffic flow model to extrapolate NAS ATM environment to the year 2060 time frame.
3. ROCKWELL COLLINS Background
Today’s National Airspace System (NAS) has served the community well in meeting past operational and safety needs. It has made effective and prudent use of air-routes, procedures, and traditional Communication, Navigation, and Surveillance systems to provide a level of capacity that was sufficient for the demand while maintaining a strong safety record. However, without change, the NAS will be unable to realize the capacity, efficiency, safety, security, and environmental improvements that are being demanded for the Next Generation Air Transportation System (NextGen) and beyond. To realize these improvements, the long term NextGen and beyond infrastructure is envisioned to be built on better, more
capable, and optimally integrated communications, navigation, surveillance, information management, and decision support systems.
Communications, including both Aircraft-to-Aircraft (A-A) and Aircraft-to-Ground (A-G), is a key infrastructure element necessary to realize the future NAS vision such that the appropriate information is available at the required quality of service to enable the Air Traffic Management (ATM) systems to better utilize the airspace through enhanced operational procedures and applications.
Today’s NAS Communications
Today’s A-A and A-G NAS ATM-relevant communications are rather limited and consist primarily of VHF, HF, and SATCOM which support the traditional communications services, plus the use of L-band (978, 1030, and 1090 MHz) to support a number of surveillance and flight information services.
Emerging is the use of 1090 MHz Extended Squitter and 978 MHz Universal Access Transceiver (UAT) for A-A and A-G Automatic Dependent Surveillance – Broadcast (ADS-B) and the A-G communications of companion traffic surveillance systems including ADS-Rebroadcast (ADS-R) and Traffic Information Services – Broadcast (TIS-B). Also, emerging or soon to emerge is the use of VHF data link (VDL) to support data communications between air traffic controllers and aircraft as well as the use of VHF Data Broadcast (VDB) to support GPS/Local Area Augmentation System (LAAS) Category I precision approaches.
Long Term Future NAS Communications
Future concepts of operation for the long term national air transportation system within the study 50 year time horizon include incorporating new types of aircraft as well as advanced operating procedures and applications that will drive the need for more A-A and A-G communications, especially data communications, at quality of service levels appropriate for the intended operations. Better communications will enable applications that enhance flight operations during all phases of flight. Examples of such future ATM applications that will be enabled or improved with enhanced communication capabilities include In-Trail Procedures (ITP), Interval Management (IM), Delegated Separation (DS), 4D Trajectory Based Operations (TBO), more highly optimized arrivals and departures, cruise climb, closely spaced parallel-runway operations (CSPO), simultaneous runway operations, and a next generation airborne collision avoidance system (ACAS-X). Examples of new aircraft types anticipated to be integrated into the NAS during the study time horizon include a wide range of Unmanned Air Vehicles (UAV), single piloted commercial aircraft, high speed transport vehicles, and commercial space-launched vehicles.
Candidate Considerations
A number of A-A and A-G communications technology candidates have been identified considering at least the following factors:
� the physics of electromagnetic wave propagation through the atmosphere,
� wireless communications being used or under development for other applications (e.g., cellular, military, commercial broadband),
� communications currently in various stages of R&D (e.g., free space optical communications),
� communication trends,
� technologies relevant to significantly improve wireless communications that are anticipated to mature during the study 50 year time horizon,
� the potential availability of spectrum,
� the ability to meet the anticipated NAS operational, performance, safety, and security requirements,
� the transition path between today’s NAS communications and the future, and
� directions being taken by relevant regulatory (e.g., FAA, FCC, ITU) and industry standards groups (e.g., ICAO, RTCA, EUROCAE).
Strategies for Addressing Long Term NAS Communication Needs
The study has identified five fundamental strategic approaches for addressing the long term NAS communication needs including:
1) Reduce the need for communications bandwidth (e.g., using techniques such as data compression),
2) More efficiently using existing aviation communications spectrum (e.g., using higher order modulations),
3) Leverage commercial communications networks to support NAS communications needs,
4) Identify and reuse existing “aviation” spectrum to support NAS communications [e.g., use of portions of the “navigation” spectrum, including portions of the VHF (VOR spectrum), C-Band (MLS spectrum), and L-band (DME spectrum) to support NAS “communications”], and
5) Identify and obtain new spectrum allocations for NAS communications.
Candidates
A-A and A-G communication candidates have been identified with due consideration given to the aforementioned factors and strategies. Figure 3 and Figure 4 list current and future Air-to-Air and Air-to-Ground communication candidates, respectively, identified as part of the study. A-A candidates include line-of-sight (LOS) candidates including VHF, UHF, L-band, and optical as well as one hop routing through future SATCOM satellites. A-G candidates include LOS candidates from VHF to optical, as well as beyond LOS candidates that include HF, SATCOM, and A-G communications enabled by A-A hopping. Additional A-A and A-G communication candidates have been identified and
evaluated as part of the study that have not been depicted in the figures below.
Current A-A Comm. Future A-A Comm. Candidates
VHF: Portion of 112-137 MHz
UHF
Optical or Hybrid RF/Optical
L-Band L Band(More Efficient Use to support TCAS Function +
Perhaps DME Freq.)
(Use small part of current VHF Comm –118-137 MHz, or reallocated VOR Freq.)
(Perhaps Use Part of TV Freq.)
SATCOM(A-A One Hop Routed Through Satellite)
(Used for TCAS, ADS-B is Emerging)
VHF: 122-123 MHz(CTAF)
Figure 3. Air-to-Air Communications
Current A-G Comm.
VHF: 118-137 MHz
HF: ~3-30 MHz
SATCOM
Future A-G Comm. Candidates
VHF: 108-137 MHz
UHF
C-Band
SATCOM
HF
L-Band
Optical or Hybrid RF/Optical
L Band
(More Efficient Use of VHF + Use of VOR/ILS Freq.in 108 – 118 MHz)
(More Efficient Use + Perhaps DME Freq.)
(More Efficient Use Ku / Ka Freq., Plus Higher Freq.)
(Perhaps Use Part of TV Freq.)
(Use MLS Freq.)
(ATCRABS Transponder, FIS-B, ADS-B is Emerging)
(VHF Data Broadcast for LAAS is just emerging in 112 – 118 MHz)
A-G Com. Via A-A Hopping(Use VHF / UHF / L-Band Freq.)
Figure 4. Air-to-Ground Communications
Interim Study Findings
As part of the study, each of the A-A and A-G candidates has been characterized as to the communication bandwidth, latency, communications range, expected user data rates, capacity, link spectral efficiency, availability, coverage, vulnerabilities, advantages, disadvantages, and technology readiness. The candidates have also been mapped to current and expected future airspace ATM applications where they will be most beneficial and cost effective. While the presentation of all the results from these assessments is beyond the scope of this paper, a summary of the interim study findings resulting from these assessments is provided below.
� Current A-A and A-G NAS communications links are insufficient to meet the anticipated future needs of the NAS.
� The future NAS will require significantly more A-A and A-G communications to support the envisioned NAS NextGen and beyond operations as envisioned in the JPDO Concept of Operations.
� Traffic is expected to increase 3X to 10X from today’s NAS traffic levels over the 50 year study time horizon, assuming a yearly nominal growth rate between 2.2% and 4.7%.
� Spectrum is a very limited resource. Allocation of it among all those who desire to use the spectrum is becoming increasingly more difficult. Many existing users of the spectrum (including aviation) will over time need to modernize their systems to improve their spectral efficiency to enable the spectrum to meet the future demands.
� Current spectrum efficiency of today’s NAS A-A and A-G communications is inefficient by today’s state of the practice for wireless communications.
� Wireless communications technologies are advancing in a number of areas that will lead to significant increases in the spectral efficiency (e.g., bits/Hz).
� The current state of the art for wireless communications achieves ~60% of Shannon’s channel capacity limit. 60% to 70% of Shannon’s channel capacity limit will likely become the state of the practice for wireless communications systems during the modernization time horizon.
� It is envisioned that commercial broadband communication networks will expand beyond what is offered today to further support ATM communications (primarily A-G, but also A-A).
� Technology will advance over the study modernization time horizon that will enable SATCOM to efficiently use RF frequencies in the K, V, and W bands (frequencies up to ~110 GHz) not including frequencies around 60 GHz, in addition to the Ku and Ka bands used today.
� Technology will advance over the study modernization time horizon that will enable use of free space optical communications for ground to satellite, satellite to aircraft, aircraft-to-ground, and aircraft-to-aircraft communications.
� Future SATCOM communication systems are anticipated to be capable of allocating communication bandwidth (BW) and quality of service (QOS) on demand to support a wide range of applications, including those in civil aviation.
� Future Aviation CNS needs will evolve during the 50 year NAS study time horizon. NAS data communications can potentially reuse aviation spectrum that is decommissioned by other NAS services. The primary opportunities identified include: 1) the MLS C-band, 2) portions of the VHF VOR/ILS Localizer bands, and 3) portions of the DME (L band).
� Obtaining significantly more spectrum allocations dedicated to support NAS A-A and/or A-G
communications will become increasingly challenging.
� Five fundamental strategic approaches have been identified for addressing the long-term NAS communication needs as described in this paper.
� As future NAS communication and information systems become more networked and provide a variety of information for enabling better airspace utilization digitally, there is the potential for increased cyber-attacks similar to those experienced by state and corporate information systems.
� Future NAS communications systems will need to address a variety of information security challenges. The successful implementation of information security will require coordination and collaboration between traditional aeronautical stakeholders (e.g., airlines, aircraft manufacturers, avionics suppliers, ground systems suppliers, aeronautical service providers, FAA/aviation authorities) and information security and information technology experts.
� The future communications infrastructure and architecture needs to be considered in the context of the overall NAS systems infrastructure and architecture such that the entire NAS infrastructure can be optimized while satisfying the operational, performance, safety, and security requirements.
� No one single communications data link technology can meet all the expected future A-A and A-G communications requirements for the NAS. A combination of various communication technologies will be needed to address the diverse aeronautical communications requirements across all the operational flight domains.
� The emerging and the predicted future communication technologies are envisioned to be able to meet the NextGen and beyond NAS aircraft-to-aircraft and aircraft-to-ground communication needs.
Additional R&D continues to be worked to more comprehensively identify, characterize, and evaluate how the A-A and A-G candidates could potentially serve the evolving long-term needs of the NAS.
4. XCELAR The XCELAR Team approached the study more from an
operator-oriented perspective than that of the equipment, service suppliers, or the ANSP. An important initial step involved defining the potential nature and capabilities of the air vehicles (manned, reduced-crew, or unmanned) and of the airspace system, in the context of benefits to the aircraft operator. A system-based model was used, with initial analysis using general functional roles (i.e., “Air Vehicle”, “Ground-based ATM”, “Ground-based Non-ATM” roles, and “To/From Vehicle”, To/From Ground-based ATM”, etc. for information flow) to define systemic capabilities, needs, and information flow decoupled from the current paradigm. Those system capabilities were then used to define the communication
capabilities required for realization, from which future data link functional requirements were derived for use in a parallel study of various candidate link technologies, topologies, and architectures. A “form follows function” approach can then be applied to the candidate link analysis, in which specific link methods and combinations of methods serve the overall needs of the system in optimized ways.
As part of this definition of the future operational environment, a Future NAS Communications Workshop was held to help define NAS Scenarios using a wider team from industry, academia, NASA, and others. Four baseline scenario types were defined: Terminal Operations – Departures; En route Operations; Terminal Operations – Arrivals; and Ground Operations. Definitions for each scenario included top-level goals, primary success criteria, and expected capabilities & needs. Future capabilities of both the vehicles and the National Airspace System (NAS) were considered, and operation types included Air Transport, including the use of reduced-crew configurations and unmanned vehicles; General Aviation and Business Aviation operators (including Very Light Jets); and other types of Unmanned Aerial Vehicle (UAV) operations. It is worthy of note that a significant level of reduced-crew and/or unmanned commercial operations was projected for the air transport sector.
A key consideration was to correctly define the underlying assumptions for the air transportation system of 50 years in the future, particularly in terms of regulatory considerations, system user expectations and sensitivities, and their rate of evolution over the 50-year period. One useful input to that process was to look back a similar period, and assess the rate of change over the past 50 years in the same industry. Examples of significant technical events approximately 50 years ago include:
� 1963 - B727 first flight
� 1963 – Cessna 336 enters service; 1965 – Cessna 337 in certification
� 1963 – Lear 23 first flight
� 1967 – B737 first flight
� SELCAL entered service approximately 50 years ago
30 years ago:
� 1983 – First cellular telephone received FAA approval (Motorola DynaTac)
� 1983 – First PDA (Psion 1); 1993 – Apple Newton
� ACARS Entered service
In that period of time, regulatory processes have adapted to accommodate a host of new technologies, including composite aircraft, glass cockpits, GPS, ADS-B, and many others. System users have accepted cellular communications, the Internet, PDAs, pervasive wireless connectivity, and increasing reliance on robotics (including unmanned surface transportation such as trams), and innumerable other technologies. The perspectives, capabilities, and adaptation of both regulators and users can be expected to continue to
progress at similar or faster rates going forward. As a result, the “Future NAS” underlying assumptions included the premise that future regulatory processes will evolve to accommodate approval and use of the technologies available, and that system users will be prepared to accept an increasing level of connectivity, communication-dependent functionality, and robotics in the future air transportation system.
To minimize replication of previous efforts, an initial Literature Review of documents from NASA, AIAA, RTCA, IEEE, MITRE/MIT, FAA, Eurocontrol, ICAO and others was conducted at the beginning of the study. This review revealed limited applicable study work in past 10–15 years; the majority of work reviewed pertains to already-identified link technologies and/or NAS concepts, rather than future concepts. Most documents are focused on specific link technologies and their capabilities, rather than on future NAS functions and unmet communication needs. Little analysis was found of link-independent, result-based data delivery concepts rather than specific links for each purpose. Based on those findings, the approach of defining the future NAS, then functions/unmet needs, then delivery solutions, was selected as the overall study methodology.
In parallel with the future NAS definition and derivation of communication functions and requirements, an initial analysis of currently known link technologies was conducted to assess their current and probable future capabilities compared to projected loads and other factors. This “look forward” analysis provides a starting point in the identification and analysis of future solutions, and quantifies potential unmet needs in current systems, and therefore functions that will require new solutions. An example is the current use of 1030/1090 mHz for ATCRBS, ADS-B, TCAS, and other proposed functions such as air-to-air linking of wake turbulence data. Initial analysis suggests that the current system will reach its capacity limit well before the 50-year future point, and alternate solutions must be considered as part of the study.
The next phase of the study includes the convergence of the parallel analyses of functional needs and candidate link solutions. The continued use of a system-based approach is planned; for example, a promising consideration for potential solutions may be the overall delivery performance of the system, not necessarily of a specific, purpose-developed link. The potential for a “delivery manager” function to aggregate multiple link capabilities, and manage not only message routing but required communication performance, with access to (or even control of) all layers of the each link’s operation, offers a potential system solution where individual links may not meet the technical and business case needs of all stakeholders.
5. CONCLUSIONS A NASA Research Announcement (NRA) study to
investigate potential future aeronautical communication technologies that could serve aviation in the 2060 time frame was awarded in 2012. This NRA study is a one-year effort with an option that has been exercised for an additional year extension. The objective of this study is to investigate future air-ground communications technologies, evaluate possible
architectures, assess future communication needs, and identify challenges that will need to be addressed in the development and implementation of such potential systems. An important element of the study is to consider technological and Air Traffic Management advances planned for implementation by the NextGen and SESAR programs. NASA awarded the study to Rockwell Collins Corporation, Honeywell Corporation and Xcelar Corporation to independently conduct the study. This paper provides results obtained to date by each company.
Preliminary findings indicate that spectrum and technology certification will continue to pose a challenge, especially in areas where software is increasingly used to perform hardware functions. It is anticipated that although some spectrum will become available as a result of the decommissioning of technologies i.e. VOR, the demand for spectrum will increase and future technologies will need to provide the ability to maximize the use of finite spectrum resources. Advances in
electronics and communications technology will enable the integration of services and applications and thus reducing the number of system deployed to the aircraft. Finally, the future aviation radio technology will depend on numerous factors including: air traffic management procedures, airline operations business models and the configuration of the airspace, which is anticipated to include Unmanned Aircraft Systems, hypersonic flights and manned aircraft.
ACKNOWLEDGMENT The authors would like to acknowledge the funding and
support of the NASA Aeronautics Research Mission Directorate’s Airspace Systems Program Office at NASA Headquarters and NASA Ames Research Center; specifically: Dr. John A. Cavolowsky, Dr. Parimal H. Kopardekar, Mr. Rudolph A. Aquilina, and, Ms. Nazaret C. Galeon.
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aten
cy
• Con
tinui
ty
• Int
egrit
y • A
vaila
bilit
y • L
ink
type
• S
pect
rum
• R
ange
• M
atur
ity /
Ris
ks
• Vul
nera
bilit
ies
• Tim
efra
me
•Air-
Air,
Air-
Gro
und
•Lin
e-of
-sig
ht,
Bey
ond
Line
-of-S
ight
•N
arro
w- &
Bro
ad-b
and
•Aer
o, C
omm
erci
al,
Non
-aer
o Sp
ecia
lized
Filte
r
•Mee
ts c
riter
ia
thr
esho
lds?
ATM
Ap
plic
atio
ns
• Airs
pace
S
epar
atio
n
• In-
Trai
l P
roce
dure
s • I
nter
val M
gmt.
• Tra
ject
ory
Bas
ed
Ope
ratio
ns
• Acc
ess
to S
WIM
• F
light
Info
rmat
ion
S
ervi
ces
Eval
uate
C
andi
date
Te
chno
logi
es
• S
core
/ R
ank
• Com
para
tive
an
alys
is
• Tim
e –p
hase
d
ro
adm
ap
IDEN
TIFY
C
HAR
AC
TER
IZE
ANA
LYZE
M
AP T
O N
EED
S R
EPO
RT
Rep
ort
1
Exis
ting
Aero
Lin
ks
Lite
ratu
re /
Pate
nts
Hon
eyw
ell S
MEs
Tech
nolo
gy T
rend
s
� IC
AO A
vion
ics
Blo
ck U
pgra
des
� N
extG
en Im
plem
enta
tion
Plan
�
Nex
tGen
Avi
onic
s R
oadm
ap
�SE
SAR
Mas
ter P
lan
Inpu
t R
ef
Doc
s
Qua
ntita
tive
/ Qua
litat
ive
Eval
uatio
n C
riter
ia a
nd T
hres
hold
s
• Mee
ts b
asic
A
TM n
eeds
?
Year
1
8
Tech
nolo
gy C
andi
date
s
•Cur
rent
Tec
hnol
ogie
s -M
ostly
nar
row
-ban
d sy
stem
s w
ith li
mite
d da
ta ra
te:
-Evo
lutio
n of
Wire
less
and
Cel
lula
r tec
hnol
ogie
s w
ill c
ontin
ue
to a
dd m
ore
capa
bilit
ies
with
tim
e -O
ther
nar
row
-ban
d sy
stem
s w
ill n
ot s
uppo
rt fu
ture
in
form
atio
n tr
ansf
er n
eeds
and
wer
e ex
clud
ed fr
om th
is s
tudy
HF
Dat
a Li
nk
300
bps
to 1
200
bps,
sha
red
chan
nel
VHF
Dat
a Li
nks
2400
bps
to 3
1,50
0 bp
s, s
hare
d ch
anne
l
Sate
llite
Dat
a Li
nks
Up
to 1
0,50
0 bp
s, s
hare
d ch
anne
l 64
Kbp
s de
dica
ted
per a
ircra
ft
L-B
and
(Mod
e-S/
UAT)
Ty
pica
lly 6
0 K
bps
but p
ossi
ble
to a
chie
ve 4
Mbp
s sh
ared
dat
a ra
te
Cel
lula
r U
p to
400
Kbp
s. F
utur
e te
chno
logy
impr
ovem
ents
ca
n de
liver
dat
a ra
tes
up to
3G
bps
Wire
less
U
p to
54
Mbp
s, s
hare
d da
ta ra
te fo
r 802
.11
a/b/
g H
as g
row
th p
oten
tial t
o 7G
bps
9
Tech
nolo
gy C
andi
date
s [C
ont..
]
•Em
ergi
ng T
echn
olog
ies
-Upc
omin
g co
mm
unic
atio
n te
chno
logi
es a
re m
igra
ting
to
broa
dban
d sy
stem
s
�D
riven
by
high
er d
eman
d fo
r lar
ge v
olum
e da
ta tr
ansf
er
�Fu
ll m
otio
n vi
deo,
VoI
P, e
tc. r
equi
re v
ery
low
late
ncy
& ji
tter
�W
irele
ss c
omm
unic
atio
ns a
re g
radu
ally
mov
ing
up th
e sp
ectra
l ban
d �
Tech
nolo
gy a
dvan
cem
ents
are
focu
sed
on im
prov
ing
spec
tral
effic
ienc
y as
mos
t of t
he p
rime
spec
trum
is a
lread
y al
loca
ted
-Not
all
tech
nolo
gica
l im
prov
emen
ts c
an b
e ut
ilize
d ef
fect
ivel
y fo
r aer
onau
tical
com
mun
icat
ions
�
Hig
her o
rder
MIM
O s
yste
ms
will
requ
ire m
ore
ante
nnas
�
Mic
ro c
ells
with
radi
us s
mal
ler t
han
50 m
iles
mig
ht n
ot b
e op
timal
for
en-ro
ute
com
mun
icat
ions
�
Atm
osph
eric
atte
nuat
ions
may
lim
it hi
gher
freq
uenc
y ra
nges
-E
mer
ging
Tec
hnol
ogie
s un
der c
onsi
dera
tion
are:
�
Wire
less
/Cel
lula
r: A
eroM
AC
S, L
TE-A
dvan
ced/
4G/5
G
�L-
band
Ter
rest
rial:
LDA
CS
�
Sat
ellit
e: A
NTA
RE
S, I
RID
IUM
Nex
t, S
wift
Bro
adba
nd, K
a/K
u B
and
10
Tech
nolo
gy C
andi
date
s [C
ont..
]
•Em
bryo
nic
Tech
nolo
gies
-P
rimar
y re
sear
ch in
free
spa
ce o
ptic
al c
omm
unic
atio
ns
�S
uita
ble
for p
oint
to p
oint
com
mun
icat
ions
onl
y •R
equi
res
line
of s
ight
�
Som
e pr
oof o
f con
cept
tria
ls in
aer
onau
tical
com
mun
icat
ions
�
Cha
lleng
es re
mai
n in
the
follo
win
g ar
eas:
•I
nitia
l tar
getin
g an
d lo
ck w
hile
mov
ing
at h
igh
spee
d (m
aybe
120
0 N
M o
r hi
gher
) •A
tmos
pher
ic a
ttenu
atio
ns
•Hea
lth H
azar
ds
�A
dvan
tage
s •V
ery
high
thro
ughp
ut a
nd lo
w la
tenc
y •P
ract
ical
ly u
nuse
d sp
ectru
m
•Inh
eren
tly s
ecur
e
-Oth
er te
chno
logi
es c
onsi
dere
d ar
e:
�X-
ray
�B
road
band
VH
F in
the
aero
naut
ical
ban
d
11
Tech
nolo
gy R
anki
ngs
from
Tas
k-1
Air
spac
e R
ank
APT
T
MA
E
NR
O
RP
1
SO-V
HF
SO-V
HF
SO-V
HF
SO-V
HF
2
Aer
oMA
CS
L-D
AC
S L-
DA
CS
Ku
SATC
OM
3 L-
DA
CS
Cel
lula
r 4G
/5G
C
ellu
lar 4
G/5
G
INM
AR
SAT
SBB
4 C
ellu
lar 4
G/5
G
Ku
SATC
OM
K
u SA
TCO
M
5
INM
AR
SAT
SBB
IN
MA
RSA
T SB
B
Air-
to-A
ir C
omm
unic
atio
ns:
Air/
Gro
und
Com
mun
icat
ions
for
ATM
: A
irsp
ace
Ran
k A
PT
TM
A
EN
R
OR
P
1
Aer
oMA
CS
SO-V
HF
SO-V
HF
Ku
SATC
OM
2 SO
-VH
F L-
DA
CS
L-D
AC
S IN
MA
RSA
T SB
B
3
L-D
AC
S C
ellu
lar 4
G/5
G
Cel
lula
r 4G
/5G
4 C
ellu
lar 4
G/5
G
Ku
SATC
OM
K
u SA
TCO
M
5
Ku
SATC
OM
IN
MA
RSA
T SB
B
INM
AR
SAT
SBB
Hig
h B
andw
idth
Fut
ure
Com
mun
icat
ions
: A
irsp
ace
Ran
k A
PT
TM
A
EN
R
OR
P
1
Opt
ical
Poi
nt-to
-Poi
nt
Opt
ical
Poi
nt-to
-Poi
nt
Opt
ical
Poi
nt-to
-Poi
nt
Opt
ical
Sat
ellit
e
2 O
ptic
al S
atel
lite
Opt
ical
Sat
ellit
e O
ptic
al S
atel
lite
Ku
Sate
llite
3 C
ellu
lar 4
G/5
G
Cel
lula
r 4G
/5G
C
ellu
lar 4
G/5
G
Ka
Sate
llite
4 K
u Sa
telli
te
Ku
Sate
llite
K
u Sa
telli
te
5
Ka
Sate
llite
K
a Sa
telli
te
Ka
Sate
llite
12
Tech
nolo
gy R
anki
ng fo
r Air-
to-A
ir C
omm
-150
-100-5
0050100
150
Technology Scores
Criti
cal S
urve
illan
ce A
pplic
atio
ns (A
ir to
Air)
APT
TMA
ENR
OPR
Supp
ort in
Appl
icat
ion
Thre
shol
d
13
Tech
nolo
gy R
anki
ng fo
r Air-
Gro
und
Com
m
-150
-100- 5
0050100
Technology Scores
Criti
cal A
TS A
pplic
atio
ns (A
ir to
Gro
und)
APT
TMA
ENR
OPR
Supp
ort in
Appl
icatio
nTh
resh
old
14
Initi
al F
indi
ngs
•Em
ergi
ng te
chno
logi
es a
re w
ell p
ositi
oned
to s
uppo
rt
Nex
tGen
com
mun
icat
ion
need
s
•Of t
he e
mbr
yoni
c te
chno
logi
es, F
ree
Spac
e O
ptic
al
tech
nolo
gy is
mos
t pro
mis
ing
•Var
ied
tech
nolo
gy s
olut
ions
will
be
need
ed to
ad
dres
s di
vers
e ae
rona
utic
al re
quire
men
ts
•Hyb
rid s
olut
ions
com
bini
ng F
ree
Spac
e O
ptic
al w
ith
Sate
llite
, L-b
and
or w
irele
ss m
ay s
uppo
rt B
eyon
d N
extG
en n
eeds
•Alg
orith
ms
dem
andi
ng h
ighe
r com
putin
g an
d si
gnal
pr
oces
sing
cap
abili
ties
will
impr
ove
spec
tral
ef
ficie
ncie
s of
futu
re c
omm
unic
atio
n sy
stem
s
Slid
e 15
Ove
rvie
w o
f R
ockw
ell C
ollin
s N
AS
A N
RA
res
earc
h f
or t
he
“Dev
elop
men
t of
Nex
tGen
Con
cep
ts f
or A
ir-t
o-A
ir a
nd
Air
-to-
Gro
un
d
Dat
a Ex
chan
ge”
A
forw
ard
look
ing
stud
y to
iden
tify
long
term
can
dida
tes
for m
eetin
g th
e ai
r-to
-air
and
air-
to-g
roun
d co
mm
unic
atio
n ne
eds
of th
e N
AS
durin
g a
50 y
ear m
oder
niza
tion
time
horiz
on.
Con
trac
t #
: N
NA
12
AB
82
C
Dev
elop
ed b
y: J
oel
M.
Wic
hg
ers
(PI)
phon
e: (
319)
295
-006
8
e-m
ail:
jmw
ichg
e@ro
ckw
ellc
ollin
s.co
m
Dat
e: S
epte
mbe
r 30
, 20
13
Dat
e:Sepppp
tem
ber
30,,
2013
2050
20
60
Prop
osed
DA
SC S
lides
for R
ockw
ell C
ollin
s Po
rtio
n
The
Nex
t G
ener
atio
n A
ir T
ran
spor
tati
on S
yste
m
(Nex
tGen
) V
isio
n f
or N
atio
nal
Air
spac
e •
Tod
ay’s
Nat
ion
al A
irsp
ace
–H
as s
erve
d us
wel
l in
mee
ting
past
ope
ratio
nal a
nd s
afet
y ne
eds
•M
ade
effe
ctiv
e an
d pr
uden
t us
e of
air
-rou
tes,
pro
cedu
res,
and
tra
ditio
nal C
NS s
yste
ms
to p
rovi
de
a le
vel o
f ca
paci
ty a
nd s
afet
y th
at w
as s
uffic
ient
for
the
dem
and
–H
owev
er,
with
out
chan
ge,
it w
ill b
e un
able
to
real
ize
the
capa
city
, ef
ficie
ncy,
sa
fety
, se
curity
, an
d en
viro
nmen
tal i
mpr
ovem
ents
tha
t ar
e ne
eded
.
•N
extG
en &
Bey
ond
Air
spac
e –
Cha
nge
way
airsp
ace
is u
tiliz
ed/m
anag
ed
to a
chie
ve s
igni
fican
t op
erat
iona
l im
prov
emen
ts
–En
able
enh
ance
d op
erat
ing
proc
edur
es
–En
able
d w
ith b
ette
r Com
/Nav
/Sur
veill
ance
sy
stem
s, a
utom
atio
n, d
ecis
ion
supp
ort,
hu
man
-mac
hine
inte
rfac
es,
etc.
–
Com
patib
le w
ith I
CAO
con
cept
s an
d ot
her
inte
rnat
iona
l ini
tiativ
es (
e.g.
, SES
AR)
16
Bet
ter
Com
m.
is a
key
Ena
bler
of N
extG
en &
Bey
ond
Airsp
ace
Vis
ion
17
Tech
nic
al A
pp
roac
h f
or B
ase
Yea
r S
tud
y
Bas
e Ye
ar T
echn
ical
App
roac
h
•S
MEs
from
Roc
kwel
l C
ollin
s, N
ASA,
FAA
, &
othe
r org
aniz
atio
ns
•D
ocum
ents
: NA
SA
, FA
A, J
PD
O, I
CAO
, R
TCA,
EU
RO
CA
E,
ITU
, NIS
T, S
AE
, E
uroc
ontro
l, R
ockw
ell
Col
lins,
etc
. •
Inte
rnal
and
pub
lishe
d R
&D
•
Lite
ratu
re
Gat
her a
nd
Assi
mila
te
Rel
evan
t Inf
o.
•Id
entif
y ex
istin
g /
emer
ging
aer
o lin
ks,
and
pote
ntia
lly
rele
vant
non
-aer
o lin
ks
•Id
entif
y tre
nds
•Id
entif
y po
tent
ial f
utur
e N
extG
en a
nd b
eyon
d ap
ps. a
nd th
eir n
eeds
•
Iden
tify
exis
ting
CN
S
infra
stru
ctur
e &
gap
s •
Iden
tify
rele
vant
te
chno
logi
es in
R&
D
•El
ectro
-mag
netic
sp
ectru
m in
vest
igat
ion
•P
ropa
gatio
n •
Atm
osph
eric
at
tenu
atio
n •
Exi
stin
g al
loca
tions
, an
d po
tent
ially
av
aila
ble
spec
trum
Iden
tify
Link
s,
Tren
ds, R
&D
, Ap
ps. &
Nee
ds
ID S
pect
rum
Su
itabl
e fo
r A-
A &
A-G
Com
•
Dev
elop
can
dida
te
sele
ctio
n cr
iteria
•
Dev
elop
and
des
crib
e lis
t of p
oten
tial A
-A
and
A-G
com
. ca
ndid
ates
•
Iden
tify
infra
stru
ctur
e an
d ar
chite
ctur
e ne
eds
of th
e ca
ndid
ates
•D
efin
e at
tribu
tes
and
char
acte
ristic
s:
−Ba
ndw
idth
−
Late
ncy
−C
om. r
ange
/ co
vera
ge
−C
apac
ity
−S
pect
ral e
ffici
ency
−
Vuln
erab
ilitie
s −
New
cap
abilit
ies
−TR
L −
etc.
•
Dev
elop
initi
al R
CP
for
ATM
app
licat
ions
•
Map
can
dida
tes
as to
th
eir a
bilit
y to
mee
t AT
M a
pplic
atio
n ne
eds
•Id
entif
y an
d ev
alua
te
thre
ats,
vul
nera
bilit
ies,
ris
ks, a
nd m
itiga
tions
ID a
nd D
escr
ibe
Pote
ntia
l Com
. C
andi
date
s
Cha
ract
eriz
e,
Dev
elop
RC
P,
Map
to A
pps.
•
Rpt
. #1:
Tec
hnol
ogy
Can
dida
tes
•R
pt. #
2: In
frast
ruct
ure
& A
rchi
tect
ure
Nee
ds
•C
onfe
renc
e P
aper
s an
d Pr
esen
tatio
ns
•B
ase
Year
Rep
ort
•M
onth
ly/Q
uarte
rly/B
i-an
nual
Rev
iew
s
Dev
elop
R
epor
ts
Gat
her
Info
. Id
entif
y Spe
ctru
m
Inve
stig
atio
n D
evel
op
Can
dida
tes
Ana
lyze
Can
dida
tes
Doc
umen
t Re
sults
Not
e: T
here
are
iter
atio
n an
d fe
edba
ck lo
ops
amon
g va
rious
st
eps
that
are
not
illu
stra
ted
for d
iagr
am s
impl
icity
.
18
Iden
tifi
ed S
et o
f A
ir-t
o-A
ir (
A-A
) C
omm
. C
and
idat
es
[In
clu
des
CN
S “
Com
m”
Fun
ctio
ns]
Cur
rent
A-A
Com
mun
icat
ions
Fu
ture
A-A
Com
mun
icat
ions
Can
dida
tes
VH
F: P
ortio
n of
112
-137
MH
z
UH
F
Opt
ical
or
Hyb
rid
RF/
Opt
ical
L-Ban
d L
Ban
d (M
ore
Effi
cien
t Use
to s
uppo
rt TC
AS
Func
tion
+ P
erha
ps
DM
E F
req.
)
(Use
sm
all p
art o
f cur
rent
VH
F C
omm
– 1
18-1
37
MH
z, o
r rea
lloca
ted
VO
R F
req.
)
(Per
haps
Use
Par
t of T
V F
req.
)
SATC
OM
(A
-A O
ne H
op R
oute
d Th
roug
h S
atel
lite)
(Use
d fo
r TC
AS
, AD
S-B
is E
mer
ging
)
VH
F: 1
22-1
23 M
Hz
(CTA
F)
Band
Fr
eque
ncy
Radio
HF
3 –
30 M
Hz
VHF
30 –
300
MH
z U
HF
300
– 10
00 M
Hz
L 1
– 2
GHz
S
2 –
4 G
Hz
C 4
– 8
GHz
X
8 –
12 G
Hz
Ku
12 –
18
GHz
K
18 –
27
GHz
Ka
27
– 4
0 G
Hz
V 40
– 7
5 G
Hz
W
75 –
110
GH
z G
110
– 30
0 G
Hz
Infr
ared
30
0 G
Hz –
430
TH
z Vi
sibl
e 43
0 –
790
THz
UV
790
THz –
30
PHz
X-Ra
y 30
PH
z – 3
0 EH
z G
amm
a-Ra
y >
10 E
Hz
A-A
Air-t
o-Ai
r (A-
A) C
omm
unic
atio
ns C
andi
date
s1
VHF
A-A
2UH
F A-
A3
L-Ba
nd A
-A4
S-Ba
nd A
-A5
C-Ba
nd A
-A6
X-Ba
nd A
-A7
Opt
ical
A-A
8Hy
brid
RF/
Opt
ical
A-A
9LE
O S
ATCO
M A
-A (O
ne H
op th
roug
h Sa
telli
te)
10G
EO S
ATCO
M A
-A (O
ne H
op th
roug
h Sa
telli
te)
11M
EO S
ATCO
M A
-A (O
ne H
op th
roug
h Sa
telli
te)
12G
EO +
HEO
SAT
COM
A-A
(One
Hop
thro
ugh
Sat.)
C a
nd X
Ban
ds
19
Iden
tifi
ed S
et o
f A
ir-t
o-G
rou
nd
(A
-G)
Com
m.
Can
did
ates
[I
ncl
ud
es C
NS
“C
omm
” Fu
nct
ion
s]
Cur
rent
A-G
Com
mun
icat
ions
VH
F: 1
18-1
37 M
Hz
HF:
~3-
30 M
Hz
SATC
OM
Futu
re A
-G C
omm
unic
atio
ns C
andi
date
s
VH
F: 1
08-1
37 M
Hz
UH
F
C a
nd X
Ban
ds
SATC
OM
HF
L-Ban
d
Opt
ical
or
Hyb
rid
RF/
Opt
ical
L Ban
d
(Mor
e E
ffici
ent U
se o
f VH
F +
Per
haps
VO
R F
req.
in 1
12 –
118
MH
z +
VH
F D
ata
Bro
adca
st o
f LA
AS
in IL
S a
nd V
OR
ban
ds 1
08 to
118
MH
z)
(Mor
e E
ffici
ent U
se +
Per
haps
DM
E F
req.
)
(Mor
e E
ffici
ent U
se K
u / K
a Fr
eq.,
Plu
s H
ighe
r Fre
q.)
(Per
haps
Use
Par
t of T
V F
req.
)
(Use
MLS
Fre
q.)
(ATC
RA
BS
Tra
nspo
nder
, FI
S-B
, AD
S-B
is E
mer
ging
)
(VH
F D
ata
Bro
adca
st fo
r LA
AS
is
just
em
ergi
ng in
112
– 1
18 M
Hz)
A-G
Com
. Via
A-A
Hop
ping
(U
se V
HF
/ UH
F / L
-Ban
d Fr
eq.)
Band
Fr
eque
ncy
Radio
HF
3 –
30 M
Hz
VHF
30 –
300
MH
z U
HF
300
– 10
00 M
Hz
L 1
– 2
GHz
S
2 –
4 G
Hz
C 4
– 8
GHz
X
8 –
12 G
Hz
Ku
12 –
18
GHz
K
18 –
27
GHz
Ka
27
– 4
0 G
Hz
V 40
– 7
5 G
Hz
W
75 –
110
GH
z G
110
– 30
0 G
Hz
Infr
ared
30
0 G
Hz –
430
TH
z Vi
sibl
e 43
0 –
790
THz
UV
790
THz –
30
PHz
X-Ra
y 30
PH
z – 3
0 EH
z G
amm
a-Ra
y >
10 E
Hz
A-G
Air
-to
-Gro
un
d (
A-G
) C
om
mu
nic
ati
on
Ca
nd
ida
tes
1H
F A
-G2
VH
F A
-G3
UH
F A
-G4
L-B
an
d A
-G5
S-B
an
d A
-G6
C-B
an
d A
-G7
Op
tica
l A
-G8
Hyb
rid
RF
/Op
tica
l A
-G9
Te
rre
stri
al
K t
o W
Ba
nd
Ne
two
rk (
e.g
., K
u B
an
d
Qu
alC
om
m+
)10
DT
V V
HF
/UH
F N
etw
ork
11
Ce
llu
lar
Ne
two
rk (
e.g
., A
irce
ll)
12
LE
O S
AT
CO
M N
etw
ork
(e
.g.,
Iri
diu
m N
ex
t+)
13
GE
O S
AT
CO
M N
etw
ork
wit
h g
lob
al
/ re
gio
na
l /
spo
t b
ea
ms
(e.g
., I
nm
ars
at
Glo
ba
l X
pre
ss+
, V
iasa
t I,
H
ug
he
s N
ex
tGe
n,
Bro
ad
ca
st S
at.
TV
+)
14
ME
O S
AT
CO
M N
etw
ork
(e
.g.
Glo
ba
lSta
r+)
15
VH
F A
-A H
op
pin
g f
or
lon
g r
an
ge
A-G
Co
m.
16
UH
F A
-A H
op
pin
g f
or
lon
g r
an
ge
A-G
Co
m.
17
L-B
an
d A
-A H
op
pin
g f
or
lon
g r
an
ge
A-G
Co
m.
18
X-B
an
d A
-G19
GE
O +
HE
O S
AT
CO
M N
etw
ork
Terr
estr
ial K
to
W B
and
20
Com
ple
ted
a S
et o
f A
nal
yses
to
Ch
arac
teri
ze a
nd
B
egin
to
Eval
uat
e Ea
ch o
f th
e A
-A a
nd
A-G
Can
did
ates
•
Qua
ntifi
ed a
ttribu
tes,
cha
ract
eris
tics,
str
engt
h/w
eakn
esse
s of
the
ca
ndid
ates
[e.
g.,
the
Act
ual C
omm
unic
atio
n Pe
rfor
man
ce (
ACP)
]
•Id
entif
ied
Futu
re A
TM u
ses/
appl
icat
ions
and
str
awm
an in
itial
Req
uire
d Com
mun
icat
ion
Perf
orm
ance
(RCP)
nee
ded
to s
uppo
rt t
hem
•M
appe
d ca
ndid
ates
to
ATM
use
s/ap
plic
atio
ns b
ased
upo
n th
eir
abili
ty t
o su
ppor
t th
e RCP
•Id
entif
ied
infr
astr
uctu
re /
arc
hite
ctur
e ne
eds
•Pe
rfor
med
an
initi
al S
ecur
ity A
sses
smen
t of
the
can
dida
tes
by id
entif
ying
th
reat
s, v
ulne
rabi
litie
s, a
nd r
isk
miti
gatio
n st
rate
gies
–
Not
es:
•In
itial
ana
lyse
s ha
ve b
een
com
plet
ed. B
efor
e an
y ca
ndid
ate
is s
erio
usly
con
side
red
for
NAS o
pera
tions
, fu
rthe
r an
alys
is,
stak
ehol
der
vett
ing,
cos
t be
nefit
s, e
tc.
is n
eede
d.
•W
hile
the
re is
insu
ffic
ient
tim
e to
dis
cuss
the
det
ails
of ea
ch o
f th
e ev
alua
tions
, a
sum
mar
y of
the
stu
dy f
indi
ngs
from
the
ev
alua
tions
is p
rovi
ded
on t
he n
ext
3 sl
ides
21
Su
mm
ary
of I
nte
rim
Stu
dy
Fin
din
gs
(Slid
e 1
of
3)
•Cur
rent
NAS c
omm
unic
atio
ns li
nks
are
insu
ffic
ient
to
mee
t fu
ture
nee
ds
and
mor
e A-A
and
A-G
dat
a co
mm
unic
atio
ns w
ill b
e ne
eded
•
Traf
fic is
exp
ecte
d to
sig
nific
antly
incr
ease
(3X
to
10X)
•Cur
rent
NAS C
om.
is in
effic
ient
by
toda
y’s
stat
e of
pra
ctic
e •
Cur
rent
sta
te o
f th
e ar
t fo
r w
irel
ess
com
mun
icat
ions
ach
ieve
s ~
60%
of
Sha
nnon
’s c
hann
el c
apac
ity li
mit.
60
% t
o 70
% w
ill li
kely
bec
ome
the
stat
e of
the
pra
ctic
e fo
r w
irel
ess
com
mun
icat
ions
sys
tem
s du
ring
the
m
oder
niza
tion
time
horizo
n.
•W
irel
ess
com
mun
icat
ions
tec
hnol
ogie
s ar
e ad
vanc
ing
in m
any
area
s th
at w
ill le
ad t
o si
gnifi
cant
incr
ease
s in
the
spe
ctra
l eff
icie
ncy
•
Use
rs o
f th
e sp
ectr
um (
incl
udin
g av
iatio
n) w
ill n
eed
to im
prov
e th
eir
spec
tral
eff
icie
ncy
to e
nabl
e th
e sp
ectr
um t
o m
eet
futu
re d
eman
ds
•O
btai
ning
sig
nific
antly
mor
e sp
ectr
um a
lloca
tions
ded
icat
ed t
o su
ppor
t N
AS A
-A a
nd/o
r A-G
com
mun
icat
ions
will
bec
ome
incr
easi
ngly
ch
alle
ngin
g
22
Su
mm
ary
of I
nte
rim
Stu
dy
Fin
din
gs
(Slid
e 2
of
3)
•Com
mer
cial
bro
adba
nd w
ill e
xpan
d be
yond
wha
t is
offer
ed t
oday
to
furt
her
supp
ort
NAS c
omm
unic
atio
ns
•Te
chno
logy
will
adv
ance
to
enab
le:
–U
se K
, V,
and
W b
ands
(up
to
~11
0 G
Hz
not
incl
udin
g ar
ound
60
GH
z) for
SATC
OM
and
ai
rpor
t su
rfac
e/te
rmin
al a
rea
links
–
Use
of fr
ee s
pace
opt
ical
com
mun
icat
ions
for
grou
nd t
o sa
telli
te, sa
telli
te t
o ai
rcra
ft,
airc
raft
-to-
grou
nd, an
d ai
rcra
ft-t
o-ai
rcra
ft c
omm
unic
atio
ns
–Fu
ture
SATC
OM
sys
tem
s ar
e an
ticip
ated
to
be c
apab
le o
f al
loca
ting
com
mun
icat
ion
band
wid
th (
BW
) an
d qu
ality
of se
rvic
e (Q
OS)
on d
eman
d
•Fu
ture
Avi
atio
n CN
S n
eeds
will
con
tinue
to
evol
ve
•N
AS d
ata
com
mun
icat
ions
can
pot
ential
ly r
euse
avi
atio
n sp
ectr
um t
hat
is d
ecom
mis
sion
ed /
or
not
bein
g us
ed b
y ot
her
NAS s
ervi
ces
•5
fund
amen
tal s
trat
egic
app
roac
hes
have
bee
n id
entif
ied
for
addr
essi
ng
the
long
ter
m N
AS c
omm
unic
atio
n ne
eds
1)Red
uce
need
for
com
m. BW
2)
Mor
e ef
ficie
ntly
use
exi
stin
g co
mm
. sp
ectr
um
3)Le
vera
ge c
omm
erci
al c
omm
. ne
twor
ks
4)Id
entif
y /
reus
e /
repu
rpos
e “a
viat
ion”
spe
ctru
m t
o su
ppor
t co
mm
. 5)
Iden
tify
& o
btai
n ne
w s
pect
rum
allo
catio
ns fo
r co
mm
.
23
Su
mm
ary
of I
nte
rim
Stu
dy
Fin
din
gs
(Slid
e 3
of
3)
•Fu
ture
NAS c
omm
unic
atio
ns s
yste
ms
will
nee
d to
add
ress
a v
arie
ty o
f in
form
atio
n se
curity
cha
lleng
es
•N
eed
to c
onsi
der
secu
rity
asp
ects
in t
he c
onte
xt o
f th
e ov
eral
l NAS
syst
ems
and
oper
atio
ns (
not
Com
m in
isol
atio
n)
•Suc
cess
ful i
mpl
emen
tatio
n of
NAS in
fo.
secu
rity
will
req
uire
co
llabo
ratio
n be
twee
n tr
aditi
onal
avi
atio
n st
akeh
olde
rs a
nd in
fo.
secu
rity
exp
erts
•
No
one
sing
le c
omm
unic
atio
ns d
ata
link
tech
nolo
gy m
eets
all
the
expe
cted
fut
ure
A-A
and
A-G
com
mun
icat
ions
req
uire
men
ts.
Nee
d to
im
plem
ent
mul
tiple
com
m.
tech
nolo
gies
. •
Emer
ging
and
the
pre
dict
ed f
utur
e co
mm
tec
hnol
ogie
s ar
e ex
pect
ed t
o be
abl
e to
mee
t fu
ture
NAS c
omm
unic
atio
n ne
eds.
Bria
n H
ayne
s –
Prin
cipa
l Inv
estig
ator
w
ww
.xce
lar.c
om
Oper
ator
Per
spec
tive
�A
n im
porta
nt in
itial
ste
p:
�D
efin
e th
e po
tent
ial n
atur
e an
d ca
pabi
litie
s of
the
air v
ehic
les
(man
ned,
redu
ced-
crew
, and
unm
anne
d)
�D
efin
e th
e N
AS
in th
e co
ntex
t of b
enef
its to
the
airc
raft
oper
ator
�
Use
d sy
stem
-bas
ed m
odel
- in
itial
ana
lysi
s us
ing
gene
ral f
unct
iona
l ro
les
to d
efin
e:
�S
yste
mic
cap
abili
ties
�N
eeds
�
Info
rmat
ion
flow
dec
oupl
ed fr
om th
e cu
rren
t par
adig
m
�S
yste
m c
apab
ilitie
s w
ere
then
use
d to
def
ine
the
com
mun
icat
ion
capa
bilit
ies
requ
ired
for r
ealiz
atio
n �
Futu
re d
ata
link
func
tiona
l req
uire
men
ts w
ere
deriv
ed fo
r use
in
a p
aral
lel s
tudy
of v
ario
us c
andi
date
link
tech
nolo
gies
, to
polo
gies
, and
arc
hite
ctur
es.
�
A “fo
rm fo
llow
s fu
nctio
n” a
ppro
ach
appl
ied
to th
e ca
ndid
ate
link
anal
ysis
(spe
cific
link
met
hods
and
com
bina
tions
of m
etho
ds
serv
e th
e ov
eral
l nee
ds o
f the
sys
tem
in o
ptim
ized
way
s)
Proc
ess
�Li
tera
ture
revi
ew: N
AS
A, A
IAA
, RTC
A, I
EE
E, M
ITR
E/M
IT, F
AA
, E
uroc
ontro
l, IC
AO
, oth
ers
�R
evea
led
very
littl
e ap
plic
able
stu
dy w
ork
with
in 1
0-15
yea
rs
�Li
ttle
anal
ysis
was
foun
d of
link
-inde
pend
ent,
resu
lt-ba
sed
data
del
iver
y co
ncep
ts
rath
er th
an s
peci
fic li
nks
for e
ach
purp
ose
�Te
am h
oste
d “F
utur
e N
AS
Com
mun
icat
ions
Wor
ksho
p”
�In
clud
ed: N
AS
A, I
ndus
try re
pres
enta
tives
, aca
dem
ia, a
nd te
am
�Fo
ur b
asel
ine
scen
ario
type
s w
ere
defin
ed: T
erm
inal
Ope
ratio
ns –
D
epar
ture
s; E
n ro
ute
Ope
ratio
ns; T
erm
inal
Ope
ratio
ns –
Arr
ival
s;
Gro
und
Ope
ratio
ns
�D
efin
ition
s fo
r eac
h sc
enar
io in
clud
ed:
Top-
leve
l goa
ls; p
rimar
y su
cces
s cr
iteria
; exp
ecte
d ca
pabi
litie
s; n
eeds
�
Futu
re c
apab
ilitie
s w
ere
cons
ider
ed
�N
AS
�
Ope
ratio
n ty
pes:
Air
Tran
spor
t, G
ener
al &
Bus
ines
s Av
iatio
n (In
cl. V
LJ),
and
Unm
anne
d A
ircra
ft S
yste
ms
�S
igni
fican
t lev
el o
f red
uced
-cre
w a
nd/o
r unm
anne
d co
mm
erci
al
oper
atio
ns w
as p
roje
cted
for t
he a
ir tra
nspo
rt se
ctor
Proc
ess
- con
tinue
d �
In p
aral
lel w
ith th
e fu
ture
NA
S d
efin
ition
and
der
ivat
ion
of
com
mun
icat
ion
func
tions
and
requ
irem
ents
: �
Initi
al a
naly
sis
of c
urre
ntly
kno
wn
link
tech
nolo
gies
was
co
nduc
ted
to a
sses
s th
eir c
urre
nt a
nd p
roba
ble
futu
re
capa
bilit
ies
com
pare
d to
pro
ject
ed lo
ads
and
othe
r fac
tors
�
This
“loo
k fo
rwar
d” a
naly
sis:
�
Pro
vide
s a
star
ting
poin
t in
the
iden
tific
atio
n an
d an
alys
is o
f fut
ure
solu
tions
�
Qua
ntifi
es p
oten
tial u
nmet
nee
ds in
cur
rent
sys
tem
s �
Func
tions
that
will
requ
ire n
ew s
olut
ions
.
�E
xam
ple:
�
Cur
rent
use
of 1
030/
1090
mH
z fo
r ATC
RB
S, A
DS
-B, T
CA
S, a
nd
othe
r pro
pose
d fu
nctio
ns s
uch
as a
ir-to
-air
linki
ng o
f wak
e tu
rbul
ence
dat
a �
Initi
al a
naly
sis
sugg
ests
that
the
curr
ent s
yste
m w
ill re
ach
its
capa
city
lim
it w
ell b
efor
e th
e 50
-yea
r fut
ure
poin
t �
Alte
rnat
e so
lutio
ns m
ust b
e co
nsid
ered
as
part
of th
e st
udy
550-Y
ear F
utur
e –
Calib
ratio
n Po
ints
50 y
ears
ago
(196
3)
�19
63 -
B72
7 fir
st fl
ight
�
1963
– C
essn
a 33
6 en
ters
se
rvic
e
�19
65 –
Ces
sna
337
in
certi
ficat
ion
�19
63 –
Lea
r 23
& F
alco
n 20
Fi
rst F
light
�
Wor
ld’s
Firs
t geo
sync
hron
ous
sate
llite
laun
ched
(Syn
chro
m
II)
�19
63 –
Firs
t Las
er R
ing
Gyr
o de
mon
stra
ted
�S
ELC
AL
Ent
ered
Ser
vice
50
year
s ag
o
50 y
ears
from
now
(206
3)
�P
rimar
y us
ers:
�
Our
chi
ldre
n’s
child
ren
and
gran
dchi
ldre
n �
Dee
p ac
cept
ance
of “
Con
nect
ed
Livi
ng”,
Rob
otic
s �
Moo
re’s
Law
– ty
pe fa
ctor
s ca
n be
app
lied
to:
�Ba
ndw
idth
, lin
k op
tions
, lin
k co
st
�W
orki
ng a
ssum
ptio
n:
�C
urre
nt-s
tyle
regu
lato
ry p
roce
ss
will
not
driv
e fu
ture
sol
utio
ns
28
Dat
alin
k S
tudy
P
roce
ss:
1s
t six
mon
ths
(in s
hade
d bo
x)
Conc
lusi
ons
•Pr
elim
inar
y fin
ding
s in
dica
te th
at s
pect
rum
and
tech
nolo
gy c
ertif
icat
ion
will
con
tinue
to p
ose
a ch
alle
nge,
esp
ecia
lly in
are
as w
here
sof
twar
e is
in
crea
sing
ly u
sed
to p
erfo
rm h
ardw
are
func
tions
. It
is a
ntic
ipat
ed th
at
alth
ough
som
e sp
ectr
um w
ill b
ecom
e av
aila
ble
as a
resu
lt of
the
deco
mm
issi
onin
g of
tech
nolo
gies
i.e.
VO
R, th
e de
man
d fo
r spe
ctru
m w
ill
incr
ease
and
futu
re te
chno
logi
es w
ill n
eed
to p
rovi
de th
e ab
ility
to
max
imiz
e th
e us
e of
fini
te s
pect
rum
reso
urce
s.
•Ad
vanc
es in
ele
ctro
nics
and
com
mun
icat
ions
tech
nolo
gy w
ill e
nabl
e th
e in
tegr
atio
n of
ser
vice
s an
d ap
plic
atio
ns a
nd th
us re
duce
the
num
ber o
f sy
stem
s de
ploy
ed to
the
airc
raft
.
•Fi
nally
, the
futu
re a
viat
ion
radi
o te
chno
logy
will
dep
end
on n
umer
ous
fact
ors
incl
udin
g: a
ir tr
affic
man
agem
ent p
roce
dure
s, a
irlin
e op
erat
ions
bu
sine
ss m
odel
s an
d th
e co
nfig
urat
ion
of th
e ai
rspa
ce, w
hich
is a
ntic
ipat
ed
to in
clud
e U
nman
ned
Airc
raft
Sys
tem
s, h
yper
soni
c fli
ghts
and
man
ned
airc
raft
.