International Civil Aviation Organization
ACP WG-F/25
WP 13
WORKING PAPER
ACP Working Group F (Frequency)
25th meeting of WG-F, Dakar, Senegal 10 – 14 October 2011
Agenda Item 6: Any Other Business
Development of Command and Non-Payload Communications Systems
for Unmanned Aircraft Systems
(Presented by Robert J. Kerczewski, U.S. National Aeronautics and Space Administration)
SUMMARY
The US National Aeronautics and Space Administration (NASA) has initiated
a project called Unmanned Aircraft Systems (UAS) Integration in the National
Airspace System (NAS). The mission of this research project is to: “Utilize
integrated system level tests in a relevant environment to reduce technical
barriers related to the safety and operational challenges of UAS National
Airspace System access and to work with key stakeholders to define necessary
deliverables/products to help enable UAS access to the NAS.”
The Communications Subproject of the UAS in the NAS Project addresses the
challenge of validating new UAS spectrum and data link communications to
enable UAS integration in the NAS. The focus of this work is the
establishment of standards for the Control and Non-Payload Communications
(CNPC) terrestrial-based system which provides secure, scalable data
communications in protected aviation safety spectrum allocation. This
includes the definition of requirements, development of standards (through
RTCA SC-203), and building and testing of prototype CNPC system
hardware. The planned frequency bands for CNPC terrestrial system are 960977 MHz and 5030-5091 MHz, allocations which are anticipated to be
approved during WRC-12 for this purpose.
ACTION
The meeting is requested to note the progress on CNPC system development
for UAS airspace integration and its dependence on the allocation of UAS
CNPC frequencies at WRC-12. The support of ICAO and member states to
enable advancement of UAS integration is requested.
1. Background
1.1
NASA’s UAS in the NAS Project addresses the increasingly urgent need to enable routine operation of
Unmanned Aircraft Systems (UAS) in the U. S. National Airspace System (NAS). The application of unmanned
aircraft to perform national security, defense, scientific, and emergency management are driving the critical need
for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of
services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry
has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS
in the NAS. The UAS in the NAS Project provides an opportunity to transition concepts, technology, algorithms,
and knowledge to the Federal Aviation Administration (FAA) and other stakeholders to help them define the
requirements, regulations, and issues for routine UAS NAS access.
The UAS in the NAS Project addresses several critical research areas needed to overcome barriers to UAS
integration that fall within NASA’s organizational mission. These are indicated by the five UAS in the NAS
Subprojects:
•
Separation Assurance
•
Human Systems Integration
•
Communications
•
Certification
•
Integrated Test and Evaluation
Of interest in this paper is the Communications Subproject. The elements of the Subproject are described below.
2. Discussion
2.1
The Communications Subproject, to be performed by NASA’s Glenn Research Center in Cleveland,
Ohio, consists of the following elements:
2.1.1 The Spectrum element has as its objective to develop data and rationale to obtain appropriate frequency
spectrum allocations to enable the safe and efficient operation of UAS in the NAS. This is to be accomplished
through participating and contributing to regulatory/standards organizations developing frequency, safety,
security, and performance requirements for UAS Control and Non-Payload Communication (CNPC) systems, in
partnership with other US government agencies and commercial entities within national and international
spectrum/regulatory bodies. This element also provides analysis and development of communications data
requirements for use in simulations, radio system design, CNPC system testing, and standardization groups, and
analysis of proposed UAS control communication spectrum bands, to determine compatibility with in-band and
adjacent band users.
2.1.2 The Datalink element has the objective to develop and validate the candidate UAS CNPC system
prototype which complies with proposed UAS international/national frequency regulations, ICAO SARPs, and
RTCA MOPS/MASPS for UAS. A channel characterization campaign will be conducted to collect measurement
data and analyze in detail the propagation environment within candidate CNPC spectrum bands, in order to
supply data required to generate simulation models and design of communication system characteristics. The
CNPC prototype will be developed to be compliant with these requirements through necessary technical
analyses, simulations, and test measurements, in one or more CNPC spectrum bands. Spiral development of
prototype CNPC system consisting of both ground and airborne CNPC radios will be accomplished through
cooperative research agreement with an industry partner, including both laboratory and flight testing in a
relevant environment. Testing will assess performance and validate and/or provide data to update proposed
system requirements.
2.1.3 The Security element will develop and validate candidate security requirements and standards for UAS
CNPC system which comply with international/national regulations. Analysis, testing, and mitigation against
security risks to the confidentiality, availability, and integrity of the integrated ATC and CNPC systems will be
performed, enabling the proposal of requirements and development of architectures/standards to support these
requirements. Proposed systems will be integrated into the CNPC system test program to validate performance
in a relevant environment. The key elements of the CNPC Security research element are:

Threat and vulnerability assessment of RF and network systems expected to be employed in the CNPC
operations

Risk mitigation strategy identify options for securely deploying a CNPC system

Prototype communications system security architecture design for CNPC

Prototype security architecture performance validation in a relevant environment
2.1.4 The Modeling and Simulation element will perform analysis to support recommendations for integration
of CNPC system and ATC communications to ensure safe and efficient operation of UAS in the NAS. CNPC
system link models will be developed for all UAS classes to predict performance during all phases of flight.
This activity supports the Datalink development. Regional and NAS-wide simulations will assess the
performance and scalability of the CNPC system. Large scale simulations of mixed traffic will determine CNPC
and ATC communication system performance impact on air traffic delays and system capacity. Simulations for
satellite communications technologies for beyond line-of-sight (BLOS) UAS CNPC systems will develop data
for supporting UAS spectrum requirements for WRC-16.
2.2
In preparation for the launch of the UAS in the NAS Project, NASA’s Integrated Systems Research
Program supported pre-project activities consisting of: an assessment and consolidation of UAS operational
concepts, including NextGen; a State of the Art assessment of aeronautical communications systems; a
technology gap analysis; an assessment of functional and operational data requirements; and a weather hazards
analysis. Functional and operational data requirements are a key element driving CNPC system design. The
requirements analysis was based on initial estimates generated by RTCA SC-203, using NATO STANAG 4586
standard. The Communications Subproject is updating the requirements document, and will continue to do so as
other Subprojects identify communications requirements for the CNPC link not previously considered.
2.3
The Datalink and Simulation and Modeling elements of the Communications Subproject will identify
and analyze candidate technologies for application to CNPC. This will be conducted in cooperation with the
Datalink industry partner, as well as RTCA SC-203 and other relevant organizations. The goal is to achieve
maximum performance and efficiency of the CNPC design.
2.4
On 30 September 2011, NASA entered into a Cooperative Agreement with Rockwell Collins Inc. (RCI),
Government Systems Division. The agreement will develop CNPC prototype radios for testing and evaluation.
NASA and RCI will jointly conduct technology assessments to determine candidate CNPC technologies. In a
spiral development process, RCI will develop three prototypes designs, each of which will be laboratory tested
and flight tested. The designs will operate in both 960-977 MHZ and 5030-5091 MHz bands. Designs will be
adjusted between each cycle to improve performance against design requirements. Concurrently, CNPC
standards will be refined through RTCA SC-203 to take into account test findings and realistic performance
expectations, such that the completion of draft standards coincides with the completion of the UAS in the NAS
Project.
2.5
The following test cycles are planned:
2.5.1 A channel characterization campaign in the 960-977 and 5030-5091 MHz bands will be conducted in the
spring of 2012. Flight tests using NASA aircraft will perform channel sounding measurements of the RF
propagation environment, including measurement of the environmental classifications: 1) open water, 2) flat
rural, 3) hilly rural, 4) mountainous rural 5) suburban and 6) urban and 7) flat/hilly and mountainous desert. The
resulting analysis of the measured data will provide accurate propagation models for simulation and analysis of
the performance of candidate CNPC communications technologies.
2.5.2 Laboratory and flight tests of the first prototype CNPC radios are scheduled for the spring/summer of
2013. Results of these tests will inform the design of the second prototype.
2.5.3 Laboratory and flight tests of the second prototype CNPC radios are scheduled for the spring of 2014.
Results of these tests will inform the design of the final prototype.
2.5.4
Laboratory and flight tests of the final prototype CNPC radios are scheduled for the spring of 2015.
2.5.5 Project level integrated flight tests will be conducted in the winter/spring of 2016. These tests will
include the CNPC systems integrated with all other elements of the UAS in the NAS Project.
2.6
Beyond Line-of-sight satellite communications for CNPC will be an analytical activity conducted by the
Modeling and Simulation element. Possible aviation spectrum allocations for CNPC systems are as yet
undetermined. A satellite payload for CNPC testing does not yet exist and is not yet planned. Therefore the
Communications Subproject will focus its satellite communications efforts on providing technical analyses for
the support of satellite communications CNPC allocations at WRC-16.
3. Proposed Action
3.1
The meeting is invited to take note of the UAS in the NAS research project now being conducted by
NASA. The Communications Subproject is focusing considerable effort on the development of CNPC systems
and standards within the appropriate aeronautical safety communications spectrum. The approval of allocations
for UAS CNPC in the 960-977 MHZ and 5030-5091 MHZ bands is anticipated, and is critical to the execution
of the project. Without UAS CNPC allocations, progress towards routine UAS access to the airspace will be
severely delayed. The support of ICAO and the member states for the UAS CNPC Allocations mentioned is
therefore solicited.