draft-ietf-drip-arch-20.txt   draft-ietf-drip-arch-21.txt 
drip S. Card drip S. Card
Internet-Draft A. Wiethuechter Internet-Draft A. Wiethuechter
Intended status: Informational AX Enterprize Intended status: Informational AX Enterprize
Expires: 1 August 2022 R. Moskowitz Expires: 8 September 2022 R. Moskowitz
HTT Consulting HTT Consulting
S. Zhao (Editor) S. Zhao (Editor)
Tencent Tencent
A. Gurtov A. Gurtov
Linköping University Linköping University
28 January 2022 7 March 2022
Drone Remote Identification Protocol (DRIP) Architecture Drone Remote Identification Protocol (DRIP) Architecture
draft-ietf-drip-arch-20 draft-ietf-drip-arch-21
Abstract Abstract
This document describes an architecture for protocols and services to This document describes an architecture for protocols and services to
support Unmanned Aircraft System Remote Identification and tracking support Unmanned Aircraft System (UAS) Remote Identification (RID)
(UAS RID), plus RID-related communications. This architecture and tracking, plus UAS RID-related communications. This architecture
adheres to the requirements listed in the DRIP Requirements document. adheres to the requirements listed in the DRIP Requirements document
(RFC9153).
Status of This Memo Status of This Memo
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provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 1 August 2022. This Internet-Draft will expire on 8 September 2022.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Overview of Unmanned Aircraft System (UAS) Remote ID (RID) 1.1. Overview of Unmanned Aircraft System (UAS) Remote ID (RID)
skipping to change at page 2, line 19 skipping to change at page 2, line 21
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Overview of Unmanned Aircraft System (UAS) Remote ID (RID) 1.1. Overview of Unmanned Aircraft System (UAS) Remote ID (RID)
and Standardization . . . . . . . . . . . . . . . . . . . 3 and Standardization . . . . . . . . . . . . . . . . . . . 3
1.2. Overview of Types of UAS Remote ID . . . . . . . . . . . 4 1.2. Overview of Types of UAS Remote ID . . . . . . . . . . . 4
1.2.1. Broadcast RID . . . . . . . . . . . . . . . . . . . . 4 1.2.1. Broadcast RID . . . . . . . . . . . . . . . . . . . . 4
1.2.2. Network RID . . . . . . . . . . . . . . . . . . . . . 5 1.2.2. Network RID . . . . . . . . . . . . . . . . . . . . . 5
1.3. Overview of USS Interoperability . . . . . . . . . . . . 7 1.3. Overview of USS Interoperability . . . . . . . . . . . . 7
1.4. Overview of DRIP Architecture . . . . . . . . . . . . . . 8 1.4. Overview of DRIP Architecture . . . . . . . . . . . . . . 8
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 9 2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 10
3. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 9 2.1. Additional Abbreviations . . . . . . . . . . . . . . . . 10
3.1. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 9 2.2. Additional Definitions . . . . . . . . . . . . . . . . . 11
3.2. Claims, Assertions, Attestations, and Certificates . . . 10 3. HHIT as the DRIP Entity Identifier . . . . . . . . . . . . . 11
3.3. Additional Definitions . . . . . . . . . . . . . . . . . 10 3.1. UAS Remote Identifiers Problem Space . . . . . . . . . . 12
4. HHIT as the DRIP Entity Identifier . . . . . . . . . . . . . 10 3.2. HHIT as A Trustworthy DRIP Entity Identifier . . . . . . 12
4.1. UAS Remote Identifiers Problem Space . . . . . . . . . . 11 3.3. HHIT for DRIP Identifier Registration and Lookup . . . . 14
4.2. HHIT as A Trustworthy DRIP Entity Identifier . . . . . . 11 3.4. HHIT as a Cryptographic Identifier . . . . . . . . . . . 14
4.3. HHIT for DRIP Identifier Registration and Lookup . . . . 13 4. DRIP Identifier Registration and Registries . . . . . . . . . 14
4.4. HHIT as a Cryptographic Identifier . . . . . . . . . . . 13 4.1. Public Information Registry . . . . . . . . . . . . . . . 15
5. DRIP Identifier Registration and Registries . . . . . . . . . 13 4.1.1. Background . . . . . . . . . . . . . . . . . . . . . 15
5.1. Public Information Registry . . . . . . . . . . . . . . . 14 4.1.2. DNS as the Public DRIP Identifier Registry . . . . . 15
5.1.1. Background . . . . . . . . . . . . . . . . . . . . . 14 4.2. Private Information Registry . . . . . . . . . . . . . . 15
5.1.2. DNS as the Public DRIP Identifier Registry . . . . . 14 4.2.1. Background . . . . . . . . . . . . . . . . . . . . . 15
5.2. Private Information Registry . . . . . . . . . . . . . . 14 4.2.2. EPP and RDAP as the Private DRIP Identifier
5.2.1. Background . . . . . . . . . . . . . . . . . . . . . 14 Registry . . . . . . . . . . . . . . . . . . . . . . 16
5.2.2. EPP and RDAP as the Private DRIP Identifier 4.2.3. Alternative Private DRIP Registry methods . . . . . . 16
Registry . . . . . . . . . . . . . . . . . . . . . . 15 5. DRIP Identifier Trust . . . . . . . . . . . . . . . . . . . . 16
5.2.3. Alternative Private DRIP Registry methods . . . . . . 15 6. Harvesting Broadcast Remote ID messages for UTM Inclusion . . 17
6. DRIP Identifier Trust . . . . . . . . . . . . . . . . . . . . 15 6.1. The CS-RID Finder . . . . . . . . . . . . . . . . . . . . 18
7. Harvesting Broadcast Remote ID messages for UTM Inclusion . . 16 6.2. The CS-RID SDSP . . . . . . . . . . . . . . . . . . . . . 18
7.1. The CS-RID Finder . . . . . . . . . . . . . . . . . . . . 17 7. DRIP Contact . . . . . . . . . . . . . . . . . . . . . . . . 18
7.2. The CS-RID SDSP . . . . . . . . . . . . . . . . . . . . . 17 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
8. DRIP Contact . . . . . . . . . . . . . . . . . . . . . . . . 17 9. Security Considerations . . . . . . . . . . . . . . . . . . . 19
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 10. Privacy & Transparency Considerations . . . . . . . . . . . . 20
10. Security Considerations . . . . . . . . . . . . . . . . . . . 18 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 20
11. Privacy & Transparency Considerations . . . . . . . . . . . . 18 11.1. Normative References . . . . . . . . . . . . . . . . . . 20
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 19 11.2. Informative References . . . . . . . . . . . . . . . . . 20
12.1. Normative References . . . . . . . . . . . . . . . . . . 19
12.2. Informative References . . . . . . . . . . . . . . . . . 19
Appendix A. Overview of Unmanned Aircraft Systems (UAS) Traffic Appendix A. Overview of Unmanned Aircraft Systems (UAS) Traffic
Management (UTM) . . . . . . . . . . . . . . . . . . . . 22 Management (UTM) . . . . . . . . . . . . . . . . . . . . 23
A.1. Operation Concept . . . . . . . . . . . . . . . . . . . . 22 A.1. Operation Concept . . . . . . . . . . . . . . . . . . . . 24
A.2. UAS Service Supplier (USS) . . . . . . . . . . . . . . . 23 A.2. UAS Service Supplier (USS) . . . . . . . . . . . . . . . 24
A.3. UTM Use Cases for UAS Operations . . . . . . . . . . . . 23 A.3. UTM Use Cases for UAS Operations . . . . . . . . . . . . 25
Appendix B. Automatic Dependent Surveillance Broadcast Appendix B. Automatic Dependent Surveillance Broadcast
(ADS-B) . . . . . . . . . . . . . . . . . . . . . . . . . 24 (ADS-B) . . . . . . . . . . . . . . . . . . . . . . . . . 25
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 24 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26
1. Introduction 1. Introduction
This document describes an architecture for protocols and services to This document describes an architecture for protocols and services to
support Unmanned Aircraft System Remote Identification and tracking support Unmanned Aircraft System (UAS) Remote Identification (RID)
(UAS RID), plus RID-related communications. The architecture takes and tracking, plus RID-related communications. The architecture
into account both current (including proposed) regulations and non- takes into account both current (including proposed) regulations and
IETF technical standards. non-IETF technical standards.
The architecture adheres to the requirements listed in the DRIP The architecture adheres to the requirements listed in the DRIP
Requirements document [I-D.ietf-drip-reqs]. The requirements Requirements document [RFC9153]. The requirements document provides
document provides an extended introduction to the problem space and an extended introduction to the problem space and use cases.
use cases.
1.1. Overview of Unmanned Aircraft System (UAS) Remote ID (RID) and 1.1. Overview of Unmanned Aircraft System (UAS) Remote ID (RID) and
Standardization Standardization
UAS Remote Identification (RID) is an application enabler for a UAS UAS Remote Identification (RID) is an application that enables a UAS
to be identified by Unmanned Aircraft Systems Traffic Management to be identified by Unmanned Aircraft Systems Traffic Management
(UTM) and UAS Service Supplier (USS) (Appendix A) or third parties (UTM) and UAS Service Supplier (USS) (Appendix A) or third party
entities such as law enforcement. Many considerations (e.g., safety) entities such as law enforcement. Many considerations (e.g., safety)
dictate that UAS be remotely identifiable. dictate that UAS be remotely identifiable.
Civil Aviation Authorities (CAAs) worldwide are mandating UAS RID. Civil Aviation Authorities (CAAs) worldwide are mandating UAS RID.
CAAs currently promulgate performance-based regulations that do not CAAs currently promulgate performance-based regulations that do not
specify techniques, but rather cite industry consensus technical specify techniques, but rather cite industry consensus technical
standards as acceptable means of compliance. standards as acceptable means of compliance.
Federal Aviation Administration (FAA) Federal Aviation Administration (FAA)
The FAA published a Notice of Proposed Rule Making [NPRM] in 2019 The FAA published a Notice of Proposed Rule Making [NPRM] in 2019
and thereafter published a "Final Rule" in 2021 [FAA_RID], and thereafter published a "Final Rule" in 2021 [FAA_RID],
imposing requirements on UAS manufacturers and operators, both imposing requirements on UAS manufacturers and operators, both
commercial and recreational. The rule clearly states that commercial and recreational. The rule clearly states that
Automatic Dependent Surveillance Broadcast (ADS-B) Out and Automatic Dependent Surveillance Broadcast (ADS-B) Out and
transponders cannot be used to satisfy the RID requirements on UAS transponders cannot be used to satisfy the UAS RID requirements on
to which the rule applies (see Appendix B). UAS to which the rule applies (see Appendix B).
European Union Aviation Safety Agency (EASA) European Union Aviation Safety Agency (EASA)
The EASA published a [Delegated] regulation in 2019 imposing The EASA published a [Delegated] regulation in 2019 imposing
requirements on UAS manufacturers and third-country operators, requirements on UAS manufacturers and third-country operators,
including but not limited to RID requirements. The EASA also including but not limited to UAS RID requirements. The EASA also
published in 2019 an [Implementing] regulation laying down published in 2019 an [Implementing] regulation laying down
detailed rules and procedures for UAS operations and operating detailed rules and procedures for UAS operations and operating
personnel. personnel.
American Society for Testing and Materials (ASTM) American Society for Testing and Materials (ASTM)
ASTM International, Technical Committee F38 (UAS), Subcommittee ASTM International, Technical Committee F38 (UAS), Subcommittee
F38.02 (Aircraft Operations), Work Item WK65041, developed the F38.02 (Aircraft Operations), Work Item WK65041, developed the
ASTM [F3411] Standard Specification for Remote ID and Tracking. ASTM [F3411] Standard Specification for Remote ID and Tracking.
ASTM defines one set of RID information and two means, MAC-layer ASTM defines one set of UAS RID information and two means, MAC-
broadcast and IP-layer network, of communicating it. If an UAS layer broadcast and IP-layer network, of communicating it. If an
uses both communication methods, the same information must be UAS uses both communication methods, the same information must be
provided via both means. [F3411] is cited by FAA in its RID final provided via both means. [F3411] is cited by the FAA in its UAS
rule [FAA_RID] as "a potential means of compliance" to a Remote ID RID final rule [FAA_RID] as "a potential means of compliance" to a
rule. Remote ID rule.
The 3rd Generation Partnership Project (3GPP) The 3rd Generation Partnership Project (3GPP)
With release 16, the 3GPP completed the UAS RID requirement study With release 16, the 3GPP completed the UAS RID requirement study
[TS-22.825] and proposed a set of use cases in the mobile network [TS-22.825] and proposed a set of use cases in the mobile network
and the services that can be offered based on RID. Release 17 and services that can be offered based on UAS RID. Release 17
specification focuses on enhanced UAS service requirements and specification focuses on enhanced UAS service requirements and
provides the protocol and application architecture support that provides the protocol and application architecture support that
will be applicable for both 4G and 5G networks. The study of will be applicable for both 4G and 5G networks. The study of
Further Architecture Enhancement for Uncrewed Aerial Vehicles Further Architecture Enhancement for Uncrewed Aerial Vehicles
(UAV) and Urban Air Mobility (UAM) [FS_AEUA] in release 18 further (UAV) and Urban Air Mobility (UAM) [FS_AEUA] in release 18 further
enhances the communication mechanism between UAS and USS/UTM. The enhances the communication mechanism between UAS and USS/UTM. The
RID discussed in Section 4 may be used as the 3GPP CAA-level ID UAS RID discussed in Section 3 may be used as the 3GPP CAA-level
for Remote Identification purposes. UAS ID for Remote Identification purposes.
1.2. Overview of Types of UAS Remote ID 1.2. Overview of Types of UAS Remote ID
This specification introduces two types UAS Remote ID defined in ASTM
[F3411].
1.2.1. Broadcast RID 1.2.1. Broadcast RID
[F3411] defines a set of RID messages for direct, one-way, broadcast [F3411] defines a set of UAS RID messages for direct, one-way,
transmissions from the UA over Bluetooth or Wi-Fi. These are broadcast transmissions from the UA over Bluetooth or Wi-Fi. These
currently defined as MAC-Layer messages. Internet (or other Wide are currently defined as MAC-Layer messages. Internet (or other Wide
Area Network) connectivity is only needed for UAS registry Area Network) connectivity is only needed for UAS registry
information lookup by Observers using the directly received UAS ID. information lookup by Observers using the directly received UAS ID.
Broadcast RID should be functionally usable in situations with no Broadcast RID should be functionally usable in situations with no
Internet connectivity. Internet connectivity.
The minimum Broadcast RID data flow is illustrated in Figure 1. The minimum Broadcast RID data flow is illustrated in Figure 1.
+------------------------+ +------------------------+
| Unmanned Aircraft (UA) | | Unmanned Aircraft (UA) |
+-----------o------------+ +-----------o------------+
skipping to change at page 5, line 23 skipping to change at page 5, line 25
| |
| |
v v
+------------------o-------------------+ +------------------o-------------------+
| Observer's device (e.g., smartphone) | | Observer's device (e.g., smartphone) |
+--------------------------------------+ +--------------------------------------+
Figure 1 Figure 1
Broadcast RID provides information only about unmanned aircraft (UA) Broadcast RID provides information only about unmanned aircraft (UA)
within direct RF LOS, typically similar to visual Line-Of-Sight within direct Radio Frequency (RF) Line-Of-Sight (LOS), typically
(LOS), with a range up to approximately 1 km. This information may similar to Visual LOS (VLOS), with a range up to approximately 1 km.
be 'harvested' from received broadcasts and made available via the This information may be 'harvested' from received broadcasts and made
Internet, enabling surveillance of areas too large for local direct available via the Internet, enabling surveillance of areas too large
visual observation or direct RF link based ID (see Section 7). for local direct visual observation or direct RF link-based ID (see
Section 6).
1.2.2. Network RID 1.2.2. Network RID
[F3411], using the same data dictionary that is the basis of [F3411], using the same data dictionary that is the basis of
Broadcast RID messages, defines a Network Remote Identification (Net- Broadcast RID messages, defines a Network Remote Identification (Net-
RID) data flow as follows. RID) data flow as follows.
* The information to be reported via RID is generated by the UAS, * The information to be reported via UAS RID is generated by the
typically some by the UA and some by the GCS (Ground Control UAS. Typically some of this data is generated by the UA and some
Station), e.g. their respective GNSS derived locations. by the GCS (Ground Control Station), e.g., their respective Global
Navigation Satellite System (GNSS) derived locations.
* The information is sent by the UAS (UA or GCS) via unspecified * The information is sent by the UAS (UA or GCS) via unspecified
means to the cognizant Network Remote Identification Service means to the cognizant Network Remote Identification Service
Provider (Net-RID SP), typically the USS under which the UAS is Provider (Net-RID SP), typically the USS under which the UAS is
operating if participating in UTM. operating if participating in UTM.
* The Net-RID SP publishes via the Discovery and Synchronization * The Net-RID SP publishes via the Discovery and Synchronization
Service (DSS) over the Internet that it has operations in various Service (DSS) over the Internet that it has operations in various
4-D airspace volumes, describing the volumes but not the 4-D airspace volumes (Section 2.2 of [RFC9153]), describing the
operations. volumes but not the operations.
* An Observer's device, expected typically but not specified to be * An Observer's device, which is expected, but not specified, to be
web based, queries a Network Remote Identification Display web-based, queries a Network Remote Identification Display
Provider (Net-RID DP), typically also a USS, about any operations Provider (Net-RID DP), typically also a USS, about any operations
in a specific 4-D airspace volume. in a specific 4-D airspace volume.
* Using fully specified web based methods over the Internet, the * Using fully specified web-based methods over the Internet, the
Net-RID DP queries all Net-RID SP that have operations in volumes Net-RID DP queries all Net-RID SP that have operations in volumes
intersecting that of the Observer's query for details on all such intersecting that of the Observer's query for details on all such
operations. operations.
* The Net-RID DP aggregates information received from all such Net- * The Net-RID DP aggregates information received from all such Net-
RID SP and responds to the Observer's query. RID SP and responds to the Observer's query.
The minimum Net-RID data flow is illustrated in Figure 2: The minimum Net-RID data flow is illustrated in Figure 2:
+-------------+ ****************** +-------------+ ******************
skipping to change at page 6, line 41 skipping to change at page 6, line 46
| | * | * +------------+ | | * | * +------------+
| | * | * | | * | *
| | * | * +------------+ | | * | * +------------+
+--o-------o--+ * '------*-----o Observer's | +--o-------o--+ * '------*-----o Observer's |
| GCS | * * | Device | | GCS | * * | Device |
+-------------+ ****************** +------------+ +-------------+ ****************** +------------+
Figure 2 Figure 2
Command and Control (C2) must flow from the GCS to the UA via some Command and Control (C2) must flow from the GCS to the UA via some
path, currently (in the year of 2021) typically a direct RF link, but path. Currently (in the year 2022) this is typically a direct RF
with increasing beyond Visual Line of Sight (BVLOS) operations, it is link; however, with increasing Beyond Visual Line of Sight (BVLOS)
expected often to be wireless links at either end with the Internet operations, it is expected often to be a wireless link at either end
between. with the Internet between.
Telemetry (at least UA's position and heading) flows from the UA to Telemetry (at least UA's position and heading) flows from the UA to
the GCS via some path, typically the reverse of the C2 path. Thus, the GCS via some path, typically the reverse of the C2 path. Thus,
RID information pertaining to both the GCS and the UA can be sent, by UAS RID information pertaining to both the GCS and the UA can be
whichever has Internet connectivity, to the Net-RID SP, typically the sent, by whichever has Internet connectivity, to the Net-RID SP,
USS managing the UAS operation. typically the USS managing the UAS operation.
The Net-RID SP forwards RID information via the Internet to The Net-RID SP forwards UAS RID information via the Internet to
subscribed Net-RID DP, typically USS. Subscribed Net-RID DP forward subscribed Net-RID DPs, typically USS. Subscribed Net-RID DPs then
RID information via the Internet to subscribed Observer devices. forward RID information via the Internet to subscribed Observer
Regulations require and [F3411] describes RID data elements that must devices. Regulations require and [F3411] describes UAS RID data
be transported end-to-end from the UAS to the subscribed Observer elements that must be transported end-to-end from the UAS to the
devices. subscribed Observer devices.
[F3411] prescribes the protocols between the Net-RID SP, Net-RID DP, [F3411] prescribes the protocols between the Net-RID SP, Net-RID DP,
and the DSS. It also prescribes data elements (in JSON) between and the DSS. It also prescribes data elements (in JSON) between the
Observer and Net-RID DP. DRIP could address standardization of Observer and the Net-RID DP. DRIP could address standardization of
secure protocols between the UA and GCS (over direct wireless and secure protocols between the UA and GCS (over direct wireless and
Internet connection), between the UAS and the Net-RID SP, and/or Internet connection), between the UAS and the Net-RID SP, and/or
between the Net-RID DP and Observer devices. between the Net-RID DP and Observer devices.
Informative note: Neither link layer protocols nor the use of Informative note: Neither link layer protocols nor the use of
links (e.g., the link often existing between the GCS and the links (e.g., the link often existing between the GCS and the
UA) for any purpose other than carriage of RID information is UA) for any purpose other than carriage of UAS RID information
in the scope of [F3411] Network RID. is in the scope of [F3411] Network RID.
1.3. Overview of USS Interoperability 1.3. Overview of USS Interoperability
With Net-RID, there is direct communication between each UAS and its With Net-RID, there is direct communication between each UAS and its
USS. Multiple USS exchange information with the assistance of a DSS USS. Multiple USS exchange information with the assistance of a DSS
so all USS collectively have knowledge about all activities in a 4D so all USS collectively have knowledge about all activities in a 4D
airspace. The interactions among an Observer, multiple UAS, and airspace. The interactions among an Observer, multiple UAS, and
their USS are shown in Figure 3. their USS are shown in Figure 3.
+------+ +----------+ +------+ +------+ +----------+ +------+
skipping to change at page 8, line 7 skipping to change at page 8, line 28
* | o----------------o | * * | o----------------o | *
* +------+ +------+ * * +------+ +------+ *
* * * *
* Internet * * Internet *
**************************************** ****************************************
Figure 3 Figure 3
1.4. Overview of DRIP Architecture 1.4. Overview of DRIP Architecture
Figure 4 illustrates the general UAS RID usage scenario. Broadcast Figure 4 illustrates a global UAS RID usage scenario. Broadcast RID
RID links are not shown as they reach from any UA to any listening links are not shown as they reach from any UA to any listening
receiver in range and thus would obscure the intent of the figure. receiver in range and thus would obscure the intent of the figure.
Figure 4 shows, as context, some entities and interfaces beyond the Figure 4 shows, as context, some entities and interfaces beyond the
scope of DRIP (as currently (2022) chartered). scope of DRIP (as currently (2022) chartered).
*************** *************** *************** ***************
* UAS1 * * UAS2 * * UAS1 * * UAS2 *
* * * * * * * *
* +--------+ * DAA/V2V * +--------+ * * +--------+ * DAA/V2V * +--------+ *
* | UA o--*----------------------------------------*--o UA | * * | UA o--*----------------------------------------*--o UA | *
* +--o--o--+ * * +--o--o--+ * * +--o--o--+ * * +--o--o--+ *
skipping to change at page 8, line 41 skipping to change at page 9, line 33
*************** ************ *************** *************** ************ ***************
| | | | | |
+----------+ | | | +----------+ +----------+ | | | +----------+
| Public o---' | '---o Private | | Public o---' | '---o Private |
| Registry | | | Registry | | Registry | | | Registry |
+----------+ | +----------+ +----------+ | +----------+
+--o--+ +--o--+
| DNS | | DNS |
+-----+ +-----+
GPOD: General Public Observer Device (for brevity in this figure) DAA: Detect And Avoid
PSOD: Public Safety Observer Device (for brevity in this figure) GPOD: General Public Observer Device
PSOD: Public Safety Observer Device
V2I: Vehicle-to-Infrastructure
V2V: Vehicle-to-Vehicle
Figure 4 Figure 4
DRIP is meant to leverage existing Internet resources (standard DRIP is meant to leverage existing Internet resources (standard
protocols, services, infrastructures, and business models) to meet protocols, services, infrastructures, and business models) to meet
UAS RID and closely related needs. DRIP will specify how to apply UAS RID and closely related needs. DRIP will specify how to apply
IETF standards, complementing [F3411] and other external standards, IETF standards, complementing [F3411] and other external standards,
to satisfy UAS RID requirements. to satisfy UAS RID requirements.
This document outlines the DRIP architecture in the context of the This document outlines the DRIP architecture in the context of the
UAS RID architecture. This includes presenting the gaps between the UAS RID architecture. This includes presenting the gaps between the
CAAs' Concepts of Operations and [F3411] as it relates to the use of CAAs' Concepts of Operations and [F3411] as it relates to the use of
Internet technologies and UA direct RF communications. Issues Internet technologies and UA direct RF communications. Issues
include, but are not limited to: include, but are not limited to:
- Design of trustworthy remote identifiers (Section 4). - Design of trustworthy remote identifiers (Section 3).
- Mechanisms to leverage Domain Name System (DNS [RFC1034]), - Mechanisms to leverage Domain Name System (DNS [RFC1034]),
Extensible Provisioning Protocol (EPP [RFC5731]) and Extensible Provisioning Protocol (EPP [RFC5731]) and
Registration Data Access Protocol (RDAP) ([RFC9082]) for Registration Data Access Protocol (RDAP) ([RFC9082]) for
publishing public and private information (see Section 5.1 and publishing public and private information (see Section 4.1 and
Section 5.2). Section 4.2).
- Specific authentication methods and message payload formats to - Specific authentication methods and message payload formats to
enable verification that Broadcast RID messages were sent by enable verification that Broadcast RID messages were sent by
the claimed sender (Section 6) and that sender is in the the claimed sender (Section 5) and that sender is in the
claimed registry (Section 5 and Section 6). claimed registry (Section 4 and Section 5).
- Harvesting broadcast RID messages for UTM inclusion - Harvesting Broadcast RID messages for UTM inclusion, with the
(Section 7). optional DRIP extension of Crowd Sourced Remote ID (CS-RID,
Section 6), using the DRIP support for gateways required by
GEN-5 [RFC9153].
- Methods for instantly establishing secure communications - Methods for instantly establishing secure communications
between an Observer and the pilot of an observed UAS between an Observer and the pilot of an observed UAS
(Section 8). (Section 7), using the DRIP support for dynamic contact
required by GEN-4 [RFC9153].
- Privacy in RID messages (PII protection) (Section 11). - Privacy in UAS RID messages (PII protection) (Section 10).
2. Conventions 2. Terms and Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
3. Terms and Definitions To encourage comprehension necessary for adoption of DRIP by the
intended user community, the UAS community's norms are respected
herein.
3.1. Abbreviations This document uses terms defined in [RFC9153].
2.1. Additional Abbreviations
DET: DRIP Entity Tag
EdDSA: Edwards-Curve Digital Signature Algorithm EdDSA: Edwards-Curve Digital Signature Algorithm
HHIT: Hierarchical HIT HHIT: Hierarchical HIT
HI: Host Identity
HIP: Host Identity Protocol HIP: Host Identity Protocol
HIT: Host Identity Tag HIT: Host Identity Tag
3.2. Claims, Assertions, Attestations, and Certificates 2.2. Additional Definitions
This section introduces the terms "Claims", "Assertions", This section introduces the terms "Claims", "Assertions",
"Attestations", and "Certificates" as used in DRIP. DRIP certificate "Attestations", and "Certificates" as used in DRIP. DRIP certificate
has a different context compared with security certificates and has a different context compared with security certificates and
Public Key Infrastructure used in X.509. Public Key Infrastructure used in X.509.
Claims: Claims:
A claim in DRIP is a predicate (e.g., "X is Y", "X has property A claim in DRIP is a predicate (e.g., "X is Y", "X has property
Y", and most importantly "X owns Y" or "X is owned by Y"). Y", and most importantly "X owns Y" or "X is owned by Y").
skipping to change at page 10, line 37 skipping to change at page 11, line 40
relationship with another entity, along with other information, relationship with another entity, along with other information,
and the asserting entity signs the assertion, thereby making it an and the asserting entity signs the assertion, thereby making it an
attestation. attestation.
Certificates: Certificates:
A certificate in DRIP is an attestation, strictly over identity A certificate in DRIP is an attestation, strictly over identity
information, signed by a third party. This third party should be information, signed by a third party. This third party should be
one with no stake in the attestation(s) over which it is signing. one with no stake in the attestation(s) over which it is signing.
3.3. Additional Definitions 3. HHIT as the DRIP Entity Identifier
This document uses terms defined in [I-D.ietf-drip-reqs].
4. HHIT as the DRIP Entity Identifier
This section describes the DRIP architectural approach to meeting the This section describes the DRIP architectural approach to meeting the
basic requirements of a DRIP entity identifier within external basic requirements of a DRIP entity identifier within external
technical standard ASTM [F3411] and regulatory constraints. It technical standard ASTM [F3411] and regulatory constraints. It
justifies and explains the use of Hierarchical Host Identity Tags justifies and explains the use of Hierarchical Host Identity Tags
(HHITs) as self-asserting IPv6 addresses suitable as a UAS ID type (HHITs) [RFC7401] as self-asserting IPv6 addresses suitable as a UAS
and more generally as trustworthy multipurpose remote identifiers. ID type and, more generally, as trustworthy multipurpose remote
identifiers.
Self-asserting in this usage is given by the Host Identity (HI), the Self-asserting in this usage means that, given the Host Identity
HHIT ORCHID construction and a signature of the HHIT by the HI can (HI), the HHIT ORCHID construction and a signature of the registry on
both be validated. The explicit registration hierarchy within the the HHIT, the HHIT can be verified by the receiver. The explicit
HHIT provides registry discovery (managed by a Registrar) to either registration hierarchy within the HHIT provides registry discovery
yield the HI for 3rd-party (who is looking for ID attestation) (managed by a Registrar) to either yield the HI for a 3rd-party
validation or prove the HHIT and HI have uniquely been registered. (seeking UAS ID attestation) validation or prove that the HHIT and HI
have been registered uniquely.
4.1. UAS Remote Identifiers Problem Space 3.1. UAS Remote Identifiers Problem Space
A DRIP entity identifier needs to be "Trustworthy" (See DRIP A DRIP entity identifier needs to be "Trustworthy" (See DRIP
Requirement GEN-1, ID-4 and ID-5 in [I-D.ietf-drip-reqs]). This Requirement GEN-1, ID-4 and ID-5 in [RFC9153]). This means that
means that given a sufficient collection of RID messages, an Observer given a sufficient collection of UAS RID messages, an Observer can
can establish that the identifier claimed therein uniquely belongs to establish that the identifier claimed therein uniquely belongs to the
the claimant. To satisfy DRIP requirements and maintain important claimant. To satisfy DRIP requirements and maintain important
security properties, the DRIP identifier should be self-generated by security properties, the DRIP identifier should be self-generated by
the entity it names (e.g., a UAS) and registered (e.g., with a USS, the entity it names (e.g., a UAS) and registered (e.g., with a USS,
see Requirements GEN-3 and ID-2). see Requirements GEN-3 and ID-2).
Broadcast RID, especially its support for Bluetooth 4, imposes severe Broadcast RID, especially its support for Bluetooth 4, imposes severe
constraints. ASTM RID [F3411] allows a UAS ID of types 1, 2 and 3 of constraints. ASTM UAS RID [F3411] allows a UAS ID of types 1, 2 and
20 bytes; a revision to [F3411], currently in balloting (as of Oct 3 of 20 bytes; a revision to [F3411], currently in balloting (as of
2021), adds type 4, Specific Session ID, to be standardized by IETF Oct 2021), adds type 4, Specific Session ID, to be standardized by
and other standard development organizations (SDOs) as extensions to IETF and other standards development organizations (SDOs) as
ASTM RID, consumes one of those bytes to index the sub-type, leaving extensions to ASTM UAS RID, consumes one of those bytes to index the
only 19 for the identifier (see DRIP Requirement ID-1). sub-type, leaving only 19 for the identifier (see DRIP Requirement
ID-1).
Likewise, the maximum ASTM RID [F3411] Authentication Message payload Likewise, the maximum ASTM UAS RID [F3411] Authentication Message
is 201 bytes for most authentication types, but for type 5, also payload is 201 bytes for most authentication types. A type 5 is also
added in this revision, for IETF and other SDOs to develop Specific added in this revision for IETF and other SDOs to develop Specific
Authentication Methods as extensions to ASTM RID, one byte is Authentication Methods as extensions to ASTM UAS RID. One byte out
consumed to index the sub-type, leaving only 200 for DRIP of 201 bytes is consumed to index the sub-type which leaves only 200
authentication payloads, including one or more DRIP entity for DRIP authentication payloads, including one or more DRIP entity
identifiers and associated authentication data. identifiers and associated authentication data.
4.2. HHIT as A Trustworthy DRIP Entity Identifier 3.2. HHIT as A Trustworthy DRIP Entity Identifier
A Remote ID that can be trustworthily used in the RID Broadcast mode A Remote UAS ID that can be trustworthy for use in Broadcast RID can
can be built from an asymmetric keypair. In this method the ID is be built from an asymmetric keypair. In this method, the UAS ID is
cryptographically derived directly from the public key. The proof of cryptographically derived directly from the public key. The proof of
ID ownership (verifiable attestation, versus mere claim) is UAS ID ownership (verifiable attestation, versus mere claim) is
guaranteed by signing this cryptographic ID with the associated guaranteed by signing this cryptographic UAS ID with the associated
private key. The association between the ID and the private key is private key. The association between the UAS ID and the private key
ensured by cryptographically binding the public key with the ID, more is ensured by cryptographically binding the public key with the UAS
specifically the ID results from the hash of the public key. The ID; more specifically, the UAS ID results from the hash of the public
public key is designated as the HI while the ID is designated as the key. The public key is designated as the HI while the UAS ID is
HIT. designated as the HIT.
By construction, the HIT is statistically unique through the By construction, the HIT is statistically unique through the
cryptographic hash feature of second-preimage resistance. The cryptographic hash feature of second-preimage resistance. The
cryptographically-bound addition of the Hierarchy and an HHIT cryptographically-bound addition of the Hierarchy and an HHIT
registration process provide complete, global HHIT uniqueness. This registration process provide complete, global HHIT uniqueness. This
registration forces the attacker to generate the same public key registration forces the attacker to generate the same public key
rather than a public key that generates the same HHIT. This is in rather than a public key that generates the same HHIT. This is in
contrast to general IDs (e.g. a UUID or device serial number) as the contrast to general IDs (e.g., a UUID or device serial number) as the
subject in an X.509 certificate. subject in an X.509 certificate.
A UA equipped for Broadcast RID SHOULD be provisioned not only with A UA equipped for Broadcast RID SHOULD be provisioned not only with
its HHIT but also with the HI public key from which the HHIT was its HHIT but also with the HI public key from which the HHIT was
derived and the corresponding private key, to enable message derived and the corresponding private key, to enable message
signature. A UAS equipped for Network RID SHOULD be provisioned signature. A UAS equipped for Network RID SHOULD be provisioned
likewise; the private key resides only in the ultimate source of likewise; the private key resides only in the ultimate source of
Network RID messages (i.e. on the UA itself if the GCS is merely Network RID messages (i.e., on the UA itself if the GCS is merely
relaying rather than sourcing Network RID messages). Each Observer relaying rather than sourcing Network RID messages). Each Observer
device SHOULD be provisioned either with public keys of the DRIP device SHOULD be provisioned either with public keys of the DRIP
identifier root registries or certificates for subordinate identifier root registries or certificates for subordinate
registries. registries.
HHITs can also be used throughout the USS/UTM system. The Operators, HHITs can also be used throughout the USS/UTM system. Operators and
Private Information Registries, as well as other UTM entities, can Private Information Registries, as well as other UTM entities, can
use HHITs for their IDs. Such HHITs can facilitate DRIP security use HHITs for their IDs. Such HHITs can facilitate DRIP security
functions such as used with HIP to strongly mutually authenticate and functions such as used with HIP to strongly mutually authenticate and
encrypt communications. encrypt communications.
A self-attestation of a HHIT used as a UAS ID can be done in as A self-attestation of a HHIT used as a UAS ID can be done in as
little as 84 bytes when Ed25519 [RFC8032] is used, by avoiding an little as 84 bytes when Ed25519 [RFC8032] is used, by avoiding an
explicit encoding technology like ASN.1 or Concise Binary Object explicit encoding technology like ASN.1 or Concise Binary Object
Representation (CBOR [RFC8949]). This attestation consists of only Representation (CBOR [RFC8949]). This attestation consists of only
the HHIT, a timestamp, and the EdDSA signature on them. the HHIT, a timestamp, and the EdDSA signature on them.
A DRIP identifier can be assigned to a UAS as a static HHIT by its A DRIP identifier can be assigned to a UAS as a static HHIT by its
manufacturer, such as a single HI and derived HHIT encoded as a manufacturer, such as a single HI and derived HHIT encoded as a
hardware serial number per [CTA2063A]. Such a static HHIT SHOULD hardware serial number per [CTA2063A]. Such a static HHIT SHOULD
only be used to bind one-time use DRIP identifiers to the unique UA. only be used to bind one-time use DRIP identifiers to the unique UA.
Depending upon implementation, this may leave a HI private key in the Depending upon implementation, this may leave a HI private key in the
possession of the manufacturer (more details in Section 10). possession of the manufacturer (more details in Section 9).
In general, Internet access may be needed to validate Attestations or In general, Internet access may be needed to validate Attestations or
Certificates. This may be obviated in the most common cases (e.g. Certificates. This may be obviated in the most common cases (e.g.,
attestation of the UAS ID), even in disconnected environments, by attestation of the UAS ID), even in disconnected environments, by
prepopulating small caches on Observer devices with Registry public prepopulating small caches on Observer devices with Registry public
keys and a chain of Attestations or Certificates (tracing a path keys and a chain of Attestations or Certificates (tracing a path
through the Registry tree). This is assuming all parties on the through the Registry tree). This is assuming all parties on the
trust path also use HHITs for their identities. trust path also use HHITs for their identities.
4.3. HHIT for DRIP Identifier Registration and Lookup 3.3. HHIT for DRIP Identifier Registration and Lookup
RID needs a deterministic lookup mechanism that rapidly provides UAS RID needs a deterministic lookup mechanism that rapidly provides
actionable information about the identified UA. Given the size actionable information about the identified UA. Given the size
constraints imposed by the Bluetooth 4 broadcast media, the UAS ID constraints imposed by the Bluetooth 4 broadcast media, the UAS ID
itself needs to be a non-spoofable inquiry input into the lookup. itself needs to be a non-spoofable inquiry input into the lookup.
A DRIP registration process based on the explicit hierarchy within a A DRIP registration process based on the explicit hierarchy within a
HHIT provides manageable uniqueness of the HI for the HHIT. This is HHIT provides manageable uniqueness of the HI for the HHIT. This is
the defense against a cryptographic hash second pre-image attack on the defense against a cryptographic hash second pre-image attack on
the HHIT (e.g. multiple HIs yielding the same HHIT, see Requirement the HHIT (e.g., multiple HIs yielding the same HHIT, see Requirement
ID-3). A lookup of the HHIT into this registration data provides the ID-3). A lookup of the HHIT into this registration data provides the
registered HI for HHIT proof of ownership. A first-come-first-serve registered HI for HHIT proof of ownership. A first-come-first-served
registration for a HHIT provides deterministic access to any other registration for a HHIT provides deterministic access to any other
needed actionable information based on inquiry access authority (more needed actionable information based on inquiry access authority (more
details in Section 5.2). details in Section 4.2).
4.4. HHIT as a Cryptographic Identifier 3.4. HHIT as a Cryptographic Identifier
The only (known to the authors at the time of this writing) extant The only (known to the authors at the time of this writing) existing
types of IP address compatible identifiers cryptographically derived types of IP address compatible identifiers cryptographically derived
from the public keys of the identified entities are Cryptographically from the public keys of the identified entities are Cryptographically
Generated Addresses (CGAs) [RFC3972] and Host Identity Tags (HITs) Generated Addresses (CGAs) [RFC3972] and Host Identity Tags (HITs)
[RFC7401]. CGAs and HITs lack registration/retrieval capability. To [RFC7401]. CGAs and HITs lack registration/retrieval capability. To
provide this, each HHIT embeds plaintext information designating the provide this, each HHIT embeds plaintext information designating the
hierarchy within which it is registered and a cryptographic hash of hierarchy within which it is registered and a cryptographic hash of
that information concatenated with the entity's public key, etc. that information concatenated with the entity's public key, etc.
Although hash collisions may occur, the registrar can detect them and Although hash collisions may occur, the registrar can detect them and
reject registration requests rather than issue credentials, e.g., by reject registration requests rather than issue credentials, e.g., by
enforcing a first-claimed, first-attested policy. Pre-image hash enforcing a first-claimed, first-attested policy. Pre-image hash
attacks are also mitigated through this registration process, locking attacks are also mitigated through this registration process, locking
the HHIT to a specific HI the HHIT to a specific HI
5. DRIP Identifier Registration and Registries 4. DRIP Identifier Registration and Registries
DRIP registries hold both public and private UAS information DRIP registries hold both public and private UAS information (See
resulting from the DRIP identifier registration process. Given these PRIV-1 in [RFC9153]) resulting from the DRIP identifier registration
different uses, and to improve scalability, security, and simplicity process. Given these different uses, and to improve scalability,
of administration, the public and private information can be stored security, and simplicity of administration, the public and private
in different registries. This section introduces the public and information can be stored in different registries. This section
private information registries for DRIP identifiers. This DRIP introduces the public and private information registries for DRIP
Identifier registration process satisfies the following DRIP identifiers. This DRIP Identifier registration process satisfies the
requirements defined in [I-D.ietf-drip-reqs]: GEN-3, GEN-4, ID-2, ID- following DRIP requirements defined in [RFC9153]: GEN-3, GEN-4, ID-2,
4, ID-6, PRIV-3, PRIV-4, REG-1, REG-2, REG-3 and REG-4. ID-4, ID-6, PRIV-3, PRIV-4, REG-1, REG-2, REG-3 and REG-4.
5.1. Public Information Registry 4.1. Public Information Registry
5.1.1. Background 4.1.1. Background
The public registry provides trustable information such as The public information registry provides trustable information such
attestations of RID ownership and registration with the HDA as attestations of UAS RID ownership and registration with the HDA
(Hierarchical HIT Domain Authority). Optionally, pointers to the (Hierarchical HIT Domain Authority). Optionally, pointers to the
registries for the HDA and RAA (Registered Assigning registries for the HDA and RAA (Registered Assigning Authority)
Authority)implicit in the RID can be included (e.g., for HDA and RAA implicit in the UAS RID can be included (e.g., for HDA and RAA
HHIT|HI used in attestation signing operations). This public HHIT|HI used in attestation signing operations). This public
information will be principally used by Observers of Broadcast RID information will be principally used by Observers of Broadcast RID
messages. Data on UAS that only use Network RID, is available via an messages. Data on UAS that only use Network RID, is available via an
Observer's Net-RID DP that would tend to directly provide all public Observer's Net-RID DP that would directly provide all public
registry information. The Observer may visually "see" these Net-RID information registry information. The Net-RID DP is the only source
UAS, but they may be silent to the Observer. The Net-RID DP is the of information for a query on an airspace volume.
only source of information based on a query for an airspace volume.
5.1.2. DNS as the Public DRIP Identifier Registry 4.1.2. DNS as the Public DRIP Identifier Registry
A DRIP identifier SHOULD be registered as an Internet domain name (at A DRIP identifier SHOULD be registered as an Internet domain name (at
an arbitrary level in the hierarchy, e.g. in .ip6.arpa). Thus DNS an arbitrary level in the hierarchy, e.g., in .ip6.arpa). Thus DNS
can provide all the needed public DRIP information. A standardized can provide all the needed public DRIP information. A standardized
HHIT FQDN (Fully Qualified Domain Name) can deliver the HI via a HIP HHIT FQDN (Fully Qualified Domain Name) can deliver the HI via a HIP
RR (Resource Record) [RFC8005] and other public information (e.g., RR (Resource Record) [RFC8005] and other public information (e.g.,
RRA and HDA PTRs, and HIP RVS (Rendezvous Servers) [RFC8004]). These RRA and HDA PTRs, and HIP RVS (Rendezvous Servers) [RFC8004]). These
public information registries can use secure DNS transport (e.g. DNS public information registries can use secure DNS transport (e.g., DNS
over TLS) to deliver public information that is not inherently over TLS) to deliver public information that is not inherently
trustable (e.g. everything other than attestations). trustable (e.g., everything other than attestations).
5.2. Private Information Registry 4.2. Private Information Registry
5.2.1. Background 4.2.1. Background
The private information required for DRIP identifiers is similar to The private information required for DRIP identifiers is similar to
that required for Internet domain name registration. A DRIP that required for Internet domain name registration. A DRIP
identifier solution can leverage existing Internet resources: identifier solution can leverage existing Internet resources:
registration protocols, infrastructure, and business models, by registration protocols, infrastructure, and business models, by
fitting into an ID structure compatible with DNS names. The HHIT fitting into an UAS ID structure compatible with DNS names. The HHIT
hierarchy can provide the needed scalability and management hierarchy can provide the needed scalability and management
structure. It is expected that the private registry function will be structure. It is expected that the private information registry
provided by the same organizations that run a USS, and likely function will be provided by the same organizations that run a USS,
integrated with a USS. The lookup function may be implemented by the and likely integrated with a USS. The lookup function may be
Net-RID DPs. implemented by the Net-RID DPs.
5.2.2. EPP and RDAP as the Private DRIP Identifier Registry 4.2.2. EPP and RDAP as the Private DRIP Identifier Registry
A DRIP private information registry supports essential registry A DRIP private information registry supports essential registry
operations (e.g. add, delete, update, query) using interoperable open operations (e.g., add, delete, update, query) using interoperable
standard protocols. It can accomplish this by using the Extensible open standard protocols. It can accomplish this by using the
Provisioning Protocol (EPP [RFC5730]) and the Registry Data Access Extensible Provisioning Protocol (EPP [RFC5730]) and the Registry
Protocol (RDAP [RFC7480] [RFC9082] [RFC9083]). The DRIP private Data Access Protocol (RDAP [RFC7480] [RFC9082] [RFC9083]). The DRIP
information registry in which a given UAS is registered needs to be private information registry in which a given UAS is registered needs
findable, starting from the UAS ID, using the methods specified in to be findable, starting from the UAS ID, using the methods specified
[RFC7484]. in [RFC7484].
5.2.3. Alternative Private DRIP Registry methods 4.2.3. Alternative Private DRIP Registry methods
A DRIP private information registry might be an access controlled DNS A DRIP private information registry might be an access-controlled DNS
(e.g. via DNS over TLS). Additionally, WebFinger [RFC7033] can be (e.g., via DNS over TLS). Additionally, WebFinger [RFC7033] can be
deployed. These alternative methods may be used by Net-RID DP with deployed. These alternative methods may be used by Net-RID DP with
specific customers. specific customers.
6. DRIP Identifier Trust 5. DRIP Identifier Trust
While the DRIP entity identifier is self-asserting, it alone does not While the DRIP entity identifier is self-asserting, it alone does not
provide the "trustworthiness" specified in [I-D.ietf-drip-reqs]. For provide the trustworthiness (non-repudiability, protection vs.
that it MUST be registered (under DRIP Registries) and be actively spoofing, message integrity protection, scalability, etc.) essential
used by the party (in most cases the UA). A sender's identity can to UAS RID, as justified in [RFC9153]. For that it MUST be
not be approved by only possessing a DET (DRIP Entity Tag which is an registered (under DRIP Registries) and be actively used by the party
HHIT-based UA ID) and broadcasting a claim that it belongs to that (in most cases the UA). A sender's identity can not be approved by
sender. Even the sender using that HI's private key to sign static only possessing a DRIP Entity Tag (DET), which is an HHIT-based UA ID
data proves nothing as well, as it is subject to trivial replay and broadcasting a claim that it belongs to that sender. Even the
attacks. Only sending the DET and a signature on frequently changing sender using that HI's private key to sign static data proves nothing
data that can be sanity checked by the Observer (such as a Location/ as well, as it is subject to trivial replay attacks. Only sending
Vector message) proves that the observed UA possesses the claimed UAS the DET and a signature on frequently changing data that can be
ID. sanity-checked by the Observer (such as a Location/Vector message)
proves that the observed UA possesses the claimed UAS ID.
For Broadcast RID, this is a challenge to balance the original For Broadcast RID, it is a challenge to balance the original
requirements of Broadcast RID and the efforts needed to satisfy the requirements of Broadcast RID and the efforts needed to satisfy the
DRIP requirements all under severe constraints. From received DRIP requirements all under severe constraints. From received
Broadcast RID messages and information that can be looked up using Broadcast RID messages and information that can be looked up using
the received UAS ID in online registries or local caches, it is the received UAS ID in online registries or local caches, it is
possible to establish levels of trust in the asserted information and possible to establish levels of trust in the asserted information and
the Operator. the Operator.
An optimization of different DRIP Authentication Messages allows an Optimization of different DRIP Authentication Messages allows an
Observer, without Internet connection (offline) or with (online), to Observer, without Internet connection (offline) or with (online), to
be able to validate a UAS DRIP ID in real-time. First is the sending be able to validate a UAS DRIP ID in real-time. First is the sending
of Broadcast Attestations (over DRIP Link Authentication Messages) of Broadcast Attestations (over DRIP Link Authentication Messages)
[I-D.ietf-drip-auth] containing the relevant registration of the UA's [I-D.ietf-drip-auth] containing the relevant registration of the UA's
DRIP ID in the claimed Registry. Next is sending DRIP Wrapper DRIP ID in the claimed Registry. Next is sending DRIP Wrapper
Authentication Messages that sign over both static (e.g. above Authentication Messages that sign over both static (e.g., above
registration) and dynamically changing data (such as UA location registration) and dynamically changing data (such as UA location
data). Combining these two sets of information an Observer can piece data). Combining these two sets of information, an Observer can
together a chain of trust and real-time evidence to make their piece together a chain of trust and real-time evidence to make their
determination of the UAs claims. determination of the UA's claims.
This process (combining the DRIP entity identifier, Registries and This process (combining the DRIP entity identifier, Registries and
Authentication Formats for Broadcast RID) can satisfy the following Authentication Formats for Broadcast RID) can satisfy the following
DRIP requirement defined in [I-D.ietf-drip-reqs]: GEN-1, GEN-2, GEN- DRIP requirement defined in [RFC9153]: GEN-1, GEN-2, GEN-3, ID-2, ID-
3, ID-2, ID-3, ID-4 and ID-5. 3, ID-4 and ID-5.
7. Harvesting Broadcast Remote ID messages for UTM Inclusion 6. Harvesting Broadcast Remote ID messages for UTM Inclusion
ASTM anticipated that regulators would require both Broadcast RID and ASTM anticipated that regulators would require both Broadcast RID and
Network RID for large UAS, but allow RID requirements for small UAS Network RID for large UAS, but allow UAS RID requirements for small
to be satisfied with the operator's choice of either Broadcast RID or UAS to be satisfied with the operator's choice of either Broadcast
Network RID. The EASA initially specified Broadcast RID for UAS of RID or Network RID. The EASA initially specified Broadcast RID for
essentially all UAS and is now also considering Network RID. The FAA essentially all UAS, and is now also considering Network RID. The
RID Final Rules [FAA_RID] permit only Broadcast RID for rule FAA UAS RID Final Rules [FAA_RID] permit only Broadcast RID for rule
compliance, but still encourage Network RID for complementary compliance, but still encourage Network RID for complementary
functionality, especially in support of UTM. functionality, especially in support of UTM.
One obvious opportunity is to enhance the architecture with gateways One obvious opportunity is to enhance the architecture with gateways
from Broadcast RID to Network RID. This provides the best of both from Broadcast RID to Network RID. This provides the best of both
and gives regulators and operators flexibility. It offers advantages and gives regulators and operators flexibility. It offers advantages
over either form of RID alone: greater fidelity than Network RID over either form of UAS RID alone: greater fidelity than Network RID
reporting of planned area operations; surveillance of areas too large reporting of planned area operations; surveillance of areas too large
for local direct visual observation and direct RF-LOS link based for local direct visual observation and direct RF-LOS link based
Broadcast RID (e.g., a city or a national forest). Broadcast RID (e.g., a city or a national forest).
These gateways could be pre-positioned (e.g. around airports, public These gateways could be pre-positioned (e.g., around airports, public
gatherings, and other sensitive areas) and/or crowd-sourced (as gatherings, and other sensitive areas) and/or crowd-sourced (as
nothing more than a smartphone with a suitable app is needed). As nothing more than a smartphone with a suitable app is needed). As
Broadcast RID media have limited range, gateways receiving messages Broadcast RID media have limited range, gateways receiving messages
claiming locations far from the gateway can alert authorities or a claiming locations far from the gateway can alert authorities or a
SDSP to the failed sanity check possibly indicating intent to SDSP to the failed sanity check possibly indicating intent to
deceive. Surveillance SDSPs can use messages with precise date/time/ deceive. Surveillance SDSPs can use messages with precise date/time/
position stamps from the gateways to multilaterate UA location, position stamps from the gateways to multilaterate UA location,
independent of the locations claimed in the messages, which are independent of the locations claimed in the messages, which are
entirely operator self-reported in UAS RID and UTM, and thus are entirely operator self-reported in UAS RID and UTM, and thus are
subject not only to natural time lag and error but also operator subject not only to natural time lag and error but also operator
misconfiguration or intentional deception. misconfiguration or intentional deception.
Further, gateways with additional sensors (e.g. smartphones with Multilateration technologies use physical layer information, such as
precise Time Of Arrival (TOA) of transmissions from mobile
transmitters at receivers with a priori precisely known locations, to
estimate the locations of the mobile transmitters.
Further, gateways with additional sensors (e.g., smartphones with
cameras) can provide independent information on the UA type and size, cameras) can provide independent information on the UA type and size,
confirming or refuting those claims made in the RID messages. This confirming or refuting those claims made in the UAS RID messages.
Crowd Sourced Remote ID (CS-RID) would be a significant enhancement, This Crowd Sourced Remote ID (CS-RID) would be a significant
beyond baseline DRIP functionality; if implemented, it adds two more enhancement, beyond baseline DRIP functionality; if implemented, it
entity types. adds two more entity types.
This approach satisfies the following DRIP requirements defined in This approach satisfies the following DRIP requirements defined in
[I-D.ietf-drip-reqs]: GEN-5, GEN-11, and REG-1. [RFC9153]: GEN-5, GEN-11, and REG-1.
7.1. The CS-RID Finder 6.1. The CS-RID Finder
A CS-RID Finder is the gateway for Broadcast Remote ID Messages into A CS-RID Finder is the gateway for Broadcast Remote ID Messages into
the UTM. It performs this gateway function via a CS-RID SDSP. A CS- UTM. It performs this gateway function via a CS-RID SDSP. A CS-RID
RID Finder could implement, integrate, or accept outputs from, a Finder could implement, integrate, or accept outputs from a Broadcast
Broadcast RID receiver. However, it should not depend upon a direct RID receiver. However, it should not depend upon a direct interface
interface with a GCS, Net-RID SP, Net-RID DP or Network RID client. with a GCS, Net-RID SP, Net-RID DP or Network RID client. It would
It would present a TBD interface to a CS-RID SDSP, similar to but present a TBD interface to a CS-RID SDSP, similar to but readily
readily distinguishable from that between a GCS and a Net-RID SP. distinguishable from that between a GCS and a Net-RID SP.
7.2. The CS-RID SDSP 6.2. The CS-RID SDSP
A CS-RID SDSP aggregates and processes (e.g., estimates UA location A CS-RID SDSP aggregates and processes (e.g., estimates UA location
using multilateration when possible) information collected by CS-RID using multilateration when possible) information collected by CS-RID
Finders. A CS-RID SDSP should appear (i.e. present the same Finders. A CS-RID SDSP should appear (i.e., present the same
interface) to a Net-RID SP as a Net-RID DP. interface) to a Net-RID SP as a Net-RID DP.
8. DRIP Contact 7. DRIP Contact
One of the ways in which DRIP can enhance [F3411] with immediately One of the ways in which DRIP can enhance [F3411] with immediately
actionable information is by enabling an Observer to instantly actionable information is by enabling an Observer to instantly
initiate secure communications with the UAS remote pilot, Pilot In initiate secure communications with the UAS remote pilot, Pilot In
Command, operator, USS under which the operation is being flown, or Command, operator, USS under which the operation is being flown, or
other entity potentially able to furnish further information other entity potentially able to furnish further information
regarding the operation and its intent and/or to immediately regarding the operation and its intent and/or to immediately
influence further conduct or termination of the operation (e.g., land influence further conduct or termination of the operation (e.g., land
or otherwise exit an airspace volume). Such potentially distracting or otherwise exit an airspace volume). Such potentially distracting
communications demand strong "AAA" (Authentication, Attestation, communications demand strong "AAA" (Authentication, Attestation,
Authorization, Access Control, Accounting, Attribution, Audit) per Authorization, Access Control, Accounting, Attribution, Audit) per
applicable policies (e.g., of the cognizant CAA). applicable policies (e.g., of the cognizant CAA).
A DRIP entity identifier based on a HHIT as outlined in Section 4 A DRIP entity identifier based on a HHIT as outlined in Section 3
embeds an identifier of the registry in which it can be found embeds an identifier of the registry in which it can be found
(expected typically to be the USS under which the UAS is flying) and (expected typically to be the USS under which the UAS is flying) and
the procedures outlined in Section 6 enable Observer verification of the procedures outlined in Section 5 enable Observer verification of
that relationship. A DRIP entity identifier with suitable records in that relationship. A DRIP entity identifier with suitable records in
public and private registries as outlined in Section 5 can enable public and private registries as outlined in Section 5 can enable
lookup not only of information regarding the UAS but also identities lookup not only of information regarding the UAS, but also identities
of and pointers to information regarding the various associated of and pointers to information regarding the various associated
entities (e.g., the USS under which the UAS is flying an operation), entities (e.g., the USS under which the UAS is flying an operation),
including means of contacting those associated entities (i.e., including means of contacting those associated entities (i.e.,
locators, typically IP addresses). An Observer equipped with HIP can locators, typically IP addresses).
initiate a Base Exchange (BEX) and establish a Bound End to End
Tunnel (BEET) protected by IPsec Encapsulating Security Payload (ESP)
encryption to a likewise equipped and identified entity: the UA
itself, if operating autonomously; the GCS, if the UA is remotely
piloted and the necessary records have been populated in DNS;
likewise the USS, etc. Certain preconditions are necessary: each
party to the communication needs a currently usable means (typically
DNS) of resolving the other party's DRIP entity identifier to a
currently usable locator (IP address); and there must be currently
usable bidirectional IP (not necessarily Internet) connectivity
between the parties. Given a BEET, arbitrary standard higher layer
protocols can then be used for Observer to Pilot (O2P) communications
(e.g., SIP [RFC3261] et seq), V2X communications (e.g., [MAVLink]),
etc. This approach satisfies DRIP requirement GEN-6 Contact,
supports satisfaction of requirements [I-D.ietf-drip-reqs] GEN-8,
GEN-9, PRIV-2, PRIV-5 and REG-3, and is compatible with all other
DRIP requirements.
9. IANA Considerations A suitably equipped Observer could initiate a cryptographic handshake
to a similarly equipped and identified entity: the UA itself, if
operating autonomously; the GCS, if the UA is remotely piloted and
the necessary records have been populated in DNS; the USS, etc.
Assuming mutual authentication is successful, keys can then be
negotiated for an IPsec Encapsulating Security Payload (ESP) tunnel,
over which arbitrary standard higher layer protocols can then be used
for Observer to Pilot (O2P)communications (e.g., SIP [RFC3261] et
seq), V2X communications (e.g., [MAVLink]), etc. Certain
preconditions are necessary: each party needs a currently usable
means (typically DNS) of resolving the other party's DRIP entity
identifier to a currently usable locator (IP address); and there must
be currently usable bidirectional IP (not necessarily Internet)
connectivity between the parties. One method directly supported by
the use of HHITs as DRIP entity identifiers is initiation of a HIP
Base Exchange (BEX) and Bound End-to-End Tunnel (BEET).
This approach satisfies DRIP requirement GEN-6 Contact, supports
satisfaction of requirements [RFC9153] GEN-8, GEN-9, PRIV-2, PRIV-5
and REG-3, and is compatible with all other DRIP requirements.
8. IANA Considerations
This document does not make any IANA request. This document does not make any IANA request.
10. Security Considerations 9. Security Considerations
The security provided by asymmetric cryptographic techniques depends The security provided by asymmetric cryptographic techniques depends
upon protection of the private keys. A manufacturer that embeds a upon protection of the private keys. A manufacturer that embeds a
private key in an UA may have retained a copy. A manufacturer whose private key in an UA may have retained a copy. A manufacturer whose
UA are configured by a closed source application on the GCS which UA are configured by a closed source application on the GCS that
communicates over the Internet with the factory may be sending a copy communicates over the Internet with the factory may be sending a copy
of a UA or GCS self-generated key back to the factory. Keys may be of a UA or GCS self-generated key back to the factory. Keys may be
extracted from a GCS or UA. The RID sender of a small harmless UA extracted from a GCS or UA. The UAS RID sender of a small harmless
(or the entire UA) could be carried by a larger dangerous UA as a UA (or the entire UA) could be carried by a larger dangerous UA as a
"false flag." Compromise of a registry private key could do "false flag." Compromise of a registry private key could do
widespread harm. Key revocation procedures are as yet to be widespread harm. Key revocation procedures are as yet to be
determined. These risks are in addition to those involving Operator determined. These risks are in addition to those involving Operator
key management practices. key management practices.
11. Privacy & Transparency Considerations 10. Privacy & Transparency Considerations
Broadcast RID messages can contain Personally Identifiable Broadcast RID messages can contain Personally Identifiable
Information (PII). A viable architecture for PII protection would be Information (PII). A viable architecture for PII protection would be
symmetric encryption of the PII using a session key known to the UAS symmetric encryption of the PII using a session key known to the UAS
and its USS. Authorized Observers could obtain plaintext in either and its USS. Authorized Observers could obtain plaintext in either
of two ways. An Observer can send the UAS ID and the cyphertext to a of two ways. An Observer can send the UAS ID and the cyphertext to a
server that offers decryption as a service. An Observer can send the server that offers decryption as a service. An Observer can send the
UAS ID only to a server that returns the session key, so that UAS ID only to a server that returns the session key, so that
Observer can directly locally decrypt all cyphertext sent by that UA Observer can directly locally decrypt all cyphertext sent by that UA
during that session (UAS operation). In either case, the server can during that session (UAS operation). In either case, the server can
be: a Public Safety USS, the Observer's own USS, or the UA's USS if be: a Public Safety USS, the Observer's own USS, or the UA's USS if
the latter can be determined (which under DRIP it can be, from the the latter can be determined (which under DRIP it can be, from the
UAS ID itself). PII can be protected unless the UAS is informed UAS ID itself). PII can be protected unless the UAS is informed
otherwise. This could come as part of UTM operation authorization. otherwise. This could come as part of UTM operation authorization.
It can be special instructions at the start or during an operation. It can be special instructions at the start or during an operation.
PII protection MUST NOT be used if the UAS loses connectivity to the PII protection MUST NOT be used if the UAS loses connectivity to the
USS. The UAS always has the option to abort the operation if PII USS. The UAS always has the option to abort the operation if PII
protection is disallowed. protection is disallowed.
12. References 11. References
12.1. Normative References
[I-D.ietf-drip-reqs] 11.1. Normative References
Card, S. W., Wiethuechter, A., Moskowitz, R., and A.
Gurtov, "Drone Remote Identification Protocol (DRIP)
Requirements", Work in Progress, Internet-Draft, draft-
ietf-drip-reqs-18, 8 September 2021,
<https://www.ietf.org/archive/id/draft-ietf-drip-reqs-
18.txt>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
12.2. Informative References [RFC9153] Card, S., Ed., Wiethuechter, A., Moskowitz, R., and A.
Gurtov, "Drone Remote Identification Protocol (DRIP)
Requirements and Terminology", RFC 9153,
DOI 10.17487/RFC9153, February 2022,
<https://www.rfc-editor.org/info/rfc9153>.
11.2. Informative References
[CTA2063A] ANSI, "Small Unmanned Aerial Systems Serial Numbers", [CTA2063A] ANSI, "Small Unmanned Aerial Systems Serial Numbers",
2019. 2019.
[Delegated] [Delegated]
European Union Aviation Safety Agency (EASA), "EU European Union Aviation Safety Agency (EASA), "EU
Commission Delegated Regulation 2019/945 of 12 March 2019 Commission Delegated Regulation 2019/945 of 12 March 2019
on unmanned aircraft systems and on third-country on unmanned aircraft systems and on third-country
operators of unmanned aircraft systems", 2019. operators of unmanned aircraft systems", 2019.
skipping to change at page 20, line 20 skipping to change at page 21, line 35
traffic_management/media/UTM_ConOps_v2.pdf>. traffic_management/media/UTM_ConOps_v2.pdf>.
[FS_AEUA] "Study of Further Architecture Enhancement for UAV and [FS_AEUA] "Study of Further Architecture Enhancement for UAV and
UAM", 2021, <https://www.3gpp.org/ftp/tsg_sa/WG2_Arch/ UAM", 2021, <https://www.3gpp.org/ftp/tsg_sa/WG2_Arch/
TSGS2_147E_Electronic_2021-10/Docs/S2-2107092.zip>. TSGS2_147E_Electronic_2021-10/Docs/S2-2107092.zip>.
[I-D.ietf-drip-auth] [I-D.ietf-drip-auth]
Wiethuechter, A., Card, S., and R. Moskowitz, "DRIP Wiethuechter, A., Card, S., and R. Moskowitz, "DRIP
Authentication Formats & Protocols for Broadcast Remote Authentication Formats & Protocols for Broadcast Remote
ID", Work in Progress, Internet-Draft, draft-ietf-drip- ID", Work in Progress, Internet-Draft, draft-ietf-drip-
auth-04, 20 December 2021, auth-05, 7 March 2022, <https://www.ietf.org/archive/id/
<https://www.ietf.org/archive/id/draft-ietf-drip-auth- draft-ietf-drip-auth-05.txt>.
04.txt>.
[Implementing] [Implementing]
European Union Aviation Safety Agency (EASA), "EU European Union Aviation Safety Agency (EASA), "EU
Commission Implementing Regulation 2019/947 of 24 May 2019 Commission Implementing Regulation 2019/947 of 24 May 2019
on the rules and procedures for the operation of unmanned on the rules and procedures for the operation of unmanned
aircraft", 2019. aircraft", 2019.
[LAANC] United States Federal Aviation Administration (FAA), "Low [LAANC] United States Federal Aviation Administration (FAA), "Low
Altitude Authorization and Notification Capability", n.d., Altitude Authorization and Notification Capability", n.d.,
<https://www.faa.gov/uas/programs_partnerships/ <https://www.faa.gov/uas/programs_partnerships/
skipping to change at page 22, line 41 skipping to change at page 24, line 8
(EUROCONTROL), "U-space Concept of Operations", 2019, (EUROCONTROL), "U-space Concept of Operations", 2019,
<https://www.sesarju.eu/sites/default/files/documents/u- <https://www.sesarju.eu/sites/default/files/documents/u-
space/CORUS%20ConOps%20vol2.pdf>. space/CORUS%20ConOps%20vol2.pdf>.
Appendix A. Overview of Unmanned Aircraft Systems (UAS) Traffic Appendix A. Overview of Unmanned Aircraft Systems (UAS) Traffic
Management (UTM) Management (UTM)
A.1. Operation Concept A.1. Operation Concept
The National Aeronautics and Space Administration (NASA) and FAA's The National Aeronautics and Space Administration (NASA) and FAA's
effort of integrating UAS's operation into the national airspace effort to integrate UAS operations into the national airspace system
system (NAS) led to the development of the concept of UTM and the (NAS) led to the development of the concept of UTM and the ecosystem
ecosystem around it. The UTM concept was initially presented in 2013 around it. The UTM concept was initially presented in 2013 and
and version 2.0 was published in 2020 [FAA_UAS_Concept_Of_Ops]. version 2.0 was published in 2020 [FAA_UAS_Concept_Of_Ops].
The eventual concept refinement, initial prototype implementation, The eventual concept refinement, initial prototype implementation,
and testing were conducted by the UTM research transition team which and testing were conducted by the joint FAA and NASA UTM research
is the joint workforce by FAA and NASA. World efforts took place transition team. World efforts took place afterward. The Single
afterward. The Single European Sky ATM Research (SESAR) started the European Sky ATM Research (SESAR) started the CORUS project to
CORUS project to research its UTM counterpart concept, namely research its UTM counterpart concept, namely [U-Space]. This effort
[U-Space]. This effort is led by the European Organization for the is led by the European Organization for the Safety of Air Navigation
Safety of Air Navigation (Eurocontrol). (Eurocontrol).
Both NASA and SESAR have published the UTM concept of operations to Both NASA and SESAR have published their UTM concepts of operations
guide the development of their future air traffic management (ATM) to guide the development of their future air traffic management (ATM)
system and ensure safe and efficient integration of manned and system and ensure safe and efficient integration of manned and
unmanned aircraft into the national airspace. unmanned aircraft into the national airspace.
The UTM comprises UAS operation infrastructure, procedures and local UTM comprises UAS operations infrastructure, procedures and local
regulation compliance policies to guarantee safe UAS integration and regulation compliance policies to guarantee safe UAS integration and
operation. The main functionality of a UTM includes, but is not operation. The main functionality of UTM includes, but is not
limited to, providing means of communication between UAS operators limited to, providing means of communication between UAS operators
and service providers and a platform to facilitate communication and service providers and a platform to facilitate communication
among UAS service providers. among UAS service providers.
A.2. UAS Service Supplier (USS) A.2. UAS Service Supplier (USS)
A USS plays an important role to fulfill the key performance A USS plays an important role to fulfill the key performance
indicators (KPIs) that a UTM has to offer. Such an Entity acts as a indicators (KPIs) that UTM has to offer. Such an Entity acts as a
proxy between UAS operators and UTM service providers. It provides proxy between UAS operators and UTM service providers. It provides
services like real-time UAS traffic monitoring and planning, services like real-time UAS traffic monitoring and planning,
aeronautical data archiving, airspace and violation control, aeronautical data archiving, airspace and violation control,
interacting with other third-party control entities, etc. A USS can interacting with other third-party control entities, etc. A USS can
coexist with other USS to build a large service coverage map that can coexist with other USS to build a large service coverage map that can
load-balance, relay, and share UAS traffic information. load-balance, relay, and share UAS traffic information.
The FAA works with UAS industry shareholders and promotes the Low The FAA works with UAS industry shareholders and promotes the Low
Altitude Authorization and Notification Capability [LAANC] program Altitude Authorization and Notification Capability [LAANC] program,
which is the first system to realize some of the UTM envisioned which is the first system to realize some of the envisioned
functionality. The LAANC program can automate the UAS operational functionality of UTM. The LAANC program can automate UAS operational
intent (flight plan) submission and application for airspace intent (flight plan) submission and application for airspace
authorization in real-time by checking against multiple aeronautical authorization in real-time by checking against multiple aeronautical
databases such as airspace classification and operating rules databases such as airspace classification and operating rules
associated with it, FAA UAS facility map, special use airspace, associated with it, FAA UAS facility map, special use airspace,
Notice to Airmen (NOTAM), and Temporary Flight Restriction (TFR). Notice to Airmen (NOTAM), and Temporary Flight Restriction (TFR).
A.3. UTM Use Cases for UAS Operations A.3. UTM Use Cases for UAS Operations
This section illustrates a couple of use case scenarios where UAS This section illustrates a couple of use case scenarios where UAS
participation in UTM has significant safety improvement. participation in UTM has significant safety improvement.
1. For a UAS participating in UTM and taking off or landing in a 1. For a UAS participating in UTM and taking off or landing in
controlled airspace (e.g., Class Bravo, Charlie, Delta, and Echo controlled airspace (e.g., Class Bravo, Charlie, Delta, and Echo
in the United States), the USS under which the UAS is operating in the United States), the USS under which the UAS is operating
is responsible for verifying UA registration, authenticating the is responsible for verifying UA registration, authenticating the
UAS operational intent (flight plan) by checking against UAS operational intent (flight plan) by checking against
designated UAS facility map database, obtaining the air traffic designated UAS facility map database, obtaining the air traffic
control (ATC) authorization, and monitoring the UAS flight path control (ATC) authorization, and monitoring the UAS flight path
in order to maintain safe margins and follow the pre-authorized in order to maintain safe margins and follow the pre-authorized
sequence of authorized 4-D volumes (route). sequence of authorized 4-D volumes (route).
2. For a UAS participating in UTM and taking off or landing in 2. For a UAS participating in UTM and taking off or landing in
uncontrolled airspace (ex. Class Golf in the United States), uncontrolled airspace (e.g., Class Golf in the United States),
pre-flight authorization must be obtained from a USS when pre-flight authorization must be obtained from a USS when
operating beyond-visual-of-sight (BVLOS). The USS either accepts operating beyond-visual-of-sight (BVLOS). The USS either accepts
or rejects the received operational intent (flight plan) from the or rejects the received operational intent (flight plan) from the
UAS. Accepted UAS operation may share its current flight data UAS. Accepted UAS operation may share its current flight data
such as GPS position and altitude to USS. The USS may keep the such as GPS position and altitude to USS. The USS may keep the
UAS operation status near real-time and may keep it as a record UAS operation status near real-time and may keep it as a record
for overall airspace air traffic monitoring. for overall airspace air traffic monitoring.
Appendix B. Automatic Dependent Surveillance Broadcast (ADS-B) Appendix B. Automatic Dependent Surveillance Broadcast (ADS-B)
The ADS-B is the de jure technology used in manned aviation for The ADS-B is the de jure technology used in manned aviation for
sharing location information, from the aircraft to ground and sharing location information, from the aircraft to ground and
satellite-based systems, designed in the early 2000s. Broadcast RID satellite-based systems, designed in the early 2000s. Broadcast RID
is conceptually similar to ADS-B, but with the receiver target being is conceptually similar to ADS-B, but with the receiver target being
the general public on generally available devices (e.g. smartphones). the general public on generally available devices (e.g.,
smartphones).
For numerous technical reasons, ADS-B itself is not suitable for low- For numerous technical reasons, ADS-B itself is not suitable for low-
flying small UA. Technical reasons include but not limited to the flying small UAS. Technical reasons include but not limited to the
following: following:
1. Lack of support for the 1090 MHz ADS-B channel on any consumer 1. Lack of support for the 1090 MHz ADS-B channel on any consumer
handheld devices handheld devices
2. Weight and cost of ADS-B transponders on CSWaP constrained UA 2. Weight and cost of ADS-B transponders on CSWaP constrained UA
3. Limited bandwidth of both uplink and downlink, which would likely 3. Limited bandwidth of both uplink and downlink, which would likely
be saturated by large numbers of UAS, endangering manned aviation be saturated by large numbers of UAS, endangering manned aviation
skipping to change at page 24, line 49 skipping to change at page 26, line 19
Acknowledgements Acknowledgements
The work of the FAA's UAS Identification and Tracking (UAS ID) The work of the FAA's UAS Identification and Tracking (UAS ID)
Aviation Rulemaking Committee (ARC) is the foundation of later ASTM Aviation Rulemaking Committee (ARC) is the foundation of later ASTM
and proposed IETF DRIP WG efforts. The work of ASTM F38.02 in and proposed IETF DRIP WG efforts. The work of ASTM F38.02 in
balancing the interests of diverse stakeholders is essential to the balancing the interests of diverse stakeholders is essential to the
necessary rapid and widespread deployment of UAS RID. Thanks to necessary rapid and widespread deployment of UAS RID. Thanks to
Alexandre Petrescu and Stephan Wenger for the helpful and positive Alexandre Petrescu and Stephan Wenger for the helpful and positive
comments. Thanks to chairs Daniel Migault and Mohamed Boucadair for comments. Thanks to chairs Daniel Migault and Mohamed Boucadair for
direction of our team of authors and editor, some of whom are direction of our team of authors and editor, some of whom are
newcomers to writing IETF documents. Thanks especially to Internet newcomers to writing IETF documents. Laura Welch is also thanked for
Area Director Eric Vyncke for guidance and support. her valuable review comments that led to great improvements of this
memo. Thanks especially to Internet Area Director Eric Vyncke for
guidance and support.
Authors' Addresses Authors' Addresses
Stuart W. Card Stuart W. Card
AX Enterprize AX Enterprize
4947 Commercial Drive 4947 Commercial Drive
Yorkville, NY, 13495 Yorkville, NY, 13495
United States of America United States of America
Email: stu.card@axenterprize.com Email: stu.card@axenterprize.com
Adam Wiethuechter Adam Wiethuechter
AX Enterprize AX Enterprize
4947 Commercial Drive 4947 Commercial Drive
Yorkville, NY, 13495 Yorkville, NY, 13495
United States of America United States of America
Email: adam.wiethuechter@axenterprize.com Email: adam.wiethuechter@axenterprize.com
Robert Moskowitz Robert Moskowitz
HTT Consulting HTT Consulting
Oak Park, MI, 48237 Oak Park, MI, 48237
United States of America United States of America
Email: rgm@labs.htt-consult.com Email: rgm@labs.htt-consult.com
Shuai Zhao Shuai Zhao
Tencent Tencent
2747 Park Blvd 2747 Park Blvd
Palo Alto, 94588 Palo Alto, 94588
United States of America United States of America
Email: shuai.zhao@ieee.org Email: shuai.zhao@ieee.org
Andrei Gurtov Andrei Gurtov
Linköping University Linköping University
IDA IDA
SE-58183 Linköping Linköping SE-58183 Linköping Linköping
Sweden Sweden
Email: gurtov@acm.org Email: gurtov@acm.org
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