Crowd Sourced Remote ID
draft-moskowitz-drip-crowd-sourced-rid-12
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Robert Moskowitz , Stuart W. Card , Adam Wiethuechter , Shuai Zhao , Henk Birkholz | ||
| Last updated | 2024-04-08 | ||
| Replaces | draft-moskowitz-tmrid-crowd-sourced-rid | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
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draft-moskowitz-drip-crowd-sourced-rid-12
DRIP R. Moskowitz
Internet-Draft HTT Consulting
Intended status: Standards Track S. Card
Expires: 10 October 2024 A. Wiethuechter
AX Enterprize
S. Zhao
Intel
H. Birkholz
Fraunhofer SIT
8 April 2024
Crowd Sourced Remote ID
draft-moskowitz-drip-crowd-sourced-rid-12
Abstract
This document describes using the ASTM Broadcast Remote ID (B-RID)
specification in a "crowd sourced" smart phone or fixed receiver
asset environment to provide much of the ASTM and FAA envisioned
Network Remote ID (Net-RID) functionality. This crowd sourced B-RID
(CS-RID) data will use multilateration to add a level of reliability
in the location data on the Uncrewed Aircraft (UA). The crowd
sourced environment will also provide a monitoring coverage map to
authorized observers.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 10 October 2024.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Role of Supplemental Data Service Provider (SDSP) . . . . 4
1.2. Draft Status . . . . . . . . . . . . . . . . . . . . . . 5
2. Terms and Definitions . . . . . . . . . . . . . . . . . . . . 5
2.1. Requirements Terminology . . . . . . . . . . . . . . . . 5
2.2. Definitions . . . . . . . . . . . . . . . . . . . . . . . 5
3. Problem Space . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. Meeting the needs of Network Remote ID . . . . . . . . . 6
3.2. Advantages of Broadcast Remote ID . . . . . . . . . . . . 6
3.3. Trustworthiness of Proxied Data . . . . . . . . . . . . . 6
3.4. Defense against fraudulent RID Messages . . . . . . . . . 7
4. The Finder - SDSP Security Relationship . . . . . . . . . . . 7
4.1. SDSP Heartbeats . . . . . . . . . . . . . . . . . . . . . 8
4.2. The Finder Map . . . . . . . . . . . . . . . . . . . . . 8
4.3. Managing Finders . . . . . . . . . . . . . . . . . . . . 8
5. UA location via multilateration . . . . . . . . . . . . . . . 8
5.1. GPS Inaccuracy . . . . . . . . . . . . . . . . . . . . . 9
6. The CS-RID Messages . . . . . . . . . . . . . . . . . . . . . 9
6.1. CS-RID MESSAGE TYPE . . . . . . . . . . . . . . . . . . . 10
6.1.1. CDDL description for CS-RID message type . . . . . . 10
6.2. The CS-RID B-RID Proxy Message . . . . . . . . . . . . . 12
6.2.1. CS-RID ID . . . . . . . . . . . . . . . . . . . . . . 13
6.2.2. CDDL description for CS-RID B-RID Proxy Message . . . 13
6.3. CS-RID Finder Registration . . . . . . . . . . . . . . . 14
6.3.1. CDDL description for Finder Registration . . . . . . 14
6.4. CS-RID SDSP Response . . . . . . . . . . . . . . . . . . 15
6.4.1. CDDL description for SDSP Response . . . . . . . . . 15
6.5. CS-RID Location Update . . . . . . . . . . . . . . . . . 16
6.5.1. CDDL description for Location Update . . . . . . . . 16
6.6. SDSP Heartbeat . . . . . . . . . . . . . . . . . . . . . 16
6.6.1. CDDL description for SDSP Heartbeat . . . . . . . . . 17
7. The Full CS-RID CDDL specification . . . . . . . . . . . . . 17
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20
9. Security Considerations . . . . . . . . . . . . . . . . . . . 20
9.1. Privacy Concerns . . . . . . . . . . . . . . . . . . . . 20
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 20
10.1. Normative References . . . . . . . . . . . . . . . . . . 20
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10.2. Informative References . . . . . . . . . . . . . . . . . 21
Appendix A. Using LIDAR for UA location . . . . . . . . . . . . 22
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 23
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction
This document defines a mechanism to capture the ASTM Broadcast
Remote ID messages (B-RID) [F3411-22a] on any Internet connected
device that receives them and can forward them to the Supplemental
Data Service Providers (SDSPs) responsible for the geographic area
the UA and receivers are in. This crowd sourced B-RID (CS-RID) will
create a ecosystem that will meet most if not all data collection
requirements that Civil Aviation Authorities (CAA) are placing on
Network Remote ID (Net-RID).
These Internet connected B-RID receivers are herein called "Finders",
as they find UAs by listening for B-RID messages. The Finders are
B-RID forwarding proxies. Their potentially limited spacial view of
RID messages could result in bad decisions on what messages to send
to the SDSP and which to drop. Thus they will send all received
messages and the SDSP will make any filtering decisions in what it
forwards into the UAS Traffic Management (UTM).
Finders can be smartphones, tablets, connected cars, or any computing
platform with Internet connectivity that can meet the requirements
defined in this document. It is not expected, nor necessary, that
Finders have any information about a UAS beyond the content in the
B-RID messages.
The SDSPs are similar to, but different from the Surveillance SDSPs
in [F3623-23]. [F3623-23] defines sensors which are predominately
radars, similar to Appendix A. The difference stems from [F3623-23]
orientation with ICAO Aircraft numbers and aviation radar history of
tracking objects in flight and trying to feed that data into UTM. It
is likely that this document will act as guidance to [F3623-23] for
future revisions to better align it with UTM over manned aviation
Aircraft Traffic Control (ATC).
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Finders MAY only need a loose association with the SDSP(s). They may
only have the SDSP's Public Key and FQDN. It would use these, along
with the Finder's Public Keypair to use Elliptic Curve Integrated
Encryption Scheme (ECIES), or other security methods, to send the
messages in a secure manner to the SDSP. The SDSP MAY require a
stronger relationship to the Finders. This may range from the
Finder's Public Key being registered to the SDSP with other
information so that the SDSP has some level of trust in the Finders
to requiring transmissions be sent over long-lived transport
connections like ESP [RFC4303] or DTLS [RFC5238].
If a 1-way only secure packet forwarding method is used (e.g., not a
TCP connection), the Finder SHOULD receive periodic "heartbeats" from
the SDSP to inform it that its transmissions are being received. The
SDSP sets the rules on when to send these heartbeats as discuss below
in Section 4.1.
1.1. Role of Supplemental Data Service Provider (SDSP)
The DRIP Architecture [RFC9434] introduces the basic CS-RID entities
including CS-RID Finder and CS-RID SDSP. This document has minimal
information about the actions of SDSPs. In general the SDSP is out
of scope of this document. That said, the SDSPs should not simply
proxy B-RID messages to the UTM(s). They should perform some minimal
level of filtering and content checking before forwarding those
messages that pass these tests in a secure manner to the UTM(s).
The SDSPs are also capable of maintaining a monitoring map, based on
location of active Finders. UTMs may use this information to notify
authorized observers of where there is and there is not monitoring
coverage. They may also use this information of where to place pro-
active monitoring coverage.
An SDSP should only forward Authenticated B-RID messages like those
defined in [drip-authentication] to the UTM(s). Further, the SDSP
SHOULD validate the Remote ID (RID) and the Authentication signature
before forwarding anything from the UA, and flagging those RIDs that
were not validated. The SDSP MAY forward all B-RID messages to the
UTM, leaving all decision making on B-RID messages veracity to the
UTM.
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When 3 or more Finders are reporting to an SDSP on a specific UA, the
SDSP is in a unique position to perform multilateration on these
messages and compute the Finder's view of the UA location to compare
with the UA Location/Vector messages. This check against the UA's
location claims is both a validation on the UA's reliability as well
as the trustworthiness of the Finders. Other than providing data to
allow for multilateration, this SDSP feature is out of scope of this
document. This function is limited by the location accuracy for both
the Finders and UA.
1.2. Draft Status
This draft is still incomplete. New features are being added as
capabilities are researched. The actual message formats also still
need work.
2. Terms and Definitions
2.1. Requirements Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
This document uses terms defined in [RFC9153] and [RFC9434].
2.2. Definitions
B-RID:
Broadcast Remote ID. A method of sending RID messages as 1-way
transmissions from the UA to any Observers within radio range.
ECIES: Elliptic Curve Integrated Encryption Scheme. A hybrid
encryption scheme which provides semantic security against an
adversary who is allowed to use chosen-plaintext and chosen-
ciphertext attacks.
Finder: In Internet connected device that can receive B-RID messages
and forward them to a UTM.
Multilateration: Multilateration (more completely, pseudo range
multilateration) is a navigation and surveillance technique based
on measurement of the times of arrival (TOAs) of energy waves
(radio, acoustic, seismic, etc.) having a known propagation speed.
Net-RID: Network Remote ID. A method of sending RID messages via
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the Internet connection of the UAS directly to the UTM.
3. Problem Space
3.1. Meeting the needs of Network Remote ID
The USA Federal Aviation Authority (FAA), in the January 2021 Remote
ID Final rule [FAA-FR], postponed Network Remote ID (Net-RID) and
focused on Broadcast Remote ID. This was in response to the UAS
vendors comments that Net-RID places considerable demands on then
currently used UAS.
However, Net-RID, or equivalent, is necessary for UTM and knowing
what soon may be in an airspace. A method that proxies B-RID into
UTM can function as an interim approach to Net-RID and continue as a
adjunct to Net-RID.
3.2. Advantages of Broadcast Remote ID
B-RID has its advantages over Net-RID.
* B-RID can more readily be implemented directly in the UA. Net-RID
will more frequently be provided by the GCS or a pilot's Internet
connected device.
- If Command and Control (C2) is bi-directional over a direct
radio connection, B-RID could be a straight-forward addition.
- Small IoT devices can be mounted on UA to provide B-RID.
* B-RID can also be used by the UA to assist in Detect and Avoid
(DAA).
* B-RID is available to observers even in situations with no
Internet like natural disaster situations.
3.3. Trustworthiness of Proxied Data
When a proxy is introduced in any communication protocol, there is a
risk of corrupted data and DOS attacks.
The Finders, in their role as proxies for B-RID, are authenticated to
the SDSP (see Section 4). The SDSP can compare the information from
multiple Finders to isolate a Finder sending fraudulent information.
SDSPs can additionally verify authenticated messages that follow
[drip-authentication].
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The SPDP can manage the number of Finders in an area (see
Section 4.3) to limit DOS attacks from a group of clustered Finders.
3.4. Defense against fraudulent RID Messages
The strongest defense against fraudulent RID messages is to focus on
[drip-authentication] conforming messages. Unless this behavior is
mandated, SPDPs will have to use assorted algorithms to isolate
messages of questionable content.
4. The Finder - SDSP Security Relationship
The SDSP(s) and Finders SHOULD use EdDSA [RFC8032] keys as their
trusted Identities. The public keys SHOULD be registered DRIP UAS
Remote ID [RFC9374] and [drip-registries]. Other similar methods may
be used.
During this registration, the Finder gets the SDSP's EdDSA Public
Key. These Public Keys allow for the following options for
authenticated messaging from the Finder to the SDSP.
The SDSP uses some process (out of scope here) to register the
Finders and their EdDSA Public Key. During this registration, the
Finder gets the SDSP's EdDSA Public Key. These Public Keys allow for
the following options for authenticated messaging from the Finder to
the SDSP.
1. EdDSA keys are converted to X25519 keys per Curve25519 [RFC7748]
to use in ECIES.
2. ECIES can be used with a unique nonce to authenticate each
message sent from a Finder to the SDSP.
3. ECIES can be used at the start of some period (e.g. day) to
establish a shared secret that is then used to authenticate each
message sent from a Finder to the SDSP sent during that period.
4. HIP [RFC7401] can be used to establish a session secret that is
then used with ESP [RFC4303] to authenticate each message sent
from a Finder to the SDSP.
5. DTLS [RFC5238] can be used to establish a secure connection that
is then used to authenticate each message sent from a Finder to
the SDSP.
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4.1. SDSP Heartbeats
If a 1-way messaging approach is used (e.g. not TCP-based), the SDSP
SHOULD send a heartbeat at some periodicity to the Finders so that
they get confirmation that there is a receiver of their
transmissions.
A simple (see Section 6.6) message that identifies the SDSP is sent
to the Finder per some published policy of the SDSP. For example, at
the first reception by the SDSP for the day, then the 1st for the
hour. It is NOT recommended for the SDSP to send a heartbeat for
every message received, as this is a potential DOS attack against the
SDSP.
4.2. The Finder Map
The Finders are regularly providing their SDSP with their location.
This is through the B-RID Proxy Messages and Finder Location Update
Messages. With this information, the SDSP can maintain a monitoring
map. That is a map of where there Finder coverage.
4.3. Managing Finders
Finder density will vary over time and space. For example, sidewalks
outside an urban train station can be packed with pedestrians at rush
hour, either coming or going to their commute trains. An SDSP may
want to proactively limit the number of active Finders in such
situations.
Using the Finder mapping feature, the SDSP can instruct Finders to
NOT proxy B-RID messages. These Finders will continue to report
their location and through that reporting, the SDSP can instruct them
to again take on the proxying role. For example a Finder moving
slowly along with dozens of other slow-moving Finders may be
instructed to suspend proxying. Whereas a fast-moving Finder at the
same location (perhaps a connected car or a pedestrian on a bus)
would not be asked to suspend proxying as it will soon be out of the
congested area.
5. UA location via multilateration
The SDSP can confirm/correct the UA location provided in the
Location/Vector message by using multilateration on data provided by
at least 3 Finders that reported a specific Location/Vector message
(Note that 4 Finders are needed to get altitude sign correctly). In
fact, the SDSP can calculate the UA location from 3 observations of
any B-RID message. This is of particular value if the UA is only
within reception range of the Finders for messages other than the
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Location/Vector message.
This feature is of particular value when the Finders are fixed assets
with highly reliable GPS location, around a high value site like an
airport or large public venue.
5.1. GPS Inaccuracy
Single-band, consumer grade, GPS on small platforms is not accurate,
particularly for altitude. Longitude/latitude measurements can
easily be off by 3M based on satellite postion and clock accuracy.
Altitude accuracy is reported in product spec sheets and actual tests
to be 3x less accurate. Altitude accuracy is hindered by ionosphere
activity. In fact, there are studies of ionospheric events (e.g.
2015 St. Patrick's day [gps-ionosphere]) as measured by GPS devices
at known locations. Thus where a UA reports it is rarely accurate,
but may be accurate enough to map to visual sightings of single UA.
Smartphones and particulary smartwatches are plagued with the same
challenge, though some of these can combine other information like
cell tower data to improve location accuracy. FCC E911 accuracy, by
FCC rules is NOT available to non-E911 applications due to privacy
concerns, but general higher accuracy is found on some smart devices
than reported for consumer UA. The SDSP MAY have information on the
Finder location accuracy that it can use in calculating the accuracy
of a multilaterated location value. When the Finders are fixed
assets, the SDSP may have very high trust in their location for
trusting the multilateration calculation over the UA reported
location.
6. The CS-RID Messages
The CS-RID messages between the Finders and the SDSPs primarily
support the proxy role of the Finders in forwarding the B-RID
messages. There are also Finder registration and status messages.
CS-RID information is represented in CBOR [RFC7049]. COSE [RFC8152]
MAY be used for CS-RID MAC and COAP [RFC7252] for the CS-RID
protocol. The CDDL [RFC8610] specification is used for CS-RID
message description.
The following is a general representation of the content in the CS-
RID messages.
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(
CS-RID MESSAGE TYPE,
CS-RID MESSAGE CONTENT,
CS-RID MAC
)
The CS-RID MESSAGE CONTENT varies by MESSAGE TYPE.
6.1. CS-RID MESSAGE TYPE
The CS-RID MESSAGE TYPE is defined in Figure 1:
Number CS-RID Message Type
------ -----------------
0 Reserved
1 B-RID Forwarding
2 Finder Registration
3 SDSP Response
4 Finder Location
5 SDSP Heartbeat
Figure 1
6.1.1. CDDL description for CS-RID message type
The overall CS-RID CDDL description is structured in Figure 2.
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CSRID_Object = {
application-context,
info => info_message,
proxy_message => broadcast_rid_proxy_message,
finder_registration => finder_registration_message,
sdsp_response => sdsp_response_message,
location_update => location_update_message,
sdsp_heartbeat => sdsp_heartbeat_message,
}
info_message = {
common_message_members,
message_content => tstr,
}
common_message_members = (
message_type => message_types,
mac_address => #6.37(bstr),
)
message_types = &(
Reserved : 0,
BRD : 1,
Finder-Registration : 2,
SDSP-Response : 3,
Finder-Location : 4,
)
Figure 2
The application context rule is defined in Figure 3 for CS-RID
application identification and version negotiation.
application-context = (
application => "DRIP-CSRID",
? version => uint .size(1..2),
)
Figure 3
The predefined CDDL text string labels (author note: for JSON
currently, will move to CBOR uint keys in upcoming versions) used in
the specification is listed in Figure 4.
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application = "application"
version = "version"
info = "message_info"
proxy_message = "proxy_message-type"
finder_registration = "finder_registration"
sdsp_response = "sdsp_response"
location_update = "location_update"
sdsp_heartbeat = "sdsp_heartbeat"
rid = "id"
message_type = "message_type"
mac_address = "mac_address"
message_content = "message_content"
timestamp = "timestamp"
gps = "gps"
radio_type = "radio_type"
broadcast_mac_address = "broadcast_mac_address"
broadcast_message = "broadcast_message"
sdsp_id = "sdsp_id"
proxy_status_type = "proxy_status_type"
update_interval = "update_interval"
Figure 4
6.2. The CS-RID B-RID Proxy Message
The Finders add their own information to the B-RID messages,
permitting the SDSP(s) to gain additional knowledge about the UA(s).
The RID information is the B-RID message content plus the MAC
address. The MAC address is critical, as it is the only field that
links a UA's B-RID messages together. Only the ASTM Basic ID Message
and possibly the Authentication Message contain the UAS ID field.
The Finders add an SDSP assigned ID, a 64 bit timestamp, GPS
information, and type of B-RID media to the B-RID message. Both the
timestamp and GPS information are for when the B-RID message(s) were
received, not forwarded to the SDSP. All this content is MACed using
a key shared between the Finder and SDSP.
The following is a representation of the content in the CS-RID
messages.
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(
CS-RID MESSAGE TYPE,
CS-RID ID,
RECEIVE TIMESTAMP,
RECEIVE GPS,
RECEIVE RADIO TYPE,
B-RID MAC ADDRESS,
B-RID MESSAGE,
CS-RID MAC
)
6.2.1. CS-RID ID
The CS-RID ID is the ID recognized by the SDSP. This may be an HHIT
[RFC9374], or any ID used by the SDSP.
6.2.2. CDDL description for CS-RID B-RID Proxy Message
The broadcast CS-RID proxy CDDL is defined in Figure 5
broadcast_rid_proxy_message = {
common_message_members,
rid => tstr,
timestamp => tdate,
gps => gps-coordinates,
radio_type => radio_types,
broadcast_mac_address => #6.37(bstr),
broadcast_message => #6.37(bstr),
}
radio_types = &(
EFL : 0,
VLF : 1,
LF : 2,
MF : 3,
HF : 4,
HF : 5,
VHF : 6,
UHF : 7,
SHF : 8,
EHF : 9,
)
gps-coordinates = [
latitude : float,
longitude: float,
altitude : float,
]
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Figure 5
6.3. CS-RID Finder Registration
The CS-RID Finder MAY use [RFC7401] with the SDSP to establish a
Security Association and a shared secret to use for the CS-RID MAC
generation. In this approach, the HIP mobility functionality and
[RFC4303] support are not used.
When HIP is used as above, the Finder Registration is a SDSP "wake
up". It is sent prior to the Finder sending any proxied B-RID
messages to ensure that the SDSP is able to receive and process the
messages.
In this usage, the CS-RID ID is the Finder HIT. If the SDSP has lost
state with the Finder, it initiates the HIP exchange with the Finder
to reestablish HIP state and a new shared secret for the CS-RID B-RID
Proxy Messages. In this case the Finder Registration Message is:
(
CS-RID MESSAGE TYPE,
CS-RID ID,
CS-RID TIMESTAMP,
CS-RID GPS,
CS-RID MAC
)
6.3.1. CDDL description for Finder Registration
The CDDL for CS-RID Finder Registration is defined in Figure 6
finder_registration_message = {
common_message_members,
rid => tstr,
timestamp => tdate,
gps => gps-coordinates,
}
gps-coordinates = [
latitude : float,
longitude: float,
altitude : float,
]
Figure 6
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6.4. CS-RID SDSP Response
The SDSP MAY respond to any Finder messages to instruct the Finder on
its behavior.
(
CS-RID MESSAGE TYPE,
SDSP ID,
CS-RID ID,
CS-RID PROXY STATUS,
CS-RID UPDATE INTERVAL,
CS-RID MAC
)
The Proxy Status instructs the Finder if it should actively proxy
B-RID messages, or suspend proxying and only report its location.
The Update Interval is the frequency that the Finder SHOULD notify
the SDSP of its current location using the Location Update message.
6.4.1. CDDL description for SDSP Response
The CDDL for CS-RID SDSP response is defined in Figure 7
sdsp_response_message = {
common_message_members,
sdsp_id => tstr,
rid => tstr,
proxy_status_type => proxy_status_types,
update_interval => uint,
}
gps-coordinates = [
latitude : float,
longitude: float,
altitude : float,
]
proxy_status_types = &(
0: "forward",
1: "reverse",
2: "bi-directional",
)
Figure 7
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6.5. CS-RID Location Update
The Finder SHOULD provide regular location updates to the SDSP. The
interval is based on the Update Interval from Section 6.4 plus a
random slew less than 1 second. The Location Update message is only
sent when no other CS-RID messages, containing the Finder's GPS
location, have been sent since the Update Interval.
If the Finder has not recieved a SDSP Registration Response, a
default of 5 minutes is used for the Update Interval.
(
CS-RID MESSAGE TYPE,
CS-RID ID,
CS-RID TIMESTAMP,
CS-RID GPS,
CS-RID MAC
)
6.5.1. CDDL description for Location Update
The CDDL for CS-RID Location update is defined in Figure 8.
location_update_message = {
common_message_members,
rid => tstr,
timestamp => tdate,
gps => gps-coordinates,
}
gps-coordinates = [
latitude : float,
longitude: float,
altitude : float,
]
Figure 8
6.6. SDSP Heartbeat
The SDSP SHOULD send a heartbeat message at some periodicity to the
Finders so that they get confirmation that their is a receiver of
their transmissions.
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(
CS-RID MESSAGE TYPE,
SDSP ID,
CS-RID TIMESTAMP,
)
6.6.1. CDDL description for SDSP Heartbeat
The CDDL for CS-RID Heartbeat is defined in Figure 9.
sdsp_heartbeat_messagege = {
common_message_members,
sdsp_id => tstr,
timestamp => tdate,
}
Figure 9
7. The Full CS-RID CDDL specification
<CODE BEGINS>
; CDDL specification for Crowd source RID
; It specifies a collection of CS message types
;
;
; The CSRID overall data structure
CSRID_Object = {
application-context,
info => info_message,
proxy_message => broadcast_rid_proxy_message,
finder_registration => finder_registration_message,
sdsp_response => sdsp_response_message,
location_update => location_update_message,
}
;
; Application context: general information about CSRID message
application-context = (
application => "DRIP-CSRID", ; TBD: consider CBOR tag
? version => uint .size(1..2),
)
; These members are include in every message
common_message_members = (
message_type => message_types,
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mac_address => #6.37(bstr),
)
;
; CSRID message general information
info_message = {
common_message_members,
message_content => tstr,
}
broadcast_rid_proxy_message = {
common_message_members,
rid => tstr,
timestamp => tdate,
gps => gps-coordinates,
radio_type => radio_types,
broadcast_mac_address => #6.37(bstr)
broadcast_message => #6.37(bstr)
}
finder_registration_message = {
common_message_members,
rid => tstr,
timestamp => tdate,
gps => gps-coordinates,
}
sdsp_response_message = {
common_message_members,
sdsp_id => tstr,
rid => tstr,
proxy_status_type => proxy_status_types,
update_interval => uint,
}
location_update_message = {
common_message_members,
rid => tstr,
timestamp => tdate,
gps => gps-coordinates,
}
;
; Common rule definition
message_types = &(
Reserved : 0,
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BRD : 1,
Finder-Registration : 2,
SDSP-Response : 3,
Finder-Location : 4,
)
gps-coordinates = [
lat: float,
long: float,
alt : float,
]
; Radio types, choose from one of radio_types (required)
radio_types = &(
EFL : 0,
VLF : 1,
LF : 2,
MF : 3,
HF : 4,
HF : 5,
VHF : 6,
UHF : 7,
SHF : 8,
EHF : 9,
)
proxy_status_types = &(
0: "forward",
1: "reverse",
2: "bi",
)
;
; JSON label names
application = "application"
version = "version"
info = "message_info"
proxy_message = "proxy_message-type"
finder_registration = "finder_registration"
sdsp_response = "sdsp_response"
location_update = "location_update"
rid = "id"
message_type = "message_type"
mac_address = "mac_address"
message_content = "message_content"
timestamp = "timestamp"
gps = "gps"
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radio_type = "radio_type"
broadcast_mac_address = "broadcast_mac_address"
broadcast_message = "broadcast_message"
sdsp_id = "sdsp_id"
proxy_status_type = "proxy_status_type"
update_interval = "update_interval"
<CODE ENDS>
8. IANA Considerations
TBD
9. Security Considerations
TBD
9.1. Privacy Concerns
TBD
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8152] Schaad, J., "CBOR Object Signing and Encryption (COSE)",
RFC 8152, DOI 10.17487/RFC8152, July 2017,
<https://www.rfc-editor.org/info/rfc8152>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8610] Birkholz, H., Vigano, C., and C. Bormann, "Concise Data
Definition Language (CDDL): A Notational Convention to
Express Concise Binary Object Representation (CBOR) and
JSON Data Structures", RFC 8610, DOI 10.17487/RFC8610,
June 2019, <https://www.rfc-editor.org/info/rfc8610>.
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[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>.
10.2. Informative References
[drip-authentication]
Wiethuechter, A., Card, S. W., and R. Moskowitz, "DRIP
Entity Tag Authentication Formats & Protocols for
Broadcast Remote ID", Work in Progress, Internet-Draft,
draft-ietf-drip-auth-49, 21 February 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-drip-
auth-49>.
[drip-registries]
Wiethuechter, A. and J. Reid, "DRIP Entity Tag (DET)
Identity Management Architecture", Work in Progress,
Internet-Draft, draft-ietf-drip-registries-15, 1 April
2024, <https://datatracker.ietf.org/doc/html/draft-ietf-
drip-registries-15>.
[F3411-22a]
ASTM International, "Standard Specification for Remote ID
and Tracking", July 2022,
<https://www.astm.org/f3411-22a.html>.
[F3623-23] ASTM International, "Standard Specification for
Surveillance Supplementary Data Service Providers",
December 2023, <https://www.astm.org/f3623-23.html>.
[FAA-FR] United States Federal Aviation Administration (FAA), "FAA
Remote Identification of Unmanned Aircraft", January 2021,
<https://www.govinfo.gov/content/pkg/FR-2021-01-15/
pdf/2020-28948.pdf>.
[gps-ionosphere]
"Ionospheric response to the 2015 St. Patrick's Day storm
A global multi-instrumental overview", September 2015,
<https://doi.org/10.1002/2015JA021629>.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, DOI 10.17487/RFC4303, December 2005,
<https://www.rfc-editor.org/info/rfc4303>.
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[RFC5238] Phelan, T., "Datagram Transport Layer Security (DTLS) over
the Datagram Congestion Control Protocol (DCCP)",
RFC 5238, DOI 10.17487/RFC5238, May 2008,
<https://www.rfc-editor.org/info/rfc5238>.
[RFC7049] Bormann, C. and P. Hoffman, "Concise Binary Object
Representation (CBOR)", RFC 7049, DOI 10.17487/RFC7049,
October 2013, <https://www.rfc-editor.org/info/rfc7049>.
[RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
Application Protocol (CoAP)", RFC 7252,
DOI 10.17487/RFC7252, June 2014,
<https://www.rfc-editor.org/info/rfc7252>.
[RFC7401] Moskowitz, R., Ed., Heer, T., Jokela, P., and T.
Henderson, "Host Identity Protocol Version 2 (HIPv2)",
RFC 7401, DOI 10.17487/RFC7401, April 2015,
<https://www.rfc-editor.org/info/rfc7401>.
[RFC7748] Langley, A., Hamburg, M., and S. Turner, "Elliptic Curves
for Security", RFC 7748, DOI 10.17487/RFC7748, January
2016, <https://www.rfc-editor.org/info/rfc7748>.
[RFC8032] Josefsson, S. and I. Liusvaara, "Edwards-Curve Digital
Signature Algorithm (EdDSA)", RFC 8032,
DOI 10.17487/RFC8032, January 2017,
<https://www.rfc-editor.org/info/rfc8032>.
[RFC9374] Moskowitz, R., Card, S., Wiethuechter, A., and A. Gurtov,
"DRIP Entity Tag (DET) for Unmanned Aircraft System Remote
ID (UAS RID)", RFC 9374, DOI 10.17487/RFC9374, March 2023,
<https://www.rfc-editor.org/info/rfc9374>.
[RFC9434] Card, S., Wiethuechter, A., Moskowitz, R., Zhao, S., Ed.,
and A. Gurtov, "Drone Remote Identification Protocol
(DRIP) Architecture", RFC 9434, DOI 10.17487/RFC9434, July
2023, <https://www.rfc-editor.org/info/rfc9434>.
Appendix A. Using LIDAR for UA location
If the Finder has LIDAR or similar detection equipment (e.g. on a
connected car) that has full sky coverage, the Finder can use this
equipment to locate UAs in its airspace. The Finder would then be
able to detect non-participating UAs. A non-participating UA is one
that the Finder can "see" with the LIDAR, but not "hear" any B-RID
messages.
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These Finders would then take the LIDAR data, construct appropriate
B-RID messages, and forward them to the SPDP as any real B-RID
messages.
The MAC address for this messages SHOULD be a locally administered,
random address. The Finder should make all effort to use the same
address for a UA detected in this manner.
The UAS ID SHOULD be a UUIDv4 (Type=3). The Finder should make all
effort to use the same UUID for a UA detected in this manner.
The SDSP would do the work of linking information on a non-
participating UA that it has received from multiple Finders with
LIDAR detection. In doing so, it would have to select a RemoteID to
use.
A seemingly non-participating UA may actually be a UA that is beyond
range for its B-RID but in the LIDAR range.
This would provide valuable information to SDSPs to forward to UTMs
on potential at-risk situations.
At this time, research on LIDAR and other detection technology is
needed. there are full-sky LIDAR for automotive use with ranges
varying from 20M to 250M. Would more than UA location information be
available? What information can be sent in a CS-RID message for such
"unmarked" UAs?
Acknowledgments
The Crowd Sourcing idea in this document came from the Apple "Find My
Device" presentation at the International Association for
Cryptographic Research's Real World Crypto 2020 conference.
Authors' Addresses
Robert Moskowitz
HTT Consulting
Oak Park, MI 48237
United States of America
Email: rgm@labs.htt-consult.com
Stuart W. Card
AX Enterprize
4947 Commercial Drive
Yorkville, NY 13495
United States of America
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Email: stu.card@axenterprize.com
Adam Wiethuechter
AX Enterprize
4947 Commercial Drive
Yorkville, NY 13495
United States of America
Email: adam.wiethuechter@axenterprize.com
Shuai Zhao
Intel
2200 Mission College Blvd
Santa Clara, CA 95054
United States of America
Email: shuai.zhao@ieee.org
Henk Birkholz
Fraunhofer SIT
Rheinstrasse 75
64295 Darmstadt
Germany
Email: henk.birkholz@sit.fraunhofer.de
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