Internet DRAFT - draft-gellens-ecrit-car-crash
draft-gellens-ecrit-car-crash
ECRIT R. Gellens
Internet-Draft Qualcomm Technologies, Inc
Intended status: Informational B. Rosen
Expires: August 17, 2014 NeuStar, Inc.
H. Tschofenig
(no affiliation)
February 13, 2014
Internet Protocol-based In-Vehicle Emergency Calls
draft-gellens-ecrit-car-crash-02.txt
Abstract
This document describes how to use IP-based emergency services
mechanisms to support the next generation of emergency calls placed
by vehicles (automatically in the event of a crash or serious
incident, or manually invoked by a vehicle occupant) and conveying
vehicle, sensor, and location data related to the crash or incident.
Such calls are often referred to as "Automatic Crash Notification"
(ACN), or "Advanced Automatic Crash Notification" (AACN), even in the
case of manual trigger. The "Advanced" qualifier refers to the
ability to carry a richer set of data.
This document also registers a MIME Content Type and an Emergency
Call Additional Data Block for the vehicle, sensor, and location data
(often referred to as "crash data" even though there is not
necessarily a crash).
Profiling and simplifications are possible due to the nature of the
functionality that is provided in vehicles with the usage of Global
Satellite Navigation System (GNSS).
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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material or to cite them other than as "work in progress."
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This Internet-Draft will expire on August 17, 2014.
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Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Overview of Current Deployment Models . . . . . . . . . . . . 6
4. Document Scope . . . . . . . . . . . . . . . . . . . . . . . 8
5. Migration to Next-Generation . . . . . . . . . . . . . . . . 8
6. Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Call Setup . . . . . . . . . . . . . . . . . . . . . . . . . 10
8. Call Routing . . . . . . . . . . . . . . . . . . . . . . . . 13
9. Test Calls . . . . . . . . . . . . . . . . . . . . . . . . . 14
10. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
11. Security Considerations . . . . . . . . . . . . . . . . . . . 16
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
12.1. Service URN Registration . . . . . . . . . . . . . . . . 16
12.2. MIME Content-type Registration for
'application/EmergencyCall.VEDS+xml' . . . . . . . . . . 17
12.3. Registration of the 'VEDS' entry in the Emergency Call
Additional Data registry . . . . . . . . . . . . . . . . 18
13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 18
14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18
15. Changes from Previous Versions . . . . . . . . . . . . . . . 18
15.1. Changes from -01 to -02 . . . . . . . . . . . . . . . . 18
15.2. Changes from -00 to -01 . . . . . . . . . . . . . . . . 18
16. References . . . . . . . . . . . . . . . . . . . . . . . . . 19
16.1. Normative References . . . . . . . . . . . . . . . . . . 19
16.2. Informative references . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
1. Terminology
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The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
This document re-uses terminology defined in Section 3 of [RFC5012].
Additionally, we use the following abbreviations:
3GPP: 3rd Generation Partnership Project
AACN: Advanced Automatic Crash Notification
ACN: Automatic Crash Notification
APCO: Association of Public-Safety Communications Officials
EENA: European Emergency Number Association
ESInet: Emergency Services IP network
GNSS: Global Satellite Navigation System (which includes the various
such systems including the Global Positioning System or GPS)
IVS: In-Vehicle System
MNO: Mobile Network Operator
NENA: National Emergency Number Association
TSP: Telematics Service Provider
VEDS: Vehicle Emergency Data Set
2. Introduction
Emergency calls made by in-vehicle systems (e.g., in the event of a
crash) assist in significantly reducing road deaths and injuries by
allowing emergency services to respond quickly and often with better
location.
Drivers often have a poor location awareness, especially outside of
major cities, at night and when away from home (especially abroad).
In the most crucial cases, the victim(s) may not be able to call
because they have been injured or trapped.
For more than a decade, some vehicles have been equipped with
telematics systems that, among other features, place an emergency
call automatically in the event of a crash or manually in response to
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an emergency call button. Such systems generally have on-board
location determination systems that make use of satellite-based
positioning technology, inertial sensors, gyroscopes, etc., to
provide a fairly accurate position for the vehicle. Such built-in
systems can take advantage of the benefits of being integrated into a
vehicle, such as more reliable power, ability to have larger or
specialized antenna, ability to be engineered to avoid or minimise
degradation by vehicle glass coatings, interference from other
vehicle systems, etc. Thus, the PSAP can be provided with a good
estimate of where the vehicle is during an emergency. Vehicle
manufacturers are increasingly adopting such systems, both for the
safety benefits and for the additional features and services they
enable (e.g., remote engine diagnostics, remote door unlock, stolen
vehicle tracking and disabling, etc.).
The general term for such systems is Automatic Crash Notification
(ACN) or "Advanced Automatic Crash Notification" (AACN). "ACN" is
used in this document as a general term. ACN systems transmit some
amount of data specific to the incident, referred to generally as
"crash data." While different systems transmit different amounts of
crash data, standardized formats, structures, and mechanisms are
needed to provide interoperability among systems and PSAPs.
Currently deployed in-vehicle telematics systems are circuit-switched
and lack a standards-based ability to convey crash data directly to
the PSAP (generally relying on either a human call taker or an
automated system to provide the PSAP call taker with some crash data
orally, or possibly a proprietary mechanism) and are difficult to
extend as new sensors are added.
The transition to next-generation calling in general, and emergency
calling in particular, provides an opportunity to vastly improve the
scope, breadth, reliability and usefulness of crash data during an
emergency by allowing it to be presented alongside the call, and to
be automatically processed by the PSAP and made available to the call
taker in an integrated, automated way. In addition, vehicle
manufacturers are provided an opportunity to take advantage of the
same standardized mechanisms for data transmission for internal use
if they wish (such as telemetry between the vehicle and a service
center for both emergency and non-emergency uses, including location-
based services, multi-media entertainment systems, and road-side
assistance applications).
Next-generation ACN provides an opportunity for such calls to be
recognized and processed as such during call set-up, and routed to a
specialized PSAP where the vehicle data is available to assist the
call taker in assessing and responding to the situation.
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An ACN call may be either occupant-initiated or automatically
triggered. (The "A" in "ACN" does stand for "Automatic," but the
term is often used to refer to the class of calls that are placed by
an in-vehicle system (IVS) and that carry incident-related data as
well as voice.) Automatically triggered calls indicate a car crash
or some other serious incident (e.g., a fire) and carry a greater
presumption of risk of injury. Manually triggered calls are often
reports of serious hazards (such as drunk drivers) and may require
different responses depending on the situation. Manually triggered
calls are also more likely to be false (e.g., accidental) calls and
may thus be subject to different handling by the PSAP.
This document describes how the IETF mechanisms for IP-based
emergency calls, including [RFC6443] and [additional-data-draft], are
used to provide the realization of next-generation ACN.
The Association of Public-Safety Communications Officials (APCO) and
the National Emergency Number Association (NENA) have jointly
developed a standardized set of incident-related vehicle data for ACN
use, called the Vehicle Emergency Data Set (VEDS) [VEDS]. Such data
is often referred to as crash data although it is applicable in
incidents other than crashes.
VEDS provides a standard data set for the transmission, exchange, and
interpretation of vehicle-related data. A standard data format
allows the data to be generated by an IVS, and interpreted by PSAPs,
emergency responders, and medical facilities (including those capable
of providing trauma level patient care). It includes incident-
related information such as airbag deployment, location of the
vehicle, if the vehicle was involved in a rollover, various sensor
data that can indicate the potential severity of the crash and the
likelihood of severe injuries to the vehicle occupants, etc. This
data better informs the PSAP and emergency responders as to the type
of response that may be needed. This information was recently
included in the federal guidelines for field triage of injured
patients. These guidelines are designed to help responders at the
accident scene identify the potential existence of severe internal
injuries and to make critical decisions about how and where a patient
needs to be transported.
This document registers the 'application/EmergencyCallData.VEDS+xml'
MIME content-type, and registers the 'VEDS' entry in the Emergency
Call Additional Data registry.
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VEDS is an XML structure (see [VEDS]). The 'application/
EmergencyCallData.VEDS+xml' MIME content-type is used to identify it.
The 'VEDS' entry in the Emergency Call Additional Data registry is
used to construct a 'purpose' parameter value for conveying VEDS data
in a Call-Info header (as described in [additional-data-draft]).
VEDS is a versatile structure that can accomodate varied needs.
However, if additional sets of data are determined to be needed, the
steps to enable each data block are very briefly summarized below:
o A standardized format and encoding (such as XML) is defined and
published by a Standards Development Organization (SDO).
o A MIME Content-Type is registered for it (typically under the
'Application' media type and with a sub-type starting with
'EmergencyCallData.').
o An entry for the block is added to the Emergency Call Additional
Data Blocks sub-registry (established by [additional-data-draft]);
the registry entry is the root of the MIME sub-type (not including
the 'EmergencyCallData' prefix and any suffix such as '+xml').
A next-generation In-Vehicle System (IVS) transmits crash data by
encoding it in a standardized and registered format (such as VEDS)
and attaching it to an INVITE as a MIME body part. The body part is
identified by its MIME content-type (such as 'application/
EmergencyCallData.VEDS+xml') in the Content-Type header field of the
body part. The body part is assigned a unique identifier which is
listed in a Content-ID header field in the body part. The INVITE is
marked as containing the crash data by adding (or appending to) a
Call-Info header field at the top level of the INVITE. The Call-Info
header field contains a CID URL referencing the body part's unique
identifier, and a 'purpose' parameter identifying the data as the
crash data per the registry entry; the 'purpose' parameter's value is
'EmergencyCallData.' and the root of the MIME type (not including the
'EmergencyCallData' prefix and any suffix such as '+xml' (e.g.,
'purpose=EmergencyCallData.VEDS').
The mechanisms described here can be used place emergency calls that
are identifiable as ACN calls and that carry one or more standardized
crash data objects in an interoperable way.
Note that while ACN systems in the U.S. and other regions are not
currently mandated, Europe has a mandated and standardized system for
emergency calls by in-vehicle systems. This pan-European system is
known as "eCall" and is not further discussed in this document but is
the subject of a separate document, [eCall-draft]
3. Overview of Current Deployment Models
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Current (circuit-switched or legacy) systems for placing emergency
calls by in-vehicle systems, including automatic crash notification
systems, generally have a limited ability to convey at least location
and in some cases telematics data to the PSAP. Most such systems use
one of three architectural models, which are described here as:
"Telematics Service Provider" (TSP), "direct", and "paired handset".
These three models are illustrated below.
In the TSP model, both emergency and non-emergency calls are placed
to a Telematics Service Provider (TSP); a proprietary technique is
used for data transfer (such as proprietary in-band modems) to the
TSP.
In an emergency, the TSP call taker bridges in the PSAP and
communicates location, crash data (such as impact severity and trauma
prediction), and other data (such as the vehicle description) to the
PSAP call taker verbally. Typically, a three-way voice call is
established between the vehicle, the TSP, and the PSAP, allowing
communication between the PSAP call taker, the TSP call taker, and
the vehicle occupants (who might be unconscious).
///----\\\ proprietary +------+ 911 trunk +------+
||| IVS |||-------------->+ TSP +------------------>+ PSAP |
\\\----/// crash data +------+ +------+
Figure 1: Legacy TSP Model.
In the paired model, the IVS uses a Bluetooth link with a previously-
paired handset to establish an emergency call with the PSAP (by
dialing a standard emergency number such as 9-1-1), and then
communicates location data to the PSAP via text-to-speech; crash data
is not conveyed. Some such systems use an automated voice prompt
menu (e.g., "this is an automatic emergency call from a vehicle;
press 1 to open a voice path to the vehicle; press 2 to hear the
location read out") to allow the call taker to request location data
via text-to-speech.
+---+
///----\\\ | H | 911/etc voice call via handset +------+
||| IVS |||-->| S +----------------------------------->+ PSAP |
\\\----/// +---+ location via text-to-speech +------+
Figure 2: Legacy Paired Model
In the direct model, the IVS directly places an emergency call with
the PSAP by dialing a standard emergency number such as 9-1-1. Such
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systems might communicate location data to the PSAP via text-to-
speech; crash data might not be conveyed.
///----\\\ 911/etc voice call via IVS +------+
||| IVS |||---------------------------------------->+ PSAP |
\\\----/// location via text-to-speech +------+
Figure 3: Legacy Direct Model
4. Document Scope
This document is focused on the interface to the PSAP, that is, how
an ACN emergency call is setup and incident-related data (including
vehicle, sensor, and location data) is transmitted to the PSAP using
IETF specifications. (The goal is to re-use specifications rather
than to invent new.) For the direct model, this is the end-to-end
description (between the vehicle and the PSAP). For the TSP model,
this describes the right-hand side (between the TSP and the PSAP),
leaving the left-hand side (between the vehicle and the TSP) up to
the entities involved (i.e., IVS and TSP vendors) who are then free
to use the same mechanism as for the right-hand side (or not).
This document does not address pan-European eCall (a mandated and
standardized system for emergency calls by in-vehicle systems within
Europe and other regions), which is the subject of a separate
document, [eCall-draft]
5. Migration to Next-Generation
Migration of emergency calls placed by in-vehicle systems to next-
generation (all-IP) technology provides a standardized mechanism to
identify such calls and to present crash data with the call. This
allows ACN calls and crash data to be automatically processed by the
PSAP and made available to the call taker in an integrated, automated
way.
Vehicle manufacturers using the TSP model may choose to take
advantage of the same mechanism to carry telematics data between the
vehicle and the TSP for both emergency and non-emergency calls.
A next-generation IVS establishes an emergency call using the 3GPP
IMS solution with a Request-URI indicating an ACN type of emergency
call with vehicle data attached; the MNO only needs to recognize the
call as an emergency call and route it to an ESInet; the ESInet
recognizes the call as an ACN with vehicle data and routes the call
to an NG-ACN capable PSAP; the PSAP interpets the vehicle data sent
with the call and makes it available to the call taker.
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Because of the need to identify and specially process Next-Generation
ACN calls (as discussed above), this document registers new service
URN children within the "sos" subservice. These URNs provide the
mechanism by which an NG-ACN call is identified, and differentiate
between manually and automatically triggered NG-ACN calls (which may
be subject to different treatment, depending on policy). The two
service URNs are: 'urn:service:sos.vehicle.automatic' and
'urn:service:sos.vehicle.manual'.
Migration of the three architectural models to next-generation (all-
IP) is described below.
In the TSP model, the IVS transmits crash and location data to the
TSP using either a protocol that is based on a proprietary design or
one that re-uses IETF specifications. In an emergency, the TSP call
taker bridges in the PSAP and the TSP transmits crash and other data
to the PSAP using IETF specifications. There is a three-way call
between the vehicle, the TSP, and the PSAP, allowing communication
between the PSAP call taker, the TSP call taker, and the vehicle
occupants (who might be unconscious).
proprietary
///----\\\ or standard +------+ standard +------+
||| IVS ||| ------------------->+ TSP +------------------->+ PSAP |
\\\----/// crash + other data +------+ crash + other data +------+
Figure 4: Next-Generation TSP Model
The vehicle manufacturer and the TSP may choose to use the same IETF
specifications to transmit crash and location data from the vehicle
to the TSP as is described here to transmit such data from the TSP to
the PSAP.
In the paired model, the IVS uses a Bluetooth link to a previously-
paired handset to establish an emergency call with the PSAP; it is
not clear what facilities are or will be available for transmitting
crash data through the Bluetooth link.
+---+
///----\\\ (unclear) | H | (unclear) +------+
||| IVS |||------------------>| S +------------------->+ PSAP |
\\\----/// (unclear) +---+ (unclear) +------+
Figure 5: Next-Generation Paired Model
In the direct model, the IVS communicates crash data to the PSAP
directly using IETF specifications.
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///----\\\ NG1-1-2/NG9-1-1 call +------+
||| IVS |||----------------------------------------->+ PSAP |
\\\----/// crash data +------+
Figure 6: Next-Generation Model
6. Profile
In the context of emergncy calls placed by an in-vehicle system it is
assumed that the car is equipped with a built-in GNSS receiver. For
this reason only geodetic location information will be sent within an
emergency call. The following location shapes MUST be implemented:
2d and 3d Point (see Section 5.2.1 of [RFC5491]), Circle (see
Section 5.2.3 of [RFC5491]), and Ellipsoid (see Section 5.2.7 of
[RFC5491]). The coordinate reference systems (CRS) specified in
[RFC5491] are also mandatory for this document. The <direction>
element, as defined in [RFC5962] which indicates the direction of
travel of the vehicle, is important for dispatch and hence it MUST be
included in the PIDF-LO . The <heading> element specified in
[RFC5962] MUST be implemented and MAY be included.
Calls by in-vehicle systems are placed via cellular networks, which
may ignore location sent by an originating device in an emergency
call INVITE, instead attaching their own location (often determined
in cooperation with the originating device). The IVS MAY attach
location data to the call INVITE. Standardized crash data structures
often include location as determined by the IVS. A benefit of this
is that it allows the PSAP to see both the location as determined by
the cellular network (often in cooperation with the originating
device) and the location as determined by the IVS.
This specification also inherits the ability to utilize test call
functionality from Section 15 of [RFC6881].
7. Call Setup
It is important that ACN calls be easily identifiable as such at all
stages of call handling, and that automatic versis manual triggering
be known. ACN calls differ from general emergency calls in several
aspects, including the presence of standardized crash data, the fact
that the call is known to be placed by an in-vehicle system (which
has implications for PSAP operational processes), and, especially for
automatic calls, information that may indicate a likelihood of severe
injury and hence need for trauma services. Knowledge that a call is
an ACN and further that it was automatically or manually invoked
carries a range of implications about the call, the circumstances,
and the vehicle occupants. Calls by in-vehicle systems may be
considered a specific sub-class of general emergency calls and need
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to be handled by a PSAP with the technical and operational
capabilities to serve such calls. (This is especially so in
environments such as the U.S. where there are many PSAPs and where
individual PSAPs have a range of capabilities.) Technical
capabilities include the ability to recognize and process
standardized crash data. Operational capabilities include training
and processes for assessing severe injury likelihood and responding
appropriately (e.g., dispatching trauma-capable medical responders,
transporting victims to a trauma center, alerting the receiving
facility, etc.).
Because ACN calls differ in significant ways from general emergency
calls, and because such calls need to be handled by specialized PSAPs
(equipped technically to interpet and make use of crash data, and
operationally to handle emergency calls placed by in-vehicle
systems), this document proposes an SOS sub-service for ACN/car
crash, specifically, "SOS.vehicle". Using a sub-service makes it
readily obvious that the call is an ACN; a further child elements is
proposed to distinguish calls automatically placed due to a crash or
other serious incident (such as a fire) from those manually invoked
by a vehicle occupant (specifically, "SOS.vehicle.automatic" and
"SOS.vehicle.manual"). The distinction between automatic and manual
invocation is also significant; automatically triggered calls
indicate a car crash or some other serious incident (e.g., a fire)
and carry a greater presumption of risk of injury and hence need for
specific responders (such as trauma or fire). Manually triggered
calls are often reports of serious hazards (such as drunk drivers)
and may require different responses depending on the situation.
Manually triggered calls are also more likely to be false (e.g.,
accidental) calls and may thus be subject to different handling by
the PSAP.
A next-generation In-Vehicle System (IVS) transmits crash data by
encoding it in a standardized and registered format and attaching it
to an INVITE as an additional data block as specified in Section 4.1
of [additional-data-draft]. As described in that document, the block
is identified by its MIME content-type, and pointed to by a CID URL
in a Call-Info header with a 'purpose' parameter value corresponding
to the block.
Specifically, the steps required during standardization are:
o A set of crash data is standardized by an SDO or appropriate
organization
o A MIME Content-Type for the crash data set is registered with IANA
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* If the data is specifically for use in emergency calling, the
MIME type is normally under the 'application' type with a
subtype starting with 'EmergencyCallData.'
* If the data format is XML, then by convention the name has a
suffix of '+xml'
o The item is registered in the Emergency Call Additional Data
registry, as defined in Section 9.1.7 of [additional-data-draft]
* For emergency-call-specific formats, the registered name is the
root of the MIME Content-Type (not including the
'EmergencyCallData' prefix and any suffix such as '+xml') as
described in Section 4.1 of [additional-data-draft]
When placing an emergency call:
o The crash data set is created and encoded per its specification
o The crash data set is attached to the emergency call INVITE as
specified in Section 4.1 of [additional-data-draft], that is, as a
MIME body part identified by its MIME Content-Type in the body
part's Content-Type header field
o The body part is assigned a unique identifier label in a Content-
ID header field of the body part
o A Call-Info header field at the top level of the INVITE references
the crash data and identifies it by its MIME root (as registered
in the Emergency Call Additional Data registry)
* The crash data is referenced in the Call-Info header field by a
CID URL that contains the unique Content ID assigned to the
crash data body part
* The crash data is identified in the Call-Info header field by a
'purpose' parameter whose value is 'EmergencyCallData.'
concatenated with the specific crash data entry in the
Emergency Call Additional Data registry
* The Call-Info header field MAY be either solely to reference
the crash data (and hence have only the one URL) or may also
contain other URLs referencing other data
o Additional crash data sets MAY be included by following the same
steps
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The Vehicle Emergency Data Set (VEDS) is an XML structure defined by
the Association of Public-Safety Communications Officials (APCO) and
the National Emergency Number Association (NENA) [VEDS]. The
'application/EmergencyCallData.VEDS+xml' MIME content-type is used to
identify it. The 'VEDS' entry in the Emergency Call Additional Data
registry is used to construct a 'purpose' parameter value for
conveying VEDS data in a Call-Info header.
The VEDS data is attached as a body part with MIME content type
'application/EmergencyCallData.VEDS+xml' which is pointed at by a
Call-Info URL of type CID with a 'purpose' parameter of
'EmergencyCallData.VEDS'.
Entities along the path between the vehicle and the PSAP are able to
identify the call as an ACN call and handle it appropriately. The
PSAP is able to identify the crash data as well as any other
additional data attached to the INVITE by examining the Call-Info
header fields for 'purpose' parameters whose values start with
'EmergencyCallData.' The PSAP is able to access and the data it is
capable of handling and is interested in by checking the 'purpose'
parameter values.
8. Call Routing
An Emergency Services IP Network (ESInet) is a network operated by
emergency services authorities. It handles emergency call routing
and processing before delivery to a PSAP. In the NG9-1-1
architecture adopted by NENA as well as the NG1-1-2 architecture
adopted by EENA, each PSAP is connected to one or more ESInets. Each
originating network is also connected to one or more ESInets. The
ESInets maintain policy-based routing rules which control the routing
and processing of emergency calls. The centralization of such rules
within ESInets provides for a cleaner separation between the
responsibilities of the originating network and that of the emergency
services network, and provides greater flexibility and control over
processing of emergency calls by the emergency services authorities.
This makes it easier to react quickly to unusual situations that
require changes in how emergency calls are routed or handled (e.g., a
natural disaster closes a PSAP), as well as ease in making long-term
changes that affect such routing (e.g., cooperative agreements to
specially handle calls requiring translation or relay services).
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In an environment that uses ESInets, the originating network need
only detect that the service URN of an emergency call is or starts
with "sos", passing all types of emergency calls to an ESInet. The
ESInet is then responsible for routing such calls to an appropriate
PSAP. In an environment without an ESInet, the emergency services
authorities and the originating carriers would need to determine how
such calls are routed.
9. Test Calls
This specification also inherits the ability to utilize test call
functionality from Section 15 of [RFC6881].
A service URN starting with "test." indicates a request for an
automated test. For example,
"urn:service:test.sos.vehicle.automatic" indicates such a test
feature. This functionality is defined in [RFC6881].
10. Example
Figure 7 shows an emergency call placed by a vehicle whereby location
information and VEDS crash data are both attached to the SIP INVITE
message. The INVITE has a request URI containing the
'urn:service:sos.vehicle.automatic' service URN and is thus
recognized as an ACN type of emergency call, and is also recognized
as a type of emergency call because the request URI starts with
'urn:service:sos'. The mobile network operator (MNO) routes the call
to an Emergency services IP Network (ESInet), as for any emergency
call. The ESInet processes the call as an ACN and routes the call to
an appropriate ACN-capable PSAP (using location information and the
fact that that it is an ACN). (In deployments where there is no
ESInet, the MNO itself needs to route directly to an appropriate ACN-
capable PSAP.) The call is processed by the Emergency Services
Routing Proxy (ESRP), as the entry point to the ESInet. The ESRP
routes the call to an appropriate ACN-capable PSAP, where the call is
received by a call taker.
+-----------------------------------------+
| |
+------------+ | +-------+ |
| | | | PSAP2 | |
| | | +-------+ |
| Originating| | |
| Mobile | | +------+ +-------+ |
Vehicle-->| Network |--+->| ESRP |---->| PSAP1 |---> Call-Taker |
| | | +------+ +-------+ |
| | | |
+------------+ | +-------+ |
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| | PSAP3 | |
| +-------+ |
| |
| |
| |
| ESInet |
+-----------------------------------------+
Figure 7: Example of Vehicle-Placed Emergency Call Message Flow
The example, shown in Figure 8, illustrates a SIP emergency call
eCall INVITE that is being conveyed with location information (a
PIDF-LO) and crash data (as VEDS data).
INVITE urn:service:sos.vehicle.automatic SIP/2.0
To: urn:service:sos.ecall.automatic
From: <sip:+13145551111@example.com>;tag=9fxced76sl
Call-ID: 3848276298220188511@atlanta.example.com
Geolocation: <cid:target123@example.com>
Geolocation-Routing: no
Call-Info: cid:1234567890@atlanta.example.com;
purpose=EmergencyCallData.VEDS
Accept: application/sdp, application/pidf+xml
CSeq: 31862 INVITE
Content-Type: multipart/mixed; boundary=boundary1
Content-Length: ...
--boundary1
Content-Type: application/sdp
...Session Description Protocol (SDP) goes here
--boundary1
Content-Type: application/pidf+xml
Content-ID: <target123@atlanta.example.com>
<?xml version="1.0" encoding="UTF-8"?>
<presence
xmlns="urn:ietf:params:xml:ns:pidf"
xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model"
xmlns:gp="urn:ietf:params:xml:ns:pidf:geopriv10"
xmlns:dyn="urn:ietf:params:xml:ns:pidf:geopriv10:dynamic"
xmlns:gml="http://www.opengis.net/gml"
xmlns:gs="http://www.opengis.net/pidflo/1.0"
entity="sip:+13145551111@example.com">
<dm:device id="123">
<gp:geopriv>
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<gp:location-info>
<gml:Point srsName="urn:ogc:def:crs:EPSG::4326">
<gml:pos>-34.407 150.883</gml:pos>
</gml:Point>
<dyn:Dynamic>
<dyn:heading>278</dyn:heading>
<dyn:direction><dyn:direction>
</dyn:Dynamic>
</gp:location-info>
<gp:usage-rules/>
<method>gps</method>
</gp:geopriv>
<timestamp>2012-04-5T10:18:29Z</timestamp>
<dm:deviceID>1M8GDM9A_KP042788</dm:deviceID>
</dm:device>
</presence>
--boundary1
Content-Type: application/EmergencyCallData.VEDS+xml
Content-ID: 1234567890@atlanta.example.com
...eCall VEDS data object goes here
--boundary1--
Figure 8: SIP INVITE indicating an In-Vehicular Emergency Call
11. Security Considerations
This document does not raise security considerations beyond those
described in [RFC5069]. As with emergency service systems with end
host provided location information there is the possibility that that
location is incorrect, either intentially (in case of an a denial of
service attack against the emergency services infrastructure) or due
to a malfunctioning devices. The reader is referred to
[I-D.ietf-ecrit-trustworthy-location] for a discussion of some of
these vulnerabilities.
12. IANA Considerations
12.1. Service URN Registration
IANA is requested to register the URN 'urn:service:sos.vehicle' under
the sub-services 'sos' registry defined in Section 4.2 of [RFC5031].
This service identifier reaches a public safety answering point
(PSAP), which in turn dispatches aid appropriate to the emergency
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related to accidents of vehicles. The following two sub-services are
registered as well:
urn:service:sos.vehicle.manual
This service URN indicates that an emergency call carrying vehicle
sensor ("crash") data has been placed by an in-vehicle system
(IVS) based on the manual interaction of the driver or a
passenger.
urn:service:sos.vehicle.automatic
This service URN indicates that an emergency call carrying vehicle
sensor ("crash") data has been placed by an in-vehicle system
(IVS) triggered automatically, for example, due to a crash.
12.2. MIME Content-type Registration for 'application/
EmergencyCall.VEDS+xml'
This specification requests the registration of a new MIME type
according to the procedures of RFC 4288 [RFC4288] and guidelines in
RFC 3023 [RFC3023].
MIME media type name: application
MIME subtype name: EmergencyCallData.VEDS+xml
Mandatory parameters: none
Optional parameters: charset
Indicates the character encoding of enclosed XML.
Encoding considerations: Uses XML, which can employ 8-bit
characters, depending on the character encoding used. See
Section 3.2 of RFC 3023 [RFC3023].
Security considerations: This content type is designed to carry
vehicle crash data during an emergency call. This data may
contains personal information including vehicle VIN, location,
direction, etc. appropriate precautions need to be taken to limit
unauthorized access, inappropriate disclosure to third parties,
and eavesdropping of this information. Please refer to Section 7
and Section 8 of [additional-data-draft] for more information.
Interoperability considerations: None
Published specification: [VEDS]
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Applications which use this media type: Emergency Services
Additional information: None
Magic Number: None
File Extension: .xml
Macintosh file type code: 'TEXT'
Person and email address for further information: Hannes
Tschofenig, Hannes.Tschofenig@gmx.net
Intended usage: LIMITED USE
Author: This specification is a work item of the IETF ECRIT
working group, with mailing list address <ecrit@ietf.org>.
Change controller: The IESG <ietf@ietf.org>
12.3. Registration of the 'VEDS' entry in the Emergency Call Additional
Data registry
This specification requests IANA to add the 'VEDS' entry to the
Emergency Call Additional Data registry, with a reference to this
document. The Emergency Call Additional Data registry has been
established by [additional-data-draft].
13. Contributors
We would like to thank Ulrich Dietz for his help with earlier
versions of the original version of this document.
14. Acknowledgements
We would like to thank Michael Montag, Arnoud van Wijk, Ban Al-Bakri,
and Gunnar Hellstrom for their feedback.
15. Changes from Previous Versions
15.1. Changes from -01 to -02
o Fixed case of 'EmergencyCallData', in accordance with changes to
[additional-data-draft]
15.2. Changes from -00 to -01
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o Now using 'EmergencyCallData' for purpose parameter values and
MIME subtypes, in accordance with changes to
[additional-data-draft]
o Added reference to RFC 6443
o Fixed bug that caused Figure captions to not appear
16. References
16.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3023] Murata, M., St. Laurent, S., and D. Kohn, "XML Media
Types", RFC 3023, January 2001.
[RFC4119] Peterson, J., "A Presence-based GEOPRIV Location Object
Format", RFC 4119, December 2005.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", RFC 4288, December 2005.
[RFC5031] Schulzrinne, H., "A Uniform Resource Name (URN) for
Emergency and Other Well-Known Services", RFC 5031,
January 2008.
[RFC5491] Winterbottom, J., Thomson, M., and H. Tschofenig, "GEOPRIV
Presence Information Data Format Location Object (PIDF-LO)
Usage Clarification, Considerations, and Recommendations",
RFC 5491, March 2009.
[RFC5962] Schulzrinne, H., Singh, V., Tschofenig, H., and M.
Thomson, "Dynamic Extensions to the Presence Information
Data Format Location Object (PIDF-LO)", RFC 5962,
September 2010.
[RFC6442] Polk, J., Rosen, B., and J. Peterson, "Location Conveyance
for the Session Initiation Protocol", RFC 6442, December
2011.
[RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton,
"Framework for Emergency Calling Using Internet
Multimedia", RFC 6443, December 2011.
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[RFC6881] Rosen, B. and J. Polk, "Best Current Practice for
Communications Services in Support of Emergency Calling",
BCP 181, RFC 6881, March 2013.
[VEDS] , "Vehicular Emergency Data Set (VEDS) version 3", July
2012, <http://apcointl.org/resources/aacn-and-veds/
2012-07-25-19-24-06.html>.
[additional-data-draft]
Rosen, B., Tschofenig, H., Marshall, R., Gellens, R., and
J. Winterbottom, "Additional Data related to an Emergency
Call", draft-ietf-ecrit-additional-data-11 (work in
progress), July 2013.
16.2. Informative references
[I-D.ietf-ecrit-trustworthy-location]
Tschofenig, H., Schulzrinne, H., and B. Aboba,
"Trustworthy Location", draft-ietf-ecrit-trustworthy-
location-07 (work in progress), July 2013.
[RFC4481] Schulzrinne, H., "Timed Presence Extensions to the
Presence Information Data Format (PIDF) to Indicate Status
Information for Past and Future Time Intervals", RFC 4481,
July 2006.
[RFC5012] Schulzrinne, H. and R. Marshall, "Requirements for
Emergency Context Resolution with Internet Technologies",
RFC 5012, January 2008.
[RFC5069] Taylor, T., Tschofenig, H., Schulzrinne, H., and M.
Shanmugam, "Security Threats and Requirements for
Emergency Call Marking and Mapping", RFC 5069, January
2008.
[eCall-draft]
Gellens, RG., "Next-Generation Pan-European eCall", 2013.
Authors' Addresses
Randall Gellens
Qualcomm Technologies, Inc
5775 Morehouse Drive
San Diego 92651
US
Email: rg+ietf@qti.qualcomm.com
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Brian Rosen
NeuStar, Inc.
470 Conrad Dr
Mars, PA 16046
US
Email: br@brianrosen.net
Hannes Tschofenig
(no affiliation)
Email: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at
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