ECRIT R. Gellens
Internet-Draft Qualcomm Technologies, Inc.
Intended status: Standards Track H. Tschofenig
Expires: August 22, 2016 (Individual)
February 19, 2016
Next-Generation Pan-European eCall
draft-ietf-ecrit-ecall-07.txt
Abstract
This document describes how to use IP-based emergency services
mechanisms to support the next generation of the Pan European in-
vehicle emergency call service defined under the eSafety initiative
of the European Commission (generally referred to as "eCall"). eCall
is a standardized and mandated system for a special form of emergency
calls placed by vehicles. eCall deployment is required in the very
near future in European Union member states, and eCall (and eCall-
compatible systems) are also being deployed in other regions. eCall
provides an integrated voice path and a standardized set of vehicle,
sensor (e.g., crash related), and location data. An eCall is
recognized and handled as a specialized form of emergency call and is
routed to a specialized eCall-capable Public Safety Answering Point
(PSAP) capable of processing the vehicle data and trained in handling
emergency calls from vehicles.
Currently, eCall functions over circuit-switched cellular telephony;
work on next-generation eCall (NG-eCall, sometimes called packet-
switched eCall or PS-eCall) is now in process, and this document
assists in that work by describing how to support eCall within the
IP-based emergency services infrastructure.
This document also registers a MIME Content Type and an Emergency
Call Additional Data Block for the eCall vehicle data.
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
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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
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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 August 22, 2016.
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Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Document Scope . . . . . . . . . . . . . . . . . . . . . . . 4
3. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
4. eCall Requirements . . . . . . . . . . . . . . . . . . . . . 6
5. Vehicle Data . . . . . . . . . . . . . . . . . . . . . . . . 7
6. Call Setup . . . . . . . . . . . . . . . . . . . . . . . . . 7
7. Call Routing . . . . . . . . . . . . . . . . . . . . . . . . 9
8. Test Calls . . . . . . . . . . . . . . . . . . . . . . . . . 9
9. eCall-Specific Control/Metadata . . . . . . . . . . . . . . . 9
9.1. The eCall Control Block . . . . . . . . . . . . . . . . . 10
9.1.1. The <ack> element . . . . . . . . . . . . . . . . . . 12
9.1.1.1. Attributes of the <ack> element . . . . . . . . . 12
9.1.1.2. Child Elements of the <ack> element . . . . . . . 12
9.1.1.3. Ack Examples . . . . . . . . . . . . . . . . . . 13
9.1.2. The <capabilities> element . . . . . . . . . . . . . 14
9.1.2.1. Child Elements of the <capabilities> element . . 14
9.1.2.2. Capabilities Example . . . . . . . . . . . . . . 15
9.1.3. The <request> element . . . . . . . . . . . . . . . . 16
9.1.3.1. Attributes of the <request> element . . . . . . . 16
9.1.3.2. Child Elements of the <request> element . . . . . 18
9.1.3.3. Request Example . . . . . . . . . . . . . . . . . 19
9.2. The emergencyCallData.eCall INFO package . . . . . . . . 19
10. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11. Security Considerations . . . . . . . . . . . . . . . . . . . 24
12. Privacy Considerations . . . . . . . . . . . . . . . . . . . 26
13. XML Schema . . . . . . . . . . . . . . . . . . . . . . . . . 26
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14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29
14.1. Service URN Registrations . . . . . . . . . . . . . . . 29
14.2. MIME Content-type Registration for
'application/emergencyCallData.eCall.MSD+xml' . . . . . 30
14.3. MIME Content-type Registration for
'application/emergencyCallData.eCall.control+xml' . . . 31
14.4. Registration of the 'eCall.MSD' entry in the Emergency
Call Additional Data Blocks registry . . . . . . . . . . 33
14.5. Registration of the 'eCall.control' entry in the
Emergency Call Additional Data Blocks registry . . . . . 33
14.6. Registration of the emergencyCallData.eCall Info Package 33
14.7. URN Sub-Namespace Registration . . . . . . . . . . . . . 33
14.7.1. Registration for urn:ietf:params:xml:ns:eCall . . . 33
14.7.2. Registration for
urn:ietf:params:xml:ns:eCall:control . . . . . . . . 34
14.8. Registry creation . . . . . . . . . . . . . . . . . . . 35
14.8.1. eCall Control Action Registry . . . . . . . . . . . 35
14.8.2. eCall Static Message Registry . . . . . . . . . . . 36
14.8.3. eCall Reason Registry . . . . . . . . . . . . . . . 37
14.8.4. eCall Lamp ID Registry . . . . . . . . . . . . . . . 38
14.8.5. eCall Camera ID Registry . . . . . . . . . . . . . . 39
15. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 39
16. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 39
17. Changes from Previous Versions . . . . . . . . . . . . . . . 39
17.1. Changes from draft-ietf-05 to draft-ietf-06 . . . . . . 40
17.2. Changes from draft-ietf-04 to draft-ietf-05 . . . . . . 40
17.3. Changes from draft-ietf-03 to draft-ietf-04 . . . . . . 40
17.4. Changes from draft-ietf-02 to draft-ietf-03 . . . . . . 40
17.5. Changes from draft-ietf-01 to draft-ietf-02 . . . . . . 40
17.6. Changes from draft-ietf-00 to draft-ietf-01 . . . . . . 41
17.7. Changes from draft-gellens-03 to draft-ietf-00 . . . . . 41
17.8. Changes from draft-gellens-02 to -03 . . . . . . . . . . 41
17.9. Changes from draft-gellens-01 to -02 . . . . . . . . . . 41
17.10. Changes from draft-gellens-00 to -01 . . . . . . . . . . 41
18. References . . . . . . . . . . . . . . . . . . . . . . . . . 41
18.1. Normative References . . . . . . . . . . . . . . . . . . 42
18.2. Informative references . . . . . . . . . . . . . . . . . 43
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 44
1. Terminology
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:
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+--------+----------------------------------------+
| Term | Expansion |
+--------+----------------------------------------+
| 3GPP | 3rd Generation Partnership Project |
| CEN | European Committee for Standardization |
| EENA | European Emergency Number Association |
| ESInet | Emergency Services IP network |
| IMS | IP Multimedia Subsystem |
| IVS | In-Vehicle System |
| MNO | Mobile Network Operator |
| MSD | Minimum Set of Data |
| PSAP | Public Safety Answering Point |
+--------+----------------------------------------+
2. Document Scope
This document is limited to the signaling, data exchange, and
protocol needs of next-generation eCall (NG-eCall, also referred to
as packet-switched eCall (PS-eCall) and all-IP eCall) within the SIP
framework for emergency calls, as described in [RFC6443] and
[RFC6881]. eCall itself is specified by 3GPP and CEN and these
specifications include far greater scope than is covered here.
The eCall service operates over cellular wireless communication, but
this document does not address cellular-specific details, nor client
domain selection (e.g., circuit-switched versus packet-switched).
All such aspects are the purview of their respective standards
bodies. The scope of this document is limited to eCall operating
within a SIP-based environment (e.g., 3GPP IMS Emergency Calling).
The technical contents of this document can be suitable for use in
other vehicle-initiated emergency call systems, but this is out of
scope for this document.
Vehicles designed for multiple regions might need to support eCall
and other Advanced Automatic Crash Notification (AACN) systems, such
as described in [I-D.ietf-ecrit-car-crash]. That system is
compatible with eCall, differing primarily in the specific data set
that is sent.
3. Introduction
Emergency calls made from vehicles (e.g., in the event of a crash)
assist in significantly reducing road deaths and injuries by allowing
emergency services to be aware of the incident, the state of the
vehicle, the location of the vehicle, and to have a voice channel
with the vehicle occupants. This enables a quick and appropriate
response.
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The European Commission initiative of eCall was conceived in the late
1990s, and has evolved to a European Parliament decision requiring
the implementation of compliant in-vehicle systems (IVS) in new
vehicles and the deployment of eCall in the European Member States in
the very near future. eCall (and eCall-compatible systems) are also
being adopted in other regions.
The pan-European eCall system provides a standardized and mandated
mechanism for emergency calls by vehicles. eCall establishes
procedures for such calls to be placed by in-vehicle systems,
recognized and processed by the network, and routed to a specialized
PSAP where the vehicle data is available to assist the call taker in
assessing and responding to the situation. eCall provides a standard
set of vehicle, sensor (e.g., crash related), and location data.
An eCall can be either user-initiated or automatically triggered.
Automatically triggered eCalls indicate a car crash or some other
serious incident and carry a greater presumption of risk of injury.
Manually triggered eCalls might be reports of serious hazards and are
likely to require a different response than an automatically
triggered eCall. Manually triggered eCalls are also more likely to
be false (e.g., accidental) calls and so might be subject to
different operational handling by the PSAP.
Currently, eCall is standardized (by 3GPP [SDO-3GPP] and CEN [CEN])
as a 3GPP circuit-switched call over GSM (2G) or UMTS (3G). Flags in
the call setup mark the call as an eCall, and further indicate if the
call was automatically or manually triggered. The call is routed to
an eCall-capable PSAP, a voice channel is established between the
vehicle and the PSAP, and an eCall in-band modem is used to carry a
defined set of vehicle, sensor (e.g., crash related), and location
data (the Minimum Set of Data or MSD) within the voice channel. The
same in-band mechanism is used for the PSAP to acknowledge successful
receipt of the MSD, and to request the vehicle to send a new MSD
(e.g., to check if the state of or location of the vehicle or its
occupants has changed). Work on next-generation eCall (NG-eCall,
also referred to as packet-switched eCall or PS eCall) is now in
process. As part of this work, the European Telecommunications
Standards Institute (ETSI) [SDO-ETSI] has published a Technical
Report titled "Mobile Standards Group (MSG); eCall for VoIP" [MSG_TR]
that presents findings and recommendations regarding support for
eCall in an all-IP environment. NG-eCall moves from circuit switched
to all-IP, and carries the vehicle data and other eCall-specific data
as additional data associated with the call. This document describes
how IETF mechanisms for IP-based emergency calls, including [RFC6443]
and [I-D.ietf-ecrit-additional-data] are used to provide the
signaling and data exchange of the next generation of pan-European
eCall.
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The [MSG_TR] recommendation for NG-eCall is to use 3GPP IMS emergency
calling with additional elements identifying the call as an eCall and
as carrying eCall data and with mechanisms for carrying the data.
3GPP IMS emergency services support multimedia, providing the ability
to carry voice, text, and video. This capability is referred to
within 3GPP as Multimedia Emergency Services (MMES).
A transition period will exist during which time the various entities
involved in initiating and handling an eCall might support next-
generation eCall, legacy eCall, or both. This transition period
might last several years or longer. The issue of migration/co-
existence during the transition period is very important but is
outside the scope of this document. The ETSI TR "Mobile Standards
Group (MSG); eCall for VoIP" [MSG_TR] discusses these issues in
Clause 7.
4. eCall Requirements
Overall eCall requirements are specified by CEN in [EN_16072] and by
3GPP in [TS22.101] clauses 10.7 and A.27. Requirements specific to
vehicle data are contained in EN 15722 [msd]. For convenience, the
requirements most applicable to the limited scope of this document
are summarized very briefly below.
eCall requires:
o The call be recognized as an eCall (which is inherently an
emergency call)
o The call setup indicates if the call was manually or automatically
triggered
o A voice channel between the vehicle and the PSAP
o Carrying the MSD intrinsically with the call (the MSD needs to be
available to the same call-taker as the voice)
o The ability for the PSAP to acknowledge receipt of the MSD
o The ability for the PSAP to request that the vehicle generate and
transmit a new MSD
o The ability of the PSAP to be able to re-contact the occupants of
vehicle after the initial eCall is concluded
o The ability to perform a test call (which can be routed to a PSAP
but is not treated as an emergency call and not handled by a call
taker)
It is recognized that NG-eCall offers many potential enhancements,
although these are not required by current EU regulations. For
convenience, the enhancements most applicable to the limited scope of
this document are summarized very briefly below.
NG-eCall is expected to offer:
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o The ability to carry more data (e.g., an enhanced MSD or an MSD
plus additional sets of data)
o The ability to handle video
o The ability to handle text
o The ability for the PSAP to access vehicle components (e.g., an
onboard camera (such as rear facing or blind-spot cameras) for a
visual assessment of the crash site situation)
o The ability for the PSAP to request the vehicle to take actions
(e.g., sound the horn, disable the ignition, lock/unlock doors)
o The ability to avoid audio muting of the voice channel (because
the MSD is not transferred using an in-band modem)
5. Vehicle Data
Pan-European eCall provides a standardized and mandated set of
vehicle related data, known as the Minimum Set of Data (MSD). The
European Committee for Standardization (CEN) has specified this data
in EN 15722 [msd], along with both ASN.1 and XML encodings for the
MSD [msd]. Circuit-switched eCall uses the ASN.1 encoding. The XML
encoding is better suited for use in SIP messages and is used in this
document. (The ASN.1 encoding is specified in Annex A of EN 15722
[msd], while the XML encoding is specified in Annex C.)
The "Additional Data related to an Emergency Call" document
[I-D.ietf-ecrit-additional-data] establishes a general mechanism for
attaching blocks of data to a SIP emergency call. This document
makes use of that mechanism to carry the eCall MSD in a SIP emergency
call.
This document registers the 'application/
emergencyCallData.eCall.MSD+xml' MIME Content-Type to enable the MSD
to be carried in SIP. This document also adds the 'eCall.MSD' entry
to the Emergency Call Additional Data Blocks registry (established by
[I-D.ietf-ecrit-additional-data]) to enable the MSD to be recognized
as such in a SIP-based eCall emergency call.
Note that if additional data sets are defined and registered (e.g.,
in the future or in other regions) and transmitted using the same
mechanisms, the size and frequency of transmission during a session
needs to be evaluated to be sure it is appropriate to use the
signaling channel.
6. Call Setup
In circuit-switched eCall, the IVS places a special form of a 112
emergency call which carries an eCall flag (indicating that the call
is an eCall and also if the call was manually or automatically
triggered); the mobile network operator (MNO) recognizes the eCall
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flag and routes the call to an eCall-capable PSAP; vehicle data is
transmitted to the PSAP via the eCall in-band modem (in the voice
channel).
///----\\\ 112 voice call with eCall flag +------+
||| IVS |||---------------------------------------->+ PSAP |
\\\----/// vehicle data via eCall in-band modem +------+
Figure 1: circuit-switched eCall
An In-Vehicle System (IVS) which supports NG-eCall transmits the MSD
in accordance with [I-D.ietf-ecrit-additional-data] by encoding it as
specified (per Appendix C of EN 15722 [msd]) and attaching it to an
INVITE as a MIME body part. The body part is identified by its MIME
content-type ('application/emergencyCallData.eCall.MSD+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 MSD
by adding (or appending to) a Call-Info header field at the top level
of the INVITE. This Call-Info header field contains a CID URL
referencing the body part's unique identifier, and a 'purpose'
parameter identifying the data as the eCall MSD 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.eCall.MSD').
For NG-eCall, the IVS establishes an emergency call using the 3GPP
IMS solution with a Request-URI indicating an eCall type of emergency
call and with vehicle data attached; the MNO or ESInet recognizes the
eCall URN and routes the call to a NG-eCall capable PSAP; the PSAP
interpets the vehicle data sent with the call and makes it available
to the call taker.
///----\\\ IMS emergency call with eCall URN +------+
IVS ----------------------------------------->+ PSAP |
\\\----/// vehicle data included in call setup +------+
Figure 2: NG-eCall
This document registers new service URN children within the "sos"
subservice. These URNs provide the mechanism by which an eCall is
identified, and differentiate between manually and automatically
triggered eCalls (which can be subject to different treatment,
depending on policy). The two service URNs are:
urn:service:sos.ecall.automatic and urn:service:sos.ecall.manual
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7. Call Routing
The routing rules for eCalls are likely to differ from those of other
emergency calls because eCalls are special types of emergency calls
(with implications for the types of response required) and need to be
handled by specially designated PSAPs. In an environment that uses
ESInets, the originating network passes all types of emergency calls
to an ESInet (which have a request URI containing the "SOS" service
URN). The ESInet is then responsible for routing such calls to the
appropriate PSAP. In an environment without an ESInet, the emergency
services authorities and the originating network jointly determine
how such calls are routed.
8. Test Calls
eCall requires the ability to place test calls. These are calls that
are recognized and treated to some extent as eCalls but are not given
emergency call treatment and are not handled by call takers. The
test call facility allows the IVS or user to verify that an eCall can
be successfully established with voice communication. The IVS can
also verify that the MSD was successfully received.
A service URN starting with "test." indicates a test call. For
eCall, "urn:service:test.sos.ecall" indicates such a test feature.
This functionality is defined in [RFC6881].
This document registers "urn:service:test.sos.ecall" for eCall test
calls.
the current eCall test call facility is a non-emergency number so
does not get treated as an emergency call. MNOs can treat a vehicle
call in the "test" service URN in a way that tests as much
functionality as desired, but this is outside the scope of this
document.
PSAPs that have the ability to process NG-eCalls SHOULD accept test
calls and send an acknowledgment if the MSD was successfully
received, per this document. Such PSAPs MAY also play an audio clip
(for example, saying that the call reached a PSAP) in addition to
supporting media loopback per [RFC6881].
9. eCall-Specific Control/Metadata
eCall requires the ability for the PSAP to acknowledge successful
receipt of an MSD sent by the IVS, and for the PSAP to request that
the IVS send an MSD (e.g., the call taker can initiate a request for
a new MSD to see if the vehicle's state or location has changed).
Future enhancements are desired to enable the PSAP to send other
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requests to the vehicle, such as locking or unlocking doors, sounding
the horn, flashing the lights, starting a video stream from on-board
cameras (such as rear focus or blind-spot), etc.
The mechanism established in [I-D.ietf-ecrit-additional-data], used
in Section 5 of this document to carry the MSD from the IVS to the
PSAP, is also used to carry a block of control data from the PSAP to
the IVS. This eCall control block (sometimes referred to as eCall
metadata) is an XML structure containing eCall-specific elements.
When the PSAP needs to send an eCall control block that is in
response to the MSD or other data sent by the IVS in a SIP request,
the control block can be sent in the SIP response to that request
(e.g., the INVITE). When the PSAP needs to send an eCall control
block that is not an immediate response to an MSD or other data sent
by the IVS, the control block can be transmitted from the PSAP to the
IVS in a SIP INFO message within the established session. The IVS
can then send any requested data (such as a new MSD) in the reply to
the INFO message. This mechanism flexibly allows the PSAP to send
eCall-specific data to the IVS and the IVS to respond. If control
data sent in a response message requests the IVS to send a new MSD or
other data block, or to perform an action other than sending data,
the IVS can send the requested data or an acknowledgment regarding
the action in an INFO message within the session (it could also use
re-INVITE but that is unnecessary when no aspect of the session or
media is changing).
This mechanism requires
o An XML definition of the eCall control object
o An extension mechanism by which new elements can be added to the
control object definition (e.g., permitting additional elements to
be included by adding their namespace)
o A MIME type registration for the control object (so it can be
carried in SIP messages and responses)
o An entry in the Emergency Call Additional Data Blocks sub-registry
(established by [I-D.ietf-ecrit-additional-data]) so that the
control block can be recognized as emergency call specific data
within the SIP messages
o An Info-Package registration per [RFC6086] permitting the control
block within Info messages
9.1. The eCall Control Block
The eCall control block is an XML data structure allowing for
acknowledgments, requests, and capabilities information. It is
carried in a SIP body part with a specific MIME content type. Three
top-level elements are defined for use within an eCall control block:
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ack Used in a control block sent by either side. The PSAP
uses this to acknowledge receipt of a data set sent by
the IVS. The IVS uses this to acknowledge receipt of a
request by the PSAP when that request would not
otherwise be acknowledged (if the PSAP requests the
vehicle to send data and the vehicle does so, the data
serves as a success acknowledgement).
capabilities: Used in a control block sent from the IVS to the PSAP
(e.g., in the initial INVITE) to inform the PSAP of the
vehicle capabilities. Child elements contain all
actions and data types supported by the vehicle and all
available lamps (lights) and cameras.
request Used in a control block sent by the PSAP to the IVS, to
request the vehicle to perform an action.
Mandatory Actions (the IVS and the PSAP MUST support):
o Transmit data object
Optional Actions (the IVS and the PSAP MAY support):
o Play and/or display static (pre-defined) message
o Speak/display dynamic text (text supplied in action)
o Flash or turn on or off a lamp (light)
o Honk horn
o Enable a camera
The <ack> element indicates the object being acknowledged (i.e., a
data object or a <request> element), and reports success or failure.
The <capabilities> element has child <request> elements to indicate
the actions supported by the IVS.
The <request> element contains attributes to indicate the request and
to supply any needed information, and MAY contain a <text> child
element to contain the text for a dynamic message. The 'action'
attribute is mandatory and indicates the specific action. An IANA
registry is created in Section 14.8.1 to contain the allowed values.
Extensibility: New elements, child elements, and attributes can be
defined in new namespaces. IANA registries are used to specify the
permitted values of several elements and attributes. These
mechanisms allow for extension.
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There is no 'request' action to play dynamic media (such as a pre-
recorded audio message). The SIP re-INVITE mechanism can be used to
establish a one-way media stream for this purpose.
9.1.1. The <ack> element
The <ack> element is transmitted by the PSAP to acknowledge receipt
of an eCall data object. An <ack> element sent by a PSAP references
the unique ID of the data object that was sent by the IVS, and
further indicates if the PSAP considers the receipt successful or
not. The <ack> element is also transmitted by the IVS to the PSAP to
acknowledge receipt of a <request> element that requested the IVS to
perform an action other than transmitting a data object (e.g., a
request to display a message would be acknowledged, but a request to
transmit a data object would not result in a separate <ack> element
being sent, since the data object itself serves as acknowledgment.)
An <ack> element sent by an IVS references the unique ID of the
request being acknowledged, indicates whether the request was
successfully performed, and if not, optionally includes an
explanation.
The <ack> element has the following attributes and child elements:
9.1.1.1. Attributes of the <ack> element
The <ack> element has the following attributes:
Name: ref
Usage: Mandatory
Type: anyURI
Description: References the Content-ID of the body part that
contained the data object or control object being acknowledged.
Example: <ack received="yes" ref="1234567890@atlanta.example.com"/>
Name: received
Usage: Conditional: mandatory in an >ack< element sent by a PSAP;
not applicable in an >ack< element sent by an IVS
Type: Boolean
Description: Indicates if the referenced object was successfully
received or not
Example: <ack received="yes" ref="1234567890@atlanta.example.com"/>
9.1.1.2. Child Elements of the <ack> element
The <ack> element has the following child elements:
Name: actionResult
Usage: Optional
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Description: An <actionResult> element indicates the result of an
action (other than a 'send-data' action). When an <ack> element
is in response to a control object with multiple <request>
elements (that are not 'send-data' actions), the <ack> element
contains an <actionResult> element for each. The <actionResult>
element has the following attributes:
Name: action
Usage: Mandatory
Type: token
Description: Contains the value of the 'action' attribute of the
<request> element
Name: success
Usage: Mandatory
Type: Boolean
Description: Indicates if the action was successfully
accomplished
Name: reason
Usage: Conditional
Type: token
Description: Used when 'success' is "False", this attribute
contains a reason code for a failure. A registry for reason
codes is defined in Section 14.8.3.
Name: details
Usage: optional
Type: string
Description: Contains further explanation of the circumstances of
a success or failure. The contents are implementation-specific
and human-readable.
Example: <actionResult action="msg-dynamic" success="true"/>
Example: <actionResult action="lamp" success="false" reason="unable"
details="The requested lamp is inoperable"/>
9.1.1.3. Ack Examples
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<?xml version="1.0" encoding="UTF-8"?>
<EmergencyCallData.eCallControl
xmlns="urn:ietf:params:xml:ns:EmergencyCallData:eCall-control"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:EmergencyCallData:
eCall-control">
<ack received="true" ref="1234567890@atlanta.example.com"/>
</EmergencyCallData.eCallControl>
Figure 3: Ack Example from PSAP to IVS
<?xml version="1.0" encoding="UTF-8"?>
<EmergencyCallData.eCallControl
xmlns="urn:ietf:params:xml:ns:EmergencyCallData:eCall-control"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:EmergencyCallData:
eCall-control">
<ack ref="1234567890@atlanta.example.com">
<actionResult action="msg-dynamic" success="true"/>
<actionResult action="lamp" success="false" reason="unable"
details="The requested lamp is inoperable"/>
</ack>
</EmergencyCallData.eCallControl>
Figure 4: Ack Example from IVS to PSAP
9.1.2. The <capabilities> element
The <capabilities> element is transmitted by the IVS to indicate to
the PSAP its capabilities. No attributes for this element are
currently defined. The following child elements are defined:
9.1.2.1. Child Elements of the <capabilities> element
The <capabilities> element has the following child elements:
Name: request
Usage: Mandatory
Description: The <capabilities> element contains a <request> child
element per action supported by the vehicle.
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Because support for a 'send-data' action is REQUIRED, a <request>
child element with a "send-data" 'action' attribute is also
REQUIRED. The 'supported-datatypes' attribute is REQUIRED in this
<request> element within a <capabilities> element, and MUST
contain at a minimum the 'eCall.MSD' data block value; it SHOULD
contain all data blocks supported by the IVS.
All other actions are OPTIONAL.
If the "msg-static" action is supported, a <request> child element
with a "msg-static" 'action' attribute is sent, with a 'msgid'
attribute set to the highest supported static message supported by
the vehicle. A registry is created in Section 14.8.2 to map
'msgid' values to static text messages. By sending the highest
supported static message number in its <capabilities> element, the
vehicle indicates its support for all static messages in the
registry up to and including that value.
If the "lamp" action is supported, a <request> child element with
a "lamp" 'action' is sent, with a 'supported-lamps' attribute set
to all supported lamp IDs.
If the "enable-camera" action is supported, a <request> child
element with an "enable-camera" 'action' is sent, with a
'supported-cameras' attribute set to all supported camera IDs.
Examples:
<request action="send-data" supported-datatypes="eCall.MSD" />
<request action="send-data" supported-datatypes="eCall.MSD; VEDS;
eCall.type2" />
<request action="msg-dynamic"/>
<request action="msg.static" msgid="17" />
9.1.2.2. Capabilities Example
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<?xml version="1.0" encoding="UTF-8"?>
<EmergencyCallData.eCallControl
xmlns="urn:ietf:params:xml:ns:EmergencyCallData:eCall-control"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:EmergencyCallData:
eCall-control">
<capabilities>
<request action="send-data" supported-datatypes="eCall.MSD"/>
<request action="lamp"
supported-lamps="head;interior;fog-front;fog-rear;brake;
position-front;position-rear;turn-left;turn-right;hazard"/>
<request action="msg-static" msgid="3"/>
<request action="msg-dynamic"/>
<request action="honk"/>
<request action="enable-camera" supported-cameras="backup; interior"/>
</capabilities>
</EmergencyCallData.eCallControl>
Figure 5: Capabilities Example
9.1.3. The <request> element
A <request> element appears one or more times on its own or as a
child of a <capabilities> element. The following attributes and
child elements are defined:
9.1.3.1. Attributes of the <request> element
The <request> element has the following attributes:
Name: action
Usage: Mandatory
Type: token
Description: Identifies the action that the vehicle is requested to
perform. An IANA registry is established in Section 14.8.1 to
contain the allowed values.
Example: action="send-data"
Name: msgid
Usage: Conditional
Type: int
Description: Mandatory with a "msg-static" action. Indicates the
identifier of the static message to be displayed and/or spoken for
the vehicle occupants. This document established an IANA registry
for messages and their IDs, in Section 14.8.2
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Example: msgid="3"
Name: persistance
Usage: Optional
Type: duration
Description: Specifies how long to carry on the specified action,
for example, how long to continue honking or flashing. If absent,
the default is indefinitely.
Example: persistance="PT1H"
Name: datatype
Usage: Conditional
Type: token
Description: Mandatory with a "send-data" action. Specifies the
data block that the IVS is requested to transmit, using the same
identifier as in the 'purpose' attribute set in a Call-Info header
field to point to the data block. Permitted values are contained
in the 'Emergency Call Data Types' IANA registry established in
[I-D.ietf-ecrit-additional-data].
Example: datatype="eCall.MSD"
Name: supported-datatypes
Usage: Conditional
Type: string
Description: Used with a 'send-data' action in a <request> element
that is a child of a <capability> element, this attribute lists
all data blocks that the vehicle can transmit, using the same
identifier as in the 'purpose' attribute in a Call-Info header
field to point to the data block. Permitted values are contained
in the 'Emergency Call Data Types' IANA registry established in
[I-D.ietf-ecrit-additional-data]. Multiple values are separated
with a semicolon.
Example: supported-datatypes="eCall.MSD; VEDS; eCall.foo"
Name: lamp-action
Usage: Conditional
Type: token
Description: Used with a 'lamp' action, indicates if the lamp is to
be illuminated, turned off, or flashed. Permitted values are
'on', 'off', and 'flash'.
Example: lamp-action="flash"
Name: lamp-ID
Usage: Conditional
Type: token
Description: Used with a 'lamp' action, indicates which lamp the
action affects. Permitted values are contained in the registry of
lamp-ID tokens created in Section 14.8.4
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Example: lamp-ID="hazard"
Name: supported-lamps
Usage: Conditional
Type: string
Description: Used with a 'lamp' action in a <request> element that
is a child of a <capability> element, this attribute lists all
supported lamps, using values in the registry of lamp-ID tokens
created in Section 14.8.4. Multiple values are separated with a
semicolon.
Example: supported-lamps="head; interior; fog-front; fog-rear;
brake; position-front; position-rear; turn-left; turn-right;
hazard"
Name: camera-ID
Usage: Conditional
Type: token
Description: Used with an 'enable-camera' action, indicates which
camera to enable. Permitted values are contained in the registry
of camera-ID tokens created in Section 14.8.5. When a vehicle
camera is enabled, the IVS sends a re-INVITE to negotiate a one-
way media stream for the camera.
Example: camera-ID="backup"
Name: supported-cameras
Usage: Conditional
Type: string
Description: Used with an 'enable-camera' action in a <request>
element that is a child of a <capability> element, this attribute
lists all cameras that the vehicle supports (can add as a video
feed in the current session), using the same identifiers as are
used in the 'camera-ID' attribute (contained in the camera ID
registry in Section 14.8.5). Multiple values are separated with a
semicolon.
Example: supported-cameras="backup; interior"
9.1.3.2. Child Elements of the <request> element
The <request> element has the following child elements:
Name: text
Usage: Conditional
Type: string
Description: Used within a <request action="msg-dynamic"> element to
contain the text to be displayed and/or spoken (via text-to-
speech) for the vehicle occupants.
Example: <text>Emergency authorities are aware of your incident and
location. Due to a multi-vehicle incident in your area, no one is
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able to speak with you right now. Please remain calm. We will
assist you soon.</text>
9.1.3.3. Request Example
<?xml version="1.0" encoding="UTF-8"?>
<EmergencyCallData.eCallControl
xmlns="urn:ietf:params:xml:ns:EmergencyCallData:eCall-control"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:EmergencyCallData:
eCall-control">
<request action="send-data" datatype="eCall.MSD"/>
<request action="lamp" lamp-id="hazard"
lamp-action="flash" persistance="PT1H"/>
<request action="msg-static" msgid="1"/>
<request action="msg-dynamic">
<text>Remain calm. Help is on the way.</text>
</request>
</EmergencyCallData.eCallControl>
Figure 6: Request Example
9.2. The emergencyCallData.eCall INFO package
This document registers the 'emergencyCallData.eCall' INFO package.
Both endpoints (the IVS and the PSAP equipment) set the Recv-Info
header field to 'emergencyCallData.eCall' per [RFC6086] to indicate
ability to receive INFO messages carrying eCall data or control
blocks.
Support for the 'emergencyCallData.eCall' INFO package indicates the
ability to receive eCall data and control blocks, which are carried
in a body part whose subtype starts with 'emergencyCallData.eCall.'.
At present there is only one defined eCall data block, which has the
'application/emergencyCallData.eCall.MSD+xml' MIME type, and one
eCall control block, which has the 'application/
emergencyCallData.eCall.control+xml' MIME type. The eCall control
block includes the ability for the IVS to indicate its capabilities,
so in the event additional eCall blocks are defined, the IVS can
indicate which it supports.
The use of INFO is based on an analysis of the requirements against
the intent and effects of INFO versus other approaches (such as SIP
MESSAGE, media plane, or non-SIP protocols). In particular, the
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transport of eCall data and control blocks is done only during an
emergency session established with SIP, using the mechanism
established in [I-D.ietf-ecrit-additional-data], and is normally
carried in the initial INVITE and its response; the use of INFO only
occurs when a data block or request needs to be sent subsequently
during the call. While MESSAGE could be used, it is not tied to a
SIP session as is INFO. REINVITE could also be used, but is normally
used to modify the session. SUBSCRIBE/NOTIFY could be coerced into
service, but the semantics are not a clean fit. Hence, INFO is
appropriate.
An INFO request message carrying an eCall data or control block has
an Info-Package header field set to 'emergencyCallData.eCall' per
[RFC6086]. The INFO request message is marked as containing the
eCall data or control block by a Call-Info header field containing a
CID URL referencing the unique identifier of the body part containing
the eCall data or control, and a 'purpose' parameter identifying the
block. Because the eCall data or control block is being carried in
an INFO request message, the body part also carries a Content-
Disposition header field set to "Info-Package".
Per [I-D.ietf-ecrit-additional-data], emergency call related
additional data MAY be included in any SIP request or response
message that can contain a body. Hence, notwithstanding
Section 4.3.2. of [RFC6086], INFO response messages MAY contain eCall
data or control blocks, provided they are included as described in
this document (with a Call-Info header field containing a CID URL
referencing the unique identifier of the body part, and a 'purpose'
parameter identifying the block). When eCall data or control blocks
are included in an INFO response message, this is done per
[I-D.ietf-ecrit-additional-data] and this document, and not under
[RFC6086]; that is, they are included as emergency call additional
data, not as an INFO package associated data.
10. Examples
Figure 7 shows an eCall. The call uses the request URI
'urn:service:sos.ecall.automatic' service URN and is recognized as an
eCall, and further as one that was invoked automatically by the IVS
due to a crash or other serious incident. In this example, the
originating network routes the call to an ESInet (as for any
emergency call in an environment with an ESInet). The ESInet routes
the call to the appropriate NG-eCall capable PSAP. The emergency
call is received by the ESInet's Emergency Services Routing Proxy
(ESRP), as the entry point into the ESInet. The ESRP routes the call
to a PSAP, where it is received by a call taker. In deployments
where there is no ESInet, the originating network routes the call
directly to the appropriate NG-eCall capable PSAP.
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+------------+ +---------------------------------------+
| | | +-------+ |
| | | | PSAP2 | |
| | | +-------+ |
| | | |
| | | +------+ +-------+ |
Vehicle-->| |--+->| ESRP |---->| PSAP1 |--> Call-Taker |
| | | +------+ +-------+ |
| | | |
| | | +-------+ |
| | | | PSAP3 | |
| Originating| | +-------+ |
| Mobile | | |
| Network | | ESInet |
+------------+ +---------------------------------------+
Figure 7: Example of NG-eCall Message Flow
The example, shown in Figure 8, illustrates a SIP eCall INVITE that
contains an MSD and an eCall control block with vehicle capabilities.
For simplicity, the example does not show all SIP headers, nor does
it show the additional data blocks added by the IVS and the
originating mobile network.
INVITE urn:service:sos.ecall.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.eCall.MSD;
cid:2345678901@atlanta.example.com;
purpose=emergencyCallData.eCall.control;
Accept: application/sdp, application/pidf+xml,
application/emergencyCallData.eCall.control
CSeq: 31862 INVITE
Recv-Info: emergencyCallData.eCall
Content-Type: multipart/mixed; boundary=boundary1
Content-Length: ...
--boundary1
Content-Type: application/sdp
...Session Description Protocol (SDP) goes here...
--boundary1
Content-Type: application/emergencyCallData.eCall.MSD+xml
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Content-ID: 1234567890@atlanta.example.com
Content-Disposition: by-reference;handling=optional
<ECallMessage>
<id>1</id>
<msd>
<msdStructure>
<messageIdentifier>1</messageIdentifier>
<control>
<automaticActivation> <true/> </automaticActivation>
<testCall> <false/> </testCall>
<positionCanBeTrusted> <true/> </positionCanBeTrusted>
<vehicleType> <passengerVehicleClassM1/> </vehicleType>
</control>
<vehicleIdentificationNumber>
<isowmi>WMI</isowmi>
<isovds>VDSVDS</isovds>
<isovisModelyear>Y</isovisModelyear>
<isovisSeqPlant>A123456</isovisSeqPlant>
</vehicleIdentificationNumber>
<vehiclePropulsionStorageType>
<gasolineTankPresent> <true/> </gasolineTankPresent>
<electricEnergyStorage> <true/> </electricEnergyStorage>
</vehiclePropulsionStorageType>
<timestamp>123456789</timestamp>
<vehicleLocation>
<positionLatitude>173881200</positionLatitude>
<positionLongitude>41822520</positionLongitude>
</vehicleLocation>
<vehicleDirection>14</vehicleDirection>
<recentVehicleLocationN1>
<latitudeDelta>10</latitudeDelta>
<longitudeDelta>-10</longitudeDelta>
</recentVehicleLocationN1>
<recentVehicleLocationN2>
<latitudeDelta>10</latitudeDelta>
<longitudeDelta>-20</longitudeDelta>
</recentVehicleLocationN2>
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<numberOfPassengers>2</numberOfPassengers>
</msdStructure>
<optionalAdditionalData>
<oid>1.2.125</oid>
<data>30304646</data>
</optionalAdditionalData>
</msd>
</ECallMessage>
--boundary1
Content-Type: application/emergencyCallData.eCall.control+xml
Content-ID: 2345678901@atlanta.example.com
Content-Disposition: by-reference;handling=optional
<?xml version="1.0" encoding="UTF-8"?>
<EmergencyCallData.eCallControl
xmlns="urn:ietf:params:xml:ns:EmergencyCallData:eCall-control"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:EmergencyCallData:
eCall-control">
<capabilities>
<request action="send-data" supported-datatypes="eCall.MSD"/>
<request action="lamp"
supported-lamps="head;interior;fog-front;fog-rear;
brake;position-front;position-rear;turn-left;
turn-right;hazard"/>
<request action="msg-static" msgid="3"/>
<request action="msg-dynamic"/>
<request action="honk"/>
<request action="enable-camera"
supported-cameras="backup; interior"/>
</capabilities>
</EmergencyCallData.eCallControl>
--boundary1--
Figure 8: SIP NG-eCall INVITE
Continuing the example, Figure 9 illustrates a SIP 200 OK response to
the INVITE of Figure 8, containing an eCall control block
acknowledging successful receipt of the eCall MSD. (For simplicity,
the example does not show all SIP headers.)
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SIP/2.0 200 OK
To: <sip:+13145551111@example.com>;tag=9fxced76sl
From: Exemplar PSAP <urn:service:sos.ecall.automatic>
Call-ID: 3848276298220188511@atlanta.example.com
Call-Info: cid:2345678901@atlanta.example.com;
purpose=emergencyCallData.eCall.control;
Accept: application/sdp, application/pidf+xml,
application/emergencyCallData.eCall.control,
application/emergencyCallData.eCall.MSD
CSeq: 31862 INVITE
Recv-Info: emergencyCallData.eCall
Content-Type: multipart/mixed; boundary=boundaryX
Content-Length: ...
--boundaryX
Content-Type: application/sdp
...Session Description Protocol (SDP) goes here...
--boundaryX
Content-Type: application/EmergencyCallData:eCall-control+xml
Content-ID: 2345678901@atlanta.example.com
Content-Disposition: by-reference;handling=optional
<?xml version="1.0" encoding="UTF-8"?>
<EmergencyCallData.eCallControl
xmlns="urn:ietf:params:xml:ns:EmergencyCallData:eCall-control"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:ietf:params:xml:ns:EmergencyCallData:
eCall-control">
<ack received="true" ref="1234567890@atlanta.example.com"/>
</EmergencyCallData.eCallControl>
--boundaryX--
Figure 9: 200 OK response to INVITE
11. Security Considerations
The security considerations described in [RFC5069] apply here.
In addition to any network-provided location that is inherently
permitted for IMS emergency calls (which might be determined solely
by the network, or in cooperation with or possibly entirely by the
originating device), an eCall carries an IVS-supplied location within
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the MSD. This is likely to be useful to the PSAP, especially when
the two locations are independently determined. Even in situations
where the network-supplied location is limited to the cell site, this
can be useful as a sanity check on the device-supplied location
contained in the MSD.
The document [RFC7378] discusses trust issues regarding location
provided by or determined in cooperation with end devices.
Security considerations specific to the mechanism by which the PSAP
sends acknowledgments and requests to the vehicle are discussed in
the "Security Considerations" block of Section 14.3. In addition to
that discussion, it's important to note that vehicles MAY decline to
carry out any requested action, e.g., if the vehicle is unable to
verify the certificate used to sign the request. The vehicle MAY use
any value in the reason registry in Section 14.8.3 to indicate why it
did not take an action (e.g., the generic "unable" or the more
specific "security-failure").
Data received from external sources inherently carries implementation
risks including buffer overflows, which in many platforms can
introduce remote code execution vulnerabilities; null characters can
corrupt strings, numeric values used for internal calculations can
result in underflow/overflow errors; malformed XML objects can expose
parsing bugs, etc. Implementations need to be cognizant of the
potential risks, observe best practices (e.g., good quality static
code analysis, fuzz testing, component isolation, avoiding use of
unsafe coding techniques, third-party attack tests, signed software,
over-the-air updates, etc.), and have multiple levels of protection.
Implementors need to be aware that, potentially, the data objects
described here and elsewhere might be malformed, might contain
unexpected characters, excessively long attribute values, elements,
etc. (This applies across the board, not just to the 'text'
attribute of a <request> element.)
Since this document depends on [I-D.ietf-ecrit-additional-data], the
security considerations discussed there apply here (see especially
the discussion of TLS, TLS versions, cypher suites, and PKI).
When vehicle data or control/metadata is contained in a signed or
encrypted body part, the enclosing multipart (e.g., multipart/signed
or multipart/encrypted) has the same Content-ID as the data part.
This allows an entity to identify and access the data blocks it is
interested in without having to dive deeply into the message
structure or decrypt parts it is not interested in. (The 'purpose'
parameter in a Call-Info header field identifies the data, and the
CID URL points to the data block in the body, which has a matching
Content-ID body part header field).
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12. Privacy Considerations
Since this document builds on [I-D.ietf-ecrit-additional-data], the
data structures specified there, and the corresponding privacy
considerations discussed there, apply here as well. The MSD carries
some additional identifying and personal information (mostly about
the vehicle and less about the owner), as well as location
information, and so needs to be protected against unauthorized
disclosure. Local regulations may impose additional privacy
protection requirements. The additional functionality enabled by
this document, such as access to vehicle camera streams, carries a
burden of protection and so implementations need to be careful that
access is only provided within the context of an emergency call and
to an emergency services provider, for example, by verifying that the
request for camera access is signed by a certificate issued by an
emergency services registrar.
Privacy considerations specific to the data structure containing
vehicle information are discussed in the "Security Considerations"
block of Section 14.2.
Privacy considerations specific to the mechanism by which the PSAP
sends acknowledgments and requests to the vehicle are discussed in
the "Security Considerations" block of Section 14.3.
13. XML Schema
This section defines the XML schema of the eCall control block. (The
schema for the MSD can be found in EN 15722 [msd].)
<?xml version="1.0"?>
<xs:schema
targetNamespace="urn:ietf:params:xml:ns:EmergencyCallData:eCall-control"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:pi="urn:ietf:params:xml:ns:EmergencyCallData:eCall-control"
xmlns:xml="http://www.w3.org/XML/1998/namespace"
elementFormDefault="qualified"
attributeFormDefault="unqualified">
<xs:import namespace="http://www.w3.org/XML/1998/namespace"
schemaLocation="http://www.w3.org/2009/01/xml.xsd"/>
<xs:element name="EmergencyCallData.eCallControl"
type="pi:eCallControlType"/>
<xs:complexType name="eCallControlType">
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<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:choice>
<xs:element name="capabilities"
type="pi:capabilitiesType"/>
<xs:element name="request" type="pi:requestType"/>
<xs:element name="ack" type="pi:ackType"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0"
maxOccurs="unbounded"/>
</xs:choice>
<xs:anyAttribute/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="ackType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence minOccurs="1" maxOccurs="unbounded">
<xs:element name="actionResult" minOccurs="0"
maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="action"
type="xs:token"
use="required"/>
<xs:attribute name="success"
type="xs:boolean"
use="required"/>
<xs:attribute name="reason"
type="xs:token">
<xs:annotation>
<xs:documentation>conditionally
mandatory when @success='false"
to indicate reason code for a
failure </xs:documentation>
</xs:annotation>
</xs:attribute>
<xs:attribute name="details"
type="xs:string"/>
<xs:anyAttribute processContents="skip"/>
</xs:complexType>
</xs:element>
<xs:any namespace="##other" processContents="lax"
minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
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<xs:attribute name="ref"
type="xs:anyURI"
use="required"/>
<xs:attribute name="received"
type="xs:boolean"/>
<xs:anyAttribute/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="capabilitiesType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:sequence minOccurs="1" maxOccurs="unbounded">
<xs:element name="request"
type="pi:requestType"
minOccurs="1"
maxOccurs="unbounded"/>
<xs:any namespace="##other" processContents="lax"
minOccurs="0"
maxOccurs="unbounded"/>
</xs:sequence>
<xs:anyAttribute/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
<xs:complexType name="requestType">
<xs:complexContent>
<xs:restriction base="xs:anyType">
<xs:choice minOccurs="1" maxOccurs="unbounded">
<xs:any namespace="##other" processContents="lax"
minOccurs="0"
maxOccurs="unbounded"/>
</xs:choice>
<xs:attribute name="action" type="xs:token" use="required"/>
<xs:attribute name="msgid" type="xs:unsignedInt"/>
<xs:attribute name="persistence" type="xs:duration"/>
<xs:attribute name="datatype" type="xs:token"/>
<xs:attribute name="supported-datatypes" type="xs:string"/>
<xs:attribute name="lamp-id" type="xs:token"/>
<xs:attribute name="lamp-action">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:pattern value=""/>
<xs:pattern value=""/>
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<xs:enumeration value="on"/>
<xs:enumeration value="off"/>
<xs:enumeration value="flash"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="supported-lamps" type="xs:string"/>
<xs:attribute name="camera-id" type="xs:token"/>
<xs:attribute name="supported-cameras" type="xs:string"/>
<xs:anyAttribute/>
</xs:restriction>
</xs:complexContent>
</xs:complexType>
</xs:schema>
Figure 10: eCall Control Block Schema
14. IANA Considerations
14.1. Service URN Registrations
IANA is requested to register the URN 'urn:service:sos.ecall' under
the sub-services 'sos' registry defined in Section 4.2 of [RFC5031].
This service identifies a type of emergency call (placed by a
specialized in-vehicle system and a carrying standardized set of data
related to the vehicle and crash or incident, and is needed to direct
the call to a specialized public safety answering point (PSAP) with
technical and operational capabilities to handle such calls. Two
sub-services are registered as well, namely
urn:service:sos.ecall.manual
This service URN indicates that an eCall had been triggered based
on the manual interaction of the driver or a passenger.
urn:service:sos.ecall.automatic
This service URN indicates that an eCall had been triggered
automatically, for example, due to a crash or other serious
incident (e.g., fire).
IANA is also requested to register the URN
'urn:service:test.sos.ecall' under the sub-service 'test' registry
defined in Setcion 17.2 of [RFC6881].
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14.2. MIME Content-type Registration for 'application/
emergencyCallData.eCall.MSD+xml'
IANA is requested to add application/emergencyCallData.eCall.MSD+xml
as a MIME content type, with a reference to this document, in
accordance to the procedures of RFC 6838 [RFC6838] and guidelines in
RFC 7303 [RFC7303].
MIME media type name: application
MIME subtype name: emergencyCallData.eCall.MSD+xml
Mandatory parameters: none
Optional parameters: charset
Indicates the character encoding of the XML content.
Encoding considerations: Uses XML, which can employ 8-bit
characters, depending on the character encoding used. See
Section 3.2 of RFC 7303 [RFC7303].
Security considerations: This content type is designed to carry
vehicle and incident-related data during an emergency call. This
data 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. In general,
it is permissible for the data to be unprotected while briefly in
transit within the Mobile Network Operator (MNO); the MNO is
trusted to not permit the data to be accessed by third parties.
Sections 7 and Section 8 of [I-D.ietf-ecrit-additional-data]
contain more discussion.
Interoperability considerations: None
Published specification: Annex C of EN 15722 [msd]
Applications which use this media type: Pan-European eCall
compliant systems
Additional information: None
Magic Number: None
File Extension: .xml
Macintosh file type code: 'TEXT'
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Person and email address for further information: Hannes
Tschofenig, Hannes.Tschofenig@gmx.net
Intended usage: LIMITED USE
Author: This specification was produced by the European Committee
For Standardization (CEN). For contact information, please see
<http://www.cen.eu/cen/Pages/contactus.aspx>.
Change controller: The European Committee For Standardization
(CEN)
14.3. MIME Content-type Registration for 'application/
emergencyCallData.eCall.control+xml'
IANA is requested to add application/
emergencyCallData.eCall.control+xml as a MIME content type, with a
reference to this document, in accordance to the procedures of RFC
6838 [RFC6838] and guidelines in RFC 7303 [RFC7303].
MIME media type name: application
MIME subtype name: emergencyCallData.eCall.control+xml
Mandatory parameters: none
Optional parameters: charset
Indicates the character encoding of the XML content.
Encoding considerations: Uses XML, which can employ 8-bit
characters, depending on the character encoding used. See
Section 3.2 of RFC 7303 [RFC7303].
Security considerations:
This content type carries metadata and control information and
requests, primarily from a Public Safety Answering Point (PSAP)
to an In-Vehicle System (IVS) during an emergency call, and
also capabilities from the IVS to the PSAP.
Metadata (such as an acknowledgment that data sent by the IVS
to the PSAP was successfully received) has limited privacy and
security implications. Control information (such as requests
from the PSAP that the vehicle perform an action) has some
privacy and important security implications. The privacy
concern arises from the ability to request the vehicle to
transmit a data set, which as described in Section 14.2, can
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contain personal information. The security concern is the
ability to request the vehicle to perform an action. It is
important that control information originate only from a PSAP
or other emergency services provider, and not be modified en-
route. The level of integrity of the cellular network over
which the emergency call is placed is important: when the IVS
initiates an eCall over a cellular network, it relies on the
MNO to route the call to a PSAP. (Calls placed using other
means, such as Wi-Fi or over-the-top services, generally incur
higher levels of risk than calls placed over cellular
networks.) A call-back from a PSAP incurs additional risk,
since the current mechanisms are not ideal for verifying that
such a call is indeed a call-back from a PSAP in response to an
emergency call placed by the IVS. See the discussion in
Section 11 and the PSAP Callback document [RFC7090]. One
safeguard, applicable regardless of which end initiated the
call and the means of the call, is for the PSAP or emergency
service provider to sign the body part using a certificate
issued by a known emergency services certificate authority and
for which the IVS can verify the root certificate.
Sections 7 and Section 8 of [I-D.ietf-ecrit-additional-data]
contain more discussion.
Interoperability considerations: None
Published specification: Annex C of EN 15722 [msd]
Applications which use this media type: Pan-European eCall
compliant systems
Additional information: None
Magic Number: None
File Extension: .xml
Macintosh file type code: 'TEXT'
Person and email address for further information: Randall Gellens,
rg+ietf@qti.qualcomm.com
Intended usage: LIMITED USE
Author: The IETF ECRIT WG.
Change controller: The IETF ECRIT WG.
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14.4. Registration of the 'eCall.MSD' entry in the Emergency Call
Additional Data Blocks registry
This specification requests IANA to add the 'eCall.MSD' entry to the
Emergency Call Additional Data Blocks registry (established by
[I-D.ietf-ecrit-additional-data]), with a reference to this document.
14.5. Registration of the 'eCall.control' entry in the Emergency Call
Additional Data Blocks registry
This specification requests IANA to add the 'eCall.control' entry to
the Emergency Call Additional Data Blocks registry (established by
[I-D.ietf-ecrit-additional-data]), with a reference to this document.
14.6. Registration of the emergencyCallData.eCall Info Package
IANA is requested to add emergencyCallData.eCall to the Info Packages
Registry under "Session Initiation Protocol (SIP) Parameters", with a
reference to this document.
14.7. URN Sub-Namespace Registration
14.7.1. Registration for urn:ietf:params:xml:ns:eCall
This section registers a new XML namespace, as per the guidelines in
RFC 3688 [RFC3688].
URI: urn:ietf:params:xml:ns:eCall
Registrant Contact: IETF, ECRIT working group, <ecrit@ietf.org>, as
delegated by the IESG <iesg@ietf.org>.
XML:
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BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
"http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type"
content="text/html;charset=iso-8859-1"/>
<title>Namespace for eCall Data</title>
</head>
<body>
<h1>Namespace for eCall Data</h1>
<p>See [TBD: This document].</p>
</body>
</html>
END
14.7.2. Registration for urn:ietf:params:xml:ns:eCall:control
This section registers a new XML namespace, as per the guidelines in
RFC 3688 [RFC3688].
URI: urn:ietf:params:xml:ns:eCall:control
Registrant Contact: IETF, ECRIT working group, <ecrit@ietf.org>, as
delegated by the IESG <iesg@ietf.org>.
XML:
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BEGIN
<?xml version="1.0"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML Basic 1.0//EN"
"http://www.w3.org/TR/xhtml-basic/xhtml-basic10.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type"
content="text/html;charset=iso-8859-1"/>
<title>Namespace for eCall Data:
Control Block</title>
</head>
<body>
<h1>Namespace for eCall Data</h1>
<h2>Control Block</h2>
<p>See [TBD: This document].</p>
</body>
</html>
END
14.8. Registry creation
This document creates a new registry called 'eCall Control Data'.
The following sub-registries are created for this registry.
14.8.1. eCall Control Action Registry
This document creates a new sub-registry called "eCall Control Action
Registry". As defined in [RFC5226], this registry operates under
"Expert Review" rules. The expert should determine that the proposed
action is within the purview of a vehicle, is sufficiently
distinguishable from other actions, and the actions is clearly and
fully described. In most cases, a published and stable document is
referenced for the description of the action.
The content of this registry includes:
Name: The identifier to be used in the 'action' attribute of an
eCall control <request> element.
Description: A description of the action. In most cases this will
be a reference to a published and stable document. The
description MUST specify if any attributes or child elements are
optional or mandatory, and describe the action to be taken by the
vehicle.
The initial set of values is listed in Table 2.
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+---------------+------------------------------+
| Name | Description |
+---------------+------------------------------+
| send-data | Section xxx of this document |
| | |
| msg-static | Section xxx of this document |
| | |
| msg-dynamic | Section xxx of this document |
| | |
| honk | Section xxx of this document |
| | |
| lamp | Section xxx of this document |
| | |
| enable-camera | Section xxx of this document |
+---------------+------------------------------+
Table 2: eCall Control Action Registry Initial Values
14.8.2. eCall Static Message Registry
This document creates a new sub-registry called "eCall Static Message
Registry". Because all compliant vehicles are expected to support
all static messages translated into all languages supported by the
vehicle, it is important to limit the number of such messages. As
defined in [RFC5226], this registry operates under "Publication
Required" rules, which require a stable, public document and imply
expert review of the publication. The expert should determine that
the document has been published by an appropriate emergency services
organization (e.g., NENA, EENA, APCO) and that the proposed message
is sufficiently distinguishable from other messages.
The content of this registry includes:
ID: An integer identifier to be used in the 'msgid' attribute of an
eCall control <request> element.
Message: The text of the message. Messages are listed in the
registry in English; vehicles are expected to implement
translations into languages supported by the vehicle.
When new messages are added to the registry, the message text is
determined by the registrant; IANA assigns the IDs. Each message is
assigned a consecutive integer value as its ID. This allows an IVS
to indicate by a single integer value that it supports all messages
with that value or lower.
The initial set of values is listed in Table 3.
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+----+--------------------------------------------------------------+
| ID | Message |
+----+--------------------------------------------------------------+
| 1 | Emergency authorities are aware of your incident and |
| | location, but are unable to speak with you right now. We |
| | will help you as soon as possible. |
+----+--------------------------------------------------------------+
Table 3: eCall Static Message Registry
14.8.3. eCall Reason Registry
This document creates a new sub-registry called "eCall Reason
Registry" which contains values for the 'reason' attribute of the
<actionResult> element. As defined in [RFC5226], this registry
operates under "Expert Review" rules. The expert should determine
that the proposed reason is sufficiently distinguishable from other
reasons and that the proposed description is understandable and
correctly worded.
The content of this registry includes:
ID: A short string identifying the reason, for use in the 'reason'
attribute of an <actionResult> element.
Description: A description of the reason.
The initial set of values is listed in Table 4.
+------------------+------------------------------------------------+
| ID | Description |
+------------------+------------------------------------------------+
| unsupported | The 'action' is not supported. |
| | |
| unable | The 'action' could not be accomplished. |
| | |
| data-unsupported | The data item referenced in a 'send-data' |
| | request is not supported. |
| | |
| security-failure | The authenticity of the request or the |
| | authority of the requestor could not be |
| | verified. |
+------------------+------------------------------------------------+
Table 4: eCall Reason Registry
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14.8.4. eCall Lamp ID Registry
This document creates a new sub-registry called "eCall Lamp ID
Registry" to standardize the names of automotive lamps (lights). As
defined in [RFC5226], this registry operates under "Expert Review"
rules. The expert should determine that the proposed lamp name is
clearly understandable and is sufficiently distinguishable from other
lamp names.
The content of this registry includes:
Name: The identifier to be used in the 'lamp-ID' attribute of an
eCall control <request> element.
Description: A description of the lamp (light).
The initial set of values is listed in Table 5.
+----------------+---------------------------------------------+
| Name | Description |
+----------------+---------------------------------------------+
| head | The main lamps used to light the road ahead |
| | |
| interior | Interior lamp, often at the top center |
| | |
| fog-front | Front fog lamps |
| | |
| fog-rear | Rear fog lamps |
| | |
| brake | Brake indicator lamps |
| | |
| position-front | Front position/parking/standing lamps |
| | |
| position-rear | Rear position/parking/standing lamps |
| | |
| turn-left | Left turn/directional lamps |
| | |
| turn-right | Right turn/directional lamps |
| | |
| hazard | Hazard/four-way lamps |
+----------------+---------------------------------------------+
Table 5: eCall Lamp ID Registry Initial Values
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14.8.5. eCall Camera ID Registry
This document creates a new sub-registry called "eCall Camera ID
Registry" to standardize the names of automotive camera. As defined
in [RFC5226], this registry operates under "Expert Review" rules.
The expert should determine that the proposed camera name is clearly
understandable and is sufficiently distinguishable from other camera
names.
The content of this registry includes:
Name: The identifier to be used in the 'camera-ID' attribute of an
eCall control <request> element.
Description: A description of the camera.
The initial set of values is listed in Table 6.
+----------+--------------------------------------------------------+
| Name | Description |
+----------+--------------------------------------------------------+
| backup | Shows what is behind the vehicle. Also known as |
| | rearview, reverse, etc. |
| | |
| interior | Shows the interior (driver) |
+----------+--------------------------------------------------------+
Table 6: eCall Camera ID Registry Initial Values
15. Contributors
Brian Rosen was a co-author of the original document upon which this
document is based.
16. Acknowledgements
We would like to thank Bob Williams and Ban Al-Bakri for their
feedback and suggestions, and Keith Drage, James Winterbottom, Wes
George, and Rex Buddenberg for their review and comments. We would
like to thank Michael Montag, Arnoud van Wijk, Gunnar Hellstrom, and
Ulrich Dietz for their help with the original document upon which
this document is based.
17. Changes from Previous Versions
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17.1. Changes from draft-ietf-05 to draft-ietf-06
o Added additional security and privacy clarifications regarding
signed and encrypted data
o Additional security and privacy text
o Deleted informative section on ESINets as unnecessary.
17.2. Changes from draft-ietf-04 to draft-ietf-05
o Reworked the security and privacy considerations material in the
document as a whole and in the MIME registation sections of the
MSD and control objects
o Clarified that the <actionResult> element can appear multiple
times within an <ack> element
o Fixed IMS definition
o Added clarifying text for the 'msgid' attribute
17.3. Changes from draft-ietf-03 to draft-ietf-04
o Added Privacy Considerations section
o Reworded most uses of non-normative "may", "should", "must", and
"recommended."
o Fixed nits in examples
17.4. Changes from draft-ietf-02 to draft-ietf-03
o Added request to enable cameras
o Improved examples and XML schema
o Clarifications and wording improvements
17.5. Changes from draft-ietf-01 to draft-ietf-02
o Added clarifying text reinforcing that the data exchange is for
small blocks of data infrequently transmitted
o Clarified that dynamic media is conveyed using SIP re-INVITE to
establish a one-way media stream
o Clarified that the scope is the needs of eCall within the SIP
emergency call environment
o Added informative statement that the document may be suitable for
reuse by other ACN systems
o Clarified that normative language for the control block applies to
both IVS and PSAP
o Removed 'ref', 'supported-mime', and <media> elements
o Minor wording improvements and clarifications
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17.6. Changes from draft-ietf-00 to draft-ietf-01
o Added further discussion of test calls
o Added further clarification to the document scope
o Mentioned that multi-region vehicles may need to support other
crash notification specifications in addition to eCall
o Added details of the eCall metadata and control functionality
o Added IANA registration for the MIME content type for the eCall
control object
o Added IANA registries for protocol elements and tokens used in the
eCall control object
o Minor wording improvements and clarifications
17.7. Changes from draft-gellens-03 to draft-ietf-00
o Renamed from draft-gellens- to draft-ietf-.
o Added mention of and reference to ETSI TR "Mobile Standards Group
(MSG); eCall for VoIP"
o Added text to Introduction regarding migration/co-existence being
out of scope
o Added mention in Security Considerations that even if the network-
supplied location is just the cell site, this can be useful as a
sanity check on the IVS-supplied location
o Minor wording improvements and clarifications
17.8. Changes from draft-gellens-02 to -03
o Clarifications and editorial improvements.
17.9. Changes from draft-gellens-01 to -02
o Minor wording improvements
o Removed ".automatic" and ".manual" from
"urn:service:test.sos.ecall" registration and discussion text.
17.10. Changes from draft-gellens-00 to -01
o Now using 'EmergencyCallData' for purpose parameter values and
MIME subtypes, in accordance with changes to
[I-D.ietf-ecrit-additional-data]
o Added reference to RFC 6443
o Fixed bug that caused Figure captions to not appear
18. References
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18.1. Normative References
[EN_16072]
CEN, , "Intelligent transport systems - eSafety - Pan-
European eCall operating requirements", December 2011.
[I-D.ietf-ecrit-additional-data]
Gellens, R., Rosen, B., Tschofenig, H., Marshall, R., and
J. Winterbottom, "Additional Data Related to an Emergency
Call", draft-ietf-ecrit-additional-data-37 (work in
progress), October 2015.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
DOI 10.17487/RFC3688, January 2004,
<http://www.rfc-editor.org/info/rfc3688>.
[RFC5031] Schulzrinne, H., "A Uniform Resource Name (URN) for
Emergency and Other Well-Known Services", RFC 5031, DOI
10.17487/RFC5031, January 2008,
<http://www.rfc-editor.org/info/rfc5031>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>.
[RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton,
"Framework for Emergency Calling Using Internet
Multimedia", RFC 6443, DOI 10.17487/RFC6443, December
2011, <http://www.rfc-editor.org/info/rfc6443>.
[RFC6838] Freed, N., Klensin, J., and T. Hansen, "Media Type
Specifications and Registration Procedures", BCP 13, RFC
6838, DOI 10.17487/RFC6838, January 2013,
<http://www.rfc-editor.org/info/rfc6838>.
[RFC6881] Rosen, B. and J. Polk, "Best Current Practice for
Communications Services in Support of Emergency Calling",
BCP 181, RFC 6881, DOI 10.17487/RFC6881, March 2013,
<http://www.rfc-editor.org/info/rfc6881>.
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[RFC7303] Thompson, H. and C. Lilley, "XML Media Types", RFC 7303,
DOI 10.17487/RFC7303, July 2014,
<http://www.rfc-editor.org/info/rfc7303>.
[TS22.101]
3GPP, , "Technical Specification Group Services and System
Aspects; Service aspects; Service principles", .
[msd] CEN, , "Intelligent transport systems -- eSafety -- eCall
minimum set of data (MSD), EN 15722", June 2011.
18.2. Informative references
[CEN] "European Committee for Standardization",
<http://www.cen.eu>.
[I-D.ietf-ecrit-car-crash]
Gellens, R., Rosen, B., and H. Tschofenig, "Next-
Generation Vehicle-Initiated Emergency Calls", draft-ietf-
ecrit-car-crash-03 (work in progress), July 2015.
[MSG_TR] ETSI, , "ETSI Mobile Standards Group (MSG); eCall for
VoIP", ETSI Technical Report TR 103 140 V1.1.1 (2014-04),
April 2014.
[RFC5012] Schulzrinne, H. and R. Marshall, Ed., "Requirements for
Emergency Context Resolution with Internet Technologies",
RFC 5012, DOI 10.17487/RFC5012, January 2008,
<http://www.rfc-editor.org/info/rfc5012>.
[RFC5069] Taylor, T., Ed., Tschofenig, H., Schulzrinne, H., and M.
Shanmugam, "Security Threats and Requirements for
Emergency Call Marking and Mapping", RFC 5069, DOI
10.17487/RFC5069, January 2008,
<http://www.rfc-editor.org/info/rfc5069>.
[RFC6086] Holmberg, C., Burger, E., and H. Kaplan, "Session
Initiation Protocol (SIP) INFO Method and Package
Framework", RFC 6086, DOI 10.17487/RFC6086, January 2011,
<http://www.rfc-editor.org/info/rfc6086>.
[RFC7090] Schulzrinne, H., Tschofenig, H., Holmberg, C., and M.
Patel, "Public Safety Answering Point (PSAP) Callback",
RFC 7090, DOI 10.17487/RFC7090, April 2014,
<http://www.rfc-editor.org/info/rfc7090>.
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[RFC7378] Tschofenig, H., Schulzrinne, H., and B. Aboba, Ed.,
"Trustworthy Location", RFC 7378, DOI 10.17487/RFC7378,
December 2014, <http://www.rfc-editor.org/info/rfc7378>.
[SDO-3GPP]
"3d Generation Partnership Project",
<http://www.3gpp.org/>.
[SDO-ETSI]
"European Telecommunications Standards Institute (ETSI)",
<http://www.etsi.org>.
Authors' Addresses
Randall Gellens
Qualcomm Technologies, Inc.
5775 Morehouse Drive
San Diego 92651
US
Email: rg+ietf@randy.pensive.org
Hannes Tschofenig
(Individual)
Email: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at
Gellens & Tschofenig Expires August 22, 2016 [Page 44]