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Versions: 00 01 02 03 04 05 06 07 08 09 RFC 5962

Network Working Group                                     H. Schulzrinne
Internet-Draft                                                  V. Singh
Intended status:  Standards Track                    Columbia University
Expires:  February 18, 2010                                H. Tschofenig
                                                  Nokia Siemens Networks
                                                              M. Thomson
                                                      Andrew Corporation
                                                         August 17, 2009


  Dynamic Extensions to the Presence Information Data Format Location
                            Object (PIDF-LO)
                 draft-singh-geopriv-pidf-lo-dynamic-07

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   This Internet-Draft is submitted to IETF in full conformance with the
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   This Internet-Draft will expire on February 18, 2010.

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   Copyright (c) 2009 IETF Trust and the persons identified as the
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Abstract

   The Geopriv Location Object introduced by the Presence Information
   Data Format - Location Object (PIDF-LO), RFC 4119, defines a basic
   XML format for carrying geographical information of a presentity.
   This document defines PIDF-LO extensions that are intended to convey
   information about moving objects.  Elements are defined that enable
   expression of spatial orientation, speed, heading, and acceleration
   of the presentity.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  Dynamic Elements . . . . . . . . . . . . . . . . . . . . . . .  3
     3.1.  Angular Measures and Coordinate Reference Systems  . . . .  5
   4.  Dynamic Feature XML Schema . . . . . . . . . . . . . . . . . .  7
   5.  Security Considerations  . . . . . . . . . . . . . . . . . . .  8
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  8
     6.1.  Dynamic Feature Extensions Namespace Registration  . . . .  8
     6.2.  Dynamic Feature Extensions Schema Registration . . . . . .  8
   7.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .  9
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . .  9
     8.1.  Normative References . . . . . . . . . . . . . . . . . . .  9
     8.2.  Informative References . . . . . . . . . . . . . . . . . .  9
   Appendix A.  Earth Centered, Earth Fixed Direction Vectors . . . . 10
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10























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1.  Introduction

   The Presence Information Data Format - Location Object (PIDF-LO) (see
   RFC 4119 [RFC4119]) provides geographical location of a presentity.
   This corresponds to a physical location at a given instance of time.
   With the extensions defined in [RFC5491] more guidelines to
   implementers are being provided with respect to the expression
   location information in PIDF-LO.

   The addition of rate of change information to the PIDF-LO enables a
   range of use cases.  These use cases either directly use dynamic
   information, or use that information for smoother tracking of a
   position over time.  For example, an application that continuously
   tracks a presentity could use velocity information to extrapolate
   positions in between times location information is measured.  A
   shipping company could directly use speed to monitor delivery truck
   speed to ensure speed limits are observed.


2.  Terminology

   In this document, the key words "MUST", "MUST NOT", "REQUIRED",
   "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
   and "OPTIONAL" are to be interpreted as described in RFC 2119
   [RFC2119].


3.  Dynamic Elements

   This document defines a new element, <Dynamic>, for the conveyance of
   dynamic information.

   Dynamic information MAY be included without any other location
   information being present.  When dynamic information is associated
   with information about the instantaneous position of the presentity,
   the <Dynamic> element MUST be included in the same <location-info>
   element as the corresponding geodetic (or civic) location
   information.

   Dynamic information can be safely ignored by a recipient that does
   not support this specification.

   The <Dynamic> element contains the following components:
   orientation:

      The <orientation> element describes the spatial orientation of the
      presentity; the direction that the object is pointing.  For a
      device, this orientation might depend on the type of device.  See



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      Section 3.1 for details.

   speed:

      Speed is the time rate of change in position of a presentity
      without regard for direction; the scalar component of velocity.
      The value for the <speed> element is a measure that is defined in
      meters per second.

   heading:

      Heading is directional component of velocity.  See Section 3.1 for
      details.

   acceleration:

      Acceleration is the time rate of change of velocity.  This element
      contains the scalar component of velocity, measured in meters per
      second per second.

   Each element can be omitted if no information is available.  In the
   following example the presentity is approximately oriented to the
   North at a slightly elevated angle.  The presentity is travelling 24
   meters per second to the West:

   <?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:dynamic"
       xmlns:gml="http://www.opengis.net/gml"
       entity="pres:alice@example.com">
       <dm:device id="abc123">
           <gp:geopriv>
               <gp:location-info>
                   <dyn:Dynamic>
                       <dyn:orientation>-3 12</dyn:orientation>
                       <dyn:speed>24</dyn:speed>
                       <dyn:heading>278</dyn:heading>
                   </dyn:Dynamic>
               </gp:location-info>
               <gp:usage-rules/>
               <method>gps</method>
           </gp:geopriv>
           <timestamp>2009-06-22T20:57:29Z</timestamp>
           <dm:deviceID>mac:1234567890ab</dm:deviceID>
       </dm:device>



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   </presence>

   Another example shows a PIDF-LO document of the presentity
   alice@example.com on a bike traveling 12 meters per second and with
   an acceleration of 2 meters per second.  Her position is indicated as
   a circle.  The values for speed and acceleration might be used by a
   receiver to adjust the uncertainty over time.

   <?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:dynamic"
       xmlns:gml="http://www.opengis.net/gml"
       xmlns:gs="http://www.opengis.net/pidflo/1.0"
       entity="pres:alice@example.com">
       <dm:device id="abc123">
           <gp:geopriv>
               <gp:location-info>
                   <gs:Circle srsName="urn:ogc:def:crs:EPSG::4326">
                       <gml:pos>42.5463 -73.2512</gml:pos>
                       <gs:radius uom="urn:ogc:def:uom:EPSG::9001">
                           100
                       </gs:radius>
                   </gs:Circle>
                   <dyn:Dynamic>
                       <dyn:speed>12</dyn:speed>
                       <dyn:acceleration>2</dyn:acceleration>
                   </dyn:Dynamic>
               </gp:location-info>
               <gp:usage-rules/>
               <method>gps</method>
           </gp:geopriv>
           <timestamp>2009-06-22T20:57:29Z</timestamp>
           <dm:deviceID>mac:1234567890ab</dm:deviceID>
       </dm:device>
   </presence>

3.1.  Angular Measures and Coordinate Reference Systems

   [RFC5491] constrains the coordinate reference system (CRS) used in
   PIDF-LO to World Geodetic System 1984 (WGS 84) using either the two-
   dimensional (latitude, longitude) CRS identified by
   "urn:ogc:def:crs:EPSG::4326" or the two-dimensional (latitude,
   longitude, altitude) CRS identified by "urn:ogc:def:crs:EPSG::4979".
   Dynamic locations similarly assume that either of these coordinate
   reference systems are used.



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   The <orientation> and <heading> establish a direction.  Both measures
   contain one or two angular values that are expressed relative to the
   current position of the presentity (see Appendix A).  Angular
   measures are expressed in degrees and values MAY be negative.  If two
   measures are present, the values MUST be separated by whitespace.

   The first measure specifies the horizontal direction from the current
   position of the presentity to a point that it either pointing towards
   or travelling towards.  Horizontal angles are measured from Northing
   to Easting.  Horizontal angles start from zero when pointing to or
   travelling towards the North and increase towards the East.

   The second measure, if present, specifies the vertical component of
   this angle.  This angle is the elevation from the local horizontal
   plane.  If the second angle value is omitted, the vertical component
   is unknown and the speed measure MAY be assumed to only contain the
   horizontal component of speed.


































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4.  Dynamic Feature XML Schema

   <?xml version="1.0"?>
   <xs:schema
       targetNamespace="urn:ietf:params:xml:ns:pidf:dynamic"
       xmlns:dyn="urn:ietf:params:xml:ns:pidf:dynamic"
       xmlns:xs="http://www.w3.org/2001/XMLSchema"
       elementFormDefault="qualified"
       attributeFormDefault="unqualified">

     <xs:element name="Dynamic" type="dyn:dynamicType"/>

     <xs:complexType name="dynamicType">
       <xs:complexContent>
         <xs:restriction base="xs:anyType">
           <xs:sequence>
             <xs:element name="orientation" minOccurs="0"
                         type="dyn:directionType"/>
             <xs:element name="speed" minOccurs="0"
                         type="xs:double"/>
             <xs:element name="heading" minOccurs="0"
                         type="dyn:directionType"/>
             <xs:element name="acceleration" minOccurs="0"
                         type="xs:double"/>
             <xs:any namespace="##other" processContents="lax"
                     minOccurs="0" maxOccurs="unbounded"/>
           </xs:sequence>
           <xs:anyAttribute namespace="##other" processContents="lax"/>
         </xs:restriction>
       </xs:complexContent>
     </xs:complexType>

     <xs:simpleType name="directionType">
       <xs:restriction base="dyn:doubleListType">
         <xs:minLength value="1"/>
         <xs:maxLength value="2"/>
       </xs:restriction>
     </xs:simpleType>

     <xs:simpleType name="doubleListType">
       <xs:list itemType="xs:double"/>
     </xs:simpleType>

   </xs:schema>







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5.  Security Considerations

   This document defines additional location elements carried by
   PIDF-LO.  No additional security considerations beyond those
   described in RFC 4119 [RFC4119] are applicable to this document.


6.  IANA Considerations

   This section registers a new XML namespace (as described in
   [RFC3688]) and a new XML schema.

6.1.  Dynamic Feature Extensions Namespace Registration

   URI:  urn:ietf:params:xml:ns:pidf:dynamic"

   Registrant Contact:  IETF Geopriv Working Group, Hannes Tschofenig
      (hannes.tschofenig@gmx.net).

   XML:

   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>
     <title>Dynamic Feature Extensions Namespace</title>
   </head>
   <body>
     <h1>Namespace for Dynamic Feature Extensions to PIDF-LO</h1>
     <h2>urn:ietf:params:xml:ns:pidf:dynamic</h2>
   <p>See <a href="[URL of published RFC]">RFCXXXX
       [NOTE TO IANA/RFC-EDITOR:
        Please replace XXXX with the RFC number of this
       specification.]</a>.</p>
   </body>
   </html>
   END

6.2.  Dynamic Feature Extensions Schema Registration

   URI:  urn:ietf:params:xml:schema:pidf:dynamic








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   Registrant Contact:  IETF Geopriv Working Group, Hannes Tschofenig
      (hannes.tschofenig@gmx.net)

   XML:  The XML schema to be registered is contained in Section 4.  Its
      first line is

   <?xml version="1.0"?>

      and its last line is

   </xs:schema>


7.  Acknowledgements

   We would like to thank Klaus Darilion, Cullen Jennings, Rohan Mahy,
   Carl Reed, and Brian Rosen for their comments.


8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              January 2004.

   [RFC4119]  Peterson, J., "A Presence-based GEOPRIV Location Object
              Format", RFC 4119, December 2005.

8.2.  Informative References

   [GeoShape]
              Thomson, M. and C. Reed, "GML 3.1.1 PIDF-LO Shape
              Application Schema for use by the Internet Engineering
              Task Force (IETF)", Candidate OpenGIS Implementation
              Specification 06-142, Version: 0.0.9, December 2006.

   [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.







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Appendix A.  Earth Centered, Earth Fixed Direction Vectors

   The absolute orientation or heading of a presentity depends on its
   latitude and longitude.  The following vectors can be used to
   determine the absolute direction in the WGS 84 Earth Centered, Earth
   Fixed (X, Y, Z) coordinate space.

   The direction of North as a unit vector in ECEF coordinates is:

      North = [ -1 * sin(latitude) * cos(longitude),
                -1 *  sin(latitude) * sin(longitude),
                cos(latitude) ]

   The direction of "up" (the upward normal of the horizontal plane) as
   a unit vector in ECEF coordinates is:

      Up = [ cos(latitude) * cos(longitude),
             cos(latitude) * sin(longitude),
             sin(latitude) ]


Authors' Addresses

   Henning Schulzrinne
   Columbia University
   Department of Computer Science
   450 Computer Science Building, New York, NY  10027
   US

   Phone:  +1 212 939 7004
   Email:  hgs@cs.columbia.edu
   URI:    http://www.cs.columbia.edu/


   Vishal Singh
   Columbia University
   Department of Computer Science
   450 Computer Science Building, New York, NY  10027
   US

   Email:  vs2140@cs.columbia.edu
   URI:    http://www.cs.columbia.edu/~vs2140









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   Hannes Tschofenig
   Nokia Siemens Networks
   Linnoitustie 6
   Espoo  02600
   Finland

   Phone:  +358 (50) 4871445
   Email:  Hannes.Tschofenig@gmx.net
   URI:    http://www.tschofenig.priv.at/


   Martin Thomson
   Andrew Corporation
   Wollongong
   NSW Australia

   Email:  martin.thomson@andrew.com


































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