1. Dynamic Feature Extensions to the Presence Information Data Format Location Object (PIDF-LO) draft-singh-geopriv-pidf-lo-dynamic-02.txt
Vishal K. Singh
Henning Schulzrinne
Hannes Tschofenig
IETF 70, Vancouver

2. Requirements and Use Cases
Mechanism to indicate temporal features of entities = location of moving objects
Use cases:
location tracking
fewer messages than providing position samples
fleet management (trucks)
safety of personnel
Extends PIDF-LO (RFC 4119) with temporal feature elements

3. Dynamic Feature Elements
Based on GML’s dynamicFeature.xsd
Speed
Measure of the rate of motion
Bearing
Horizontal direction of one terrestrial point from other
type gml:DirectionPropertyType
Acceleration
Change of speed
directionOfObject
Instantaneous horizontal of front of object relative to true north and vertical angle relative to earth’s spheroid
type gml:DirectionVector
dropped elevation

4. Example xmlns:gml=“http://www.opengis.net/gml” <gml:bearing>
<presence xmlns="urn:ietf:params:xml:ns:pidf“
xmlns:gp=“urn:ietf:params:xml:ns:pidf:geopriv10”
xmlns:gml=“
<tuple id="sg89ae">
<status>
<gp:geopriv>
<gp:location-info>
<gml:location> ………… </gml:location>
<gml:speed uom="#m/s">12</temp:speed>
<gml:bearing>
<gml:DirectionVector>
<gml:vector> </gml:vector>
</gml:DirectionVector>
</gml:bearing>
</gp:location-info>
<gp:usage-rules>
………… ………… …………
</gp:usage-rules>
</gp:geopriv>
</status>
<timestamp> T20:57:29Z</timestamp>
</tuple>
</presence>

5. Indicating use of Dynamic Feature PIDF-LO using SIP
Use of SIP Accept header
Proposes use of “supported” parameter
For example:
Accept: application/pidf+xml;
supported="geopriv-temporal-features"
Content-Type header
Content-Type: application/pidf+xml

6. Open Issues Units of measurements
could also assume single default unit (m/s, m2/s)
Restrict options for bearing and directionOfObject to <vector>
others (compass point) can be translated to angles or are not interopable (DirectionKeyword)
How to indicate use of dynamic feature PIDF-LO in HELD?

7. Next Steps Adopt this as WG draft Submit a new version
Close the open issues
IANA considerations
Revise the text

8. Backup Slides

9. Multiple Moving Object Elements
Watchers may request to receive multiple location vector objects together
Use of <timed-status> to transfer multiple location vector objects
<tuple>
<status>
<gp:geopriv> </gp:geopriv>
</status>
<timestamp>.....</timestamp>
<timed-status from="some time" until="some time">
<gp:geopriv> </gp:geopriv>
<gp:geopriv> </gp:geopriv>
</timed-status>
</tuple>
<tuple> </tuple>

10. Alternatives Considered
Could use <MovingObjectStatus> or its parent element <track> from GML’s dynamicFeature.xsd
But…
Backward compatibility problems OR
<location> appears twice
tuple 1
status
geopriv 1
location-info movingobjectstatus
location
speed location-info geopriv 2
old system won’t find <location>
duplicate <location> - mandatory below <movingobjectstatus>
tuple 1
status
geopriv 1
location-info location movingobjectstatus
location
speed geopriv 2