# Dynamic Extensions to the Presence Information Data Format Location Object (PIDF-LO) RFC 5962

Discuss

Yes

(Robert Sparks)

No Objection

(Dan Romascanu)
(Jari Arkko)
(Lisa Dusseault)
(Ron Bonica)
(Ross Callon)
(Russ Housley)

Note: This ballot was opened for revision 09 and is now closed.

Cullen Jennings Former IESG member
(was Yes) Discuss
Discuss [Treat as non-blocking comment] (2010-02-24)
`Waiting to see if any LC comment are received. LC End Mar 24.`
Robert Sparks Former IESG member
(was No Objection) Yes
Yes ()

No Objection
No Objection (2010-03-01)
```I'm not entering a Discuss, but I have a number of fairly strong Comments that I hope you will feel able to debate in email and make updates to the draft accordingly.

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This document defines PIDF-LO extensions that are intended to convey

Perhaps you could be a little more afirmative? Such as:

This document defines PIDF-LO extensions to convey information about
moving objects.

---

Why is the directional component of acceleration not supplied?

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In Section 3.1

The <orientation> and <heading> establish a direction.

Aren't they both directions in their own right? And can't they be
different?

<orientation> establishes a "direction of facing" while <heading>
establishes a "direction of travel".

---

In Section 3.1

Angular
measures are expressed in degrees and values MAY be negative.

Are you sure that this is an RFC 2119 "MAY"? Wouldn't "may" be perfectly

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In Section 3.1

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.

You (I hope) don't mean "either". Hopefully there is a little more
predictability! I think you mean:

The first measure specifies the horizontal direction from the current
position of the presentity to a point that it is pointing towards
(for <orientation>) or travelling towards (for <heading>).

---

In Section 3.1

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.

Well, surely it is only if the second angle value of <heading> is
omitted that you can make that assumption. If the second angle of
<orientation> is absent, it says nothing about speed.

Additionally, when you say "MAY" in this case, it implies that the
normal case is something else that you have not stated.

---

Section 5

At the very least, you are introducing additional information that may
be distributed. Knowledge of that information makes a presentity more
vulnerable, therefore the definition of additional Presence Information
puts further weight behind the need to use security mechanisms.```
Alexey Melnikov Former IESG member
No Objection
No Objection (2010-03-25)
```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,

s/two-dimensional/three-dimensional

longitude, altitude) CRS identified by "urn:ogc:def:crs:EPSG::4979".```
Dan Romascanu Former IESG member
(was Discuss) No Objection
No Objection ()

Jari Arkko Former IESG member
No Objection
No Objection ()

Lisa Dusseault Former IESG member
No Objection
No Objection ()

Ralph Droms Former IESG member
No Objection
No Objection (2010-03-03)
`It wouldn't hurt to add a definition or pointer to a definition of "presentity" to the Terminology section.`
Ron Bonica Former IESG member
No Objection
No Objection ()

Ross Callon Former IESG member
No Objection
No Objection ()

Russ Housley Former IESG member
No Objection
No Objection ()

Sean Turner Former IESG member
No Objection
No Objection (2010-05-21)
```One question and two nits.

I almost made this a DISCUSS but I decided against it.  Question:

Was there any thought given to allowing a system of measurement parameter (i.e., imperial vs metric) to allow different speed measurements (e.g., feet/second vs meters/second)?

Nits:

Section 2: r/through/throughout
Section 2: r/[RFC4079])/[RFC4079]```
Tim Polk Former IESG member
No Objection
No Objection (2010-03-03)
```I would also like to see some discussion of Adrian's comments.  I am particularly interested
in the decision to adopt the commonly used scalar definition of acceleration instead of the