Subject: RE: [Geopriv] WGLC for draft-ietf-geopriv-pidf-lo-01.txt

From: "Abbott, Nadine B." <[email-masked]>
Date: Fri, 19 Mar 2004 14:24:50 -0500

draft-ietf-geopriv-pidf-lo-01 defines the optional 'timestamp' element as:
"designates the time at which the PIDF document was created."

If the UA creates the pidf-lo at the time that it determines/receives its
location and then saves it for insertion later in session initiation
signaling, then it would seem to meet the need identified by Scott.  If,
however, the pidf is created at the time of session initiation to an ECC,
then it doesn't seem to match.  Is it possible to assume/indicate that the
LO part of the PIDF-LO should be created when location is
determined/received?  If not, could the defintion of the "timestamp" be
changed to indicate "the time at which the LO was
determined/received/updated"?  That would seem to be more useful anyway,
since the time that the session was initiated could be determined/inferred
from other information, I think.

There is then the question of when the location object itself was actually
created (e.g., via "wiremap" updates vs. real-time GPS acquisition), as
opposed the time it was associated with the UA? (i.e., how good is the
wiremap?)   I'm not sure how the ECC could use this anyway, since some
wiremaps might not change or be updated for a year or more and still be
accurate. In addition, a "creation" timestamp would affect the definitions
of location objects in draft-ietf-geopriv-dhcp-lci-option-03.txt and
draft-ietf-geopriv-dhcp-civil-01. Probably not possible to add there at this
time, anyway. So, I've convinced at least myself that this doesn't need to
be considered.

-----Original Message-----
From: [email-masked]
To: [email-masked]
Cc: 'James M. Polk'; 'Peterson, Jon'; 'Rosen, Brian'; [email-masked];
'Rick Jones (AOL)'; [email-masked]
Sent: 3/18/2004 11:30 PM
Subject: Re: [Geopriv] WGLC for draft-ietf-geopriv-pidf-lo-01.txt

> Field addition needed to civil and geo location formats: the time at
> which the information was derived by an endpoint or network element.
> Note that this is different from a timestamp on a packet that shows
when
> the location information was transported with an emergency call.

The optional <timestamp> field in PIDF (the 'ancestor' of PIDF-LO) 
contains such data. Is there a reason it cannot be used here?

_______________________________________________
Geopriv mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/geopriv

_______________________________________________
Geopriv mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/geopriv

---

From: Henning Schulzrinne <[email-masked]>
Date: Fri, 19 Mar 2004 17:46:43 -0500

At least my understanding was that the timestamp reflects the time when
the information in PIDF-LO was current, regardless of whether it is sent
immediately or not. (There may be good reasons to delay the sending of
this information in non-emergency situations; for example, privacy
concerns might make it seem advisable to only let you know where I was,
not where I'm currently at. This is sufficient for bookkeeping for an
employer, for example. I admit this is a bit contrived.)

As you say, there is other information that indicates when the message
was actually sent, such as the timestamp in the SIP message.

It might be helpful to document this more precise understanding somewhere.