ecrit@ietf.org
[Top] [All Lists]

Re: [Ecrit] Consensus Call: Precise Location Information not available t

Subject: Re: [Ecrit] Consensus Call: Precise Location Information not available to End Host
From: Hannes Tschofenig
Date: Sun, 22 Apr 2007 21:57:16 +0200
Henning Schulzrinne wrote:
We had talked about a more generic 2D polygon description earlier, primarily for wireless cases, so we may just get to do it now rather than later.

We could do that. That's true.
For the cellular case we could support the full http://www.ietf.org/internet-drafts/draft-ietf-geopriv-pdif-lo-profile-06.txt. I would, however, leave this as an extension for later. For the service boundary case we could obviously go for a much simpler approach.


We already have the necessary location profile (polygon), as it is used for the boundary.
Yes.

I don't see how re-using the service boundary reference helps. The UA still has to understand the reference and polygon. Can you describe exactly how this would work? I'd rather avoid special-casing this particular use case ("do one thing when you get a reference to a point, do something completely different when you get a reference to a polygon").

I also believe that defining a new location profile (or extending an existing one) would be much simpler.



On Apr 20, 2007, at 3:50 PM, Andrew Newton wrote:

After having some more time to noodle on this...

On Apr 20, 2007, at 4:50 AM, Hannes Tschofenig wrote:

7. A VSP wishing to validate the PSAP URI takes the LbyR and dereferences it. The result will be the same (coarse) location the endpoint got. The VSP does a LoST query with that location, and should get the same PSAP URI that is in the Request URI on the call. This validation works for coarse or fine validation, and of course works for LbyV without the dereference step.

This works without modification of LoST for civic, but I think it requires a modification of LoST for geo. The LoST geodetic-2d location profile takes a point as input, not an area.

That being said, I'm willing to live with the change to LoST to accommodate this requirement. We could create a new location profile or modify geodetic-2d, but then every geodetic (or non-civic) location profile would have to accommodate this use case. If we are to do this, I'd rather have a more generic mechanism that requires no changes to location profiles by re-using the service boundary reference. Such a service boundary reference could be conveyed in a PIDF-LO in a new element. That also allows LoST resolvers to optimize their lookup to a simple key vs. the more complex location information. The VSP wouldn't use the <findService> query for policing, but the <getServiceBoundary> query.

-andy

_______________________________________________
Ecrit mailing list
Ecrit@xxxxxxxx
https://www1.ietf.org/mailman/listinfo/ecrit


_______________________________________________
Ecrit mailing list
Ecrit@xxxxxxxx
https://www1.ietf.org/mailman/listinfo/ecrit

<Prev in Thread] Current Thread [Next in Thread>