RE: AW: [Geopriv] Quickrandomcommentsondraft-ietf-geopriv-pdif-l o -profile-00

Hang on.....

> 
> For geo, the problem is that different jurisdictions have 
> different requirements for accuracy, e.g., the FCC rules for 
> wireless devices that speak of probabilities for different 
> accuracy levels. Since jurisdictional boundaries for PSAPs 
> are typically aligned on property lines, i.e., individual 
> residences, for residential or commercial use, you could have 
> a 1 foot error put you erroneously in the wrong county and 
> PSAP. I don't think this matters in practice, but it 
> indicates that picking a number will be rather difficult. I 
> suspect that in almost all cases, people will simply provide 
> whatever accuracy they can get from their GPS or other 
> location device and set the bit count to "max", regardless of 
> whether this is actually true or not. (Converting the 
> circular accuracy estimates you get from your GPS unit to the 
> units used in 3825 requires a bit of spherical geometry 
> calculations that I don't see your average local wiremap 
> maintainer performing.)

I accept the fact that RFC-3825 obviously fails in expressing this
adequately, my bad.

HEAR YE, HEAR YE:

RFC-3825 is not intended to convey the accuracy anomalies associated with
the measuring geo coordinates.  Nor, is RFC-3825, in it's current state,
intended to convey 'bounding boxes' typically associated with geo
triangulation measuring techniques.

Rationale: As stated in RFC-3825, although subtly:

"The goal of this option is to enable a wired Ethernet host to obtain its
location,"

It is/was assumed by the authors of RFC-3825 that operators of multi-story
structures *may* have at their disposable geo information that is more
accurate than a 2 second fix from a consumer grade gps standing outside of
their respective structure (although a 20 second fix is pretty good, and
well within *most* location use cases, with today's technology).  IF such
geo information is available, maybe from the surveyor/engineer associated
with the building, this data *should* not include accuracy components.  (If
you hire a surveyor that supplies you with an accuracy component, disregard
the data and hire another one! (Hmm, I think your property line is here and
I think your building is there!))

"This resolution sub-field accommodates the desire to easily adjust the
precision of a reported location."

The intended resolution sub-field purpose:

1) The ability to convey the data more accurately - The data I have does not
match the resolution the LO is capable of conveying (don't believe the
lower-order bits).

2) To satisfy the privacy requirements within GeoPriv during the RFC-3825
timeframe (the ability to 'hide').

I hope this helps in further understanding use cases for RFC-3825.

-Marc-

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