RE: Confidence (was: Geopriv WG - meeting 5-6 Jun, other news)

In the LIF variant, confidence (although I'm not sure that's the right
word here) is expressed as a shape.

You can see examples of this in the LIF (Location Interoperability
Forum) Mobile Location Protocol specification (technically "LIF TS 101
v2.0.0"). I hope you IETF folks are referring to that, we spent a lot
of time getting it right (especially in the public-within-weeks LIF TS
101 v3.0.0, which incorporates shapes and coordinate reference systems
from OGC's GML (Geographic Markup Language).

In particular, some typical regions are

. A circle or ellipse (if you are doing cell-id with a tower with a
non-directional antenna, or GPS).
. A cone (if you are doing cell-id with a directional antenna on a
tower)
. A "banana" (if you are doing cell-id with a directional antenna on a
tower, and you are using timing-advance)

You get some really funky regions if you have detailed coverage
information and you are in a mountainous region. A set of disjoint
mountaintops, for example.

Dan Greening, Ph.D. CEO, BigTribe Corporation
              330 Townsend Street, Suite 209, San Francisco, CA
94107-1662
              greening@bigtribe.com +1(415)995-7151 fax 995-7155

-----Original Message-----
From: Zmolek, Andrew (Andrew) [mailto:zmolek@avaya.com]
Sent: Friday, May 17, 2002 10:24 AM
To: Richard Shockey; James M. Polk; Allison Mankin;
ietf-geopriv@mail.apps.ietf.org
Cc: ned.freed@mrochek.com; rg+ietf@qualcomm.com
Subject: Confidence (was: Geopriv WG - meeting 5-6 Jun, other news)

Richard Shockey wrote:

> I have to admit that I am struggling with how to
> express the concept of confidence in the accuracy
> of the location data source..
> if you look at the problem set in wireless it might
> help in determine what may or may not be needed here

Wireless confidence is very focused on measurement, but let's keep in
mind that confidence might also be expressible in terms of intelligence
that can infer location indirectly (i.e. based on what I know I'm 70%
sure you are in your office right now). If this intelligence wasn't
derived by signal triangulation or GPS, than confidence measurement is a
bit more subjective.

--Andy Zmolek
    Technology & Standards Engineer
      CTO Standards
        Avaya Inc.

            zmolek@avaya.com
              +1 720 444 4001
                sip:zmolek@avaya.com
Received on Sat May 18 13:02:58 2002