Subject: RE: [Geopriv] Making decisions based on location information

From: "James Winterbottom" <[email-masked]>
Date: Wed, 3 Aug 2005 09:41:45 +1000

Henning,

I do not believe that the PIDF-LO profile draft mentions technology, but it
clearly talks about minimum levels of location precision. There are clear
rules for some applications around this in the US with regard to cellular
positioning (50 metre accuracy if the endpoint is used to held determine the
location). The appendix to this draft provides a detailed example and of how
to construct a PIDF-LO from data received from DHCP option 123, and states
the required number of precision bits to achieve an accuracy of 100 metres
to meet US FCC network determined location requests for Geo.

I believe that it would be very beneficial to provide similar guidelines for
the civic location. The civic location definition without this basically
meaningless because ALL fields are optional, at least with the geodetic
representation the forms are defined by specific GML rules. I believe that
failure to provide at least some level of guidance in this direction is
tantamount to saying "Do not use Civic data as anything other that an
informational only". Which I am prepared to do, but I do not believe that
that is the intent of it.

So far the only concerns I am hearing against including this data are from
you. I would like to hear from other people if they have concerns in this
direction also.

Cheers
James

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf
Of Henning Schulzrinne
Sent: Wednesday, 3 August 2005 3:03 AM
To: Thomson, Martin [WOLL:5500:EXCH]
Cc: [email-masked]
Subject: Re: [Geopriv] Making decisions based on location information

> I am aware of the FCC mandate, however, if you read my comments, I am
> not talking about emergency routing only.  A recommendation of this 
> nature would extend to routing applications.

Then I'm even less sure what this would accomplish, given that the 
requirements may differ even more for other applications. (One could 
argue that pizza delivery has higher requirements since accidents and 
fires tend to announce themselves even if you're 100' away from the 
scene, while your pizza craving is unlikely to be as visible. But other 
location-based routing applications, such as calling an on-demand-bus to 
the nearest bus stop may have lower requirements, since the points of 
service delivery are limited.)

> WAAS isn't an option outside of the US, so I don't know why you would
> suggest it.

It illustrates that a resolution value that might be reasonable or 
desirable within the US is unavailable elsewhere.

> If you look at the cellular case, the same location information is NOT
> likely to be used for routing and dispatch.  I don't see why that model 
> is so irrelevant in this case.  Do a little research and you can 
> discover that in 15 seconds I can do an assisted GPS fix - obviously not 
> something you want to do before routing, but certainly very helpful in 
> dispatch.

Again, a case where this strongly depends on technology. Unless you 
restrict the technology, you are only going to be able to recommend the 
least-restrictive solution.

> Because an implementer is not always across all these issues.  A
> recommendation of this nature provides a goal, or a yardstick - 
> precisely the sort of thing that was requested in ECRIT earlier.
> 
>  > I don't think padding documents with recommendations that  > have 
> no sound  > technical basis, depend on technology choices we don't
>  > control and are
>  > likely to be overridden by people who actually matter in this
>  > discussion
>  > serves no purpose except to generate mailing list discussion.
>  >
> 
> You are yet to convince me of any of those statements.

You will see, I believe, that any suggestion of a number will yield 
endless and non-terminable debates as it will be essentially arbitrary. 
The IETF does not do technology requirements - almost never for its own 
technology and never for technology that is outside its scope of influence.

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---

From: John Schnizlein <[email-masked]>
Date: Wed, 3 Aug 2005 09:48:22 +0200

OK, although I am usually loathe to join the me-to contingent, I agree 
that attempts to include arbitrary mandatory precision statements in 
the protocol or requirements documents is a mistake.  It is not 
possible to anticipate the minimum requirements of all applications 
that might use location information.

John

On Aug 3, 2005, at 1:41 AM, James Winterbottom wrote:
>
> So far the only concerns I am hearing against including this data are 
> from you. I would like to hear from other people if they have concerns 
> in this direction also.
>
>> From: [email-masked] [mailto:[email-masked]] On 
>> Behalf Of Henning Schulzrinne
>> ...

---

From: "Brian Rosen" <[email-masked]>
Date: Wed, 3 Aug 2005 04:03:37 -0400

I do think that accuracy guidelines are helpful.  I'd like to propose some:

Lat/Lon - 10 meters is the requirement, 1 meter is desirable

Altitude - 1 meter is the requirement.  The actual requirement is an
unambiguous floor.

The FCC rule was a compromise primarily for outdoor use, and made
accommodations for the existing technology.  It doesn't represent what the
actual need is.

Brian

  _____  

From: [email-masked] [mailto:[email-masked]] On Behalf
Of James Winterbottom
Sent: Tuesday, August 02, 2005 7:42 PM
To: Henning Schulzrinne; Martin Thomson
Cc: [email-masked]
Subject: RE: [Geopriv] Making decisions based on location information

Henning, 

Cheers 
James

---

From: "Marc Linsner" <[email-masked]>
Date: Wed, 3 Aug 2005 04:43:59 -0400

I don't believe Geopriv can/should make accuracy recommendations, this is
most certainly a local policy.  I do agree that showing how an existing
local policy can be represented within the protocol is good appendix
material.
 
-Marc-

  _____  

From: [email-masked] [mailto:[email-masked]] On Behalf
Of Brian Rosen
Sent: Wednesday, August 03, 2005 4:04 AM
To: 'James Winterbottom'; 'Henning Schulzrinne'; 'Martin Thomson'
Cc: [email-masked]
Subject: RE: [Geopriv] Making decisions based on location information

Brian

  _____  

Henning, 

Cheers 
James

---

From: Henning Schulzrinne <[email-masked]>
Date: Wed, 03 Aug 2005 05:09:11 -0400

To clarify: I would also find guidance on mapping common meter/feet 
accuracy (say, 50/100/200/300m) to bit-level metrics very useful, 
although this obviously depends on where on earth one is located.

The DHCP civic draft already contains a list of items that are relevant 
for common countries. If there are additional countries where we can 
provide guidance, that might also be useful. The only other issue I can 
think of is to amplify that specifying random low-level items without 
the parent items is a bad idea (as in "Main Street, US").

Marc Linsner wrote:
> I don't believe Geopriv can/should make accuracy recommendations, this 
> is most certainly a local policy.  I do agree that showing how an 
> existing local policy can be represented within the protocol is good 
> appendix material.