Re: [Geopriv] HELD comment on responseTime parameter

From: Cullen Jennings ^lt;fluffy@cisco.com>
Date: Tue Aug 14 2007 - 22:46:14 EDT

On Aug 14, 2007, at 5:52 PM, Dawson, Martin wrote:

> Hi Cullen,
>
> Thank you - and you've still got your head :)

An issue that people are working on correcting :-)

>
> My quick response is:
>
> I think the client *has* to know what the application for the location
> is. If the client is implemented as an "agent" on the device through
> which other applications query, then that agent needs to support an
> API
> through which the applications can prescribe the sensible response
> time.

Sure, makes sense, but I think my question is much more naive and
simple minded. Assuming you have all this, what is the right time to
put in for the E911 application? How many seconds? Does it change in
different situations?

>
> If the client doesn't know what response time is appropriate then it's
> not going to know any more if the LIS replies with some information
> about a better location being available if you'd like to hang around.

Hmm - this point has not been obvious to me. You could be right - I'm
just trying to still get my head around this. Take for example the
GPS navigation system in my car. Imagine it was getting it's location
not via GPS but via this protocol. This particular application is
totally useless unless it gets a location so there is no point
returning until a location is available. Would it put more or less
infinity in the time? On the other hand, once it have a location
with a hundred meters or so it is typically pretty useful so it
certainly does not want to wait for some estimate that has a 99%
change of being within 0.2 meters. I'm not going anywhere with this
argument other than trying to explain some of the things that cloud
the issue for me on the hope that folks on this list can provide
clarity. Again, for this specific application, as an implementor of
the client, I really don't know what I would put in the responseTime.
Suggestions?

>
> If the client doesn't know how quickly it needs location then all bets
> are off. It also can't say whether ASAP or "MostAccurate" are
> appropriate.
>
> Cheers,
> Martin
>
> Oh - you're right LIS means exactly the same thing as LCS.

No worries here but I think we still might be talking pas each other
a little. I suspect you and I think of a LIS as about the same thing
since I got my definition of it from some excellent book called "IP
Location" but I think of the LCS having much less functionality than
a LIS. I suspect you view LCS functionality as being roughly
equivalent or the same as LIS. I don't think any of this matters for
the conversation about responseTime but later we will have to be
careful with the terms to make sure everyone is clearly understanding.

> (LCS=LIS=LS+LG) I use the term because LIS is what is used in the
> vernacular in the rest of the industry. I think all the regulars in
> Geopriv understand this but occasional visitors from the wider
> industry
> do not. LCS was coined relatively recently - and for no apparent
> useful
> purpose that I can fathom. The term "configuration" was only ever
> adopted to resonate with DHCP - and despite the fact that location
> isn't
> being "configured" in the same sense that a host is being
> "configured".
> I like "LIS", people outside Geopriv know what it means, it can be
> pronounced, and it doesn't have the namespace collision that LCS has
> with 3GPP. Call me an oddball - but I'll keep using it.

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Received on Tue, 14 Aug 2007 19:46:14 -0700

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