Subject: RE: [Seamoby] Examples of CAR discovery

From: "Hemant Chaskar" <[email-masked]>
Date: Tue, 26 Mar 2002 22:32:58

Hi Henrik:

There is no doubt that MN-centric is fundamental point. But, here is what I 
mean by this statement:

CAR discovery in its simplest terms is about comparing "MN requirements" 
with "GAAR capabilities". The "place" where this comparison is done 
(processor MIPs for comparison instructions are executed) is 
solution-specific and neither relevant in problem statement phase nor 
requirements phase.

An example where such comparison may occur in network is when there is only 
one interface on MN and it can listen only to radio beacons of surrounding 
access points. This is similar to break-before-make handoff case. Here, MN 
cannot receive capabilities of GAARs without letting go the previous 
connection. Do you think that such cases are not relevant and we should 
exclude such cases right at the problem statement/requirements stage?

BR,
Hemant

>From: "Henrik Levkowetz" <[email-masked]>
>To: "Hemant Chaskar" <[email-masked]>, <[email-masked]>
>Subject: RE: [Seamoby] Examples of CAR discovery
>Date: Tue, 26 Mar 2002 23:10:47 +0100
>
>Catching up on this thread. Sorry if this point has already
>been made:
>
>Hemant wrote:
>...<snip>>
> > - The problem statement does not advocate any specific way 
>(network-based or
> > MN-based or hybrid) of performing CAR discovery.
>
>I believe this is pointing us in the wrong direction. I believe it is
>an essential part of CAR discovery that it is MN-centric. In other
>words, CAR discovery is the process of the Networks, Current Active
>Access Points and the MN itself (through stored information, scanning,
>this, that, and whatever other magic is available) providing *the MN*
>with information that *the MN* can use to assemble the most appropriate
>list of GAARs for *that MN* at that moment, from which *the MN* can
>destill its CARs.
>
>	Regards,
>		Henrik
>
>
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---

From: "Henrik Levkowetz" <[email-masked]>
Date: Tue, 26 Mar 2002 23:59:24 +0100

> solution-specific and neither relevant in problem statement phase nor 

Fine. The problem is, now is the time to agree on the constraints on the
solution, so that we don't design something inappropriate, or unduly
complex. I, for one, believe that it is an important characteristic of
this problem, and any appropriate solution, that not only the CAR -> TAR
process, but already the final assembly of the GAAR list, and from there
the generation of the CAR list, of necessity must reside in the MN as soon
as we try to be access technology agnostic. The activities of one particular
access technology network in determining handovers for that network should
of course influence which of that network's APs appear in the GAAR list.

> exclude such cases right at the problem statement/requirements stage?

I think that designing for the one access technology case will cripple
the solution.

	Regards,
		Henrik

---

From: "Henrik Levkowetz" <[email-masked]>
Date: Tue, 26 Mar 2002 23:59:24 +0100

Regards,
		Henrik