Subject: RE: [mobile-ip] Heterogeneous Handover - How Would it Work?

From: "Dahl, Peter" <[email-masked]>
Date: Tue, 7 Aug 2001 09:32:58 -0700

FYI, the Wireless ISPs (WISPs) are already talking about such roaming
issues.  

There appear to be 2 emerging forums for these discussions, one under the
auspices of WECA (http://www.weca.net) known as the WISPr group ('r' being
for roaming), the other a yet to be finalized 'WISP Forum' the prime mover
for which is a company in Luxembourg (www.excilan.com).  

Regards

-----Original Message-----
From: James Kempf [mailto:[email-masked]]
Sent: Tuesday, August 07, 2001 8:58 AM
To: [email-masked]; [email-masked]
Subject: Re: [mobile-ip] Heterogeneous Handover - How Would it Work?

>On the other hand, the home address must belong to some ISP/operator.
>That ISP must provide a home agent and an ip address, and a CoA when the
>MN is connected to other than the home subnet. Other ISPs that are used
>are only access providers, and would give the MN its CoA. This of course
>would cause political problems. Who are the ISPs that are willing to be
>access providers only, and who will be providing home agent and home
>address as well?
>

This is an issue. What happens if you have one access provider on
one interface, say the wCDMA interface, and another on another, say 802.11?
There are now in the US a growing number of 802.11 access providers,
and I can imagine someone with a laptop having a wCDMA modem and
an 802.11 card. 

Maybe something like the "roaming consortia" that have sprung up
around ISP access might evolve, but the protocol design/engineering
issue is whether there is any additional work (such as the NAI in
the roaming consortia example) needed to enable sharing of a home
address among interfaces for which different ISPs are responsible.

Something like SUCV, that would allow an ISP to cryptographically identify
to what other ISP an address belonged, might be useful in this context.

		jak

---

From: Pat Calhoun <[email-masked]>
Date: Tue, 7 Aug 2001 09:30:01 -0700

Also, I believe that ETSI is working on a standard called GRX for GSM<->802.11
roaming.

PatC

---

From: "Brad Casemore" <[email-masked]>
Date: Tue, 7 Aug 2001 13:05:05 -0400

Aside from the relatively expensive proposition of joining WECA, could
anybody point me to a source that could provide an update on WISPr
progress? An article appeared in Network World at the end of May, but I
haven't seen or heard anything since.

> From: [email-masked] [mailto:owner-mobile-
> [email-masked]] On Behalf Of Dahl, Peter
> Sent: Tuesday, August 07, 2001 12:33 PM
> To: [email-masked]'
> Subject: RE: [mobile-ip] Heterogeneous Handover - How Would it Work?
>