Subject: Re: [Seamoby] Examples of CAR discovery

From: Parviz Yegani <[email-masked]>
Date: Mon, 01 Apr 2002 00:32:00 -0800

Hi Jim,

Comments inline...

At 10:35 AM 3/31/2002 -0800, James Kempf wrote:
>Hi Charlie,
>
> > I didn't know that NSIS was gearing up to supply the needs
> > of handovers -- and, in a way, I hope they don't because I
> > can't follow that many mailing litss.  And besides, if smooth
> > handovers is not part of [seamoby] charter, what is?!
> > Lastly, I claim that QoS management in the small is a
> > pretty essential requirement for smooth handovers.
> > Surely, remote signaling is to be avoided.
> >
>
>Well, we need to confirm this with Allison, but my reading of the
>Seamoby charter does not include anything on doing QoS for handover.

What do you mean by "QoS for handover"? Are there any requirements defined
for this in IETF?
I hope this will be done in Seamoby. As Charlie said there are too many 
mailing
lists and it's very hard for one to follow all the email discussions on 
these lists.

>I
>believe NSIS was established for purposes of consolidating all the QoS
>for wireless work.

Could you please briefly tell us what NSIS is supposed to accomplish as far 
as QoS
for wireless is concerned? As you may both 3GPP and 3GPP2 folks are working on
an end-to-end QoS solution for mobile wireless systems and applications 
(beyond 3G).
In this work we are heavily relying on the IETF existing protocols. It 
would be interesting
to know if IETF is going to standardize yet another protocol specifically 
tailored/designed
for wireless applications.

Thanks,
Parviz
>Of course, if that isn't covered and the WG wants to
>expand the charter we could discuss it when we finish our current work
>items.

> > This is true, but that's the breaks.  A lot of bad things could
>happen,
> > and if there is a recognized danger, then we should go with the
>provisional
> > short-lived reservations.
> >
>
>Right, well, some of the bad things that can happen are large scale
>hysterisis in which MNs rythmically switch between cells. There are
>explicit measures taken in cellular protocols to avoid this kind of
>behavior (e.g. add and delete power levels for adding or removing BTSs
>from the active set), because it makes load management difficult. Such
>nonlinear effects are typical when the time constants between two
>different but linked processes are an order of magnitude or more
>different. Of course, simulations are in order here to see if this
>intuition applies to this particular case, mitigation may be possible
>and even easy as in the CDMA power level case.
>
>BTW, I was not speaking here about, for example, advertising that a
>particular wireless link was configured with so-and-so much bandwidth
>capacity. I think that could be useful, for example, in order for an MN
>to determine whether it wanted to make use of some hotspot support. A
>specific example, suppose I have two choices for hotspot support,
>802.11b at 5 Mbps and Bluetooth at 600 kbps. and suppose that the type
>of media didnt' allow me to differentiate, ie. I could have 802.11 at a
>lower or higher rate. The MN could use this information to determine
>what kind of hotspot media it wanted.
>
>                 jak
>
>
>_______________________________________________
>Seamoby mailing list
>[email-masked]
>https://www1.ietf.org/mailman/listinfo/seamoby

_________________
Parviz Yegani, Ph.D.
Mobile Wireless Group
Cisco Systems
3625 Cisco Way
San Jose, CA 95134
(408) 853-9018 (voice)
(408) 832-5729 (mobile)
(408) 853-3543 (fax)
Email: [email-masked]

_______________________________________________
Seamoby mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/seamoby

---

From: Parviz Yegani <[email-masked]>
Date: Mon, 01 Apr 2002 00:32:00 -0800

Hi Jim,

Comments inline...

Thanks,
Parviz

_________________
Parviz Yegani, Ph.D.
Mobile Wireless Group
Cisco Systems
3625 Cisco Way
San Jose, CA 95134
(408) 853-9018 (voice)
(408) 832-5729 (mobile)
(408) 853-3543 (fax)
Email: [email-masked]

---

From: "James Kempf" <[email-masked]>
Date: Mon, 1 Apr 2002 09:26:11 -0800

Parviz,

> What do you mean by "QoS for handover"?

As I see it, there are two issues:

1) Providing the mobile with a CAR capability that gives the configured
QoS of an access router. The configured capability would change very
slowly, if at all.

2) Providing the mobile with dynamic IP level QoS measurements at the
time of handover, on a time scale similar to power measurements, so the
mobile could use that in addition to power levels to determine handover.

>Are there any requirements defined
> for this in IETF?

We are in the process of defining CAR discovery requirements, so that
would cover 1) above. 2) is currently under debate as to whether Seamoby
is the right place to investigate it.

> lists and it's very hard for one to follow all the email discussions
on

I appreciate the problem, but IETF WGs typically have fixed charters. To
succeed, a WG must focus on its charter, otherwise, it can easily become
distracted and not get anything done. If dynamic QoS determination at
handover is decided not to be in Seamoby's charter, then the discussion
must be moved elsewhere. It is possible to change the charter with
approval of the AD, but I feel that Seamoby's charter is now a good
match between the amount of work and the number of people who have
actually exhibited an inclination to work on the charter items (as
opposed to those who insist on including charter items and then vanish
when there is work to do on them).

> for wireless applications.

Please read the NSIS WG page, available through the IETF web site.

            jak

---

From: "James Kempf" <[email-masked]>
Date: Mon, 1 Apr 2002 09:26:11 -0800

Parviz,

            jak

---

From: Teemu Rinta-aho <[email-masked]>
Date: Tue, 2 Apr 2002 12:19:00 +0300 (EEST)

On Fri, 29 Mar 2002, James Kempf wrote:

> > > I'd like it if, eventually, availability of QoS would be considered
> > > a "Capability", and discoverable by way of this CAR protocol that
> > > is under discussion. Such information is not static.
> > >
> > > Indeed, I'd like it if the actual qualifications for candidacy of an
> > > access router were _data_, separated from the actual discovery
> > > protocol, as far as possible.
> >
> > I like what Charlie is saying here and that was my original thoughts
> with
> > contract NET protocols (CNP) being used to decide on the best handoff
> > candidate based on vectors of metrics exchanged between the mobile and
> the
> > AR/AP (watcha callits).
> >
> 
> So the problem I have with this is that, given one (1) specific wireless
> link protocol,
> I can't see why the QoS or any other characteristic should differ
> between one access
> point and another.

What if these two access points doing the same wireless link protocol are
connected to different access routers, possibly belonging to different
ISPs? Then they can have different QoS all the way from the MN to the CN.
For example, the first access router may be connected to the internet with
broadband cable and the other access router may be a mobile router using
satellite uplink?

BR,
Teemu

-- 
Teemu Rinta-aho                    Tel: +358 9 299 3078
NomadicLab, Ericsson Research      Fax: +358 9 299 5055
Oy L M Ericsson Ab                 Mobile: +358 40 562 3066
FIN-02131 Espoo, Finland           E-mail: [email-masked]

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From: Teemu Rinta-aho <[email-masked]>
Date: Tue, 2 Apr 2002 12:19:00 +0300 (EEST)

BR,
Teemu