Subject: [MOBILE-IP] handover: proactive versus reactive

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 14:56:47 +0100

Hi all,

    I have listened the discussion about generic link layer assistance
in handing off between cells and it looks to me that most people would
appreciate some standardised 'hints' by the link layer that would enable
more proactive rather than reactive handoff. Does proactive handoff
encompass in your thinking the handoff at will (user-initiated based on
qos policy)

I do not know how much people agree on this or not but giving too much
freedom to a mobile node in handing off creates mobility patterns (on
the network side) with rather high entropy. That effectively renders
less predictable the service provisioning in a wireless network  cell (I
am trying to look at these issues for my research - so if any comments
please hit me hard).

Of course it is nice to have the freedom on the mobile to handoff
whenever it is deemed necessary.  The question is what is considered as
'necessary': Connectivity, quality in service. feature diversity, power
control? I feel that it should be the network that should impose some
order on who and when is handing off, unless mitigating circumastances
dictate the opposite - but even then should be negotiated. Otherwise we
provide serious incentives for somewhat 'anarchic' inter cell mobility,
which can well be within protocol bounds. My question on this one
(anyone that wishes please argue) given the mobile node the freedom to
handoff, how prepared should the wireless backbone be in coping with
proactive handoff practices (the benefits of proactive handoff are clear
to me).

With regard to some comments on the work on the people from HUT, I agree
that by trying to decide when to handoff you are eating up your time to
handoff within time (and maintain you connection) but I guess you could
buy some time by playing with you mobility pattern (another thing that
bugs me). Basically by playing with your velocity vector you can buy
some slack on the handoff decision (remember buffer playout delay?). So
things here are not as bad as they look unless you are driving for
formula 1.

I have some techinical questions from what I have heard in the previous
discussion on the matter.  I understand that this may not be quite the
right place for these to ask, but considering mobile as my 'home' I
thought that I should seek help here

Are wireless modem (say 802.11) half duplex of full duplex . If full
duplex is it on the same channel? Does that hold for cellular and
satellite

As a wireless node how many PN sequences do you have? Is that PN
sequence (for autocorrelation ) the same for a single wireless segment
among all nodes, or is it different per node. When handing off between
cells do you adopt a different PN or does the BS register your own.

Thanks

Theo

---

From: Amanda Walker <[email-masked]>
Date: Fri, 28 Apr 2000 10:42:18 -0400

> am trying to look at these issues for my research - so if any comments

This is certainly so.  Of course, neither the mobile nor the network has
complete information.  The mobile has information about its state (available
links, active services or bandwidth requirements, etc.) and their status
that in many cases is much more accurate than the network's.  However, the
network has more information about *its* state (congestion and resource
allocation, upstream connectivity) than the mobile does, and may even have
useful information about the mobile that the mobile itself doesn't have
(physical location and speed, historical usage statistics, etc.).

As a result, neither the mobile or the node can make an optimal handoff
decision, and they may not be able to consult extensively at handoff time
itself(when communication has just been unexpectedly disrupted, for
example).  This complexity is then multiplied when multiple networks are
involved, since the mobile will know some information about them that they
won't know about each other.

Inter-provider handoff (or, more generally, inter-infastructure handoff) may
not be an immediate concern with current networks, but it's a concern where
different networks with widely varying coverage and capacity characteristics
coexist (802.11/cellular/satellite/etc.).  This is becoming more and more
the default case.

Amanda Walker <[email-masked]>
Lucent Technologies, InterNetworking Systems

---

From: Phil Neumiller <[email-masked]>
Date: Fri, 28 Apr 2000 09:25:56 -0500

> encompass in your thinking the handoff at will (user-initiated based on

Yes, there are either hints provided by the link layer or standardized
hooks (API) in the network layer for "events" that occur at the link layer.
Maybe this is a two way street, i.e. hints and standardized hooks are
provided by both the network layer and mobile link layers (moving wires).

For an example, if you look at the L2CAP link adaptation layer in the
Bluetooth standard it sort of provides this type of framework.

> am trying to look at these issues for my research - so if any comments

I am not sure about this being less predictable.  I am sure that it will
lend itself to some kind of statistical work-load model albeit slightly
different than the strictly network controlled case.  Don't forget AAA
authentication and QoS admission control which will give most routed
traffic a network centric pattern.

> control?

I see the world breaking into two camps.  Best effort mobility, and controlled
mobility, where QoS and AAA factors are enforced.  Best effort mobility would
most likely be offered free on all access networks.  It just gives you an IP
pipe with some sort of high probability that it will follow you as you move.
To provide virtual circuit types of QoS connections to mobile hosts requires more
work.  I think all would agree that we never want to limit people's freedoms
to handoff.  What has to be limited though is the ability to handoff with
"expectations" of security, QoS, etc.

> Are wireless modem (say 802.11) half duplex of full duplex. If full

802.11 is not a "modem" it is a wireless LAN.  As such it employs a MAC
mechanism to share the physical media, in this case RF energy through
space.  So its behavior is much more like Ethernet which in its most
basic implementations is half-duplex with a random back-off sort of
guaranteeing "fairness".  NOTE: there are implementations of Ethernet
and 802.3 that are indeed full duplex!

> cells do you adopt a different PN or does the BS register your own.

How is this relevant to Mobile-IP?  This is strictly an air interface
(link layer) issue.

:-) Have a mobile day!  -Phil

---

From: Gerald Maguire <[email-masked]>
Date: Fri, 28 Apr 2000 17:06:30 +0200

Amanda Walker wrote:
        ... However, the
        ...

Having the network keep track of historical information does not scale
well nor does it inherently preserve user privacy. See the earlier
doctoral thesis of George Liu and patent:

    George Liu, U.S. and International Patent, No. 08,329,608, entitled
    "Method and Apparatus for Detecting and Predicting Motion of Mobile
    Terminals," filed on October 26, 1994.

Information such as physical location and velocity may in fact be very
well known by the mobile (which is using this data to provide various
high level services with location and context awareness) -- this can
come from many sources including accelerometers and can be used to
extend the userfulness of GPS to areas of shadows, etc. (see
SiRF's SiRFstarII (http://www.sirf.com) for an example of a system
which uses algorithms to extend GPS)

As to infrastructure resources, shouldn't the access point be
advertising this information as part of its rate/resources
information?

I agree that inter-provider/inter-infrastructure handoff is going to
be much more common as mobiles have access to multiple networks
(especially when some of these networks have very limited coverage
areas). As you note "This is becoming more and more the default case.",
hence I think this is why more of the handoff must be initiated by the
mobile, of course it will want to cooperate with the different
infrastructures -- in order to be able to get a better rate {for
example, an infrastructure might offer a discount for service if the
mobile gives it advanced notice, but a higher rate if there is no
advanced notice}.

Chip

---

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 16:30:03 +0100

> mobile gives it advanced notice, but a higher rate if there is no

Chip,

  do you opt out cross domain negotiation of handoff (no mobile node involvement)?  I
personally don't. On the contrary even if the mobile has the powers to handoff to a
diff wireless domain it is really up to that domain to accomodate it or reject it.
Thus, I think that the ability for the mobile node to initiate the handoff is rather
elusive as it is the receiving domain that will decide whether to accomodate or not.

In terms of advertising capabilities I do not think that there is much benefit for
the client unless there is network diversity on the same geographical location. What
I mean is that even if the network tells you that we can give you 50 Kbps of
bandwidth you are really stranded with either using it or switch off unless you can
go supersonic to the next cross domain cell crossing.. It may be possible however to
use that info to prepare the user for a perceptible service adaptation.

I agree that filling the network with per-MN state history won't be manageable,  it's
best kept on the MN. However, this 'history' on the MN could be the passport for
cross domain movement that is delegated and really carried out between the networks.

Theo

---

From: cnyap <[email-masked]>
Date: Fri, 28 Apr 2000 14:34:50 +0100

Hi all

We think there isn't an necessity to come out with a
generic link layer technology for link layer hint.
There already existed one.

PPP is capable for giving link layer hint to IP for mobility
Our paper in IEE 3G conference show just how PPP
can go about doing that.

Moreover, if just thinking further ahead.
UTRA, CDMA2000, Bluetooth, HiperLan2,
LMDS based on DOCSIS or DAVIC all support PPP.
Even current modem support PPP.
All these technology support PPP where bother to get
another generic link layer then?

Any Ideas
-------------------------------------------------------------------
Chern Nam Yap
Mobile Communication System Researcher
University of Sheffield
Department of Electronic and Electrical Engineering
Regent Court
211 Portobello Street
Sheffield S1 4DP, England
Tel: +44 114 222 3308
Web: http://www.mobile1.net
E-mail: [email-masked]

---

From: Gerald Maguire <[email-masked]>
Date: Fri, 28 Apr 2000 18:06:06 +0200

Theo wrote:

No, I think that there will be plenty of cross domain negotiation of
handoff -- but I don't think that the mobile node will be uninvolved
in it, since the mobile also needs to decide if it will make use of
the service (even if offered it). For example, consider the an
employee of company X who is standing in the building where my
department is, will their policy based routing module be willing to
accept service from the local operator (who might in fact be a
competitor to X) -- this is despite the fact that their usual WAN
operator might have a local agreement with the in-building operator to
provide local service. However, the mobile can also decide to accept
service from any operator that it wants and may want to use the cross
domain handoff offered services because it might provide low handoff
latency, ... .

Don't you expect a lot of network diversity? On my desktop I have IR,
802.11b, several ethernets (attached to different infrastructures), my
choice of at least 3 wireless WAN operators (one of whom has 3 base
stations in the building), ... . This is not even including the
cordless DECT infrastructure or POTS lines. My point was that if an
infrastructure wants to be used, there needs to be some way for a user
to know about it. It would seem that there has to be enough
information available for the user to make a decision of if they want
to use this infrastructure or not.

Indeed, one of the things which George Liu explored was having the
mobile provide advance notice to the infrastructure of its likely
movements so that the that infrastructure could plan and do efficient
resource allocation in advance.

Chip

---

From: Amanda Walker <[email-masked]>
Date: Fri, 28 Apr 2000 12:14:58 -0400

> another generic link layer then?

Two reasons spring to mind:

(a) these are not at all the only links on which MIP is useful.  I don't
    want to have to pretend to be using a modem for Ethernet and WLAN
    connections.
(b) using PPP locks everything into a circuit-switched model.

Now, granted, selling everyone lots of RAS and LNS equipment to provide
wireless PPP termination services would indeed be very profitable for those
of us who manufacture such equipment :-).  However, I think it's very
premature to conclude that this is the one true way.  PPP is useful in a lot
more situations than its designers originally envisioned, but it's very much
a circuit-switched approach.

Amanda Walker <[email-masked]>
Lucent Technologies InterNetworking Systems

---

From: "[email-masked]" <[email-masked]>
Date: Fri, 28 Apr 2000 09:37:00 -0700

> There already existed one.

...and that one would be?

> Our paper in IEE 3G conference show just how PPP

Well, the PPP that I know doesn't. I believe that I can say that with a
certain amount of certainty, given that I've written a PPP implementation, and
worked in network access for longer than I care to mention.

> another generic link layer then?

Now, let me ask you a question. Why exactly do you propose the use of a
connection oriented link layer to achieve mobility? Why do you want a protocol
that requires well over 10 round trips in order to get IP packets delivered? A
protocol that needs to be re-established everytime a hand-off occurs in order
to get the PPP NCPs back in the open state?

I must admit that I am a little confused by your statement.

> Any Ideas

Oh, plenty!

PatC

---

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 18:49:20 +0100

> Chip,
>
>    Getting involved (in terms of requesting) is different in my understanding from who is
> effecting it. That means for me that I may request it but it will be someone else (the
> network) that will hand me off to the new cell.  By the way can we get hold of G. Liu
> simulations?
>
> I definetely see (as everybody else) wireless overlays (hi Mark). But I thought that the
> user seeks connectivity (regardless which is the accomodating network which really you don't
> want to care about and most probably you won't know about). Imagine you are driving and you
> try to decide which network you are selecting....crash...
>
> My angle is that the user should not need to make a decision about using the infrastructure
> ...he should
> just use it (getting disconnected is the only easy bit) . Otherwise we start defeating the
> element of mobility which fades away as the user concentrates which wireless overlay to use
> and thus disruption of service is imminent. I think wireless network usage decisions and
> mobility are somewhat contradicting in terms of criticality (depending of course on the
> pattern of mobility and time-criticality of the application).
>
> Theo

---

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 19:01:54 +0100

Pat,

  I thought that the original issue was getting hints by the link layer in
assisting handoffs.

Theo

---

From: "[email-masked]" <[email-masked]>
Date: Fri, 28 Apr 2000 11:14:29 -0700

>   I thought that the original issue was getting hints by the link layer in

So did I, but the e-mail I was responding stated that PPP provides these
hints, and I know for a fact that it doesn't. Actually I should re-phrase, it
does provide a disconnect notification, which could be used to know that a
mobile has disappeared.

PatC

---

From: Amanda Walker <[email-masked]>
Date: Fri, 28 Apr 2000 14:42:19 -0400

Theo PAGTZIS wrote:
> the client unless there is network diversity on the same
> geographical location.

There already is.  Sitting here at my desk I can think of over 8 different
available network links for the laptop I'm typing this on.  Even out in the
parking lot there are at least 4, each with a unique set of attributes.

> What
> go supersonic to the next cross domain cell crossing..

This is only true in a single provider environment, which is less and less
prevalent as time goes on.  Especially in urban areas, there are a wide
variety of overlapping coverage areas for services with a variety of
different characteristics already.  This will only increase--the demand for
mobile connectivity far outstrips supply.

---

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 19:53:26 +0100

> I'm not suggesting that the user get a query (which could be audio or
> visual), but rather that they can estability policy (or perhaps they

> are supplied with policy by someone else).

> It is this policy mechansim
> which the user's agent uses to decide upon whose service offering to
> make use of at agive time.  So it is a user controlled agent which

> actually makes the decisions.

That means you want to involve the user,   right (user-controlled)?  -
while on the move (remember you do not know which network you will
encounter as you move from one location  to the other).

There are certain mobility roles that you want to opt out from that.

I think I am looking things from more of a service provisioning aspect
(intserv - diffserv). If you are bound by admission control for instance,
the decision is not really yours whether you can handoff in the new
wireless domain or not. Which brings us to the issue that for mobile
service provisioning, MN enabled handoffs and admission control (the
network) may get somewhat conflicting. It is not efficient to try and
handoff in a cell for which you may not be admitted. That is why I am
thinking in terms of letting the network do more work on the handoff
side, since it will get into the trouble in offering qualitative
guarantees (I know...statistical) which will have to encompass handoff
deadline constraints.

Theo

---

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 19:53:31 +0100

> parking lot there are at least 4, each with a unique set of attributes.

Which reminds me it is time for me for an internship...  :)

Anyone knows anything happening around?

---

From: Gerald Maguire <[email-masked]>
Date: Fri, 28 Apr 2000 22:11:45 +0200

Theo said:

User control does not necessary mean that a user has to manually hit a
button to make a decision each time that a handover might happen.

If a network does not want to take on any users, then it advertises 0
capacity (or does not advertise at all)! If it does not want to take
on a specific user, then it will tell that user "No"; if it does not
want to take on a specific user at this time and place, it will say
"Not right now or Not right here".

I'm willing to posit that given the very large number of access points
that there will be in the future, (statistically) most access points
will not have any traffic for significant periods of time. {I know
this should make the access point manufacturers happy.} Thus
accepting a handoff will not require significant resource planning.

Operators of networks that consistently fail to accept users wanting
to use their services will find that other operators will build around
them (i.e., users will occasionally upload data about where they were
not able to get service and a wise ISP will install an access point
there with a time inversely proportional to the number of users with
this same complain and directly proportional to their desire to
support the set of customers who report this specific lack of
service). Now you might ask, "Why would an operator install more
capacity?" -- the answers include: (1) keep this customer, (2) take
market from their competitors, ... .

As Amanda Walker and I have pointed out there are plenty of different
network options -- especially in high density areas (which is where
most of the users are). So I will posit that networks operators that
consistently fail to support their users, had better have a monopoly
position, deep pockets, or a deep commitments to go bankrupt.

Chip

---

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 22:22:13 +0100

Chip,

> button to make a decision each time that a handover might happen.

(Referring to cross W-ISP handoffs). True only in the case your agent auctions
your requirements to the available W-ISPs.  Otherwise you have to contribute (as
user) somehow (Policies are really enforced rules effected by the net).

I think here that we have to differentiate between intra-domain and inter-domain
handoffs. The diffserv people will highly appreciate this.

> "Not right now or Not right here".

Capacity and bandwidth are highly dynamic resources. This leaves the possibility
of effecting handoffs yet refusing admission due to resource unavailability.

> accepting a handoff will not require significant resource planning.

This sounds good from a different perspective... : if an ISP is really clever
then it can recruit bandwidth resources (borrow-enabled servicing) from the
neighbouring (or overlaid cells) keep any potential hotspots cooler and maintain
servicing abilities. So the rate of handoffs per cell (inter/intra) may be the
indication of resource borrow (where possible) to sustain high percentage of
successfull handoffs.

> market from their competitors, ... .

That goes without saying... but in wireless where the frequency spectrum is
highly regulated how do you install more capacity?

> position, deep pockets, or a deep commitments to go bankrupt.

Surely although we have to bridge a gap of moving between ISPs 'seemlessly'. And
getting different ISP to agree in a tranparent service is not quite trivial;
especially in highly aggressive markets...where each ISP tries to grab the
biggest piece of the pie...competition in itself is constant heterogeneous
issue. Which means that it will keep us going for a long time when it comes to
cross domain handoffs.

Theo

---

From: cnyap <[email-masked]>
Date: Fri, 28 Apr 2000 20:38:18 +0100

> to get the PPP NCPs back in the open state?

Hi

Under the IIP scheme PPP does provide the link layer hint.
Please read through our paper.

Below are some of my doubts.
Why use a "connection oriented" MIP layer that as well require
10 round trips in order to get IP packet delivered?
Why develop alternatives where PPP is already doing the job?

Cheers

---

From: cnyap <[email-masked]>
Date: Fri, 28 Apr 2000 20:47:14 +0100

Hi

Why do so many recent wireless technologies support PPP?

Cheers

---

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 22:51:07 +0100

Arthur,

Just to expand on the previous msg.

I have been talking about inter-domain handoff  bearing in mind a set of
heterogeneous wireless cell (air interfaces that is) that (hopefully) span globally
(and thus ubiquity is effected). I think that network diversity depending on the
ease and purpose of deployment (per technology) will always be there offering
something different than existing ones. The reason? Evolving needs and potential.

Thus, I gather that  a minimalist air interface will also render  minimalist
capabilities on which you can build on top...(I don't know if the analogy of  a
RISC-like architecture over a unified air interface bears viable grounds)

Looks like the notion of splitting core networks and access networks (is that a
follow on from TINA over wireless ?????) tries to do the trick but considering how
far TINA went dunno if UMTS is that promising...

Theo

---

From: "[email-masked]" <[email-masked]>
Date: Fri, 28 Apr 2000 15:01:02 -0700

> Why do so many recent wireless technologies support PPP?

Well, at the expense of making lots of friends in other standards
organizations that actually do the cellular work, I will attempt make answer
this question as best as I can.

years ago, when the work of providing data services over cellular networks was
started, they needed a method of allowing nodes to dial into the network and
get Internet access (2nd generation services). Now, these were not intended to
be "roaming" users, since the connection was fixed to a single access server.
Therefore, PPP was an appropriate link layer.

However, as technology changed, they began looking at providing mobility
services (3rd generation), and not requiring that the mobile use a circuit
switch connection to get data services. This is where Mobile IP came into
their architecture. Now, for reasons that are really more business and
politically oriented than technical, PPP remained in the architecture.

So, in my honest opinion, PPP is NOT appropriate here. We should strive for a
services that provides always on wireless connectivity, and does not borrow
from the circuit switched model. Many enhancements have been made to Mobile IP
so that it doesn't require PPP's configuration negotiation to get mobiles
access.

Network access such as 802.11 is a good model, and that should be our ultimate
target.

ok, that said, I will sit and wait for the flames to start filling up my inbox.
 PatC

---

From: Gerald Maguire <[email-masked]>
Date: Sat, 29 Apr 2000 00:05:56 +0200

Because there is lots of spectrum available (especially for short
range use), the question is only if it is worth while using it and if
the users will carry interfaces that work with it.

As several people have pointed out (Martin Cooper, Arthur Ross, and
others) -- there is an enormous gain because of spatial re-use. This
is why I and others have been very interested in how to build (and
field) very very inexpensive access points. With WLAN access points
(each providing ~10Mbps) already being feasible for under US$100 cost
-- it is pretty straight forward to put a lot of these into a high
density area of users and provide an awful lot of aggregate bandwidth
- for the cost of one $10-$100K basestation which provides perhaps
20-60 Mbps aggregate bandwidth.

However, the down side of having lots of small cells is that the
probability of a handoff increases for a moving user; hence the
concerns with handoff.

Chip

---

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 23:10:39 +0100

Pat,

    perhaps Chern signals more about the precedence in the semantics conveyed in
terms of link layer hints rather than PPP itself. I have not read his document but
this is the feeling that I get.

Is that so Chern?

Theo

---

From: Theo PAGTZIS <[email-masked]>
Date: Fri, 28 Apr 2000 23:15:25 +0100

Why can't we exploit the precedence with handoff servicing speeds on cellular nets. I
think MSCs can do well in excess of 3000 handoffs/sec.

Theo

---

From: Gerald Maguire <[email-masked]>
Date: Sat, 29 Apr 2000 01:28:18 +0200

From J-T Liu Licentiate thesis pp. 121-122

System coverage area of 36 km^2
population density of 400 km^2
percentage of mobile owner 80%
power percentage 80%
avergae velocity 10km/h

with some suitable simplification (to rounds cells, etc)

for 20m radius cells this worked out to ~3763 handovers per second

If we think that the population density could be ~15,000 users per
km^2 {this is an approximation of the 17203 people/km^2 of Monaco},
then we see that the number of handoffs per second would go up more
than 2 orders of magnitude.

If the cell size is going to go down to ~10m radius the number of
handovers goes up 4x.

So it would seem that traditional MSCs (using your number of 3K
handoffs/s) are probably not the right way to build such
infrastructures.

Worse is that in some settings, such as our campus, roughly 8K people
in a ~1 km^2 area change their locations at about the same time during
fixed intervals! So we have the problems of correlation movements in
shorter time interfaces causing very high peaks in the handover rate.

Imaging what this would be like in the Univ. of Pittsburgh's
"Cathedral of Learning" (almost an entire university in one tall
building).

Chip

---

From: Jim Willkie <[email-masked]>
Date: Fri, 28 Apr 2000 21:28:22 -0700

>ok, that said, I will sit and wait for the flames to start filling up my
inbox.

Pat's position does have some merit. But there are major practical
realities in place: 1) how many of today's laptop computers have PPP? (all
100 million of them). How many have mobileIIP? (none that are
off-the-shelf) 2) Does Msoft plan on rolling out MobileIP capability? (no,
not even on Windows CE).

I have been following MobileIP for 7 years of so. At this point it appears
to many of us wireless data folks that MobileIP will only occur in the
wireless portion of the network. That is, no MobileIP components will be
put into laptops because a huge majority of the laptop market does not need
MobileIP. So the position that PPP can be replaced in the laptop by some
mobileIP component that is slightly cleaner does not seem practical.

I also don't see why PPP is a shortcoming for 'always on'. A PDSN with
dormancy can always find the mobile. And what is inherently bad about
borrowing from the circuit-switched model?

Jim Willkie

---

From: Theo PAGTZIS <[email-masked]>
Date: Sat, 29 Apr 2000 10:06:13 +0100

Chip

   Could I have a look on this thesis?

   Do you think it would be viable to set a smart layout of interleaving
handoff controllers (handoff zones between which you could interleave) so
that you could bring up the number of possible handoffs? I definetely see
your point about revisiting (at the very least ) the way MSC may be
tackling the handoff for dense population (this could be a nice
paper...Handoff sparse mode and handoff dense mode situations).

Theo

---

From: Phil Neumiller <[email-masked]>
Date: Sat, 29 Apr 2000 07:39:52 -0500

> Network access such as 802.11 is a good model, and that should be our
ultimate

No Pat, I am (sort of, albeit a malcontent), a cellular insider, having
worked in that
industry for over 12 years.  My feeling is that PPP must be disposed of
ASAP.
This is not a very popular opinion among those that do set the standards for
cellular
in those groups like 3G.IP, 3GPP, 3GPP2, etc.  I believe we can still rescue
Bluetooth
from this "circuit" mind set, by recommending an L2CAP link adaptation for
IPv4 and
IPv6 that works precisely like that of 802.11 in the Pittsburgh BOF.

-Phil

---

From: Gerald Maguire <[email-masked]>
Date: Sat, 29 Apr 2000 16:35:08 +0200

You will find the thesis at:
       http://www.i.tkh.se/~maguire/JT-Liu-lic-thesis.pdf

The problem becomes more complex as there will be many different
infrastructures involved.

Chip

---

From: Gerald Maguire <[email-masked]>
Date: Sat, 29 Apr 2000 17:35:23 +0200

There is also a MS (actually an austrian Diplom) thesis
written by Andreas Schmidt which goes even farther in to detail about
the traffic between access points and the device which is providing
(local) mobility support, see:
        http://www.it.kth.se/~maguire/DA-990525-Andreas.pdf

Chip