RE: Requirements

[James Kempf <James.Kempf@Sun.COM>]

Dana,

While I agree with you in principle, I think a case can be made that
some wireless L2 protocols are better engineered for IP than others,
handoff not included.

In particular, I think the 3G wireless protocols like wCDMA, which were
not originally designed for IP (but rather primarily for ATM-like
voice) are not as optimally designed as, say, 802.11.

One useful thing would be to try to get a handle on what makes
a "good" L2 for IP. We have tried to do that for handoff in
draft-manyfolks-mobilereq-ipv6-00.txt, which includes requirements
for an L2 trigger API or protocol.

		jak 

>From: "Dana L. Blair" <dblair@cisco.com>
>To: "Robinson, Richard" <RRobin01@sprintspectrum.com>, "John G. Waclawsky" 
<jgw@cisco.com>
>Cc: <more@ops.ietf.org>
>Subject: RE: Requirements
>Date: Fri, 20 Jul 2001 17:42:59 -0400
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>
>My comments below.
>
>...
>
>>   > it is just that the mobility of wireless subscribers as well as some
>>   unique
>>   > performance requirements/problems in the air interface may
>>   indeed bring
>>   out
>>   > special requirements - perhaps more so in the macro cell
>>   environment of
>>   > wireless operators than in controlled micro/pico cell links
>
>For the past 2.5 years I have been asking the question is
>there anything special about wireless that impacts application,
>transport, or IP protocols that is different than wired.
>
>Up til now, the only exception for wireless than wired that
>I have discovered is handoff.  I believe that we SHOULD
>view the wireless access network as just another Layer 2.
>
>Here are some examples of suggested differences.
>
>1.  Wireless links are special because they have low bandwidth and 	large
>latency.
>
>	Some wired links are slow and have large latency too.
>
>	V.22 modems run over the PSTN and are slow with large latency.  	
TCP was
>designed to optimize bandwidth on slow and fast links.
>	V.42bis, MNP compression, and Header compression were 	invented several
>years ago to improve performance n
>	wired links.
>
>2.  Wireless links are special because they are error prone.
>
>	Some wired links are error prone too.
>
>	Many PSTN connections are error prone depending on wiring.
>	MNP and V.42 error correction protocols were created several 	years 
ago to
>fix errors in the link layer.
>
>	The RLP layer of cellular standards provides the same
>	function.
>
>3.  Wireless devices are special because they move.
>
>	Roaming:
>	Wired devices roam too.
>	My laptop roams because it plugs into an ethernet at
>	home or in the office depending on where I want to
>	work.
>
>	Handoff:
>	One possible exception for wireless is handoff.  There is
>	really no need that I can think of for handoff in
>	the wired world, but the Mobile IP WG seems to getting
>	the right idea of Internet Handoff for wireless devices.
>
>4.  Wireless devices are special because they need to know where 	they are 
-
>Location services.
>
>	Wired elements devices can benefit from location services
>	too, and be supported with a small inexpensive GPS chip.
>
>thanks,
>Dana
>
>>   >
>>   > some of these come through in Paul Reynolds draft - as
>>   wireless operators
>>   > get engaged in these requirements some of the things that
>>   make wireless
>>   > different may be highlighted - i'm reviewing the draft now
>>   >
>>   > Richard Robinson
>>   > Sprint PCS
>>   > 15405 College Boulevard
>>   > Lenexa, Kansas 66219
>>   > 913.890.4242 (fax 4100)
>>   > MS - KSLNXZ0201
>>   > rrobin01@sprintspectrum.com
>>   >
>>   > -----Original Message-----
>>   > From: tim clifford [mailto:tjc@lacunanet.net]
>>   > Sent: Monday, July 16, 2001 11:23 AM
>>   > To: James Kempf; more@ops.ietf.org; jgw@cisco.com
>>   > Subject: RE: Requirements
>>   >
>>   > which would seem to imply that we need to try to convince
>>   people at the
>>   ietf
>>   > (i think its a misnomer to say "convince the ietf") that we're talking
>>   about
>>   > more than a link layer, maybe the right term is mobility, or roaming
>>   > services, or disadvantaged user devices, or large populations
>>   of always on
>>   > subscribers  ;-)
>>   >
>>   > tc
>>   >
>>   > > -----Original Message-----
>>   > > From: owner-more@ops.ietf.org
>>   [mailto:owner-more@ops.ietf.org]On Behalf
>>   > > Of James Kempf
>>   > > Sent: Monday, July 16, 2001 11:47 AM
>>   > > To: more@ops.ietf.org; jgw@cisco.com
>>   > > Subject: Re: Requirements
>>   > >
>>   > >
>>   > > John,
>>   > >
>>   > > There is no such catalog. In general, IETF has been resistent to
>>   > > making wireless a special category. It is viewed as just
>>   another link
>>   > > layer.
>>   > >
>>   > >               jak
>>   > >
>>   > > >Date: Sat, 14 Jul 2001 11:15:34 -0400
>>   > > >From: "John G. Waclawsky" <jgw@cisco.com>
>>   > > >To: more@ops.ietf.org
>>   > > >Subject: Re: Requirements
>>   > > >
>>   > > >Does anyone know if the IETF does an cataloguing of activities
>>   > > with regards to
>>   > > wireless?
>>   > > >For example is there a cross reference anywhere that
>>   describes wireless
>>   > > activities going
>>   > > >on in the IETF?  This information would probably be very uesful
>>   > > for the mobile
>>   > > >operators.    Regards  John
>>   > > >
>>   > > >
>>   > >
>>
>
>