Subject: RE: New area for the group?

From: "Falk, Aaron" <[email-masked]>
Date: Tue, 4 Jul 2000 09:27:27 -0400

Marie-Jose-

Well, in the satellite industry we sometimes talk about 'backhoe fades' to
refer to fiber cable breaks but I've never heard of 'hairdryer fades'
before. :^)

On a more serious note, PILC has made a consistant effort to abstract
specific link technologies (wireless, satellite, cable-modem, etc) into
their performance-affecting characteristics (low bit rate, high errors, etc)
rather than focus on the technologies themselves. This allows us to
understand better the performance problems that might be already solved by
other communities versus areas that might deserve more attention. This also
enables us to focus on addressing the performance problems in the most
general fashion.

If you could describe the link characteristics of HANs and any performance
issues they've created (in an email or I-D), this would make it easier for
us to evaluate whether the issues merit working group cycles.

Thanks,

--aaron

-----Original Message-----
From: Marie-Jose Montpetit
To: [email-masked]
Sent: 7/4/00 8:54 AM
Subject: New area for the group?

I guess with the IETF coming the traffic on the list will grow soon. I
would like to submit a few discussion topics that are closely related to
IP performance over links that exhibit special characteristics. 

I have the impression that our focus up to now has been mostly on the
WAN. How about now looking at the Home Networks, the so called HANs
(Home Area Networks)? While I do believe that what the group has done in
the current drafts applies to the home ethernets and even the wireless
LANs (802.11 and Bluetooth) I think we may want to put our brains
together to make sure it does. I also think that the use of power lines
provided new challenges. While the current implementations are pretty
low bit rate the next generation (read this fall) is moving to the
megabits per second. The way I understand them the link layer of these
networks is the use of error protection mechanisms (FEC and what I would
classify as "fade protection" potentially variable rates) to ensure some
performance in spite of air conditioners or hair dryers and in general a
pretty noisy environment. These mechanisms will have impacts on TCP as
we well know. Do we want to add something in the LINK draft to cover
those or do we believe we have enough right now? There is probably other
issues in the HAN that may need our attention but may also be covered by
other groups.

Anyway my views.

Happy 4th of July!

Marie-Jose

Marie-Jose Montpetit
Nokia Venture Organization
[email-masked]/[email-masked]
 <<Card for Marie-Jose Montpetit>>

---

From: Zach Shelby <[email-masked]>
Date: Tue, 4 Jul 2000 18:12:23 +0300

I agree with the previous point that this working group has kept it's
link characteristic analysis general enough to apply to wireless
links.

We do research on these HAN wireless technologies in our
group. This includes IEEE 802.11, Bluetooth, HomeRF, and Hiperlan
(although expensive for home!!). These technologies are used in homes
and other small ad-hoc networks.

The PILC documents on links with errors, and slow links cover all the
aspects involved with these technologies quite well.  They also
correspond with the scientific literature in this area.  The PEP draft
goes further to look at techniques which can be used to improve
performance of these wireless networks as well. This draft did need
some improvement in regard to small wireless networks, but I have
already posted comments. (I can resend to anyone who didn't receive).

If there are more areas missed by these drafts it's best to make
comments on the mailing list?

Regards,
Zach Shelby

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