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Norman,
I
agree with Bob's response from a process perspective and would like to take this
opportunity to address the market issues which you raise.
The
IEEE P802.3ae draft standard currently provides multiple solutions for short
reach links. Depending on your definition of "short", either 850 nm VCSEL, 1310
nm VCSEL, 1310 nm DFB or 1310 nm CWDM solutions adequately cover all customer
distance and fiber type requirements with significant overlap. I'm unaware of
any significant change since this decision, but I have seen a huge discounting
of highly integrated 10G optical module solutions relative to the timeframe of
the decision. Looking into the future, vendors are already addressing short
reach links with more compact optical module solutions which will adequately and
economically meet customer requirements. I beg to differ with you on your
statement that: "Customers don't care how many PMDs". This is not what I've
heard from any system supplier at IEEE 802.3ae Task Force
meetings.
Lastly, I don't perceive that anything is "broken" with
the current specification (of PMDs). This is usually the impetus for change. In
my view, the PMDs specified in IEEE P802.3ae adequately and economically allow
customers to deploy 10GbE equipment.
If you
believe that you have enough support for a Call for Interest for a 10GbE 1310 nm
FP PMD, the call must be initiated through IEEE 802.3, not
802.3ae.
Best
Regards,
Rich
---------------------------------------------------------
Richard
Taborek
Sr.
Intel Corporation
XAUI
Sherpa
Intel Communications Group
3101 Jay Street, Suite 110
Optical Strategic Marketing
Santa Clara, CA
95054 Santa Clara
Design
Center
408-496-3423
JAY1-101
Cell:
408-832-3957 mailto:rich.taborek@xxxxxxxxx
Fax:
408-486-9783
http://www.intel.com
Bob,
Thanks for your quick response. If it is a
right thing to do, it never be too late. Imagine if majority of the
short reach link deployed in next few years are using FP lasers and it is
not covered by the standard, it will go down to the history book that the
committee did not do a good job of serving the industry. Since the
committee discussed and make the decision a long time ago, many things have
been changed. Many technologies promised to deliver low cost products have not
done it yet for variety of reasons. FP lasers has
been available and always be available to serve the industry. There
are concern of too many PMDs in the standard, the keys is how many PMD are low
cost and can deliver in volume. Customers don't care how many PMDs, all
they care is how they can get parts that can do the job, cheap and
reliable. I'd urge the committee should initiate a call for
interest for this topic. Thanks
Norman Kwong
CTO
Archcom Technology
Office: 626-969-0681 x121
1335 W. Foothill Blvd.
Azusa, CA 91702
----- Original Message -----
Sent: Thursday, March 28, 2002 4:58
PM
Subject: RE: [802.3ae] Bad idea...not
including FP laser in PMD
Norman:
It is too late to add major functionality you
describe to the 802.3ae project. As you point out, the committee
discussed the topic and made its decision a long time ago. The
P802.3ae draft has completed Working Group and is in the final stages of
Sponsor ballot. The addition you propose is outside the scope of the
current Sponsor recirculation ballot and therefore should not be considered
by the P802.3ae Task Force.
Bob Grow
Chair, IEEE 802.3 Working Group
Intel, EC2-101
13290
Evening Creek Drive
San Diego, CA 92128
phone: 858-391-4622
mobile: 858-705-1829
fax: 858-391-4580
Dear 802.3ae
members
I understand that this is an old topic, but I still strongly
believe that it is a bad idea not to include 1310 nm Fabry-Perot (FP)
lasers in the PMD. Let me
re-cap some of the advantages of FP lasers:
- Low cost comparing to DFB lasers: high yield single-growth wafer
process, less sensitive to back reflection that eliminates the need for
isolator in package. (1.3
VCSEL yield/cost is not clear now, therefore it is hard to
compare.)
- Edge emitting lasers (FP and DFB) are more mature technology and
have been deployed in market for many years. Both lasers are available today
through multiple vendors.
- FP laser can handle at least 0 to 2km (some test even indicate
7km is possible). And majority of the 10G Ethernet applications fall
into this range.
- Some companies are shipping transceiver/transponder products
using 1310 FP lasers today, but unfortunately they are being treated as
non-802.3ae standard products.
The current
1310 PMD specification has a 30 dB SMSR spec that prohibits the use of FP
lasers. I believe that it is
to the best interest of our industry to standardize a PMD based on 1310 nm
FP lasers. If there is a way
to start a new project or modify the current specifications to include FP
lasers, I'll love to lead an effort on it.
Norman
Kwong
CTO
Archcom
Technology
Office:
626-969-0681
x121
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