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.
Office: 626-969-0681 x121
1335 W. Foothill Blvd.
Azusa, CA 91702
----- Original Message -----
Sent: Thursday, March 28, 2002 4:58
Subject: RE: [802.3ae] Bad idea...not
including FP laser in PMD
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.
Chair, IEEE 802.3 Working Group
Evening Creek Drive
San Diego, CA 92128
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
- 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
- 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.