| Thread Links | Date Links | ||||
|---|---|---|---|---|---|
| Thread Prev | Thread Next | Thread Index | Date Prev | Date Next | Date Index |
|
Brad, Thanks for bringing this up via the
exploder. A difficulty with your proposal of using “H”
for either “Higher power” or “Higher intensity” is that
the total average launch power max for LR4 is greater than that for ER4.
The OMA max power for the two is the same and only the Average min and OMA min are
lower for LR4 than ER4. I think that describing ER4 as “higher
power” cannot really be defended. LR4 ER4 Total average launch power (max) 10.5 8.9 dBm Average launch power, each lane (max) 4.5 2.9 dBm Average launch power, each lane (min) –4.3 -2.9 dBm Optical Modulation Amplitude (OMA), each
lane (max) 4.5 4.5 dBm Optical Modulation Amplitude (OMA), each
lane (min) –1.3 0.1 dBm The real difference between the two PMDs
is that the ER4 receiver is much more sensitive than the LR4 receiver (-21.4
dBm vs. -8.4 dBm) which enables longer reach. The unused letters on the list in booth_01_0709.pdf
are A, H, J, N, V, Y Assuming that the Task Force were to agree
to change the nomenclature, I think that you would need something like 100GBASE-HR4 – long wavelength with
high sensitivity 100GBASE-VR4 – long wavelength with
very long reach Regards, Pete Anslow Nortel Networks UK Limited, External +44 1279 402540 ESN 742
2540 Fax +44 1279 402543 From: Brad Booth
[mailto:bbooth@xxxxxxxx] Folks, I
wanted to call to your attention that I’ve submitted a comment against
the definition of SR and LR, and against the use of ER in P802.3ba. 802.3
has been very consistent over the last 10 years in trying to maintain
nomenclature definitions. While people in the industry may have used S
for short-reach, L for long-reach and E for extended-reach, the real use of
them in IEEE Std. 802.3-2008 is for short wavelength, long wavelength and extra
long wavelength. I
believe that it would be good for the Task Force to maintain consistency with
the base standard so that there is no confusion when the P802.3ba amendment is
merged into the base document. I’ve
attached a document that highlights how 802.3 has been using its
nomenclature. The original document was created in 2000 (during 802.3ae)
and has been updated and followed since that time. The
proposals in my comments are to maintain consistency for SR and LR. For
ER, I am proposing a new nomenclature: HR. The “H” in my
comment refers to higher-power 1310nm wavelength optics. Upon
further thought, I have realized that the term “higher-power” may
carry some baggage. I also realized that there may be a desire for other
optical PMDs to have greater optical power. The term
“higher-intensity” may be better. And it may be more
appropriate to follow what LRM did and create a 3 letter acronym: LRH or HLR (I
prefer the latter). I
would be interested in hearing any feedback and thoughts you may have. Thank
you, Brad <<booth_01_0709.pdf>> |