Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: OMA vs. OMA/2 poll




I prefer what we had before: OMA (mW) and dBm(OMA/2).

This provides familiarity for each camp yet avoids the disadvantage of (c)
below.

Notice that a choice between (a), (b), (c) or what we had before is not
affected by our intention to be consistent at transmitter and receiver.  Nor
does the waveform midpoint come into a divide by two calculation - even
though really it is the distance from mid to top/bottom which "matters" and
determines performance, not the distance from top to bottom.

To repeat: the advantage of dBm(OMA/2) is that it comes in the same units as
average power which is very well entrenched in SONET and other optical
standards.  We can't ask them to go back and change their optical power
measure to dB0.5m can we?

OMA (mW) direct, rather than OMA/2, seems to align with what scopes do.

Tom's point 4, that making the OMA and average power definitions look
similar could allow sloppy thinking, is worth considering.

Piers

> -----Original Message-----
> From: David Kabal [mailto:dkabal@xxxxxxxxxxxxx]
> Sent: 20 April 2001 20:09
> To: stds-802-3-hssg-serialpmd@xxxxxxxx
> Subject: OMA vs. OMA/2 poll
> 
> 
> Serial PMDers:
> 
> I volunteered to set up an informal poll (based on the lack 
> of participation
> at the last Serial PMD conference call: we lacked quorum) on 
> whether to
> specify in Clause 52, for example, Receive Sensitivity for 
> each of the PMDs,
> in OMA or OMA/2. 
> 
> Background:
> Originally, all values in the tables and receive sensitivity 
> were OMA/2. As
> of D3.0, we voted to change everything to OMA, but the triple 
> trade off
> tables still have both OMA and OMA/2 values listed.
> 
> Discussion:
> There has been some discussion on this on the reflector, see thread: 
> http://www.ieee802.org/3/10G_study/public/serial_adhoc/email/m
> sg00228.html
> 
> I propose that we have a single solution for all instances in 
> Clause 52.
> 
> a) specify everything in OMA
> b) specifiy everything in OMA/2
> c) specify everything in both (very difficult to read)
> 
> Please post your comments and input to the reflector. 
> 
> Cheers,
> Dave
> ------
> David Kabal
> Picolight
> 
> Phone:	303-530-3189 ext. 272
> Fax:	303-527-4968
>