Re: [802.3BA] Longer OM3 Reach Objective
I've been preaching Single Mode to the Desk for going
on 10 years now. The fiber is cheaper and has much higher ultimate
bandwidth, connectors are not too much different, but transceivers have
always been the gating item. In a sense it's "chicken or the egg" circle -
standards such as 802.3 only recognize SM as the long distance (10 km) solution,
and MMF as the short distance (<300 meter), so SM transceiver vendors don't
spend time trying to come up with ways to make a low cost 300 m SM transceiver
since there's no market.
It may be that alignment physics dictate that SM will
always be enough more expensive to keep MMF as the preferred short distance
solution, but let's recognize the way technology is chosen for standards guides
product development.
Mikael,
The reason why there is still a deployment of MMF is the
cost. SMF modules (10km) for 100 GbE is more than one magnitude higher cost than
MMF 100m over OM3. For that reason, MMF will continue to play an important role,
until there is parity in cost between the two solutions.
Regards,
Peter
Petar
Pepeljugoski
IBM Research
P.O.Box 218 (mail)
1101 Kitchawan Road, Rte.
134 (shipping)
Yorktown Heights, NY 10598
e-mail:
petarp@us.ibm.com
phone: (914)-945-3761
fax:
(914)-945-4134
| Mikael Abrahamsson
<swmike@SWM.PP.SE>
03/17/2008 09:42 AM
|
Please respond
to
Mikael Abrahamsson
<swmike@SWM.PP.SE> |
|
|
To
| STDS-802-3-HSSG@LISTSERV.IEEE.ORG
|
|
cc
|
|
|
Subject
| Re: [802.3BA] Longer OM3 Reach
Objective |
|
On Mon, 17 Mar 2008, Petar Pepeljugoski wrote:
> We have seen
this happen with copper - lengths are shrinking, and MMF is
> filling the
void for ever shorter links. The same will inevitably happen
> to MMF on
the longer side of the links. where SMF will be more
>
competitive.
I am very curious as to why someone would do new deployments
of MMF today.
I know quite a few in the ISP business who has decided to go
solely to SMF
to try to cut down on number of spare parts and types of
cables. Cost of
cables and installation seems very similar.
Is there
really an end user cost benefit with MMF today? Also,
theoretically, will
MMF survive the next leap in speed again, isn't it
just a matter of time
before everybody has to switch to SMF anyway?
--
Mikael Abrahamsson
email: swmike@swm.pp.se