|
| | | 
Junior Member
 
Group: Forum Members
Last Login: Tuesday, May 17, 2011 5:32 AM
Posts: 13, Visits: 56 |
| I am not sure when OM4 will be included in an addendum to TIA568-C.3, but I guess it will and when it does (or even before then) what do you think it will mean to those currently who have OM3 in their data centre??
Andrew Sedman RCDD/NTSTechnical Director R&M MEA |
| |
| | | Forum Guru
Group: Forum Members
Last Login: Wednesday, May 09, 2012 11:38 PM
Posts: 64, Visits: 189 |
| | Nothing, At this stage both OM3 & OM4 will have 40G & 100G to at least 100m. OM4 may be a bit longer. 10G on OM4 with short haul VCSEL's will go 550m instead of 300m with OM3. Depends on how big your data centre is. NOTE: draft standards always change and we will not know for sure until the standard is published. |
| |
| | | 
Forum Newbie
Group: Forum Members
Last Login: Friday, April 16, 2010 2:46 PM
Posts: 4, Visits: 20 |
| | What are the design considerations to keep in mind when using the solution preconectorizadas OM3 fiber?. For example as it affects the number of cassettes or length of the trunk cables of the link. There a reference or bibliography that you can use? Thank you. |
| |
| | | 
Forum Guru
Group: Forum Members
Last Login: Thursday, May 03, 2012 9:32 AM
Posts: 85, Visits: 171 |
| Good question!
TIA-492AAAD was published in September 2009 to introduce a specification for OM4.
Interesting to see the Attenuation Coefficient 2.5 dB/km @ 850 nm and 0.8 dB/km @ 1300 nm. Needed to make the math work for the Channel Insertion Loss stated below. Overfilled bandwidth is 3500 MHz.km, under filled (effective bandwidth) will be 4700 MHz.km.
As a cable only standard, there is no reference to support of 10GBASE-SR, 40GBASE-SR4 or 100GBASE-SR10 distances.
If we look to the draft of IEEE 802.3ba which references TIA-492AAAD, and Table 86–1—Summary of 40GBASE–SR4 and 100GBASE–SR10, we see OM3 0.5 m to 100 m and OM4 0.5 m to 125 m for both 40 and 100G options. The Channel Insertion Loss of 1.9 dB can be found in the same draft standard in Table 86-9, again for both 40G and 100G options.
So OM4 will get you another 25 meters compared to OM3. At a recent BICSI meeting I listened carefully to the audience during the coffee break and they were questioning the benefit of OM4 over OM3 given that their data centers typically have much shorter links than 100 m. I'm not making a judgment here, but I do not expect OM3 to go away anytime soon. I am also seeing long term veterans suggesting going to Singlemode.
I would of course be interested to hear other views. At the end of the day, I'm just the tester guy.
Kind regards
Adrian Young
Senior Technical Support Engineer
Fluke Networks Technical Assistance Center
Are you testing LC Duplex Links correctly? This video will let you know |
| |
|
|
