As we have reported in the past, the TR-42.1 Commercial Building Telecommunications Cabling Subcommittee of the TR-42 Telecommunications Cabling Systems Committee, continues to work on TIA-942-A, the first revision of the Telecommunications Infrastructure Standard for Data Centers.
Previously we told you that the standard will no longer recognize OM1 and OM2 multimode fiber-optic cable for backbone and horizontal cabling in the data center. Instead, OM3 and OM4 multimode fiber are the recognized media. At TR-42.1's most recent meeting, held on June 16, the subcommittee went a step further. It designated OM4 as the recommended multimode fiber for data centers. In its current draft, the TIA-942-A standard still recognizes both OM3 and OM4 as it previously had, but OM4 has been elevated from recognized to recommended.
The TR-42 Committee meets three times per year, and many of its subcommittees meet with the same frequency. The TR-42 Committee is scheduled to meet next in October. There is no established timetable for approval and publication of TIA-942-A, but based on the anticipated meeting schedule it looks like 2012, not 2011, will be the year.
Below is a list of other ways in which TIA-942-A will be different from the original TIA-942 standard.
- The addenda, TIA-942-1 and TIA-942-2, have been incorporated into 942-A; those two addenda will be superseded by TIA-942-A.
- Grounding and bonding content from TIA-942 has been removed and incorporated into TIA-607-B.
- Administration content has been removed and incorporated into the proposed TIA-606-B.
- Most content regarding cabinets/racks and power/telecommunications separation has been removed and incorporated into the proposed TIA-569-C.
- Outside-plant pathways content has been removed and incorporated into TIA-758-B.
- The 100-meter length limitation for optical-fiber horizontal cabling has been removed. Horizontal cabling distances for optical fiber are based on individual application requirements.
- Category 3 and Category 5e are no longer recognized for horizontal cabling. The draft recognizes Category 6 and Category 6A balanced twisted-pair cable types for horizontal cabling. Both types of cabling are still permitted for backbone cabling.
- The recognized optical-fiber connectors are LC for one or two fibers and MPO for more than two fibers.
- The intermediate distribution area (IDA) has been added to the data center topology.
- An allowance for midspan powering equipment in the zone distribution area (ZDA) has been removed.
- A section on energy efficiency has been added.
- The terms "equipment outlet" (EO) and "external network interface" (ENI) from the ISO/IEC 24764 standard have been added.
