Several issues were addressed during the recent TIA meetings. Here's a look at what was accomplished during the sessions...
July 1, 2001
The TIA Engineering Committee TR-42 met in Providence, Rhode Island during the week of June 11-14. Following is a broad-brush overview of what happened within the different TR-42 subcommittees:
A new Working Group was formed to study telecommunications infrastructure requirements for network distribution nodes. These nodes are often referred to as data centres and storage area networks (SANs), which encompass a concentration of data processing equipment including servers, switches, routers and storage devices. This was the first meeting of the group and it generated a high level of interest. Contributions were presented on fiber implementation and design challenges. And a press release was approved by TR-42 to invite industry experts to participate in this new initiative.
An addendum to ANSI/TIA/EIA 568-B.1 on patch cord bend radius was approved for publication. The minimum bend radius for UTP patch cords was changed from four times the cable diameter to one times the cable diameter.
Addendum no. 6 to ANSI/TIA/EIA 569-A on multi-tenant pathways and spaces was approved for publication. Also, a future addendum on cable tray and wireway distribution systems is now under development and was approved for a first ballot after an editing session.
An addendum to ANSI/TIA/EIA 570-A on residential security cabling systems was approved for a first ballot after an editing session.
A discussion was held on the different aspects involved in implementing “tiny TRs”. This is a new idea that is under study in the TR 42.3 subcommittee at the request of BICSI. Opinion on the subject is divided, specifically on its applicability to the concept of structured cabling. There are many issues involved, such as security and access, heat dissipation, bonding and grounding, administration and installation. A task group will meet July 23 to determine how to proceed.
Ballot resolution was held on the proposed revision to TIA/EIA 606-A administration standard (SP-4156-RV1). There was not enough time to finish ballot resolution of the 209 comments that were received. The TR-42.6 Subcommittee plans to finish the ballot resolution in August and release another ballot for the November meeting.
Ballot resolution was held on the proposed addendum to ANSI/TIA/EIA 568-B.2 for 4-Pair 100 W Category 6 cabling. All of the technical comments were answered, albeit with some “unhappiness” related to the Category 6 connector requirements and measurement procedures. The subcommittee agreed that once the draft is updated to incorporate the changes that were agreed upon during the meeting, another ballot should be issued.
The ballot (SP-3894-AD1) on additional transmission performance specifications for 50/125W optical fiber cables was reviewed during this meeting. This addendum is on hold until the measurement standards for differential mode delay and laser launch power distribution are completed.
A liaison letter requesting the use of unallocated margin for additional connector losses for 10-Gigabit Ethernet will be forwarded to IEEE 802.3.
The committee approved publication of TIA/EIA TSB 125 on “Guidelines for Maintaining Optical Fiber Polarity Through Reverse-Pair Positioning.”
A working draft of the Industrial Cabling Standard (Draft 2.1) was presented in the TR 42.9 subcommittee. There are still a lot of issues regarding the type of connectivity (8-pin modular vs. M12), the cabling performance requirements for EMC, and the bonding and grounding requirements and terminology.
THE LAST TECHNICAL HURDLE
No meeting would be complete without talk of Category 6. So, let me leave you with a word on the proposed Category 6 standard for twisted-pair copper cabling. The main issue that still remains to be resolved is the specification for “connecting hardware interoperability”. In order to achieve Interoperability, a set of test plugs has to be determined for qualifying Category 6 connecting hardware. These test plugs are specified in terms of their NEXT and FEXT performance. The test procedure used to specify these plugs is still under development. The problem seems to be the measurement accuracy between different labs. It was determined that the type of fixtures, plug construction and calibration procedures will need to be more consistent. Likewise, some experts feel that range of plugs currently specified is too wide to ensure Interoperability.
All of these issues were referred to the Connector Working Group for resolution before the next meetingCS
Paul Kish is Director of IBDN Systems & Standards at NORDX/CDT in Pointe Claire, PQ. He is also Chair of the TR-42 engineering committee.
Disclaimer: The information presented is the author’s view and is not official TIA correspondence.