Bravo to Bob Kenny for his "Beyond Category 6: What's the big deal?" (October 2003, page 30). I question, however, the statement, "There is a significant installed base of Category 6 already in place." I guess the word "significant" can mean different things to different people—like more now than before.
TIA-568B.2-1-2002 Addendum 1—Transmission Performance Specifications for 4-Pair 100 Ohm Category 6 Cabling, is only a year old. TIA-568B.2-6-2003 Addendum 6—Category 6 Related Component Test Procedures, has just been published. These are the "TIA Category 6 standard" today.
Not all of the "Category 6" cabling components manufactured and sold before the ink was dry will meet the published standard. (Hint: check the date stamp on the box or reels and bags that you are buying.) But this does not mean that it will not support 1000Base-T—just like Category 5e.
TIA-568A-1999 Addendum 5, Transmission Performance Specification for 4-Pair 100 Ohm Category 5e Cabling, "drove the stake in the ground" for Category 5e cabling in 1999.
10G on UTP
As previously detailed, just about everywhere on milk cartons, IEEE 802.3 is currently considering 10GBase-T PAR.
Recent reports have demonstrated that "standard Category 6 channel" will not support 10GBase-T in the future.
According to IEEE 802.3 10GBase-T Study Group chair Chris DiMinico of MC Communications, his group's objectives include supporting 10GBase-T over a four-pair, four-connector channel for at least 100 meters on four-pair Class F (Category 7) balanced copper cabling, and at least 55 meters on four-pair Class E (Category 6) balanced copper cabling.
In support of this effort, DiMinico asked TIA TR-42 for its assistance in characterizing the installed base of balanced cabling up to 625 MHz. Translation: TIA, tell IEEE what performance we expect from the cabling that has already been installed.
TIA has agreed to investigate Category 5e cabling for 10GBase-T applications and to share those findings directly with the IEEE 802.3 10GBase-T Task Force. TIA will also investigate Category 6 cabling for 10GBase-T applications and report those findings
in either a new Telecommunications Systems Bulletin (TSB) or Engineering Publication.
Note that there are no plans to publish the Category 5e findings. Wonder why?
If TIA-568 is the "holy grail" for telecommunications structured cabling, then the 100-meter channel is the "golden rule." As evident from the Study Group request, today's Category 5e and Category 6 will not support a 10GBase-T 100-meter channel. But if we are going to toss the "golden rule" for Category 6 and support a shorter channel (I am hearing numbers like "between 75 and 100 meters"), why not for Category 5e as well? Could it be because the experts who are working so diligently on the characterization are marketing Category 6, and not Category 5e cabling today? I am hearing numbers like, "between 45 and 100 meters." Forty-five meters is a long run from a TE to a work-area outlet.
Augie, the golden cat
No, Augie is not a children's book.
Last month, I asked you to think about this:
- The TIA-568 era gave us Categories 3, 4, and 5;
- The TIA-568A era gave us Category 5e;
- The TIA-568B era gave us Category 6;
- And whether the TIA-568C era will give us a new "gee-whiz Category 6" copper cabling to install.
Right on schedule, at the October meeting review of the "wish list" for 568C, a new copper cabling category was introduced.
Believe it or not, there is a new cabling standards effort in the works. Current moniker "augmented Category 6" is a new work item for TR-42.7. They are to develop cabling and component specifications as well as test procedures to support the operation of IEEE 802.3 10GBase-T over 100 meters of structured balanced twisted-pair copper cabling, and publish either an addendum to the TIA-568B standard or incorporate "augmented Category 6" directly into the TIA-568C standard.
This means not only extending the frequency range to 625 MHz, but also adding additional requirements to those specified in TIA-568B.2-1 ... like alien NEXT and balance.
History repeats itself, almost
Remember when "standard Category 5" would not support 1000Base-T, and "standard Category 5e" was written as a temporary solution, while work continued on Category 6?
For most manufacturers, going for a Category 5 to Category 5e was no problem. It was the same cable that was tested for more characteristics.
This will not be the case for Category 6 to "augmented Category 6."
"Augmented" means something has been added—simple enough. But if speed and performance are not the only things that are added, then we may have other problems.
To mitigate alien crosstalk, it is likely that the copper conductors will have to be made larger than those in Category 6 cable—which already are larger than those in Category 5e cable. This would mean yet a fatter cable, a stiffer cable and, of course, a more expensive cable. But this is only a cable-cost issue.
What about the pathways? In large institutional buildings, like universities, hospitals, government buildings, etc., cabling comes and (if you are following the new abandoned-cable directives), cabling goes. But pathways are typically designed for the usable life of the building. We have been sizing cabling pathways for years based on a maximum 0.25-inch cable diameter with a maximum 1-inch bend radius (four times the cable diameter). A fatter, stiffer cable could mean that our pathways would not support the "augmentation."
Synonyms for augmented cable include improved, better, bigger. And "augmented Category 6" will certainly be improved over any previous versions of UTP. To answer the ultimate question, "What can an 'augmented Category 6' do that a Category 6 or a Category 5e cable cannot?"; if they do it right, "augmented Category 6" will support a 10GBase-T 100-meter channel in the future.
So, where does that leave us? Your mission, should you decide to accept it, is to convince the end user to pay more and installers to work with yet another category of cabling that will require yet a smarter field tester, and whose targeted application standard will not be available until at least late 2006.
After that, a balanced federal budget and world peace should be a snap.
Augmented? Why augmented? Actually heard at the coffee break at the October TIA meeting: "All the really good names were already trademarked."
Donna Ballast is BICSI's standards representative, and a BICSI registered communications distribution designer (RCDD). Send your questions to Donna via e-mail: [email protected]
ISO working on cabling standard for wireless access points
Aworking group within the International Organization for Standardization (ISO; www.iso.ch) is in the initial stages of defining specifications for the cabling used for WLAN access points. The group is the ISO Joint Technical Committee (JTC) 1, Subcommittee (SC) 25, Working Group (WG) 3—JTC1/SC25/WG3.
That group is working on document number ISO/IEC CD TR 24704 Information Technology—Customer Premises Cabling for Wireless Access Points.
The document has gone through the ISO standards-making group's preliminary, proposal and preparatory stages, and currently is in the committee stage. Within the committee stage, the document has passed through the committee draft (CD) registration and CD study/ballot initiation processes.
At present, the document sits at the comments/voting summary circulation stage. From this point, it will be referred back to the Working Group for further proceeding or abandonment. Assuming it proceeds further, it still must pass through the enquiry and approval stages before publication.
The enquiry stage includes ballot initiation (which, according to ISO procedures, is a five-month process), dispatching of voting summary, circulation of a full report, and another decision to abandon or proceed.
The approval stage includes a two-month initiation, another voting-summary dispatch, and referral back to Subcommittee 25.
The ISO's JTC1/SC25 is the entity that produces the ISO/IEC-11801 standard series, often referred to as the "international" equivalent of the TIA/EIA-568 standards series. The two sets of standards do differ, though harmonization between the two groups is a goal of both parties.
Often, the ISO standards process precedes TIA standard ratification; one example is that the ISO recognized the permanent link in a cabling system while the TIA still referred to the basic link.
Some interested parties expect that the TIA will closely monitor the ISO's progress toward a "cabling for wireless" standard, and could follow suit.
Cabling Installation & Maintenance will follow these developments and keep you informed of their progress.
—Patrick McLaughlin