It is gratifying to note that TIA TR-42.7 has met all eight objectives that were established nearly five years ago.
ANSI/TIA-568-B.2-1, the official designation of the Category 6 standard, was published on June 20. The publication of these specifications marks a milestone for the cabling industry as a whole, and for many individuals who worked diligently on the project.
The Telecommunications Industry Association (TIA-www.tiaonline.org) first discussed Category 6 at the TR-41.8.1 meeting in Quebec City on August 20, 1997. Based on these initial discussions, a list of eight objectives was established during a teleconference later that month. The objectives were:
- Significant improvement over Category 5. Proposed delta is at least two times the Category 5 frequency specification (200 MHz). For a next-generation channel, the maximum attenuation and minimum multi-disturber near-end crosstalk difference shall be similar to the Category 5 channel at 100 MHz.
- Next-generation cabling shall continue the sequential progression of Categories originally developed by TIA TR-41.8.1.
- Next-generation cabling shall be backward-compatible with existing Category 5 cabling; i.e., it will be a "strict superset of Category 5" as requested by IEEE. This means that the modular jack interface shall be maintained for all user interfaces at the work area and that "Category 6" components will be electrically compatible with those of the other categories. That is, if the components (i.e., plugs and outlets) are able to be mixed, the mated combination will at least meet the transmission re quire ments of the lower-performing component.
- Next-generation cabling shall meet the horizontal cabling topol ogy (100 meters) as specified in TIA-568-A and TIA-569-A.
- Next-generation cabling shall be a system specification including procedures for laboratory and field testing, installation practices, and other practical considerations (e.g., reliability, durability).
- TIA TR-41.8.1 will actively solicit input from application committees such as IEEE and ATM Forum to incorporate the needs of future applications, including new parameters.
- TIA UTP Systems task group will provide input to ICEA to harmonize with the development of extended-frequency cable specifications.
- TIA TR-41.8.1 will develop detailed technical requirements for connecting-hardware transmission for next-generation cabling, based on an applied statistical model, combined with known constraints on channel and cable requirements.
Of course, some things have changed since August 1997. The TR-41.8 subcommittee is now the TR-42 Engineering Committee, and the group responsible for the Category 6 specifications is the TR-42.7 Telecommunications Copper Cabling Systems Committee.
Mission accomplished
The objective list was communicated to the U.S. Technical Advisory Group for ISO/IEC/JTC1/SC25/WG3, and became the framework for the Category 6 project, both in the TIA and in the second edition of IS 11801. It is gratifying to note that TIA TR-42.7 has met all eight objectives that were established nearly five years ago.
Category 6 doubles the bandwidth of Category 5e, vastly improves signal-to-noise margins, and has much better isolation from external noise because of improved electromagnetic compatibility performance. It supports all legacy applications supported by Categories 3, 5, and 5e, while paving the way for emerging multi-gigabit applications.
Now that the standard is published, customers should look carefully at Category 6's cost/benefit ratio compared to other cabling systems, and make an informed judgment on what best suits their needs.
Connecting hardware was the single biggest technical challenge in the development of the Category 6 standard. In addition to developing the requirements for Category 6 connecting hardware, TR-42.7 members had to invent new measurement technology to be able to measure connecting hardware at Category 6 levels. This technology includes detailed measurement procedures, measurement fixtures, and reproducibility requirements to ensure consistent measurements between laboratories.
The connecting-hardware committee also had to ensure backward compatibility to Category 3, Category 5, and Category 5e, as well as plug-and-jack interoperability among manufacturers to complete the objectives. This work required many rounds of round-robin testing, several laboratory meetings in which procedures and interoperability requirements were checked out, and extensive simulations and modeling to ensure that Category 6 performance could be achieved with real-world manufacturing variability.
The technical challenges associated with connecting hardware, however, were not the sole reason that the Category 6 specifications took nearly five years to complete. Until March 2001, the Category 6 project was considered a "second priority" by TIA. Other projects that took precedence over Category 6 included TSB-95, the Category 5e specifications, and the development of the TIA-568-B specification series. Once these higher-priority projects were completed, the TR-42.7 subcommittee, its working groups, and its task groups all went into high gear to rapidly complete the PN-3727 Category 6 project.
All members of and participants in the TR-42.7 engineering subcommittee, the TR-42.7.1 copper connecting hardware working group, the TR-42.7.2 copper cable working group, and several other task groups should be congratulated for their contributions. The committee included world-class experts in the technology of signal transmission, who worked together to make sure that Category 6 became a reality.
Masood Shariff chairs the TIA's TR-42.7 Telecommunications Copper Cabling Systems Committee.