TIA's big debate on Cat 8

Many members of the Subcommittee are concerned about how to name such a new system. supporters and opponents of this new system both stick to their positions and hold a heated debate. However, the real question is how much confusion the name of Category 8 will bring to the industry.

Generally, the high level of a cabling system is a low level superset-meaning that the High Level cabling system meets and surpasses all electrical and mechanical requirements of the Low Level cabling system and is backward compatible with low performance levels. When TIA details the performance of cata 6 or later cabling systems, TIA does not use category 7 or 7A like ISO/IEC. TIA has now decided to use Ccategory 8 to name its next generation balanced twisted pair cabling system to avoid confusion with the issued ISO/IEC 7 and 7A standards. In ISO/IEC, its 7 categories and 7A categories are actually the supersets of 6A categories. Although the proposed performance specification for category 8 Initially defines a transmission performance indicator up to 2 GHz, the ISO/IEC-defined performance indicator for category 7A is only 1 GHz, however, the performance indicators proposed by category 8 cannot meet or exceed the performance requirements of category 7A within 1 GHz.

Therefore, it brings about a difficult problem: category 8 will have different channel topologies and will not be a super set of 7A performance. In fact, any performance parameter except ripple loss is within 1 GHz, the channel and permanent link parameter requirements for ISO/IEC category 7A are more stringent than those for the category 8 parameter proposed by TR-42.7. In terms of internal crosstalk parameters, the difference is very big: category 7A is better than category 8 with a performance of more than 20 dB!

What about the standard bandwidth? Although currently category 7A is set to 1 GHz, new work items, such as the recently finalized IEC 61076-3-104 Standard for the category 7A connector, the performance parameter of category 7A has been extended to 2 GHz. The current situation is that there are two sets of 2 GHz cabling specifications, and the performance parameter of category 8 is much lower than that of category 7A, which is really confusing.

Naming a next-generation cabling system is not just a problem with TIA. ISO/IEC faces the same challenges in two new projects: how to describe the capabilities of existing cabling systems (6A and 7A) and new cabling systems (Class I and Class II) to support 40 Gbps data transmission. Although ISO/IEC currently has a placeholder for the new term in its draft, "category 8" is definitely not considered in terms of its channel and permanent link ".

In the defense of TIA, it is believed that other naming options may lead to deviations from the conventions of the familiar Category numbers, and may also lead to unpleasant effects. Although TIA's decision is not hasty and some people think it is the least troublesome choice to make from a few unappealing choices, the whole industry needs to understand that the former jinke Yulu, that is, a higher category is a superset of a lower category, which has been broken. Let us hope that the next great TIA debate will not be whether the next generation cabling system should be called "category 8A" or "category 8e ".