Category 7/Class F

Proposed category 7/class F cabling will likely be supported by an entirely new connecting hardware design.

Proposed category 7/class F requirements are being developed for fully shielded (i.e., overall shield and individually shielded pairs) twisted-pair cabling. Category 7/class F will most likely be supported by an entirely new interface design (i.e. plug and socket). Even though these requirements will be supported by a new connecting hardware interface, category 7/class F will also be backward compatible with lower performing categories and classes. It is anticipated that the category 7/class F requirements will be specified in the frequency band of at least 1-600 MHz. At this time, there are no applications, either pending or proposed, that are under development for operation over category 7/class F cabling.

It is interesting to note that TIA is not actively developing a standard for category 7 and will most likely harmonize with the class F requirements put forth by ISO. If industry consensus is achieved on the selection of a category 7 work area interface design, it is conceivable that the class F requirements will be available in the same time frame as the category 6/class E specifications.

Performance Comparison Chart:

Table 2 provides comparative channel performance data at 100 MHz and other frequency values of interest for the TIA category 5, 5e, and 6 and ISO class D, E, and F performance standards.

Table 2:Industry Standards Performance Comparison Worst-case channel performance at 100 MHz
Parameter	Category 5 and Class D with additional requirements TSB95 and FDAM 2	Category 5e ('568-A-5)	Proposed Category 6 Class E (Performance at 250 MHz shown in parentheses)	Proposed Category 7 Class F (Performance at 600 MHz shown in parentheses)
Specified frequency range	1-100 MHz	1-100 MHz	1-250 MHz	1-600 MHz
Attenuation	24 dB	24 dB	21.7 dB (36 dB)	20.8 dB (54.1 dB)
NEXT	27.1 dB	30.1 dB	39.9 dB (33.1 dB)	62.1 dB (51 dB)
Power-sum NEXT	N/A*	27.1 dB	37.1 dB (30.2 dB)	59.1 dB (48 dB)
ACR	3.1 dB	6.1 dB	18.2 dB (-2.9 dB)	41.3 dB (-3.1 dB)**
Power-sum ACR	N/A	3.1 dB	15.4 dB (-5.8 dB)	38.3 dB (-6.1 dB)**
ELFEXT	17 dB (new requirement)	17.4 dB	23.2 dB (15.3 dB)	ffs***
Power-sum ELFEXT	14.4 dB (new requirement)	14.4 dB	20.2 dB (12.3 dB)	ffs***
Return loss	8 dB* (new requirement)	10 dB	12 dB (8 dB)	14.1 dB (8.7 dB)
Propagation delay	548 nsec	548 nsec	548 nsec (546 nsec)	504 nsec (501 nsec)
Delay skew	50 nsec	50 nsec	50 nsec	20 nsec

Note: Industry channel-performance requirements for Category 6 and Category 7 are currently under development.

* Class D return-loss requirement at 100 MHz is 10 dB. Class D power-sum NEXT loss is 24.1 dB at 100 MHz.

** Positive ACR at 600 MHz is accomplished with the typical Class F implementation with interconnect environment and without transition point.

*** ffs-The parameters are marked for future study by the ISO standards group, and anticipated performance requirements are under development.

Conclusion:

When designing and installing structured cabling systems, chose the strongest foundation to support your present and future networking needs. To ensure support of emerging technologies that utilize the latest advances in signaling schemes, it is critical to be as informed as possible. Trust the TIA and ISO standards developmental groups to specify complete cabling criteria capable of providing applications assurance for tomorrow's technologies today.

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De-Mystifying Category 5, 5e, 6, and 7 Performance Specifications	\|	Important Definitions

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