Data rates of 10 Gbit/s will not be sufficient in a few years, to meet the exploding demand for bandwidth in data centers. Thereupon IEEE 802.3 has approved by a large majority to establish a 40-GBASE-T Study Group.
Class I + II
Cat8 channel and link is offset according to draft TIA-568-C.2. The transmission link is based on Cat.6A with extended frequency range up to 2000 MHz. A backward compatibility is given only up to Cat.6A. Within the TIA standards, there is no specification for category 7 and 7A existing.
Within the draft standard ISO / IEC TR 11801-99-1, are the new standards with the classes I and II in development. Currently is 1600 and 2000 MHz in the discussion for the bandwidth / frequency range.
The transmission link Class I / Cat8.1: based on Cat.6A and corresponds approximately with Cat.8 according to TIA-568-C.2.1 with extended frequency range up to 2000 MHz Cat8.1 is backward compatible only up to Cat.6A.
The transmission link Class II /Cat8.2 is based on Cat.7A with extended frequency range. Cat8.2 is backward compatible with Cat.7A and all categories below.
Source: Draka UC Data Cable brochure