If you’ve been in LAN cabling business, you should have heard about CAT5, CAT6 and probably CAT7 standards. It would not be therefore hard to guess that the next standard in network copper cabling would be CAT8 (Category 8) standard.
In this article I try to give a very short and effective idea of what all these category standards are about and then explain what you should expect from the next upcoming standard – CAT 8.
Category Standards for Twisted Pair Cables
Category standards defined by ISO/IEC 11801 international standard define the characteristics of telecommunication cabling systems for both twisted pair and FO cabling. Here I will only focus on twisted pair.
Without making it should too complicated, the reason you see copper cables used in communications (being it voice or data) are twisted as pairs, is because by twisting the two wires that are used for transmission of communication signals, the wires would to some extent “contain” the electromagnetic field that would be created as a result of such electrical signals passing the wires.
The actual speed of data you can pass through a twisted pair would be limited by the frequency characteristics of the twisted wire/cable. The higher the frequency characteristics, it means that the cable can “contain” the electromagnetic fields at higher frequencies allowing higher speed throughputs. (If can be mathematically proved that the higher the data speed, the higher is the created frequency).
One of the factors that increases frequency characteristics of twisted pair cables is how much “twisted they are” – more twist equals better frequency characteristics. The other factor would be the separation between different twisted pairs including by using individual shielded pairs.
Now, as the technology evolves there is increasing demand for higher data speeds and hence the need for defining and manufacturing twisted pair cables that can support those higher speeds.
The table below briefly shows the current Category standards for twisted pair cables (I’ve simplified it a bit):
| Standard | Frequency Limit | Data Speed | Date of Usage |
| CAT 2 | 1 MHz | 4 Mbps | 1980s |
| CAT 3 | 16 MHz | 10 Mbps | 1990s |
| CAT 5/5e | 100 MHz | 100 Mbps | 2000-2010 |
| CAT 6 | 250 MHz | 1 Gbps | 2005 – onwards |
| CAT 7 | 600 MHz | 10 Gbps | 2010 – onwards |
| CAT 7a | 1000 MHZ | 10 Gbps+ | 2014 – onwards |
Note: CAT5e standard was introduced as improvement of CAT5e and can actually support up to 1Gbps. There is a CAT6a standard commonly referred to by manufacturers but that is not actually an official ISO standard.
Category 8 Standard
As explained above, obviously CAT8 standard is expected to provide better frequency characteristics / hence support for higher speeds of data.
The standard has been under development since March 2013 and a draft was finally published for review in June 2016. The final version of the standard can be out as early as Q4 2016.
CAT8 is expected to support bandwidths of up to 2 GHz (2000 MHz) for up to 30 meters of cabling and can support 25Gbps / 40Gbps speeds.
CAT8 cables will look similar to lower category cables and will most probably still be terminated in RJ45 connections.
As the cable length for such speeds is limited to 30 meters, they will most probably be used in form of factory-made patch cords for interconnection of equipment in data centers.
Conclusion
The current CAT8 standard is expected to be finalized sometime in late 2016. We might need to wait for another year before seeing related products (CAT8 cables, connectors, patch panels …) in the market.
However at least for now, it seems that CAT8 usage will be more limited to server rooms and data-centers as an easier alternative to make high-speed interconnection between servers and networking appliances by using the very much familiar copper patch cords.
