"Cabling confusion" – New and emerging standards
Now, with the emergence of more new copper cabling standards, it has never been so easy for people installing structured cabling to get confused about what the new and emerging standards actually mean. This can complicate things when advising customers on system selection, or responding to vague tender specifications.
Currently, the most commonly installed copper twisted pair systems are Category 5e, and Category 6, most often in Unshielded Twisted Pair (UTP) form. Increasingly, newer categories of copper twisted pair are being discussed – namely Augmented Category 6 (Cat6A) and Category 7.
As newer systems emerge, customer’s expectations will be for installers to offer concise and accurate guidance on what is available. To do this, it will be important to understand what the customer intends to transmit over these cabling systems.
For example, most end-users are running 100Mbps to the desktop (work area PC). In fact, nobody in the normal business world is using above 1000Mbps (Gigabit) to the desktop. Both Cat5e and Cat6 UTP will support this – so the question many will ask is: “Why are people now asking about 'Cat6A’ and Cat7?” There are a number of reasons for this.
Starting with transmission speeds, the next jump from Gigabit is 10 Gigabit transmission – 10 times faster than Gigabit. This has been driven by the demands of high-speed operations within Data Centres. The constant resistance of the industry to use optical fibre has also driven the development of new copper cabling systems to support 10Gigabit (10G).
In addition to this, IT managers are becoming increasingly concerned with future applications, and the need for the cabling to support these outside of data centres. Consequently, new copper cabling standards have emerged and are emerging. Category 7 has been around for sometime, and the next new standard to be ratified will be Category 6 Augmented (Cat6A), which is currently in draft form only, but is due for ratification later this year.
Further to this, standards bodies have also been busy investigating the ability of existing cable categories to support 10G. This has resulted in the recognition of the existing Category 6 Foil Twisted Pair (FTP) standard as being able to support 10G to 100m, and the recognition that Category 6 UTP will support 10G, but at a reduced distance of 55m.
At present, a number of manufacturers have taken to releasing 'Cat6A’ products prior to the standard being ratified, basing designs on the draft documents or predictions of the likely final version. Whilst Cat6A will support 10G, Category 7 has more bandwidth than Cat6A – 600MHz for Cat7 versus 500MHz for Cat6A. Whilst this extra bandwidth may not see any use in the normal PC user environment currently, it does offer the capacity to support a number of applications that may emerge over the next few years.
These include a range of new television broadcast applications being promoted by some suppliers. Video phones and Video on Demand at the desktop are two applications where Cat7 could prevail, as companies investigate more effective ways to deliver services such as video training sessions to their employees via their PC work station.
Many people may question the need to develop Cat6A when Cat7 already exists. One of the main reasons for this happening is that Cat7 is only specified in European and International Standards (EN and ISO), not in the USA (ANSI/TIA/EIA). In addition to this Cat7 was not only developed with 10G in mind, it was proposed as a very high bandwidth shielded cable that could perhaps support anything likely to be developed in the near future.
Heavily screened Cat7 cables are also outside of the norm for the UTP dominated market in the US, as are the different connectors that they use. With this in mind, the US instigated the development of an Augmented Category 6 solution, to bring the benefits of Cat7 to the world of Cat6, and to hopefully develop an unshielded solution for 10G.
Further to this, Europe and the rest of the non-US world have recognised and readily accepted that there may be applications for a Cat6A solution. The possibility of 10G over a UTP cable, and a normal RJ45 connector, are two of the reasons for this interest.
A major factor driving 'Cat6A’ in Europe has also been the perceived negatives associated with Cat7. Firstly, it utilises a thick, stiff, heavily screened cable that is similar in size to an old Type 1 cable. This presents a range of problems for the installer trying to deploy it in anything but a perfect false-floor environment.
Secondly, it does not use a 'normal’ RJ45 connector, using TERA or GG45 connectors. This provides issues for connectivity to most equipment, and, whilst the GG45 connects to an RJ45, it is different and has not been rapidly accepted. These factors combined have contributed to the minimal uptake of Cat7 in the UK, and in many other parts of Europe. In spite of this, there is currently an Augmented Category 7 (Cat7A) standard on the drawing board, which aims to deliver up to 1000MHz bandwidth. However, many of the same physical attributes are likely to apply.
One major cause for confusion in all of this is the subject of shielded cabling versus UTP. As I mentioned earlier, existing Cat6 UTP systems may support 10G, but only up to 55m. One of the reasons for this shorted distance is the effect of Alien Crosstalk. This is electrical noise from outside of the cable that can influence the copper pairs within. This noise can come from other UTP cables within the same bundle or vicinity, not just from 'traditional’ electrical noise sources such as power cables and generators.
The transmission of 10G up to 100m demands superior protection against this, and Cat6 UTP doesn’t make the mark. As a result, great debate has arisen over the subject of shielded versus UTP cables for the new 'Cat6A’ standard. In response, the exponents of UTP systems have designed their cables to counter-act Alien Crosstalk by using alternative cable designs and shapes. The exponents of shielded systems have questioned the reasons for staying with UTP, and promote shielded systems as the safest bet.
The fact is that UTP cables have always been slimmer, and containment systems are not generally designed around thick, stiff, shielded cables. They have also traditionally been much faster to terminate, and have always been less expensive. However, emerging 'Cat6A’ UTP systems are now also employing thicker cables – so UTP may not be the slimmer option in the future.
To summarise, Category 6 remains the highest performing unshielded cabling standard. The FTP variants of Category 6 also support 10G to 100m, and are recognised in the guidelines for the support of 10G over existing cabling systems. Whilst Category 7 has been around for some time, it is likely that the next new standard to make a real impact will be Category 6 Augmented (Cat6A). However, this standard is not yet ratified, and any Cat6A product currently available risks not matching the requirements of the final standard.
The current trend also suggests that the vast majority of manufacturers are aligning themselves to shielded versions, as concerns over Alien Crosstalk in the field increase, despite the traditional lean towards UTP systems. UTP or shielded, one thing that is for certain is that the cabling world, and containment designers, will be forced to allow for the new age of thicker cables and deeper connectors.
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