Structured cabling - MS Elektro Olomouc

Structured cabling is a general term for metallic and optical elements which enable to interconnect individual users within a computer network.


It is a universal system which:

• supports the transfer of digital and analogue signals
• includes connection points that are installed even in places where they are not currently required
• uses data cables with four twisted pairs and optical fibre cables
• is supposed to have long moral and technical life
• whose proper functionality is as vital for the company as the functioning of electric lines and other elements of the company’s infrastructure

The system brings the following advantages:

• high baud rate
• optional decentralisation the system and easy expandability
• flexible system for configuration modifications
• new HW technologies are easy to connect

We offer the implementation of computer networks - using the structured cabling system KE Line.
The structured cabling may used in modular arrangement and operatively not only for the PC network data transfer, telephone network but also for the distribution of the industrial television - CCTV, identification systems etc.

« structured cabling elements »

Structured cabling is not a commodity!

Information technologies are the most rapidly developing industry. The structured cabling systems are their integral component. They represent an infrastructure which must always correspond to the state-of-the-art technologies and applications. Compared with the power supply lines, which principally did not change during the last 50 years, the data networks see a revolutionary turnover every two or three years. Abandonment of these changes or ignoring the known trends will lead to an inadequate selection of cabling. This will consequently degrade the serviceability of other elements of the information system which are usually drastically more expensive than the cabling itself.

For long years, selection of the structured cabling has been influenced by the largest international IT authorities. These authorities have either furthered their own cabling systems or recommended other top-quality alternatives which they had tested and approved themselves. As a result of the new strategy applied by these “IT giants” concentrated exclusively on the “core business”, the cabling systems found themselves on the margins. The task of a competent consultant and supplier was partially assumed by some companies which specialise in the network installation and system integration. The majority of the market space has been gained by the whole-sale companies trading in the wiring material, heavy-current electro-installation companies, etc. Many of them still lack profound knowledge about the products and issues related with the data networks. Therefore, the structured cabling systems are still seen as a commodity and the only selection criterion is the price. Another very important market factor is the fact that the selection of the cabling is usually carried out by the financial manager of the investor, instead of the future user, operator or administrator of the network. The risk of unqualified decision therefore increases.

To protect the interests at the user and to promote the top-quality solution with a sufficient moral lifetime will be only possible if the structured cabling is again seen as a high-tech discipline, not a commodity! In order for the customer to be able to define his requirements and to assess the quality of individual solution, he must be provided with all the necessary information. The information must be true, updated and comprehensible.

Moral lifetime as a value

The required volume of transferred data is increasing each year. The majority of users nowadays uses a baud rate that is 10 times higher than that in the middle of the 1990’s. This trend will also continue in the future. With the same growth rate, the required baud rate will reach 10 Gb/sec in 5 to 10 years. As the lifetime of buildings is several decades and everybody would like to avoid the necessity of replacing the cabling systems, it is necessary that the systems being installed today already have the properties which will come in handy in the future. The timelessness is the most important property of the structured cabling system, by ignoring the timelessness you practically waste the resources you have invested in the data infrastructure. Consulting companies recommend that their clients should move only to the areas and buildings equipped with a structured cabling that is prepared for the future, complying with all the international and national standards, made by the approved and reliable manufacturer and adequately certified.

The level of this IT infrastructure is also a significant factor influencing the amount of the rent, or the building itself.

Vision of the future

The international standard ISO/IEC 11801 of 2002 differentiates three performance categories of the structured cabling, as seen in the following schemes:

Cat. 5E represents a quality level complying with the current requirements. It is able to transfer all the standardised protocols at a baud rate of 1 Gb/s, including Gigabit Ethernet.



Cat. 6E | 7E these categories were defined as perspective and timeless solution for the operation of the future high-speed applications.




Nowadays, the Ethernet is obviously the only perspective data transfer protocol, therefore its development becomes decisive even for the field of the structured cabling.

In June 2006, the international commission IEEE 802.3 approved a new transfer protocol called “10 Gigabit Ethernet”. This protocol also sets out new requirements for the cabling systems which proved to be different from those implied by ISO/IEC 11801 of 2002 (illustrated in the previous image). Therefore, it was necessary to introduce a new performance category, Cat. 6A with a required band width of 500 MHz and new requirements for the resistance of the system to the crosstalk from the adjacent cables, or ports (as expressed by the parameter Alien crosstalk). In this context, the original classification of the transfer paths (of 2002) has been overridden. The new situation may be illustrated by the scheme below..

The new situation brings forth a revolutionary perspective of the performance category in terms of its timelessness. It is less important whether the system belongs to Cat. SE, Cat. 6 or Cat. 7. What is important is the answer to the question whether the system is/is not able to transfer the 10 Gigabit Ethernet. All the systems, where the answer is negative, get to the same level as the Cat. 5E, which enables the maximum baud rate of 1 Gb/sec.

In other words: with the higher costs of installation of the Cat. 6 cabling, the user will not gain any advantage in comparison with the Cat 5E system in terms of the data transfer rate.

It must be mentioned that the ability to transfer the 10 Gigabit Ethernet is a property of the cabling system as a whole. Therefore, it is impossible to combine the components of different systems, even if they are certified for Cat. 6A!

Shielded or unshielded?

The tests of various cabling systems, as carried out by the standardisation commission for the development of the 10GBase-T, produced interesting outcomes. The unshielded Cat. 6 cabling was proved to be unable to transfer the 10 Gigabit Ethernet to a distance of 100 metres, as prescribed by the standard.

It was also demonstrated that the new unshielded cabling, specially designed for the 10 Gigabit Ethernet, do achieve the required parameters of the Alien crosstalk but only at the cost of complicated and expensive technical solutions which unreasonably increase the price of such systems. The unshielded Cat. 6A cabling also lost the previous advantage of their smaller cable diameter in comparison with the shielded ones. The absence of shielding must be compensated for by a larger span between the transferring elements of the cable.

On the other hand, many shielded Cat 6A cabling systems complied with the requirements for the transfer of the 10GBase-T, concerning the band width of 500 MHz and the Alien crosstalk values. Manufacturers of the quality shielded cabling systems, Cat. 6, did not have to develop the new products of Cat. 6A. They might as well have the original Cat. 6 cabling “re-certified” by any independent laboratory to the Cat. 6A system. In addition, the previously implemented installation of superior quality exclusively consisted of re-certified products and also complied with the requirements for the 10 Gigabit Ethernet transfer.

PVC, LSOH or LSFROH?

All the cables with the PVC, LSOH or LSFROH sheath comply with the requirements for the fire safety in buildings, i.e. they are non-combustible and do not diffuse the fire.
Nevertheless, the PVC cables during fire generate a thick smoke and release poisonous gases which are partial cause of casualties and damages to the property comparable to the flames themselves (the 1987 London underground disaster, 1996 Düsseldorf airport disaster, 2000 Kitzsteinhorn underground funicular railway disaster). The combustion gases have corrosive effect on all electronic devices and they cause their gradual non-functionality. The halogen-free cables LSOH and LSFROH have no such negative effects.
In spite of the aforementioned dangers posed by the PVC cable installation, their use has not been legally restricted in all the countries yet. Preference is given to the halogen-free cables only on the basis of the ethics and moral responsibility of the investor for the consequences of potential fire. Slovakia is the honourable exception among the Eastern European countries, as the use of halogen-free cables in this country is already governed by the legal regulations (the Ministry of Interior decree No. 94/2004 Coll.).

Note: the halogen-free cables LSOH and LSFROH only differ from each other by the degree of resistance to the flame propagation, where the LSFROH cables meet the stricter criteria.

Recommendations

• Try to separate the structure cabling from the general delivery of the construction and to discuss it with a professional firm specialising in this area. It is a part of Your IT infrastructure!
• Prefer the cabling with a long-term (20-25 year) system guarantee covering the functionality of all the standardised protocols, provided directly by the manufacturer.
• Do not define you requirements on the basis of the current needs, but always take into account the entire period for which you plan to use the cabling system. In the short-term leased areas, in networks with several connecting points and for operations with minimum demands for the data transfer, the Cat. SE cabling is just sufficient. In all other cases, we recommend to use the performance category Cat. 6A (guaranteed moral lifetime of at least 10-15 years).
• When comparing the price quotations, please take into account the moral lifetime of the individual solutions. Also, consider the costs which you would incur if the cabling system needs to be replaced prematurely.
• Do not believe anyone! Always request from your supplier the reliable certificates, list of references, testing and measurement reports, and certificates of calibration for the measuring devices used. With respect to the price and the reserve in the transmission band width, it is more favourable to use the Cat. 6A shielded systems.

With respect to the price and the reserve in the transmission band width, it is more favourable to use the Cat. 6A shielded systems.

Ethernet in optical networks

Same as with the metallic cabling, the Ethernet is the most promising data transfer protocol in optical fibre networks. The maximum transfer distance of the Ethernet application depends on the type of optical fibre used in the cable. For proper selection of the optical fibre cables we think it is useful to mention the table giving the maximum lengths of segments depending on the protocol and the performance category of the optical fibres.

« structured cabling elements »