MIDDLE EAST ELECTRICITY - DECEMBER - DATA CABLE - …



The latest in data cable, for industry, commerce and the home

Today, with the use of data cable expanding almost exponentially, installers need to know how to build a large data cable network, whether fibre or copper based. Also, data cable is being used more and more to ‘power’ the so-called ‘smart home’ with its control, systems for heating, ventilation, lighting, home cinema and other facilities. Voltimum UK Managing Editor James Hunt introduces the VoltiBULLETIN by examining some of these issues:

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Photo - data cable courtesy of Pirelli

Data systems are now essential for the vast majority of businesses in the UK. Currently, data cabling is moving from being an 'IT product' to being a commodity 'building' product, and more and more installers are offering installations. As data rates increase, resulting in products becoming more technical, a corresponding move from voice cable installations to the latest generation of standards-based cabling for communications has occurred - from Cat5 / Cat5e cables to the 250MHz Cat6.

Most of today's data / telecommunications cabling is still copper but, increasingly, optical fibre solutions are required, especially for higher end applications working over longer distances. However, despite the fact that Storage Area Networks (SANs) tend to have relatively short links with many terminations, they already use a cabling technology that supports 10 Gigabit Ethernet. Today, this is optical fibre, and though some say that it is probably the sole fully risk-free choice for 10Gigabit cabling available, Voltimum Founder Member Company, the cable giant Nexans, already guarantees that its Cat7 system that will support the copper based 10 gigabit solution which is under development by the the IEEE - known as 10GBase-T. Says Nexans, 'there is no question but that 10Gigabit is being developed for use over copper with plans to have the application standard completed in 2006.

So, for most other applications, such as telecom network cables, interconnection systems and data transmission cables, copper is still king. Data cabling has to meet the needs of Local Area Networks (LANs), access, long distance and city networks, and they also have to cope with the increasing requirement for greater bandwidth and data throughputs. This has resulted in an ever larger, mainly copper-based, Cat6 structured cabling requirement in mainly commercial operations. Cat6 represents a major improvement over earlier systems, as it allows generic cabling to work at modern broadband performance levels. It also ensures considerable 'future-proofing', with greater reliability for existing applications and better potential for supporting the increasing array of 'IP devices' such as IP cameras etc.

Treating voice more like data, Voice over IP (VoIP) is a worry for traditional telephone service suppliers. VoIP is one of the most recent digital technologies to have an effect on business sectors, and is voice communication transmitted using the IP protocol. It can use two types of medium: the Internet, or dedicated lines. VoIP can allow major savings to be made. Calls are routed over existing data lines, so that the phone bill is virtually eliminated, and – moreover - the length and distance of calls are irrelevant. VoIP can also cater for universal messaging, IP Telephony (IPT), fax, and other features. The benefits of VoIP can be very significant for companies whose phone bills are very large.

The cable categories:

It is essential to choose the correct ‘Category’ of cabling system, as a wrong choice could be disastrous. Ignoring obsolete Categories, the Categories to consider are:

1. Cat5E (Class D) -This is cost-effective and simple to install. It supports various applications, and its100MHz bandwidth will deliver Gigabit Ethernet.

2. Category 6 (Class E) - This is slightly more costly but offers 250MHz bandwidth. However, UTP cannot support 10GBase-T beyond about 55m although screened Cat 6 should be able to support 100m in most instances. Despite this, Cat 6 is the commonly used in new projects as it provides improved reliability and resilience.

3. Augmented Category 6 - This is the UTP cabling platform in the early stages of development for10GBase-T. However, while 10GBase-T was originally developed to work over copper, it is still un-ratified as such, so cabling systems claiming support for Augmented Category 6 would be proprietary. In order to achieve the performance levels required to support 10GbaseT on UTP, the early cable designs being promoted are frequently larger and less flexible than Cat 7 screened cables, closing the gap between screened and unscreened technologies.

4. Category 7 - This boats a 600MHz bandwidth and is fully shielded, so it is more expensive and comparatively difficult to install than traditional Cat 6. Cat7 uses the GG45 type Cat7 connector (backwards compatible with the RJ45), as the ubiquitous RJ45 connector is being pushed to its limits for Cat6 installations. Currently, only a small, but increasing, proportion of all installed data cable is Cat7, and - as always - there is a trade off between cost and performance.

Fibre optics:

In general copper is used almost exclusively for desktop ‘horizontal’ connections, whereas fibre is used more for backbone connections and for interbuilding ‘campus’ links. Fibre optics cable has been around for some time, and is, perhaps with modern small form factor (SFF) connectors that improve density, the best choice for long distances and where there are few terminations, for example, a backbone link.

However, for most applications, copper is still superior, as it is well understood, simple, tough, very reliable and comparatively cheap (around 60% less than fibre). Therefore, fibre optic cable is unlikely to replace copper totally for data communications. Even so, as traditional applications require ever-greater bandwidth, and as new applications for LAN cabling systems, SANs and data centres become apparent, more and more fibre networks will be installed. For example, Nexans has estimated a 40 - 60% growth year on year, valued at $5.3bn by 2006. Enterprise data storage growth confirms this – it has grown from 800k Tbytes in 2002 to a projected 7m Tbytes by 2006. Today, high bandwidth multimode fibre is the most common solution for SANs, though – as stated – copper is being developed to cope.

Installation tips:

Good training is essential for modern data cable installations to work correctly. Unfortunately, training has often been neglected, so that, with increasing numbers of people becoming involved in installation work, good practice is crucial. In the UK, existing guidance must generally be followed, and BS 6701:2004 (specification for telecommunications equipment) is in force. Installers should always install to local standards, but Cats 5 to 7 are global standards. Some manufacturers will provide training.

There are many very knowledgeable and professional data installers around, but there has been a discernible trend where data installations are becoming more closely linked to the M&E tenders. In some cases, there is a tendency for certain electrical contractors to take on this work, particularly for smaller projects, without really understanding the different needs that data installations demand. So, there is a need for installers to invest heavily in a training and accreditation programme with preferred system vendors.

Working knowledge of standards is crucial. The most obvious standard is the new BS6701:2004, ’Telecommunications Equipment & Telecommunications Cabling – Specification for installation, Operation and maintenance’. This replaces the old version but is a very different document. The main differences are that, whereas the old version gave recommendations, the new version makes reference to the wiring regulations, so that certain clauses become mandatory. It also gives clear responsibilities for installers, consultants and end users, which can be used as a legal reference in the event of a dispute. A guide to this standard, BIP0007 is available from the TIA, FIA, and also from Voltimum.

It is important to realise that quality is designed and built on site, and is not that which is measured and inspected, important though this is. Neatly made cable bundles not only look more professional (and are easier to work on if trouble occurs); they also make commissioning simpler. Also, don't untwist the pairs, and cable ties that are too tight are not a good plan - ensure that ties allow a little freedom to breath and do not distort cable bundles.

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It doesn’t need to be a mess – and it shouldn’t be…

Increasing bandwidth means that it is very important to ensure that the minimum external bend radius is typically 50mm (or about 8 X cable diameter). Failure to do this may result in data loss. Many modern Cat6 data cable management products have been designed to address this point.

For those installers used to UTP, it is a significant jump to a fully screened system (for example, it’s essential that screen terminations are the same length). However, recent developments in FTP cable have meant that this ‘jump’ is not as large as it once was. In any case, Nexans has available a special tool which helps greatly.

Separation between copper data and telecommunications cables and mains power cables must be in accordance with guidelines, because of electromagnetic and radio frequency noise. Fibre has a big advantage here, as it is immune. Firebreak integrity must be maintained.

An important point is to pay very careful attention to detail, and to the proper labelling of cables, as well as to the patching. This makes for a neater job and helps future maintenance.

What the future holds:

Data systems will become more prevalent in buildings and will become a 4th utility. Manufacturers are increasingly likely to provide guarantees for installations using their components. For example, in the UK, Merlin Gerin's system guarantee ensures that any of its VDI Network Solutions installed cabling infrastructures will conform to the now mandatory BS 6701. Such schemes are likely to become common in other parts of the world in relation to local standards. Another example: Nexans' audit services provide network managers with a baseline to make informed investment decisions. Also, manufacturers offer solutions that will allow installers to offer instant warranties through on-line certification and, generally, interactive web-based services will become more common.

Installations will become increasingly easy to expand, and they will include more compatible and simple to use products. There will be increasing demand for higher frequencies with more specifications beyond the existing Cat6. Lower insertion losses will be another requirement, and a new factor to watch for is 'alien cross talk' (AXT), which is uncancellable noise in a bundle or group of copper cables.

Another issue is ‘power over Ethernet, where power and data are supplied over the same cable – for example, to supply an IP camera with pan and tilt facilities. The system will need to be developed to provide a greater power handling capacity and better attenuation.

As data installations increase, companies installing networks will need a clear understanding both of what to install and how to install it. Additionally, new requirements relating to safety and fire grading will also become more important with new standards expected in the coming period. Watch this space!

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