Blown Fibre -

Old Technology for the New Era







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Case Study

If there is one thing that is certain in IT Infrastructure, it is that you can never be certain of what the future might bring. Everything is getting faster, and users are getting more demanding. As a result, making decisions on a new infrastructure can be stressful. If the wrong decision is made fingers will be pointing faster than you can say Gigabit Ethernet ! However, in respect to Optical Fibre systems, there are tried and tested technologies available to help take the risk out of choosing the correct solution, whatever your business or organisation - even if you change your mind in a years time. They can save money too.
Imagine being able to install an Optical Fibre backbone, or even fibres to the desk, within your building that can then be upgraded, re-routed or repaired rapidly, inexpensively and with the minimum of disruption. Blown Fibre technology can offer these benefits to everyone.

Lets go through what Blown Fibre actually is and how it works. There are several vendors that offer these products, the products themselves vary slightly, however the fundamental principles remain the same. Originally invented by BT in the 1980’s for use in the OSP (Outside Plant) environment, Blown Fibre consists of a system of empty tubes (called microducts) that can be populated with Optical Fibres by using an air compressor to ‘feed’ the fibres into the tubes. Different systems vary, some use compressed air to lift the fibres away from the walls of the tubes, so they can be gently pushed in with a mechanical wheel under no friction. Others use coatings on the fibres themselves that trap air vortexes and ‘draw’ themselves into the tubes. Some vendors offer individual fibres, and some offer bundles of 2, 4, 8, 12 or 24 cores that can be ‘blown’ in at once, saving time. The tubes themselves also come in multiples with anything up to bundles of 36. At the Patch Panel or outlet, the cores are treated as per a normal fibre cable.

There are many benefits to Blown Fibre systems. From the cynical perspective, it is a great decision avoidance tool. This is due to ability to install a passive network of tubes, that can have fibres blown in, and then blown-out and replaced in the future as new applications and fibre media types emerge. Ripping-out and replacing traditional optical fibre cables is a messy business and means getting access to what can sometimes be awkward cable pathways. For tenants in shared offices, getting access to a shared riser can be grief in itself. With a blown fibre system, the tubes only have to be installed once. The only access that is needed is to the comms room, so the engineer can set-up his blowing-kit and install your fibres. Consequently, this is a far quicker process, meaning less installation costs. If a fibre is damaged or vandalised, the repair process means just blowing-out the damaged fibre, and blowing in the new. The microduct itself can be simply cut and re-joined with a push-fit collar, meaning no re-installation of the tubes.




Blown Fibre solutions offer potential benefits to anyone who is unsure of future requirements, or needs to be able to upgrade or add additional fibres to the network with minimal disruption. Many hospitals, airports, University campuses and Military sites were the first to realise the advantages of these technologies. Imagine having to close an airport run-way because a trench needs to be accessed to add some additional fibres! Network Managers in the financial, legal and insurance verticals are also realising the benefits, resulting in some major installations around the UK in recent years. Many users are also installing empty tubes to desk locations - in readiness for a possible fibre to-the-desk deployment in the future.

In some instances, Blown Fibre has been used a means of splitting infrastructure costs between departments. For example a recent project saw the facilities department funding the installation of a whole network of blown-fibre microducts. As each area of the site was populated and fibres blown to those areas, the IT department was billed for the fibres as and when they were required to be installed. There is mileage here for operators of serviced offices and business parks who are constantly looking to add potential new services for their tenants to purchase from them. Likewise, Disaster Recovery DataCentres can utilise Blown Fibre to enable them to provide the exact fibre connectivity that a particular client requires when they take rack space in their sites, at short notice. The ability to defer costs like this means that money is not wasted installing traditional spare ‘dark’ fibres that may not even be what is required in the future.

From a practical perspective, installing blown-fibre when refurbishing or fitting-out a new building cuts down the risk of project programme delays. Often, when fibre cables are installed on a busy building site, they get crushed, cut, or otherwise damaged before they are even terminated. The cabling contractor can install the passive tubes (which are very easy and cheap to repair), and come back once the dust has settled, when the other trades have gone, and blow-in the fibres just in time for project completion.

With OM1, OM2, OM3 and OS1 category optical fibres now all available in blown-form, Blown Fibre can meet anyone’s requirement. Furthermore, the technology is not new - it has been around for decades. For any newOptical Fibre installation, this technology can offer the most robust and future-proofed option.