Flexibility in fibre

Pirelli’s Nick Bishop makes the case for blown fibre as a cost effective product and installation offering for Middle East fibre implementations. He says the approach is not well known in the region but can provide considerable savings.

  • E-Mail
By  Simon Duddy Published  September 17, 2005

|~|blown-fibre-2_m.jpg|~|Blown fibre solutions provide flexibility by leaving empty tubes that can later be filled with fibre.|~|Pirelli’s Nick Bishop makes the case for blown fibre as a cost effective product and installation offering for Middle East fibre implementations. He says the approach is not well known in the region but can provide considerable savings. Choosing the right communications network can be a strain on the brain as well as on the pocket. The chosen solution must be capable of providing a working system for today while ensuring some resilience against an uncertain future. But, often the more the allowances are built in to compensate for unknowns, the more up-front costs will multiply — spare capacity, built-in redundancy and dark fibres all equal extra costs. Where do I use optical and where copper? Do I install optical all of the way or restrict it to the backbone? What fibre should I be using? Do I need OM3 fibre so that I can get 10Gigabit performance when I need it sometime in the future? If I use OM1 or OM2 will I be forced to rip out my network in a year because I’ve outgrown it? In my copper distribution network do I use unscreened twisted pair (UTP) cables or get some noise protection from screening or shielding? Do I chose some cables that have been around for a while like Cat 5e or Cat 6 or do I risk building my network with cables that are predicted to meet new standards yet to be fully defined? Can I rely on advice from manufacturers as it is often conflicting, promoting the latest solutions that each has available while hinting at the disadvantages of alternative solutions they don’t possess? Or, do I go for advice to a consultant? If so, will I always get the result that is best for me and my network? His proposals will be determined by his personal views on risk; either promoting traditional safe solutions or he might be a maverick who always goes for the latest technology and the highest specifications, with high start-up costs often an unfortunate result. Obviously good consultants and good manufacturers will play fair and assess the user’s requirements both today and their expectations for the future and will offer advice on the best way to cater to all these needs with the solution proposed. The concern for anyone embarking on a new network build is that any of the products that could be offered, from Cat 5e UTP to high capacity OM3 fibre cable could be a solution for today’s needs, but at a widely divergent cost. It is only when and if the system fails to meet expectations that the appropriateness of the chosen system is challenged. While the ability of a low cost Cat 5e solution may be brought into question earlier than other options, that does not mean the suitability of high capacity OM3 will never be questioned, it may simply be a matter of time. In fact, in one environment the justification for using OM3 fibre may be quickly ratified by the early introduction of equipment requiring 10Gigabit operation but if media access control (MAC) address churn is high, the cable locations may become suspect and a revisit to the drawing board may be required. On the other hand, the application of Cat 5e UTP in a benign environment with lower MAC levels and limited growth in capacity may be assessed as an effective solution for a longer period. If part, or all, of the network build programme requires optical fibres then a further consideration is whether to use traditional optical cable or blown fibre. It would be rare to find an application when only one option is valid, but blown fibre is generally recognised today as a realistic alternative for lower fibre count networks in access, last mile, premises and campus environments. Traditional solutions using tight buffered cables (most suited to internal applications) or loose tube options (most attractive for external networks) generally achieve flexibility and resilience by building in excess capacity in the form of higher fibre counts (incorporating dark fibre) and / or higher fibre performances (often at higher cost). Blown fibre solutions provide this flexibility by leaving empty tubes that can later be filled with more fibre and higher performance fibre when and if required. This may mean that initial build costs are higher, installing empty tubes rather than ‘empty’ fibre but in so doing can create a more robust infrastructure capable of adapting to changing needs and supporting a rapid response to those changes. Blown fibre has a range of applications from in-building riser and horizontal connections, campus and LAN / WAN links to extensive FTTb and FTTh networks. Commercial, retail and industrial premises, military vehicles, mobile phone mast connections, sport stadiums and mines have all benefited from using blown fibre. Every network is different, even though it will be made up of x km of cable, x patch panels and x output ports, and so on. The requirements that will be placed on that network today and how it will be expected to evolve will be key to determining the most appropriate solution. Without a very reliable crystal ball, it is most likely that the expectations will be wrong and the network that is put in place today will need to be modified in the future. Building spare capacity in the form of additional fibres and / or higher capacity fibres may provide the solution. But building spare capacity through empty tubes that allow later addition of more fibres or higher performance fibres (whatever they might be at the time) and allow for a network extension to put capacity where it will do most good may be a better solution. Blown fibre will not replace the need for good planning but it can make good planning more capable of adjusting to the unplanned future.||**||

Add a Comment

Your display name This field is mandatory

Your e-mail address This field is mandatory (Your e-mail address won't be published)

Security code