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Traditionally, copper networks have been cheaper than their optical counterparts, but as data rates increase, the costs of installing these media will converge. This is likely to happen at rates of about 2.5 Gbs.

The Future

Obviously, all predictions about future requirements are fraught with difficulty and we must rely heavily on past experience. Errors of judgement when dealing with the horizontal networking are expensive and have long lasting consequences. There is usually only one chance to get it right as the lifetime for horizontal wiring is 10 years or more. By way of contrast, the lifetime of a p.c. is about 2 - 3 years and that of an ether switch 3 - 5 years. In view of this, it is crucial that the right choices are made for horizontal cabling.

For 10 Mbs working, copper category 3 cabling is quite adequate. For 100 Mbs working, copper category 5 cabling is required. For 1 Gbs working, copper category 5e cabling is required.

For 10 Gbs working, extended working 50/125μm fibre optic cabling is required

If, as trends suggest, we may expect 10 Gbs operation within the lifetime of the wiring and in view of the fact that horizontal wiring is expensive to alter, we should try to make any current installation as so called \as we can. As the solution offered by improved copper cabling is likely to be transient and is likely to be just as expensive as fibre, we need to consider the provision of fibre for all new work. If, because of current cost, fibre is not actually installed in any given project, at the very least, space provision in the cable containment ought to be made in order to accommodate its future adoption. One way of achieving this without laying any actual fibre is to make use of \fibre\conduits. This is a technique whereby conduits for fibres are installed alongside traditional wiring. They may subsequently be brought into operation by

using compressed air to blow fibres down the pre-installed conduits to their destination. This has the following advantages: There is minimal disturbance to decoration.

There is minimal disruption to the normal working patterns of the building's staff. The extra bandwidth that fibre offers can be provided on a piecemeal basis and in parallel with existing wiring when need or budget permits. It allows expenditure to be deferred.

Blown fibre is \fibre (about 0.1mm diameter). It is protected from damage by the pre-installed conduits. It is cheaper than traditional fibre cable where fibres are encased in the familiar plastic sheath.

The grade of fibre can be changed if circumstances change or if damage occurs. Old fibres can be quickly and easily withdrawn and replaced by different ones.

Conduits are small and can be carried by traditional cable containment. Damaged conduit can be repaired by cutting out and the damaged section and replacing it with new tube.

As fibre has all the advantages of proven technology, far superior immunity to electrical noise, intrinsic electrical safety, superior bandwidth capability, a high degree of data security and the ability to carry signals over long distances permitting the use of \backbone\topologies, its use or potential use ought to be seriously considered for all new cable installations.

If history teaches us anything, it's that no solution is \proof\