【正文】 per cabling (category 6 or 7) in data works are likely to be limited and short lived. In order to avoid serious work disruptions in the future and save costly reworking, optical fibre to the desktop deserves serious consideration for new projects. This is also a business critical decision which could impact on your petitiveness. We should do what we can now to ensure our new work installations do not bee the legacy works of the (perhaps none too distant) future. Monotonous Rise in Network Data Rates since the 198039。s Law closely in the past but recently, it has shown evidence of an acceleration faster than that predicted by the law. Onegigabit data rates are available now and 10gigabit rates are predicted by 2021. Vertical LAN In any building distribution, the vertical work carries about 80% of the traffic. This part of a building local area work (LAN) is business critical but fortunately, it is relatively easy to make changes to it. Quite often, this part of the work is realised as optical fibre. At one time, the bandwidth offered by optical fibre was regarded as unlimited but that is not the case now. For example, at 1gigabit rates, there is a length limit of about 220m when using popular about 500m when using 50/125181。s Law, showing the recent accelerating trend but lagging the vertical data rates by 5 years. So, we would expect 1gigabit data rates by year 2021 and 10gigabit data rates by year 2021. Indeed, 1gigabit work interface cards (NIC) are being shipped now。s vertical LAN, the horizontal work is very costly to upgrade. Installations always mean serious disruption to normal work for a building39。s only a matter of how much you are willing to pay for the encoder and decoder! Limitations of Copper Cabling There are intrinsic limitations to the use of UTP copper cabling at very high data rates. These are: The susceptibility of the metallic conductor39。s length. These weak receive signals can be swamped by the unwanted coupled signal from the transmitter. To overe these difficulties, more has to be spent in the design of the transceiver hardware. The cost of these items will rise as bandwidth is increased. Category 6 cable has been developed in order to address some of these problems but, at the moment, no standards have been ratified. Apart from these fluid aspects of copper solutions, there are other factors regarding their choice that should be borne in mind. Perhaps the most important consideration is the rather low bandwidth improvement that category 6 cable will offer. The ever rising expectations of work bandwidth will soon overtake the Gbs1 theoretical through put that it may provide. The respite that it may give is likely to be short. There are further worries about its interoperability and its backward patibility with existing installations. Category 7 cable is still under development and many experts in the industry believe the Ramp。m 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 futureproof 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 blown fibre conduits. This is a technique whereby conduits for fibres are installed alongside traditional wiring. They may subsequently be brought into operation by using pressed air to blow fibres down the preinstalled 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 building39。s that no solution is futureproof