Fibre Optics Advantages
High capacity
A fibre optic system may have very high bandwidth, sometimes operating at data rates of 10Gb/s, equivalent to more than 120,000 standard telephone calls over one pair of optical fibres (one transmitting and one receiving).
Under Lab conditions, data rates as high as 10 terabits per second have been demonstrated (150 million telephone calls).
Datacomms type fibres have a lower information carrying capacity but are capable of 1Gb/s with some 10 Gigabit systems now in use.
Long distances
Due to the low attenuation (or signal loss) exhibited by optical fibres, signals can be transmitted very long distances. In subsea telecommunications, distances of up to 280km have been used without the requirement for repeaters or boosters. Repeatered systems can span as much as 10,000 to 15,000km, where optical amplifiers are used to boost the signal levels typically around every 80km or so,.
Datacomms optical fibres have higher losses but can easily cope with the longest cable runs likely to be encountered in LANS.
Lightweight and compact
An optical fibre is extremely light, a 2km bobbin would only weigh approx. 1lB, therefore it is ideal for use in applications where weight is critical. Equally, a coated optical fibre is only 250 microns (a quarter of a millimetre) in diameter, a 12 core (12 fibre) cable may be less than 8mm in diameter for indoor use.
Secure
Operational fibres do not radiate any signal, the optical signal is completely contained in the middle of the fibre. This means that fibres are frequently used for applications where data security is important such as military and government communications.
Even if attempts are made to ‘tap into’ a fibre optic cable by isolating a bare fibre and putting a tight bend onto it so that some of the signal escapes, this intrusion can be detected by monitoring the power of the transmitted signal, and located using an OTDR technique (Optical Time Domain Reflectometry). |