What is Bandwidth?

The topic of our conversation today is the throughput of fiber. Over the last 30 years it has been increased several times. The bandwidth of fiber transmission has grown much faster than even the increase in the volume of electronic memory chips or the power of microprocessors. Although in recent cases progress has made a big leap over these years.

Let's see what the bandwidth depends on. First of all, this is significantly affected by the length of the fiber. Hence it follows that the larger it is, the more harmful the effects will be. They are still called "chromatic or inter-house dispersion." And the more such effects, the less possible transmission speed.

For small distances, such as several hundred meters or less (networks for data storage), multi-house fibers are often used. This is due to the fact that they are cheaper in terms of installation (they have a larger area of the fiber core, which makes them easier to join). The data transfer speed in this case can range from several hundred megabits to ten gigabits per second. This will depend on what kind of data technology is used for transmission, as well as the length of the fiber. The bandwidth of the Internet in this case will be sufficient for comfortable work.

As for single-mode fiber, it is usually used at long distances, ranging from a few kilometers and beyond. In modern commercial telecommunication systems, the throughput ranges from two and a half to ten gigabits per second per channel of information transmission. This is an indicator for a distance of ten kilometers or more.

In the near future, these systems will be able to use an even faster data transfer rate. Its performance will start from forty gigabits per second and reach even one hundred and sixty. Today, the existing total power is achieved through the transmission of multiple channels with different wavelengths across the fibers. This is called spectral compaction. The total transmission rate can reach several terabits per second. This will be quite enough to transfer multimillion-dollar telephone channels at the same time. But even these indicators are not the physical limit of optical fiber to date. It is also worth noting that fiber-optic cables can contain several layers.

Summing up, it can be concluded that there is no reason to worry that the technical limitations for optical fiber in the future may become a serious impediment to data transmission. On the contrary, the possibility of information transfer can progress much faster than the same storage systems or computing power. This is an inspiration for some people who dare to predict that any transmission restriction will become obsolete in the future. There are also suggestions that large systems of storage of objects and calculations in high-capacity data transmission networks will acquire a wide demand. This development will be more limited by security and software. Physical throughput will play a much smaller role in this.