Hello, everyone!
Today, I would like to share with you an article about if there are limits on bandwidth demands.
Is there a fundamental limit to demand for faster Internet access?
In principle, there should be, because the performance of the human brain and senses (primarily vision) is limited. In particular, the resolution of 4K and 8K video already matches or exceeds the capacity of human vision, while adding a 3D and surround capacity will probably increase the streaming data rate by a factor of 2–4x, to some 300 Mb/s.
The best audio (192 kHz sampling, 24-bit coding, six channels, uncompressed) needs only approx. 30 Mb/s. Still, there is the need for rapid transfer of massive files with movies, games, or photos. Or, a complete backup of data stored on a PC to a cloud storage.
Transfer of 20 TB from a machine with the two largest hard disk drives available now (10TB) in 5 hours requires 10 Gb/s, exactly the fastest fiber access available in 2017 (see Figure 1).
Will subscribers need even more? Probably not, if cloud services replace local storage and streaming replaces file downloading, the mainstream demand can then saturate at 1 Gbit/s.
A significant increase of bit rate above 10 Gb/s will be difficult even in FTTH networks due to high chromatic dispersion of standard single-mode fiber at 1550nm, and the need to use low-cost transceivers with non-return-to-zero (NRZ) modulation and direct detection.
With this technology, transmission distance is inversely proportional to the square of bit rate: approx. 80 km at 10 Gb/s, 20 km at 20 Gb/s, and only 5 km at 40 Gb/s.
This is a “hard” limit, costly to break (by employing coherent detection and digital dispersion compensation), resembling the situation in commercial aviation, where cost and noise issues associated with breaking the sound barrier keep speeds below 950 km/h.
Figure 1. Top download rates offered to residential customers
You are welcome to leave a message and exchange in the comment area. Thank you!
