250 Gigabit Optical Cable across the Atlantic: Nokia Case
Nokia has commissioned a transatlantic fiber-optic cable for Facebook. During the test run, the speed reached 200-250 Gbit / s with transmission over 5500 kilometers.
According to company representatives, the technology used under the name PCS (Probabilistic Constellation Shaping) has increased the efficiency of data transfer between New York and Ireland 2.5 times.
/ Photo Groman123 CC
')
PCS and non-linearity compensation methods in fiber made it possible to achieve spectral efficiency of 7.46 bps per Hertz with modulation of 64-QAM. The word constellation (“group”) in the name of a technology is a reference to the number of states that can be represented due to changes in amplitude and phase. For example, the image below shows the 16-QAM scheme:
In the particular case of modulation points have equal weights - all points are used with the same frequency. The PCS algorithm, on the other hand, selects the optimal group of points that is most suitable for the channel state.
At the same time, representatives of the company say: “PSC uses signal points with high amplitude less frequently. As a result, the transmitted signal acquires resistance to noise and interference. All this allows you to adapt the data stream and increase the speed of translation by about 30%. "
Last year, Nokia has already demonstrated the capabilities of its technology. Then the scientists managed to transfer data at a rate of 1 Tbit / s in the fiber-optic network of Deutsche Telekom. According to experts, they almost reached the so-called Shannon border, established in 1945. The Shannon boundary is understood as the maximum transmission rate at which errors in a channel with a given signal-to-noise ratio can be corrected.
Nokia is convinced that in the future PCS will allow cables to reach 32 Tbit / s. Markus Weldon, president of Nokia Bell Labs (Marcus Weldon), says that the fiber optic networks of the future will not only provide fast transmission of large data arrays, but will also dynamically adapt to the channels used and current traffic needs.
It is not known when this technology will take effect in practice, but the tests, as has been said, were held in “real conditions”. At the same time, it is expected that it will become an integral part of the 5G protocol, the introduction of which is planned for 2020.
PS Other materials from the blog of the First Corporate IaaS Blog:
According to company representatives, the technology used under the name PCS (Probabilistic Constellation Shaping) has increased the efficiency of data transfer between New York and Ireland 2.5 times.
/ Photo Groman123 CC')
PCS and non-linearity compensation methods in fiber made it possible to achieve spectral efficiency of 7.46 bps per Hertz with modulation of 64-QAM. The word constellation (“group”) in the name of a technology is a reference to the number of states that can be represented due to changes in amplitude and phase. For example, the image below shows the 16-QAM scheme:
In the particular case of modulation points have equal weights - all points are used with the same frequency. The PCS algorithm, on the other hand, selects the optimal group of points that is most suitable for the channel state.
At the same time, representatives of the company say: “PSC uses signal points with high amplitude less frequently. As a result, the transmitted signal acquires resistance to noise and interference. All this allows you to adapt the data stream and increase the speed of translation by about 30%. "
Last year, Nokia has already demonstrated the capabilities of its technology. Then the scientists managed to transfer data at a rate of 1 Tbit / s in the fiber-optic network of Deutsche Telekom. According to experts, they almost reached the so-called Shannon border, established in 1945. The Shannon boundary is understood as the maximum transmission rate at which errors in a channel with a given signal-to-noise ratio can be corrected.
Recommended to read: Our digests
Nokia is convinced that in the future PCS will allow cables to reach 32 Tbit / s. Markus Weldon, president of Nokia Bell Labs (Marcus Weldon), says that the fiber optic networks of the future will not only provide fast transmission of large data arrays, but will also dynamically adapt to the channels used and current traffic needs.
It is not known when this technology will take effect in practice, but the tests, as has been said, were held in “real conditions”. At the same time, it is expected that it will become an integral part of the 5G protocol, the introduction of which is planned for 2020.
PS Other materials from the blog of the First Corporate IaaS Blog:
- Southern distribution company: experience of using 1C SaaS in the IT-GRAD IaaS cloud for wholesale tasks
- IaaS in the world of music: how the cloud becomes the standard for placing audio content
- vCloud Availability: deep immersion in traffic replication
- vCloud Director: how to create a secure connection between two organizations
- Pulkovo Airport: Experience in using the IaaS cloud for the implementation of an international project and the organization of a reserve site
- VMware Cloud Foundation: Simplified Software Data Center and Hybrid Cloud Deployment
Source: https://habr.com/ru/post/323950/
All Articles