World record for wireless data transmission: 40 Gb / s per 11 kilometers
In August 2019, in Russia for the first time in the world (Yes, that's true), they completed a commercial project for wireless redundancy of a 40 Gb / s trunk optical cable. The Unity operator, a Norilsk Nickel subsidiary, through such a channel forwarded an 11-kilometer wireless backup through the Yenisei.
From time to time in the press, and on Habré including, there are notes about world records of wireless communications . They are interesting from the point of view of technological progress, but these are always research tests. And here is a real commercial project, and not in the conditions of Silicon Valley or a European university, but right in the taiga on the Arctic Circle. Surprisingly, but it is a huge country, difficult geographical and climatic conditions that create the prerequisites for projects that give odds to the best research laboratories.
As a matter of fact, there could have been no wireless record in the Arctic Circle if it had not been for the ice drift on the Yenisei. The background to the project is as follows: in 2017, after the Big Three operators refused to develop communications in the Taimyr direction, the MMC Norilsk Nickel PJSC, using its own funds, built an enormous (956 km) fiber optic backbone (FOCL) from Novy Urengya to Norilsk with a capacity of 40 Gb / s. This is a really difficult track, passing through difficult terrain, and its builders received government awards for this work.
One of the problems during operation - the passage of a 40-gigabit FOCL cable through the Yenisei in the absence of bridges, it was decided to run along the bottom of the river, and several cables were laid for reliability. But ice drift easily damages the optics. Moreover, the ice drift on the Yenisei is not an event for one day, and no repair work on the water has been allowed all this time due to the high danger to people.
In addition to additional cables at the bottom of the Yenisei, the route was reserved by a wireless radio relay channel 1 Gbit / cc of telecommunication towers on both sides of the river, in Igarka and the village of Priluki (this radio channel is visible on the top photo - a large plate). But what is 1 Gbit / s to provide for the entire Norilsk industrial region in case of damage to the optics ... - tears. Therefore, in the autumn-winter period of 2018-2019, the Norilsk operator Unity, part of the structure of PJSC MMC Norilsk Nickel, began design work on the construction of a wireless channel through the Yenisei with a capacity not inferior to the fiber optic link.
To the surprise of the specialists of Unity, none of the world telecommunication brands accepted the proposal for the supply of equipment for a 40-gigabit wireless channel at a distance of 11 km. And the point here is in the complex combination of high channel capacity and range. Modern serial equipment with a capacity of 10 Gb / s and more for the 70/80 GHz range has such a feature as a very limited range. This is due to the fact that with complex coding schemes such as QAM128 or QAM256 - and they alone can provide a bandwidth of 10 Gb / s or more - it is difficult to ensure how much significant transmitter power is. 3-5 km routes are easy, but at 11 km the signal attenuation becomes unnecessarily large and no connection in the 10GE standard can be obtained.
The call was accepted by the domestic developer from St. Petersburg - the DOK company . She already had the development of radio bridges that provided the necessary range. And before this project, they tested a 40 Gbit / s channel in the form of 4 jointly operating 10 Gbit / s radio bridges at their 4 km range, and they were sure that such a capacity could be obtained. But in practice, no one in the telecommunications industry has ever tried to put together 4 parallel 10 Gb / s radio bridges at a distance of 11 km.
Having received rejections from global brands, the customer represented by Unity LLC was also not sure that domestic equipment would cope with the project. Therefore, it was decided at the beginning to supply as a pilot phase only one radio bridge 10 Gbit / s per 11 km. And if he recommends himself well, then already scale the task to 4 parallel operating radio bridges.
But there was a problem in that, unlike an optical cable, where the signal through parallel fibers does not affect each other in any way, the radio channels have mutual interference up to a complete communication failure. They are struggling with this by applying different polarization of the signal and spreading the signals in frequency. But it’s easier to say, it’s much more difficult to implement “in hardware”. Petersburgers made circuitry on large microwave circuits (MMIC, Monolithic Microwave Integrated Circuit) based on gallium arsenide and were confident in their circuitry solution.
“Modern 10GE standard radio bridges all over the world are made using purchased microwave circuits. In this area, it is inefficient to conduct vertically integrated development when all technical processes are carried out in one company - from the deposition of microwave chips to the assembly of components into a finished product. This is about the same as many companies make computer boards based on chips from Intel and AMD. However, unlike mass motherboards for PCs, tuning the microwave chips, amplifying the signal and feeding it to the antenna requires special expertise, and this, in fact, is the subject of the Know-How of Companies, ”commented Valery Salomatov, project manager LLC DOK.
The 10 Gb / s PPC-10G-E-HP pilot radio bridge successfully worked on towers along the banks of the Yenisei for a couple of months (May-June 2019). Summer rains are the most difficult time for millimeter-wave radio communications, as raindrops are commensurate with the wavelength (about 4 mm), which causes attenuation of the signal. In winter, this problem does not happen, because snowflakes, as well as fog and smoke, are transparent for wireless communication in the 70/80 GHz band.
A 10 Gbit / s radio bridge from DOK LLC coped with weather conditions and distance, after which, based on the statistics of the availability of the communication line, the Unity operator decided to scale into 4 parallel wireless channels with a capacity of 10GE each. Installation was performed by specialists of the company "Unity", who independently figured out the intricacies of tuning according to the instructions for the equipment. At the end of July 2019, the radio bridge
40 Gbit / s (4 × 10 Gbit / s) through the Yenisei was put into commercial operation in the presence of the installation supervision team from the DOK company.
From time to time in the press, and on Habré including, there are notes about world records of wireless communications . They are interesting from the point of view of technological progress, but these are always research tests. And here is a real commercial project, and not in the conditions of Silicon Valley or a European university, but right in the taiga on the Arctic Circle. Surprisingly, but it is a huge country, difficult geographical and climatic conditions that create the prerequisites for projects that give odds to the best research laboratories.
Timeline of the latest wireless records:
- May 2013 , 40 Gb / s per km at an experimental frequency of 240 GHz as a joint experiment by scientists from the Karlsruhe Institute of Technology, Radiometer Physics GmbH and the Fraunhofer Institute for Applied Solid State Physics. Signal frequency is not available for commercial use.
- May 2016 : 6 Gb / s at 37 km in the 70/80 GHz band, the same team, but as a new experiment at the frequencies allocated for commercial projects,
- November 2016 : 20 Gbps per 13 km , Facebook Connectivity Lab Research Center,
- January 2019 , 40 Gbit / s per 1.4 km , the Deutsche Telekom training ground on Ericsson serial equipment, in May 2019 scaling the same links on the same training ground to 8 in a row yielded about 100 Gbit / s,
- August 2019 , 40 Gbit / s at 11 km , the Unity operator Norilsk on serial equipment of LLC DOK (St. Petersburg).
As a matter of fact, there could have been no wireless record in the Arctic Circle if it had not been for the ice drift on the Yenisei. The background to the project is as follows: in 2017, after the Big Three operators refused to develop communications in the Taimyr direction, the MMC Norilsk Nickel PJSC, using its own funds, built an enormous (956 km) fiber optic backbone (FOCL) from Novy Urengya to Norilsk with a capacity of 40 Gb / s. This is a really difficult track, passing through difficult terrain, and its builders received government awards for this work.
One of the problems during operation - the passage of a 40-gigabit FOCL cable through the Yenisei in the absence of bridges, it was decided to run along the bottom of the river, and several cables were laid for reliability. But ice drift easily damages the optics. Moreover, the ice drift on the Yenisei is not an event for one day, and no repair work on the water has been allowed all this time due to the high danger to people.
In addition to additional cables at the bottom of the Yenisei, the route was reserved by a wireless radio relay channel 1 Gbit / cc of telecommunication towers on both sides of the river, in Igarka and the village of Priluki (this radio channel is visible on the top photo - a large plate). But what is 1 Gbit / s to provide for the entire Norilsk industrial region in case of damage to the optics ... - tears. Therefore, in the autumn-winter period of 2018-2019, the Norilsk operator Unity, part of the structure of PJSC MMC Norilsk Nickel, began design work on the construction of a wireless channel through the Yenisei with a capacity not inferior to the fiber optic link.
To the surprise of the specialists of Unity, none of the world telecommunication brands accepted the proposal for the supply of equipment for a 40-gigabit wireless channel at a distance of 11 km. And the point here is in the complex combination of high channel capacity and range. Modern serial equipment with a capacity of 10 Gb / s and more for the 70/80 GHz range has such a feature as a very limited range. This is due to the fact that with complex coding schemes such as QAM128 or QAM256 - and they alone can provide a bandwidth of 10 Gb / s or more - it is difficult to ensure how much significant transmitter power is. 3-5 km routes are easy, but at 11 km the signal attenuation becomes unnecessarily large and no connection in the 10GE standard can be obtained.
The call was accepted by the domestic developer from St. Petersburg - the DOK company . She already had the development of radio bridges that provided the necessary range. And before this project, they tested a 40 Gbit / s channel in the form of 4 jointly operating 10 Gbit / s radio bridges at their 4 km range, and they were sure that such a capacity could be obtained. But in practice, no one in the telecommunications industry has ever tried to put together 4 parallel 10 Gb / s radio bridges at a distance of 11 km.
Having received rejections from global brands, the customer represented by Unity LLC was also not sure that domestic equipment would cope with the project. Therefore, it was decided at the beginning to supply as a pilot phase only one radio bridge 10 Gbit / s per 11 km. And if he recommends himself well, then already scale the task to 4 parallel operating radio bridges.
From a technical point of view, it is completely optional to transmit 40 Gbit / s in one channel, both over the air and through an optical cable. It is much easier to transfer data over several parallel 10 Gb / s “strings”. 10GE networking is cheaper and more affordable than 40GE switches. In addition, parallel "threads" give greater reliability for the entire channel.
But there was a problem in that, unlike an optical cable, where the signal through parallel fibers does not affect each other in any way, the radio channels have mutual interference up to a complete communication failure. They are struggling with this by applying different polarization of the signal and spreading the signals in frequency. But it’s easier to say, it’s much more difficult to implement “in hardware”. Petersburgers made circuitry on large microwave circuits (MMIC, Monolithic Microwave Integrated Circuit) based on gallium arsenide and were confident in their circuitry solution.
“Modern 10GE standard radio bridges all over the world are made using purchased microwave circuits. In this area, it is inefficient to conduct vertically integrated development when all technical processes are carried out in one company - from the deposition of microwave chips to the assembly of components into a finished product. This is about the same as many companies make computer boards based on chips from Intel and AMD. However, unlike mass motherboards for PCs, tuning the microwave chips, amplifying the signal and feeding it to the antenna requires special expertise, and this, in fact, is the subject of the Know-How of Companies, ”commented Valery Salomatov, project manager LLC DOK.
The 10 Gb / s PPC-10G-E-HP pilot radio bridge successfully worked on towers along the banks of the Yenisei for a couple of months (May-June 2019). Summer rains are the most difficult time for millimeter-wave radio communications, as raindrops are commensurate with the wavelength (about 4 mm), which causes attenuation of the signal. In winter, this problem does not happen, because snowflakes, as well as fog and smoke, are transparent for wireless communication in the 70/80 GHz band.
A 10 Gbit / s radio bridge from DOK LLC coped with weather conditions and distance, after which, based on the statistics of the availability of the communication line, the Unity operator decided to scale into 4 parallel wireless channels with a capacity of 10GE each. Installation was performed by specialists of the company "Unity", who independently figured out the intricacies of tuning according to the instructions for the equipment. At the end of July 2019, the radio bridge
40 Gbit / s (4 × 10 Gbit / s) through the Yenisei was put into commercial operation in the presence of the installation supervision team from the DOK company.
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