How it works: frequency selection for 5G
5G can make a real revolution in the quality of life, so the interest in new technology is much higher than it used to be in 4G. So, the number of companies launching devices in the initial deployment has changed from four for 4G LTE to 20 for 5G. Test launches and development of services for the use of 5G are carried out all over the world, including through incubators to attract startups. One of them - from MTS - also works in Russia.
There is a widespread belief that LTE speeds suit everyone and so, and no ordinary user is required to accelerate to 10 Gb / s. This is not entirely true. 5G application scenarios lie in the plane of connecting the infrastructure, creating new opportunities for the use of AR and VR, drones and other, rather, infrastructure and business solutions. Accelerating the reception and transmission of traffic makes it possible to quickly free up the network resource for the consumer, so as not to encounter a situation when the page opens very slowly when there are users. It is impossible to delay the expansion of network bandwidth until the subscribers are faced with a deterioration in the quality of communication due to network congestion.
The speed of network deployment will depend on how quickly a portion of the spectrum for 5G is determined, and what it will be.
The easiest way to explain how this works is through a traditional radio. You tune your radio to a wave, for example, 97 FM, where a specific station is broadcasting at a frequency of 97 megahertz. If you want to turn on another radio station, say, 103.5 FM, you need to switch to it. That is, two stations never transmit on the same spectrum at the same time in the same zone, otherwise they will interfere with each other. In this case, in another region at the frequency of your favorite radio station, another station may be located, since wireless signals are transmitted only at a certain distance.
For a full launch of 5G, a certain range of radio spectrum is required. The amount of spectrum allocated for 5G will determine how fast networks based on this technology will be. The spectrum should be versatile enough for all of the different usage scenarios, which would probably mean using several different frequency bands. In general, frequencies are necessary in three bands: up to 1 GHz, 1-6 GHz and above 6 GHz.
The signal in various parts of the spectrum extends to a certain distance. The wavelength is inversely proportional to the frequency: that is, high frequencies have a shorter wavelength. For example, 30 Hz (low frequency) has a wavelength of 10,000 km (more than 6,000 miles), and 300 GHz (high frequency) is only 1 mm. But when the wavelength is really small (for example, the frequency at the upper end of the spectrum), it can easily be distorted. Therefore, really high frequencies cannot propagate as low frequencies. The quality of the connection is also affected by the bandwidth, which is measured by the difference between the highest and lowest signal frequencies. As you move up the radio spectrum to achieve higher ranges, the bandwidth increases, and therefore the bandwidth increases (that is, you get higher download speeds).
For example, millimeter waves (mmWave, technically covers frequencies in the range 30–300 GHz, but more often refers to bands above 24 GHz) are in the high-frequency spectrum and have the advantage of the ability to transmit large amounts of data. But they are also more easily absorbed by gases in the air, trees and nearby buildings. Therefore, the mmWave spectrum cannot be used to transmit data over long distances. These shortcomings can be partially overcome by directional antennas, implemented on the basis of technologies such as Massive MIMO and beamforming (beamforming), but the signal at these frequencies cannot stably propagate over long distances. MmWave frequencies will also be used in tandem with lower frequency ranges to provide the coverage and capacity that 5G will require.
In addition to the available mmWave frequencies, you can clear already used ranges and redeploy them. This process is called refarming. In fact, it can be compared with processing the field: if the field is used for tomatoes, you cannot plant corn there until all tomatoes are harvested. This process is complicated by the fact that the frequencies occupied by previous generations of communication are still used. In addition, their frequency range is limited, and in order to realize the full potential of 5G, take advantage of the higher speeds offered by this specification, the International Association of Mobile Telecommunications Operators (GSMA) proposes to allocate at least 100 MHz in the middle frequencies to each mobile operator. For example, China Mobile will be assigned 300 MHz in the 2.6 GHz and 4.9 GHz bands.
The main range for the fifth generation of communications around the world is 3.5 GHz with a total bandwidth of up to 400 MHz in the range from 3.4 to 3.8 GHz. It is more attractive due to wider availability in the whole world and a large amount of spectrum. Its allocation has already been agreed, for example, in Europe: European regulators have identified the band 3.4-3.8 GHz and plan to harmonize it to make it suitable for 5G. In Russia, the situation is different: the key users of this range are the Ministry of Defense and Roscosmos. Therefore, now we are considering the option to deploy 5G in the range of 4.4-4.99 GHz. It is used by Japan and China.
The discrepancy in the selected frequencies creates a number of problems. There is such a thing as data roaming. We could all face this when the first iPhone model with 4G support came out, but in Russia it was impossible to use this service - the chip in the phone was designed for the frequencies that were chosen for LTE in the USA. In Russia, as in Europe, 4G worked in a different range. A similar situation can be repeated with 5G, since the main range for the deployment of such networks in the world is 3.5 GHz and millimeter waves. And one of the largest developers of the Qualcomm mobile ecosystem makes chipsets and modules designed for these ranges. The same ranges are supported by the already presented flagships with 5G support, for example, Galaxy S10.
The main task now is to choose the universal spectrum of the required capacity, otherwise all the “buns” that this technology can give us - from the development of drones to fast traffic - will be delayed for an indefinite period.
Denis Panasenko,
Head of 5G MTS Incubator.
There is a widespread belief that LTE speeds suit everyone and so, and no ordinary user is required to accelerate to 10 Gb / s. This is not entirely true. 5G application scenarios lie in the plane of connecting the infrastructure, creating new opportunities for the use of AR and VR, drones and other, rather, infrastructure and business solutions. Accelerating the reception and transmission of traffic makes it possible to quickly free up the network resource for the consumer, so as not to encounter a situation when the page opens very slowly when there are users. It is impossible to delay the expansion of network bandwidth until the subscribers are faced with a deterioration in the quality of communication due to network congestion.
The speed of network deployment will depend on how quickly a portion of the spectrum for 5G is determined, and what it will be.
The easiest way to explain how this works is through a traditional radio. You tune your radio to a wave, for example, 97 FM, where a specific station is broadcasting at a frequency of 97 megahertz. If you want to turn on another radio station, say, 103.5 FM, you need to switch to it. That is, two stations never transmit on the same spectrum at the same time in the same zone, otherwise they will interfere with each other. In this case, in another region at the frequency of your favorite radio station, another station may be located, since wireless signals are transmitted only at a certain distance.
For a full launch of 5G, a certain range of radio spectrum is required. The amount of spectrum allocated for 5G will determine how fast networks based on this technology will be. The spectrum should be versatile enough for all of the different usage scenarios, which would probably mean using several different frequency bands. In general, frequencies are necessary in three bands: up to 1 GHz, 1-6 GHz and above 6 GHz.
The signal in various parts of the spectrum extends to a certain distance. The wavelength is inversely proportional to the frequency: that is, high frequencies have a shorter wavelength. For example, 30 Hz (low frequency) has a wavelength of 10,000 km (more than 6,000 miles), and 300 GHz (high frequency) is only 1 mm. But when the wavelength is really small (for example, the frequency at the upper end of the spectrum), it can easily be distorted. Therefore, really high frequencies cannot propagate as low frequencies. The quality of the connection is also affected by the bandwidth, which is measured by the difference between the highest and lowest signal frequencies. As you move up the radio spectrum to achieve higher ranges, the bandwidth increases, and therefore the bandwidth increases (that is, you get higher download speeds).
For example, millimeter waves (mmWave, technically covers frequencies in the range 30–300 GHz, but more often refers to bands above 24 GHz) are in the high-frequency spectrum and have the advantage of the ability to transmit large amounts of data. But they are also more easily absorbed by gases in the air, trees and nearby buildings. Therefore, the mmWave spectrum cannot be used to transmit data over long distances. These shortcomings can be partially overcome by directional antennas, implemented on the basis of technologies such as Massive MIMO and beamforming (beamforming), but the signal at these frequencies cannot stably propagate over long distances. MmWave frequencies will also be used in tandem with lower frequency ranges to provide the coverage and capacity that 5G will require.
In addition to the available mmWave frequencies, you can clear already used ranges and redeploy them. This process is called refarming. In fact, it can be compared with processing the field: if the field is used for tomatoes, you cannot plant corn there until all tomatoes are harvested. This process is complicated by the fact that the frequencies occupied by previous generations of communication are still used. In addition, their frequency range is limited, and in order to realize the full potential of 5G, take advantage of the higher speeds offered by this specification, the International Association of Mobile Telecommunications Operators (GSMA) proposes to allocate at least 100 MHz in the middle frequencies to each mobile operator. For example, China Mobile will be assigned 300 MHz in the 2.6 GHz and 4.9 GHz bands.
The main range for the fifth generation of communications around the world is 3.5 GHz with a total bandwidth of up to 400 MHz in the range from 3.4 to 3.8 GHz. It is more attractive due to wider availability in the whole world and a large amount of spectrum. Its allocation has already been agreed, for example, in Europe: European regulators have identified the band 3.4-3.8 GHz and plan to harmonize it to make it suitable for 5G. In Russia, the situation is different: the key users of this range are the Ministry of Defense and Roscosmos. Therefore, now we are considering the option to deploy 5G in the range of 4.4-4.99 GHz. It is used by Japan and China.
The discrepancy in the selected frequencies creates a number of problems. There is such a thing as data roaming. We could all face this when the first iPhone model with 4G support came out, but in Russia it was impossible to use this service - the chip in the phone was designed for the frequencies that were chosen for LTE in the USA. In Russia, as in Europe, 4G worked in a different range. A similar situation can be repeated with 5G, since the main range for the deployment of such networks in the world is 3.5 GHz and millimeter waves. And one of the largest developers of the Qualcomm mobile ecosystem makes chipsets and modules designed for these ranges. The same ranges are supported by the already presented flagships with 5G support, for example, Galaxy S10.
The main task now is to choose the universal spectrum of the required capacity, otherwise all the “buns” that this technology can give us - from the development of drones to fast traffic - will be delayed for an indefinite period.
Denis Panasenko,
Head of 5G MTS Incubator.
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