Everyone who bought a smartphone abroad, could face the fact that a new and fully functional gadget for some reason refuses to function in Russian 4G networks. The problem is that the fourth-generation networks are built in a wide range of frequency bands. And devaysy, as a rule, let out under this or that set of these ranges, instead of under any possible ranges and their combinations. In order not to regret buying, you need to understand some technological details, and we will try to help you in this.
Speaking about the correct choice of smartphone, this time we do not mean the platform on which it is assembled, the operating system or the camera. We will concentrate on the parameters that ensure the best performance of your device in 4G / LTE networks. This is especially important for all those who actively use the mobile Internet. The user experience in the LTE network usually differs markedly from the user experience in the 3G network, even in the HSPA + version. Simply put, if you are in the zone of confident coverage of LTE, and the gadget supports modern modes of data transfer, you, as they say, "everything flies." But about what smartphone features are important for achieving maximum speed - read in the article.
Frequencies of LTE: what are these bands and why are they important?
Why do we need to bother at all, after all, we do not choose smartphones based on the features of their work with 3G? It's simple. For 3G / WCDMA technologies, the frequency band in the 2100 MHz band is fixed in the world. Since these frequencies are not enough, in some places for 3G, the 900 MHz band is also used. In most cases, any modern device supports 3G operation in both these ranges. "Pure" 3G is nowhere used anywhere, so the smartphone should also understand such "extensions" of technology, such as HSPA and HSPA +, speeding up the work with mobile Internet. More often new devices support these technologies.
Another thing is with LTE. This standard originally meant the possibility of building communication networks and mobile Internet in a variety of frequency bands. In the world of their use more than a dozen, and in different countries - different combinations of frequencies. Not every operator supports the same set of ranges even within the same country. In Russia, the set of frequency bands used by LTE is not that great. Nevertheless, buying a smartphone abroad (for example, in an online store), you can stay without 4G because of the incompatibility of the purchased device with one or another of our network.
To avoid this, it is advisable to select a gadget based on which LTE frequencies the operator supports in your region. The situation changes over time, operators get all the new frequencies, so you should think about compatibility every time you buy a new device.
Today in Russia, operators of the Big Four have LTE networks in the following main ranges: 1800 MHz (b3), 2.5-2.7 GHz (b7), 800 MHz (b20). The letter bc in brackets is the "band", the name of the band according to the classification of the international group 3GPP, which develops the LTE standards. The above ranges are used to organize FDD LTE networks with so-called frequency division channels, when incoming and outgoing data streams are at different frequencies. There is also time division TDD technology: when incoming and outgoing data streams are alternately chased between the device and the network using the same frequency band. In Russia, this technology is also used. The range covered by it is 2.5-2.6 GHz (b38).
Summary: what frequencies are needed in Russia. Ideally, your smartphone must necessarily support the ranges of b3 and b7 - this is the basis for a good mobile Internet. A range of b20 is desirable: there are places where it is the only way to access LTE. As for b38, it can be compared with a cherry on the cake - you can live without it, but as a decoration it does not hurt.
CAT categories: the higher, the faster
What is more important is another aspect, which should be given attention when choosing a new device. Today, LTE networks often support the operation of smartphones in several frequency bands simultaneously. It is customary to call this mode of operation the aggregation of frequencies (LTE-A). By driving data in just a few frequency bands, you can achieve higher download and transmission speeds. However, in order for this circuit to work, several conditions must be met. At the point where you are now, there should be coverage in just a few frequency bands of LTE, the operator's equipment should be tuned to work with devices supporting LTE-A, and your smartphone - to support LTE-A, and precisely those combinations of frequencies that Provides an operator. Sounds extremely difficult? In fact, you should think about this only when you buy the device.
And here's another feature worth paying attention to. It's about the so-called device category. Usually it is marked with a single-digit or two-digit number from 0 to 17. Until recently, it was believed that support for a Cat.3 smartphone is enough to use LTE services in Russia. Today the "enough" level has risen to Cat.4 (theoretically speeds of up to 150 Mbit / s are supported), and for fans of the fastest Internet it is necessary to recommend devices supporting the mode of aggregation of frequencies, which corresponds to Cat.6. (Up to 300 Mbit / s). The number in brackets is the so-called peak velocities. Download data at such speeds in real life will not work, but high peak speeds, as a rule, result in higher average download speeds.
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