Comparison Nomi i220 vs Nomi i281

Characteristics of the main (and most often the only) display installed in the device.

In addition to the basic properties - such as size, resolution (according to it, screens are conventionally divided into HD, Full HD, 2K and more), sensor type (most often IPS, OLED, AMOLED, Super AMOLED, Dynamic AMOLED,), this list can more specific features. Among them are the shape of the surface ( flat or curved), the presence and version of the Gorilla Glass coating (including the top v6 and Victus), HDR support and the refresh rate (a frequency on top 60 Hz is considered high, namely 90 Hz, 120 Hz and 144 Hz) . Here is a more detailed description of the characteristics relevant to modern displays:

- Size. Traditionally, the screen size is indicated in inches. A larger display i...s more convenient to use: more information is placed on it, and the image itself is better readable. The downside of increasing the size is an increase in the dimensions of the device. Today, smartphones with screens of 5" or less are considered small. 5.6 - 6" and up to 6.5" is already a medium format. Also, many modern models have a size of 6.5". Classic phones without touch screens do not need a large size - in them it usually does not exceed 3".

- Permission. Screen resolution is specified based on its vertical and horizontal dimensions in dots (pixels). The larger these dimensions (with the same size) - the more detailed and smoothed the picture looks and the less individual pixels are visible on it. On the other hand, increasing the resolution increases both the cost of the display itself and the requirements for the phone's hardware. It is also worth noting that the same resolution on screens of different sizes looks different; so when evaluating detail, it is worth considering not only this parameter, but also the PPI number (see below).

— PPI. The density of dots (pixels) on the screen of the device. It is indicated by the number of dots per " (points per ") - the number of pixels for each horizontal or vertical segment of 1 ". This indicator depends both on the size and resolution, but in the end it is the PPI number that determines how smooth and detailed the image on the display is. For comparison, we note that at a distance of about 25 - 30 cm from the eyes, a density of 300 PPI or more makes individual pixels almost invisible to a person with normal vision, the picture is perceived as a complete one; at greater distances, a similar effect is noticeable at a lower point density.

— Matrix type. The technology by which the screen sensor is made. This parameter is indicated only for relatively advanced displays that are superior in performance to the simplest LCD screens of push-button phones. The most widespread in our time are the following types of matrices:

• IPS. The most popular technology for the screens of modern smartphones. It provides a very decent image quality, viewing angles and response speed, although it is somewhat inferior in these parameters to many more advanced options (see below). On the other hand, IPS also has important advantages: durability, uniform wear, and also a rather low cost. Thanks to this, such screens can be found in all categories of smartphones - from low-cost to top-end.
• AMOLED. Organic light-emitting diode (OLED) sensor technology developed by Samsung. One of the key differences between such matrices and more traditional displays is that they do not require external illumination: each pixel is its own light source. Because of this, the power consumption of such a screen depends on the characteristics of the displayed image, but in general it turns out to be quite low. In addition, AMOLED matrices are distinguished by wide viewing angles, excellent brightness and contrast ratios, high color reproduction quality and fast response time. Due to this, such screens continue to be used in modern smartphones, despite the emergence of more advanced technologies; they can be found even in top-end models. The main disadvantage of this technology is the relatively high cost and uneven wear of the pixels: dots that work longer and more often at high brightness burn out faster. However, usually this effect becomes noticeable only after several years of intensive use - a period comparable to the operational resource of the smartphone itself.
• AMOLED (LTPO). An advanced version of AMOLED panels with the ability to dynamically adjust the refresh rate depending on the tasks performed. The abbreviation LTPO stands for Low Temperature Polycrystalline Oxide. Behind this term is a combination of traditional LTPS technology and a thin layer of TFT oxide film with the addition of hybrid-oxide polycrystalline silicon to drive the sweep switching circuits. AMOLED panels (LTPO) reduce the energy consumption of the gadget by an order of magnitude. So, when performing active actions, the device screen uses the maximum or high refresh rate, and while viewing pictures or reading text, the display reduces the rate to a minimum.
• Super AMOLED. An improved version of the AMOLED technology described on top One of the key improvements is that in Super AMOLED screens there is no air gap between the touch layer and the display located under it. This made it possible to further increase the brightness and image quality, increase the speed and reliability of the sensor response and at the same time reduce power consumption. The disadvantages of such matrices are the same as the original AMOLED. In general, they are quite widespread; most smartphones with similar screens belong to the middle and top categories, but there are also low-cost models.
• OLED. Various types of matrices based on the use of organic light emitting diodes; in fact - analogues of AMOLED and Super AMOLED, produced not by Samsung, but by other companies. The specific features of such screens may be different, but for the most part they are, on the one hand, more expensive than popular IPS, on the other hand, they provide higher image quality (including brightness, contrast, viewing angles and color fidelity), and also consume less energy and have small thickness. The main disadvantages of OLED screens are the high price (which, however, is constantly decreasing as the technology develops and improves), as well as the susceptibility of organic pixels to burn-in when broadcasting static images for a long time or images with static elements (notification panel, on-screen buttons, etc.). ).
• OLED (polymer). Organic Light-Emitting Diode (OLED) screens, which do not use glass as a base, but a transparent polymer material. We emphasize that we are talking about the basis of the sensor; from on top it is covered with the same glass as in other types of screens. However, this design offers a number of advantages over traditional "glass" matrices: it provides additional impact resistance and is great for creating curved displays. On the other hand, in terms of optical properties, plastic still falls short of glass; so screens of this type are often inferior in image quality to their “peers” made using traditional OLED technology, and with a similar picture quality, they are noticeably more expensive.
• OLED (LTPO). OLED-matrices with adaptive refresh rate, which can be changed in a wide range based on the tasks performed. In games, screens with LTPO technology automatically raise the refresh rate to the maximum values, while viewing static images, they reduce it to a minimum (from 1 Hz). At the heart of the technology is a traditional LTPS substrate with a thin TFT oxide film on top of the TFT base. The ability to control the flow of electrons provides dynamic control over the refresh rate. The competitive advantage of OLED (LTPO) is reduced power consumption.

In addition, screens in modern smartphones can be made using the following technologies:

• pls. A variation of IPS technology created by Samsung. In some respects - in particular, brightness, contrast and viewing angles - it surpasses the original, while it is cheaper to manufacture and allows you to create flexible displays. However, for a number of reasons, it is not particularly popular.
• Super AMOLED Plus. A further development of the Super AMOLED technology described on top. Allows you to create even brighter, more contrasting and at the same time thin and energy-efficient screens. However, most often such screens in our time are simply referred to as "Super AMOLED", without the "Plus" prefix.
• Dynamic AMOLED. Another AMOLED improvement introduced in 2019. The main features of such matrices are increased brightness without a significant increase in power consumption, as well as 100% coverage of the DCI-P3 color space and compatibility with HDR10 +; the last two points, in particular, make it possible to reproduce modern high-low-cost cinema on such screens with the highest quality. The main disadvantage of Dynamic AMOLED is traditional - the high price; so such matrices are found mainly in top models.
• Super Clear TFT. A joint development by Samsung and Sony, which appeared as a forced alternative to Super AMOLED matrices (the demand for them at one time significantly exceeded production capabilities). True, the image quality of Super Clear TFT is somewhat lower - but in production such matrices are noticeably simpler and cheaper, but in terms of performance they still surpass most IPS screens. However, in our time, this technology is rare, giving way to AMOLED in different versions.
• super LCD. Another alternative to various kinds of AMOLED technology; used mainly in HTC smartphones. Similar to Super AMOLED, such screens do not have an extra air gap, which has a positive effect on both image quality and the clarity of sensor responses. A notable advantage of the Super LCD is its good power efficiency, especially when displaying bright whites; but in terms of overall color saturation (including black), this technology is noticeably inferior to AMOLED.
• LTPS. An advanced type of TFT matrices, created on the basis of the so-called. low temperature polycrystalline silicon. It allows you to easily create screens with a very high pixel density (more than 500 PPI - see on top), achieving high resolutions even with a small size. In addition, part of the control electronics can be built directly into the sensor, reducing the overall thickness of the display. The main disadvantage of LTPS is the relatively high cost, but nowadays such screens can be found even in low-cost smartphones.
• S-PureLED. A technology developed by Sharp and used primarily in its smartphones. Actually, the technology of the matrices themselves in this case is called S-CG Silicon TFT, and S-PureLED is the name of a special layer used to increase transparency. S-CG Silicon TFT is positioned by the creators as a modification of the LTPS technology described on top, which allows to further increase the resolution of the display and at the same time build more control electronics into it (up to a whole “processor on glass”) without increasing the thickness. Of course, these screens are not cheap.
• e-ink. Matrices based on the so-called "electronic ink" - a technology common primarily in electronic books. The main feature of such a screen is that during its operation, energy is spent only on changing the image; a still picture does not require power and can remain on the display even in the absence of power. In addition, by default, E-Ink matrices do not glow on their own, but reflect outside light - so their own backlight is not necessary for them (although it can be provided for work at dusk and darkness). All this provides a solid energy savings; and for some users, such screens are purely subjectively more comfortable and less tiring than traditional matrices. On the other hand, E-Ink technology also has serious drawbacks - first of all, a long response time, as well as the complexity and high cost of color displays, combined with poor color reproduction quality on them. In light of this, in smartphones, such matrices are a very rare and exotic option.

— Sweep frequency. The maximum display refresh rate, in other words, the highest frame rate that it can effectively reproduce. The higher this figure, the smoother and smoother the image is, the less noticeable the “slideshow effect” and blurring of objects when moving on the screen. At the same time, it should be borne in mind that the refresh rate of 60 Hz, supported by almost any modern smartphone, is quite sufficient for most tasks; even high-definition videos hardly make use of high frame rates these days. Therefore, the scanning frequency in our catalog is specially specified mainly for screens capable of delivering more than 60 Hz (in some models - up to 240 Hz). Such a high frequency can be useful in games and some other tasks, it also improves the overall experience of the OS interface and applications - moving elements in such interfaces move as smoothly as possible and without blurring.

HDR. A technology that allows you to expand the dynamic range of the screen. In this case, the range of brightness is implied - simply put, the presence of HDR allows the screen to display brighter whites and darker blacks than on displays without support for this technology. In practice, this gives a noticeable improvement in image quality: the saturation and reliability of the transmission of various colors improves, and the details in very light or very dark areas of the frame do not “sink” in white or black. However, all these advantages become noticeable only on the condition that the content being played is originally recorded in HDR. Nowadays, several varieties of this technology are used, here are their features:

• HDR10. Historically the first of the consumer HDR formats, it is extremely popular today: in particular, it is supported by almost all streaming services with HDR content and is standardly used for such content on Blu-ray discs. Provides a color depth of 10 bits (more than a billion shades). At the same time, HDR10+ format content (see below) can also be played on devices with this technology, except that its quality will be limited by the capabilities of the original HDR10.
• HDR10+. An improved version of HDR10. With the same color depth (10 bits), it uses the so-called dynamic metadata, which allows transmitting information about the color depth not only for groups of several frames, but also for individual frames. This results in an additional improvement in color reproduction.
• Dolby vision. An advanced standard used particularly in professional cinematography. It allows you to achieve a color depth of 12 bits (almost 69 billion shades), uses the dynamic metadata mentioned on top, and also makes it possible to transmit two image options at once in one video stream - HDR and normal (SDR). At the same time, Dolby Vision is based on the same technology as HDR10, so in modern electronics this format is often combined with HDR10 or HDR10 +.

- DC Dimming support. Literally from English, Direct Current Dimming is translated as direct current dimming. This technology is designed to minimize flicker in OLED and AMOLED screens, which, in turn, reduces the load on the user's visual apparatus and protects eyesight. The “flicker-free” effect is achieved by directly controlling the brightness of the backlight LEDs by changing the voltage applied to them. Due to this, a decrease in the intensity of the glow of the screen is ensured.

- Curved screen. A screen that has curved edges to which the displayed image extends. In other words, in this case, not only glass is curved, but also part of the active sensor. Displays where both edges are curved are sometimes referred to as "2.5D glass" as well; also there are devices where the screen is bent only on one side. In any case, this feature gives the smartphone an interesting appearance and improves the visibility of the image from some angles, but it significantly affects the cost and can create inconvenience when holding (especially without a case). So before buying a model with such equipment, ideally, you should hold the device in your hand and make sure that it is comfortable enough.

- Gorilla Glass. Special high-strength glass used as a display cover. It is characterized by endurance and resistance to scratches, many times superior to ordinary glass in these indicators. It is widely used in smartphones, where large screen sizes put forward increased requirements for coverage reliability. Modern phones may have different versions of this glass, here are the features of different options:

• Gorilla Glass v3. The oldest of the current versions is released in 2013; now found mainly among inexpensive or obsolete devices. However, this coating also has undoubted advantages: this is the first generation of Gorilla Glass, where the creators have made a noticeable emphasis on resistance to scratches from keys, coins and other objects that the phone can “collide” in a pocket or bag. In this respect, the v3 version remained unsurpassed until the release of Gorilla Glass Victus in 2020.
• Gorilla Glass v4. Version released in 2014. A key feature was that the development of this coating focused on impact resistance (whereas previous generations focused mainly on scratch resistance). As a result, the glass is twice as strong as in version 3, despite the fact that its thickness is only 0.4 mm. But here's the scratch resistance, compared with its predecessor, has decreased slightly.
• Gorilla Glass v5. A gorilla improvement released in 2016 to further improve impact resistance. According to the developers, the glass of the v5 version is 1.8 times stronger than its predecessor, remaining intact in 80% of drops from a height of 1.6 m "face down" on a rough surface (and guaranteed impact resistance is 1.2 m). Scratch resistance has also improved somewhat, but this material still falls short of v3 performance.
• Gorilla Glass v6. Version introduced in 2018. For this coating, a 2-fold increase in strength compared to its predecessors is claimed, as well as the ability to endure multiple drops on a hard surface (in tests, v6 glass successfully endured 15 drops from a height of 1 m). The maximum drop height (single) with guaranteed integrity is declared at 1.6 m. Scratch resistance has received practically no improvement.
• Gorilla Glass 7. Original name for Gorilla Glass Victus - see below.
• Gorilla Glass Victus. The "heir" of Gorilla Glass 6, released in the summer of 2020. In this coating, the creators paid attention not only to increasing the overall strength, but also to improving scratch resistance. According to the latter indicator, Victus surpasses even the v3 version, not to mention more sensitive materials (and compared to v6, scratch resistance is claimed to be twice as high). As for durability, it allows you to guarantee to endure single drops from a height of up to 2 m, as well as up to 20 consecutive drops from a height of 1 m.

The clock frequency of the CPU that the device is equipped with. For multi-core processors, which are standard in modern smartphones, the frequency of each individual core is implied; and if the processor has cores with different frequencies (see "Number of cores") — usually, the maximum indicator is given.

In general, high performance smartphones have high frequency of the processor. However, note that this parameter itself is not directly related to the capabilities of the CPU: many other features of the chip affect the actual performance, and often a low cost solution with a higher clock speed turns out to be less performant than an expensive one, and at the same time, presumably, more "slow" processor. In addition, the overall performance of the system directly depends on a whole set of other factors — primarily the amount of RAM. Therefore, when evaluating a smartphone, it is worth focus not so much on the frequency of the processor, but on the general specs of the system and visual indicators like the results in tests (see below).

The largest volume of memory card with which the phone supports. For more information about the cards themselves, see "Memory Card Slot"; here we note that capacious cards often use advanced technologies that are not supported by all devices, and sometimes phones simply do not have enough power to process large amounts of data. Therefore, for the convenience of choosing in our catalog, the maximum supported volume is indicated.

In fact, there are cases when some devices may exceed the claimed characteristics. However, it is worth focusing on official data, because, if officially supported volume is exceeded, normal operation of the card is not guaranteed.

Specifications of the main lens of the rear camera installed in the phone. In models with several lenses (see “Number of lenses”), the main one is responsible for basic shooting capabilities and does not have a pronounced specialization (wide-angle, telephoto, etc.). Four main parameters can be indicated here: resolution, aperture ( high aperture optics are quite common), focal length, additional sensor data.

Resolution(in megapixels, MP)
Resolution of the sensor used for the main lens. Budget options are equipped with a module 8 MP and below, many models have 12 MP camera / 13 MP, also recently a trend towards increasing megapixels has been popular. Often in smartphones you can find the main photomodule at 48 MP, 50 MP< /a>, 64 MP and even 108 MP .

The maximum resolution of the resulting image directly depends on the resolution of the sensor; and the high resolution of the "picture", in turn, allows you to better display fine details. On the other hand, an increase in the number of megapixels in itself can lead to a deterioration in the overall image quality - due to the smaller size of each individual pixel, the noise le...vel increases. As a result, the direct resolution of the camera has little effect on the quality of the shooting - more depends on the physical size of the matrix, the features of the optics and various design tricks used by the manufacturer.

Aperture
Aperture describes the ability of a lens to transmit light. It is written as a fractional number, for example f/1.9. Moreover, the larger the number in the denominator, the lower the aperture ratio, the less light passes through the optics, all other things being equal. For example, an f/2.6 lens will be “darker” than f/1.9.

High aperture gives the camera a number of advantages. First, it improves the quality of shooting in low light. Secondly, it's possible to shoot at low shutter speeds, minimizing the effect of "stirring" and blurring of moving objects in the frame. Thirdly, with fast optics it is easier to achieve a beautiful background blur ("bokeh") — for example, when shooting portraits.

Focal length(in millimetres)
The focal length is a distance between the sensor and the centre of the lens (focused to infinity), at which the most clear image is obtained on the matrix. However, for smartphones, the specifications indicate not the actual, but the so-called equivalent focal length — a conditional indicator recalculated using special formulas. This indicator can be used to evaluate and compare cameras with different sensor sizes (the actual focal length cannot be used for this, since with a different sensor size the same real focal length will correspond to different viewing angles). (It is also worth saying that the equivalent focal length can be noticeably larger than the thickness of the case — there is nothing unusual in this, since this is a conditional, and not a real indicator).

Anyway, the field of view and the degree of magnification directly depend on the equivalent focal length: a larger focal length gives a smaller field of view and a larger size of individual objects that fall into the frame, and a decrease in this distance, in turn, allows you to cover more space. In most modern smartphones, the focal length of the main camera ranges from 13 to 35 mm; if compared with the optics of traditional cameras, then lenses with equivalent focal length up to 25 mm can be attributed to wide-angle lenses, more than 25 mm — to universal models “with a bias towards wide-angle shooting”. Such values are chosen due the fact that smartphones are often used for shooting in cramped conditions, when a fairly large space needs to fit into the frame at a small distance. Enlargement of the picture, if necessary, is most often carried out digitally — due to the reserve of megapixels on the sensor; but there are also models with optical zoom (see below) — for them, not one value is given, but the entire working range of the equivalent focal length (recall, optical zoom is carried out by changing the focal length).

Field of view(in degrees). It characterizes the size of the area covered by the lens, as well as the size of individual objects "seen" by the camera. The larger this field, the more of the scene gets into the frame, but the smaller the individual objects in the image are. The field of view is directly related to the focal length (see above): increasing this distance narrows the field of view of the lens, and vice versa.

Note that this parameter is generally considered important for professional use of the camera rather than for amateur photography. Therefore, viewing angle data is given mainly for smartphones equipped with advanced cameras — including in order to emphasize the high class of cameras. As for specific values, for the main lens they usually are in the range from 70° to 82° — this corresponds to the general specifics of such optics (universal shooting with an emphasis on general scenes and extensive coverage at short distances).

Additional Sensor Data
Additional information regarding the sensor installed in the main lens. This item can specify both the size (in inches) and the sensor model, and sometimes both parameters at once. Anyway, such data is provided only if the device is equipped with a high-end sensor. With the model, everything is quite simple: knowing the name of the sensor, you can find detailed data on it. The size is worth considering a little more.

The size of the sensor is traditionally indicated in fractional parts of an inch — accordingly, for example, a 1/2.3" sensor will be larger than 1/2.6". Larger sensors are considered more advanced, as they provide better image quality at the same resolution. The logic here is simple - due to the large sensor area, each individual pixel is also larger and gets more light, which improves sensitivity and reduces noise. Of course, the actual image quality will also depend on a number of other parameters, but in general, a larger sensor size usually means a more advanced camera. In advanced photo flagships, you can find matrices with a physical size of 1”, which is comparable to image sensors used in top compact cameras with fixed lenses.

The presence of a flash on the main camera of the phone.

Flash is a lamp for illuminating the photographed scene, it significantly expands the possibilities of shooting. In particular, it allows you to shoot in low light and against bright light. In addition, the flash can usually also be used as a flashlight(see "Options"), which eliminates the need to install two light sources in the phone.

Types of communications supported by the device in addition to mobile networks.

This list includes two types of characteristics. The first is the communication technology itself: Wi-Fi (including advanced standards Wi-Fi 5 (802.11ac) , Wi-Fi 6 (802.11ax), Wi-Fi 6E (802.11ax) , Wi-Fi 7 (802.11be)), Bluetooth (including the new generation Bluetooth v 5 in the form of a version 5.0, 5.1, 5.2, 5.3 and 5.4), NFC, satellite communication. The second type is additional functions implemented through one or another communication standard: this is primarily aptX support (including aptX HD, aptX Adaptive and aptX Lossless) and even a built-in walkie-talkie. Here is a more detailed description of each of these characteristics:

— Wi-Fi 4 (802.11n). Wi-Fi is a wireless communication technology that in modern phones can be used both to access the Inte...rnet through wireless access points, and for direct communication with other devices (in particular, cameras and drones). Wi-Fi is a must for smartphones, but is extremely rare in traditional phones. Specifically, Wi-Fi 4 (802.11n) provides data transfer speeds of up to 600 Mbit/s and uses two frequency ranges at once - 2.4 GHz and 5 GHz, making it compatible with earlier 802.11 b/g standards and with more new Wi-Fi 5 (see below). Wi-Fi 4 is considered a relatively modest standard by modern standards, but it is still quite sufficient for most tasks.

- Wi-Fi 5 (802.11ac). The Wi-Fi standard (see above), which is the successor to Wi-Fi 4. In theory, it supports speeds of up to 6.77 Gbps, and also uses the 5 GHz band - it is less loaded with extraneous signals and more noise-resistant than the traditional 2.4 GHz. For compatibility purposes, a smartphone with a Wi-Fi 5 module may provide support for earlier standards, but it would not hurt to clarify this point separately.

- WiGig (802.11ad). Further, after Wi-Fi 5, the development of Wi-Fi standards, characterized primarily by the use of the 60 GHz band. In terms of maximum speed, it is virtually no different from Wi-Fi 5, however, the higher frequency increases the channel capacity, so that when several gadgets simultaneously communicate with one common device (for example, a router), the communication speed does not drop as much as in earlier standards. On the other hand, the 802.11ad signal is almost incapable of passing through walls; Manufacturers use various tricks to compensate for this shortcoming, but the best communication quality is still achieved only with direct visibility. Relatively little equipment for the WiGig standard is currently being produced, and it is not compatible with earlier versions of Wi-Fi; Therefore, smartphones usually provide support for other standards.

- Wi-Fi 6 (802.11ax). A standard developed as a direct development and improvement of Wi-Fi 5. Uses the ranges from 1 to 7 GHz - that is, it is capable of operating at standard frequencies of 2.4 GHz and 5 GHz (including equipment of earlier standards), and in others frequency bands. The maximum data transfer rate has increased to 10 Gbps, but the main advantage of Wi-Fi 6 was not even this, but the further optimization of the simultaneous operation of several devices on the same channel (improving the technical solutions used in Wi-Fi 5 and WiGig). Thanks to this, Wi-Fi 6 gives the lowest speed drop among modern standards when the channel is busy.

- Wi-Fi 6E (802.11ax). The Wi-Fi 6E standard is technically called 802.11ax. But unlike basic Wi-Fi 6 (for more details, see the corresponding paragraph), which is named similarly, it provides for operation in the unused 6 GHz band. In total, the standard uses 14 different frequency bands, offering high throughput in the most crowded places with many active connections. And it is backwards compatible with previous versions.

— Wi-Fi 7 (802.11be). The technology, like the previous Wi-Fi 6E, is capable of operating in three frequency ranges: 2.4 GHz, 5 GHz and 6 GHz. At the same time, the maximum bandwidth in Wi-Fi 7 was increased from 160 MHz to 320 MHz - the wider the channel, the more data it can transmit. The IEEE 802.11be standard uses 4096-QAM modulation, which also allows more symbols to be accommodated in a data transmission unit. From Wi-Fi 7 you can squeeze out a maximum theoretical information exchange speed of up to 46 Gbps. In the context of using wireless connections for streaming and video games, the implemented MLO (Multi-Link Operation) development seems very interesting. With its help, you can aggregate several channels in different ranges, which significantly reduces delays in data transmission and ensures low and stable ping. And Multi-RU (Multiple Resource Unit) technology is designed to minimize communication delays when there are many connected client devices.

— Bluetooth. Direct wireless communication technology between various devices. In mobile phones it is used primarily for connecting headphones, headsets and wrist gadgets such as fitness bracelets, but other methods of application are also possible - remote control mode, direct file transfer, etc. In modern mobile phones there can be different versions of Bluetooth, here are their features:

• Bluetooth v 4.0. A fundamental update (after version 3.0), introducing another data transmission format - Bluetooth Low Energy (LE). This protocol is designed primarily for miniature devices that transmit small amounts of information, such as fitness bracelets and medical sensors. Bluetooth LE allows you to significantly save energy during such communication.
• Bluetooth v4.1. Development and improvement of Bluetooth 4.0. One of the key improvements was the optimization of collaboration with 4G LTE communication modules - so that Bluetooth and LTE do not interfere with each other. In addition, this version makes it possible to simultaneously use a Bluetooth device in several roles - for example, to remotely control an external device while simultaneously streaming music to headphones.
• Bluetooth v4.2. Further, after 4.1, the development of the Bluetooth standard. It did not provide any fundamental updates, but received a number of improvements regarding reliability and noise immunity, as well as improved compatibility with the Internet of Things.
• Bluetooth v 5.0. Version introduced in 2016. The key innovations were the further expansion of capabilities associated with the Internet of Things. In particular, in the Bluetooth Low Energy protocol (see above), it became possible to double the data transfer rate (up to 2 Mbit/s) at the cost of reducing the range, and also quadruple the range at the cost of reducing the speed; In addition, a number of improvements have been introduced regarding simultaneous work with a large number of connected devices.
• Bluetooth v5.1. Update of the version described above v 5.0. In addition to general improvements in the quality and reliability of communication, this update introduced such an interesting feature as determining the direction from which the Bluetooth signal is coming. Thanks to this, it becomes possible to determine the location of connected devices with centimeter accuracy, which can be useful, for example, when searching for wireless headphones.
• Bluetooth v 5.2. The next update after 5.1 is Bluetooth 5 generation. The main innovations in this version are a number of security improvements, additional optimization of power consumption in LE mode and a new audio signal format for synchronizing parallel playback on multiple devices.
• Bluetooth v 5.3. The Bluetooth v 5.3 wireless protocol was introduced at the dawn of 2022. Among the innovations in it, they accelerated the process of negotiating a communication channel between the controller and the device, implemented the function of quickly switching between the operating state in a low duty cycle and a high-speed mode, and improved the throughput and stability of the communication by reducing susceptibility to interference. When unexpected interference occurs in Low Energy mode, the procedure for selecting a communication channel to switch from now on has been accelerated. There are no fundamental innovations in protocol 5.3, but a number of qualitative improvements are evident in it.
• Bluetooth v5.4. Protocol version 5.4, which was introduced at the beginning of 2023, increased the range and speed of data exchange, which is well suited for use in applications that require communication over long distances (for example, smart home systems). Also in Bluetooth v 5.4, the energy-saving BLE mode has been improved. This version of the protocol uses new security features to protect data from unauthorized access, has increased communication reliability by selecting the best channel for communication, and prevents communication losses due to interference.

- aptX support. aptX technology was developed to improve the quality of sound transmitted over Bluetooth. When transmitting sound in a regular format, without aptX, the signal is compressed quite heavily, which affects the sound quality; This is not critical when talking on the phone, but it can significantly spoil the impression of listening to music. In turn, aptX allows you to transmit an audio signal with virtually no compression and achieve sound quality comparable to a wired communication. Such features will be especially appreciated by music lovers who prefer Bluetooth headphones or wireless speakers. Of course, to use aptX, both your smartphone and external audio device must support it.

- aptX HD support. aptX HD is a further development and improvement of the original aptX technology, allowing you to transmit sound in even higher quality - Hi-Res (24-bits/48kHz). According to the creators, this standard allows you to achieve signal quality superior to AudioCD and sound purity comparable to wired communication. The latter is often questionable, but it can be argued that overall aptX HD provides very high sound quality. On the other hand, all the advantages of this technology become noticeable only on Hi-Res audio - with quality 24-bits/48kHz or higher; otherwise, the quality is limited not so much by the characteristics of the communication as by the properties of the source files.

- Support for aptX LL. A modification of aptX technology, designed to minimize signal transmission delays. Encoding and decoding a signal when transmitting audio via Blueooth with aptX inevitably takes some time; This is not critical when listening to music, but in videos or games there may be a noticeable desynchronization between the image and sound. The aptX LL technology does not have this shortcoming; it also gives a delay, but this delay is so small that a person does not notice it.

- Support for aptX Adaptive. Further development of aptX; actually combines the capabilities of aptX HD and aptX Low Latency, but is not limited to this. One of the main features of this standard is the so-called adaptive bitrate: the codec automatically adjusts the actual data transfer rate based on the characteristics of the broadcast content (music, game audio, voice communications, etc.) and the congestion of the frequencies used. This, in particular, helps reduce energy consumption and increase communication reliability; and special algorithms allow you to broadcast sound quality comparable to aptX HD (24 bits/48 kHz), using much less transmitted data. And the minimum data transfer latency (at the aptX LL level) makes this codec excellent for games and movies.

– Support for aptX Lossless. The next branch of development of aptX technology, which allows you to transmit CD-quality sound over a wireless Bluetooth network without loss or use of compression. At the same time, audio broadcasting with sampling parameters of 16 bits / 44.1 kHz is carried out with a bitrate of about 1.4 Mbit/s - this is about three times faster than in the aptX Adaptive edition. Support for aptX Lossless began to be introduced in late 2021 as part of Qualcomm's Snapdragon Sound initiative, which is available on smartphones, headphones and speakers with a Snapdragon 8 Gen 1 processor and later.

— NFC chip. NFC is a technology for wireless communication over ultra-low distances, up to 10 cm. One of the most popular applications of this technology in smartphones is contactless payments, when the device actually plays the role of a credit card: just bring the device to a terminal that supports contactless technology like PayPass or PayWave. Another common way to use NFC is to automatically connect to another NFC-compatible device via Wi-Fi or Bluetooth: gadgets brought close to each other automatically set up a communication, and the customer only needs to confirm it. Other options are technically possible: recognizing smart cards and RFID tags, using the device as a travel card, access card, etc. However, such use formats are much less common.

- Infrared port. The infrared port looks like a small “eye”, usually on the top end of the phone. This equipment allows you to turn your phone into a remote control for controlling various equipment - just install the appropriate application. At the same time, we note that among such applications you can find an option for almost any device - from TVs to air conditioners, hoods, etc. Accordingly, the “smartphone remote control” turns out to be very universal.

— Walkie-talkie. Built-in radio module that allows you to use the phone as a walkie-talkie - for communication over relatively low distances without using SIM cards. Of course, for such communication you will need another walkie-talkie (or a phone with this function). The specific frequencies supported by the built-in radio module should be clarified separately; however, all phones with this feature operate in one or more standard bands. In practice, this means that they are capable of communicating not only with similar phones, but also with classic civilian walkie-talkies - provided they match the supported bands. The communication range is usually quite low; however, the built-in walkie-talkie can be very useful for tech in situations where conventional mobile communications are ineffective or unavailable. Typical examples of such situations are staying “far from civilization”, in an area of poor treatment, or traveling abroad, where roaming is expensive.

– Satellite communication. The satellite communication function is intended to send emergency alerts to rescue services in emergency situations. Smartphones with the ability to connect to satellite frequencies can communicate with emergency services in areas where there is no mobile network treatment. For better signal reception from satellites, it is advisable for the customer to be in an open space. At the stage of function formation, only ready-made requests can be transferred. In the future, it is planned to support full messaging via satellite communications, but a separate fee will be charged for them.

Inputs and outputs of the smartphone.

This paragraph usually specifies the type of charging and data port (most often it's USB-C), and whether the smartphone has a mini-jack (3.5 mm)(there are devices without it). It can also indicate the interface of the USB-C port up to the high-speed third version ( USB-C v 3), the location of the 3.5 mm jack (headphone output) and additional ports for a more specific purpose.

The main ports are used primarily for charging the battery, for connecting various accessories to the phone and for connecting the device itself to the computer via a cable. 3.5 mm port (mini-Jack) is intended primarily for headphones and other audio accessories, although other usage formats are possible. Here is a more detailed description of the different types of connectors:

— USB-C. A relatively new type of universal interface, a kind of successor to microUSB, which is increasingly used in mobile devices. USB-C differs from its predecessor primarily in slightly larger dimensions and a convenient two-sided design: thanks to it, it does not matter which side to insert the plug. In addition, this interface allows you to implement more advanced functions than microUSB — in particular, certain fast charging technologies were originally created specifically for USB-C. USB standard supporte...d by this type of connector can be specified separately. Today the options are:

• USB-C 3.2 gen1. The standard formerly known as USB 3.0 and USB 3.1 gen1. Provides data transfer rates up to 4.8 Gbps.
• USB-C 3.2 gen2. The current name for the standard, formerly USB 3.1, then USB 3.1 gen2. The connection speed on this interface can reach 10 Gbps.
• USB-C 3.2 gen2x2. A standard (formerly known as USB 3.2) that delivers twice the speed of "regular" USB 3.2 gen2, up to 20Gbps. Unlike previous versions, it was created specifically for the USB-C connector.

— microUSB. A universal connector, which formerly was extremely widely used in portable devices (with the exception of Apple devices). It is less convenient and technically advanced than USB-C, therefore it is gradually losing popularity; however, there are still quite a few devices with microUSB out there.

— Lightning. Apple's proprietary connector used exclusively in the iPhone. It has a double-sided design that allows you to connect the plug in either direction. In modern iPhones, it is used both as a universal one and for connecting headphones (in 2016, Apple abandoned the 3.5 mm audio output in their smartphones).

— Original port. The one that does not belong to the types described above. Nowadays, such solutions are extremely rare — standard interfaces are more convenient and versatile, as they allow you to use not only "native" accessories, but also solutions from third-party manufacturers.

— USB A. Full-size USB port — similar to those used in PCs and laptops for connecting various peripherals. It has a similar purpose in phones, it is mainly used for flash drives and other external accessories (the specific set of supported devices should be specified separately). Usually, it is supplemented with a more traditional universal connector like microUSB or USB-C; in general, for a number of reasons, it is very rare.

— Magnetic connector. A connector that uses a permanent magnet instead of a standard plug system to hold the cable. Such solutions are used mainly in devices with water protection (see "Waterproof"), and most often — to charge the battery in addition to standard universal connectors (usually microUSB or USB-C). The main convenience of the magnetic connector is that it does not need plugs to protect it from water. It simplifies the connection and disconnection of the charger, and secondly, the wear of the plugs on standard ports is minimized — they do not need to be opened and closed every time you charge the smartphone. However only a special “native” cable is suitable for a magnetic connector; but if this cable is lost or broken, it may be possible to charge in the usual way, through a traditional universal connector.

— Mods contacts. Contacts for connecting special additional modules that expand the functionality of the device. Such equipment is usually found in some rugged phones. The modules themselves are usually a kind of "cases" that are put on the back of a smartphone; in such a “case” there may be, for example, an additional battery, a gamepad or even a thermal vision mod.

— Mini-jack (3.5 mm). A connector primarily used to connect wired headphones and other audio devices (such as portable wired speakers). Such a connection is extremely popular among audio accessories (and not only for "mobile" purposes); so finding headphones, a headset or speakers for this connector is usually not a problem. In addition, the 3.5 mm jack can also be used for more specific tasks — for example, connecting a selfie stick, a card reader or exchanging data with wearable fitness sensors and other specific equipment. However, such features are rarely used and require the installation of special applications, but connecting headphones is the initial function of such a connector, available by default. So the mini-jack connector is often called the "headphone output".

— Location of the headphone output. The 3.5 mm output described above in modern phones can be located on the top, bottom or side of the device. However, the latter option is generally less convenient than the first two, and therefore is rare. And the choice for this indicator depends primarily on how exactly you are going to carry the phone and which side will be used to connect headphones to it; For different situations, the options will also be different.

Additional features and capabilities of the device.

In modern mobile phones (especially smartphones) a very extensive amount of additional features can be provided. These can be both already familiar features, many of which are directly related to the original purpose of the device, as well as fairly new and/or unusual ones. The first category includes an emergency call button(often found on phones for the elderly), noise cancellation, FM receiver, notification light and a light sensor. The second category includes a face and fingerprint scanner (the latter can be located on the back cover, side panel, front and even right under the screen), gyroscope, advanced full-fledged flashlight, stereo sound, 3D surround sound, Hi-Res Audio and even such exotics as a barometer. Here is a more detailed description of each of th...ese options:

— 3D face scanner. A special technology for recognizing the user's face — not just by photographing, but by building a three-dimensional model of the face based on data from a special module on the front panel. This technology is constantly being improved, nowadays it is able to take into account the change of hairstyles and facial hair, the presence of glasses, makeup, etc. At the same time, the recognition of twins and children's faces still remains weak points (they have fewer individual features than adults ). The main use of a face scanner is authentication when unlocking a smartphone, entering applications, making payments, etc. At the same time, other, more original use cases are possible. For example, in some applications, the face scanner reads the user's facial expressions, and then this facial expression is repeated by an emoji on the phone screen.

— Fingerprint scanner. Fingerprint reader. It is mainly used for user authorization - for example, when unlocking the device, entering certain applications or accounts, confirming payments, etc. As for placement options, fingerprint scanners are increasingly moving from the back cover of the device to the surface of the side power / unlock button - to You can touch the sensor on the side with your thumb without releasing the smartphone from your hands and practically without changing your grip. Some time ago, sensors on the front of the case were quite popular - in particular, thanks to Apple, which was the first to tightly implement fingerprint recognition in its gadgets. However, such placement inevitably increases the size of the bottom frame, so the front fingerprint scanner is rare in modern smartphones. A good alternative to it is scanners right on the screen (more precisely, under the display matrix), which do not take up extra space on the front panel.

— Stereo sound. The ability to play full stereo sound through your phone's own speakers, without external audio devices. There must be at least two speakers for this task. This complicates the design and increases its cost, but it has a positive effect on the sound quality: the sound is more expressive and detailed than when using a single speaker, it has a volume effect, as well as a higher volume.

– 3D surround sound. The mechanics of spatial surround sound with localization of sound sources in three-dimensional space allows you to deeply immerse yourself in the atmosphere of films, enjoy listening to audio tracks, or completely immerse yourself in mobile gameplay. Algorithms for implementing 3D sound in smartphones differ in terms of software and hardware support, but they are all aimed at achieving the effect of realistic sound stage. Note that support for 3D surround sound can mean both commonly used technologies such as Dolby Atmos or DTS:X Ultra, as well as proprietary solutions from individual audio brands that have a hand in the sound subsystem of a mobile device (AKG, JBL, Harman, Huawei / Honor Histen, etc.).

– Hi-Res Audio. Mobile device support for high-resolution audio Hi-Res Audio - a digital signal with parameters from 96 kHz / 24 bits. Audio tracks in this format sound as close as possible to the original ideas of the authors of the compositions. The result is a sound that is as close as possible to what was recorded in the studio.

— FM receiver. Built-in module for receiving radio stations broadcasting in the FM band. Some devices also support other bands, but FM is the most popular nowadays (due to the ability to transmit stereo sound), it is in it that music radio stations usually broadcast. Note that some devices for reliable reception may require the connection of wired headphones — their cable plays the role of an external antenna.

— Notification indicator. Physically separate light beacon, pulsating or being constantly lighted up in response to incoming notifications of missed calls and received messages (including the ones from instant messengers and social network clients). Also, the indicator light usually signals a low remaining battery level and lights up during the battery recharging. The implementation of the notification indicator can be different: for some phones it is single-colour, for others it has colour coding of signals, flexibly adjustable for certain events through the settings menu. The light beacon allows you to visually comprehend the presence of incoming notifications without having to turn on the smartphone screen.

— Emergency call button. A separate button designed for use in critical situations. The specific features of such a button may be different, depending on the model: sending “alarming” SMS to selected numbers, automatically receiving calls from these numbers or calling them in turn, turning on the siren, etc. Anyway, the “emergency” button is usually clearly visible, and its presence is especially useful if the phone is used by an elderly person (in fact, in specialized devices designed for elderly, this button is almost mandatory).

— Noise suppression. An electronic filter that cleans the user's voice from extraneous noise (sounds of the street, the rumble of the wind in the microphone grille, etc.). Thus, the person at the other end of the line hears only the voice, with virtually no extra sounds. Of course, no noise reduction system is perfect; however, in most cases, this feature significantly improves the quality of the speech transmitted by the phone to the other person.

— Gyroscope. A device that tracks the rotation of a mobile phone in space. Modern gyroscopes, usually, work on all three axes and are able to recognize both the angle and the rate of turn; in addition, this feature almost necessarily means the presence of an accelerometer, which allows (among other things) to detect tremors and sharp movements of the device.

— Full-fledged flashlight. The presence of an advanced flashlight in the phone — more powerful than the usual one. The specific design and capabilities of such a flashlight may be different. So, in some devices, a separate LED (or a set of LEDs) is provided on the upper end, and this light source is used only as a flashlight. In others (mainly smartphones), we are talking about a special design of the flash: it consists of several LEDs, and only a part of them is usually used to illuminate when shooting, and all at once to work in flashlight mode. And the additional features of such a light source may include a laser pointer, beam focus, brightness control, etc. Anyway, most models with this feature are rugged devices with increased resistance to dust, moisture and shock (however, there are exceptions).

— Light sensor. A sensor that monitors the level of ambient light. It is mainly used to automatically adjust the brightness of the screen: in bright ambient light, it increases so that the image remains visible, and in twilight and darkness it decreases, which saves battery power and reduces eye fatigue.

— Barometer. Sensor for measuring atmospheric pressure. By itself, the barometer only determines this pressure at the current time, but the methods of using such data may be different, depending on the software installed on the phone. For example, some navigation applications can determine the elevation difference between individual points on the ground by the difference in atmospheric pressure at these points; and in weather programs, barometer data can improve the accuracy of weather forecasts. Also, this feature will be useful for weather-sensitive people: it signals a change in the weather, allowing you to more accurately determine the cause of ailments and take measures to eliminate them.

The capacity of the battery that the mobile phone is equipped with.

Theoretically, the high capacity of the battery allows the device to work longer on one charge. However, actual battery life time will also depend on the power consumption of the gadget — and it is determined by the hardware specs, the operating system, special solutions provided in the design, etc. So in fact, phones with capacious batteries in general have "long battery life”, however, the actual battery life can differ markedly even for two models with similar specifisations. Therefore, for an accurate assessment, it is better to focus not on the battery capacity, but on the operating time in different modes directly claimed by the manufacturer (see below).