Bluetooth 2.0 data rate. The most common Bluetooth profiles

Bluetooth technology, which was developed back in 1994 by the Swedish company Ericsson, was originally intended not for mobile phones at all, but for the Flyway concept created in those years (www.swedetrack.com). Flyway is a personal automatic transport system. It is a branched monorail with trailers of small capacity. Each of them can move along their own individual route within the network - something like a taxi, only without a driver. Bluetooth technology played a key role in this new transport system: it was with its help that all elements exchanged data with each other.

Samo Bluetooth name was originally just a code name for this project. It comes from the nickname of the Danish king Harold Blatand, who, according to legend, got it because of his rotten teeth. Why then blue? It turns out that in Viking times the word "blah" meant both "blue" and "black". Despite not quite healthy teeth, the king was able to unite the isolated specific principalities of Denmark and create a strong state. The idea of ​​bringing people together became fundamental in the development of Flyway and its synchronization protocol. When it came to the commercial launch of the technology, the developers of the standard could not come up with a more appropriate name than the code Bluetooth.

The first steps of the new standard

Already during the development of the technology, Ericsson realized that it would be perfect for transferring data between mobile devices. In 1998, at the initiative of the company, the Bluetooth Special Interest Group (Bluetooth SIG, www.bluetooth.com) was created, which also included IBM, Intel, Toshiba and Nokia. In the same year, a version Bluetooth protocol 1.0, and a little later, in early 1999, its corrected version, Bluetooth 1.0B, saw the light. In these versions of the protocol, in order to establish a connection, devices required the transmission of their hardware addresses, which made anonymous connections impossible. In the first specifications, some specifications. Because of this, equipment from different manufacturers turned out to be virtually incompatible with each other: setting up two different Bluetooth devices was, to put it mildly, not easy.

frequency hopping

In 2001, the Bluetooth 1.1 specification was introduced - it did not have full backward compatibility with the two previous versions of the 1.0 protocol, but the developers corrected all the shortcomings and errors.

New features also appeared: the connection could be unencrypted, the devices displayed the level of the received signal. And most importantly, all subsequent versions of the Bluetooth protocol are backwards compatible with Bluetooth 1.1, so it can still be found in many working devices. Bluetooth 1.1 modules are now so simple and cheap that their presence increases the cost of the product by only a few cents.

In 2003, the Bluetooth 1.2 specification was released. It used AFH technology to give priority to the least noisy frequencies. This significantly increased the noise immunity of communication and made it possible to increase the data transfer rate. However, no new modulation schemes were used, so maximum speed Bluetooth remains the same - 721 kbps. The only difference compared to version 1.1 was that Bluetooth 1.2 had a real speed that was closer to theoretically possible limit due to the presence of AFH.

Then, due to eSCO technology, voice quality improved. In addition, the new version doubles the speed of discovering and pairing devices, and has the optional ability to connect two devices at the same time. Together with version 1.2, stereo sound transmission over the A2DP profile began.

Transition to the second level

In November 2004, a new version of Bluetooth 2.0 was released, in which EDR technology was optionally implemented for the first time - devices with its support are still marked as "2.0 + EDR". Through the application the latest algorithms EDR signal coding allows you to transfer data 3 times faster - up to 2.1 Mbps. In the data stream itself, the transmission rate can reach 3 Mbps. However, part of this bandwidth"eaten" - spent on resending erroneous packets (due to interference). In addition, service traffic is consumed - for encoding and encrypting information.

The increase in data transfer rate, together with the increase in noise immunity, made it possible to reduce the power consumption of Bluetooth by approximately three times. True, this statement is not true for all devices, but only for those that do not require an increased data transfer rate (for example, headsets). Simultaneous connection of several devices has also been simplified: due to the increase in the bit depth of addressing, it became possible to build a local wireless network use in it not 8, as before, but 256 devices.

Modern stage of development

In 2007, the Bluetooth specification was updated to version 2.1 (also with optional EDR support), which received advanced device feature query technology for quick setup all profiles.

In addition, it has been added energy saving technology Sniff Subrating with optimized work and wait cycles. It allows you to increase the operating time of a Bluetooth device on a single battery charge by up to five times. The updated specification of the Bluetooth 2.1 wireless standard has greatly simplified and accelerated the establishment of a connection between two devices and allowed the encryption key to be updated without breaking the connection, which improves protection. True, such a simplification of establishing a connection is only possible if both devices are equipped with NFC modules. They create an electromagnetic field in a small radius around them: it is enough to bring the devices to each other to start the connection process.

Most existing adapters (here we take into account not only custom, but also corporate systems) is equipped with obsolete Bluetooth modules 1.1 and 1.2. Support for the Bluetooth 2.0 + EDR standard is present in modern models of phones and laptops. As for Bluetooth 2.1+EDR, the new version of the standard has not been widely used until recently: for some reason, many manufacturers ignore this version.

Perhaps the reason is this: all its advantages are achieved only with a built-in NFC module, which requires at least additional antenna. But there is a simpler explanation: older Bluetooth 2.0 modules are cheaper, so it is more profitable to use them in the most modern models.

BLUETOOTH FOR CLOTHING

Creating an energy-saving version of Bluetooth 4.0 opens up exciting prospects for developers. For example, Swany G-CELL Gloves can connect with a mobile phone. They are equipped special buttons to answer or hang up calls, built-in microphone and speaker, so that the owner does not even have to take out the phone to talk. Now they are equipped with a Bluetooth 2.0 module and are able to work on a single charge for only 48 hours of talk time and 240 hours of standby time. Switching to Bluetooth 4.0 eliminates the need for constant battery recharging.

High Speed ​​Bluetooth

In 2009, the next Bluetooth 3.0+HS specification was adopted. HS (High Speed) is new level data transfer rate, which can reach 24 Mbps. To many experts, this parameter seemed unrealistic, however latest modules and are indeed faster than their Bluetooth 2.1 predecessors. Indeed, it looks implausible: if Intel releases new processors that outperform older models by a few percent, all computer magazines write about it as an incredible achievement. And when the Bluetooth SIG consortium creates a new specification for a wireless standard that speeds up data transfer by 10 times (!), the event remains out of sight of most users, as if it does not concern them at all.

The fact is that such a high speed is not possible at all when transferring data via Bluetooth: it still has a maximum speed limited to 2.1 Mbps, as was the case with the use of EDR technology. To switch to 24 Mbps, a direct Wi-Fi connection is used. The Bluetooth protocol in this case is used not at the physical, but only at the logical level: to organize the connection itself between devices. Wi-Fi acts as a radio transport protocol, while the Bluetooth interface itself remains only as a framework for linking devices.

However, the use of Wi-Fi technology for data transmission does not mean that a Bluetooth device is compatible with conventional Wi-Fi networks. It's about only about using the same physical model transmission according to the IEEE 802.11 standard - there was no logical compatibility with 802.11a / b / g / n networks for phones and smartphones with Bluetooth, and there is not.

perpetual motion machine

Of course, Bluetooth 3.0 + HS can be considered a real technological breakthrough, but, like any great achievement, it has flip side. Working at such a high speed quickly drains the battery, so the creators of the new standard immediately ran into the problem of energy saving. To solve this problem, the latest Bluetooth 4.0 specification was released in December 2009, which can also be considered an extraordinary event: if we turn to history, we will see that earlier, as a rule, 4 to 5 years passed between releases of Bluetooth versions. In Bluetooth 4.0, there are no fundamental changes regarding the data transfer rate, innovations concern only power consumption. This standard is intended to be used primarily in various sensors that can be used in simulators, medical devices, and automobiles. The Bluetooth transmitter is turned on only for the time of sending data, which ensures that the module can operate from one watch battery for several years! In this mode, the standard provides a data transfer rate of 1 Mbps with a packet size of 8–27 bytes. The connection is much faster: two Bluetooth devices can establish a connection in less than 5 milliseconds and maintain a distance of up to 100 m. For this, advanced error correction is used, and 128-bit AES encryption provides the required level of security.

Bluetooth profiles

Each Bluetooth device supports a certain set of so-called profiles - they are standardized data exchange algorithms. Support for certain profiles makes it easy to determine the capabilities of the device. This feature requires the profile to be supported by both Bluetooth devices.

For better sound transmission, A2DP (Advanced Audio Distribution Profile)– extended audio distribution profile. It is responsible for transmitting stereo sound over a Bluetooth radio channel to any receiving device. The profile distinguishes between two types of devices: a transmitter (A2DP-SRC - Advanced Audio Distribution Source), such as a telephone; receiver (A2DP-SNK - Advanced Audio Distribution Sink), such as headphones. When establishing communication, the transmitter and receiver agree on the codec to be applied and the encoding parameters: bit rate, sampling rate, etc. The standard defines one mandatory SBC codec - it does not require a large computing power for encoding and decoding, but has poor sound quality. SBC is selected if the receiver and transmitter cannot "agree" on the use of other codecs: MP3, AAC, ATRAC.

Typically, devices that work with A2DP also support the profile AVRCP (Audio/Video Remote Control Profile). It is intended for remote control source and in version AVRCP 1.0 allows you to start or stop playback, rewind and skip between tracks. In version 1.3 of the AVRCP profile, the protocol conveys the current state of the source and metadata about the media element itself, such as the title of the song. In version AVRCP 1.4, it became possible to view playlists and select a song.

HID (Human Interface Device Profile) provides support for input devices: mice, joysticks, keyboards. There is also quite a large number of and other Bluetooth profiles - their total number reaches 28 (data at the time of this writing).

Bluetooth stacks

In addition to the profile, Bluetooth has such a thing as a stack. For ease of understanding, you can think of it as software that controls a hardware module, that is, a set of device drivers. Each of these drivers is responsible for implementing a specific profile. For the user, the difference in the availability of a particular Bluetooth stack on a computer lies in the support for a certain set of profiles and in various GUI to work with them.

Widcomm

Widcomm was the first Bluetooth stack for Windows operating systems. Following the acquisition of Widcomm by Broadcom, it was renamed the Broadcom stack accordingly. Currently, this stack is not widespread and only works with devices whose manufacturers have purchased a license from Broadcom. It supports profiles that are rare, but necessary for some users - HCRP, BPP and BIP. And besides, it has a friendly interface that fits perfectly into the standard Windows interface.

Microsoft

On Windows, starting with exit Windows XP SP2, got its own Bluetooth stack. It has been updated in Windows Vista to include support for pre-OS HID devices, A2DP and AVRCP profiles. Additional profiles like FTP, BIP, BPP have become available as plug-ins released by third parties. Provided Bluetooth support 2.0+EDR, and the Vista Feature Pack also includes Bluetooth 2.1+EDR, which is also supported in the standard Windows 7 stack.

Blue Soleil

Among the alternative stacks, BlueSoleil, proposed by IVT Corporation, is the most common. Disadvantage of BlueSoleil - incorrect work with Bluetooth modules various manufacturers. By periodically accessing its server, the stack may suddenly find out that the hardware address of the device is not licensed, after which it will go into reduced functionality mode, in which only 5 MB of data can be transferred. Subsequently, you will need reactivation the BlueSoleil stack.

Behind Lately the number of users of mobile gadgets has increased significantly, which means that a large number of different technical issues remain dark horses for novice users. One of these nuances is the Bluetooth version.

Despite the fact that the compatibility of bluetooth versions is at a fairly high level, there are still situations in which it becomes impossible to pair two devices. And the point here is precisely in the protocols, and not in the profiles. And in order to justify the aforementioned impossibility, you first need to figure out what is the difference between these two concepts.

A protocol is a set of instructions through which various information is transmitted. He is the one who sets the order. operating frequency and the duration of the work of a particular component. And profiles are called additional add-ons that allow you to operate with information of a certain type. For example, A2DP is a profile that allows a bluetooth module to work with stereo sound, where, when paired, the codecs that will be used are also negotiated.

If you look at the global plan, then the version of the protocols is more important than the significance of the profile. If both devices have the same protocol version, then they will have access to all standard functions and features that the module supports. But with profiles, things are different. Since they are added optionally, in order for them to be used and work, they will need to be present in both gadgets. If only one bluetooth module supports the required profile, it will not be involved in data transfer.

Many users are interested in the question of how to find out the bluetooth version. There are several ways to do this, but the easiest is to read the device specification. But it is much more important to understand what is hidden behind these figures.

How to check Bluetooth version: Video

Technical data of various protocols

This description will not contain the most complete list of protocol versions, but only the most significant for the entire technology as a whole. And, of course, it’s worth starting with the very first one, which was created without a couple of years almost two decades ago - in 1998, by the SIG partner group or the Special Interested Group. The primary development was established by the then Swedish company Ericsson 4 years before entering the market. As a result of successful research, a worthy analogue of wired technologies was created and named after the Danish king of the northern Vikings, Harald the First Blue-toothed.

The first version had simply stunning compatibility between devices from different manufacturers. The speed was tiny, and the range clearly did not meet the established standard. If it were not for prompt attempts to refine the technology, the whole idea could have sunk into oblivion. And the professional qualities of the workers did not disappoint, because soon version 1.1 came out first, and then 1.2, which became the pinnacle of the evolution of the first generation modules. The overall compatibility was raised to a fairly high level, the range was set to an honest ten meters, the transfer speed was simply sky-high - 721 Kbps, of course, theoretically.

Version 2.1

The second generation made a revolution, but it was version 2.1 that became the guiding star that is still used today. A lot of devices of the primary and middle class use this particular variation of the bluetooth module. The main emphasis was placed on speed, and the EDR add-on became the solution. It was thanks to her that it became possible to transmit at speeds close to 3 Mbps, and the level of energy consumption was reduced by five times. Of course, various profiles and add-ons have appeared, up to the ability to distribute network access.

Third version

The high-speed 3.0 specification had much in common with Wi-Fi, but did not have direct compatibility with it, and the use of SLI technology, by which two bluetooth modules were connected into one system, made it possible to increase the transfer rate to 24 Mbps. And when moving large files a more high-speed, but also energy-consuming protocol was used, and for small files it was very economical.

Hardly any technology has predicted demise more often than Bluetooth. That being said, it's impossible not to recognize the idea of ​​wireless as a success: Bluetooth 1.0 has been on the market for over 15 years, and Bluetooth has never been used in as many devices as it is now. All thanks to version Bluetooth 4.0, which now, however, seems rather slow.

Upgrade to 4.1

One billion Bluetooth devices are sold every year. But there are still few gadgets with Bluetooth 4.1. On the this moment announced smart bracelet Huawei Talk Band B1. Many modern chipsets, such as in the OnePlus smartphone, will also be upgraded to 4.1.

Comes to replace Bluetooth Low Energy(or Bluetooth Smart) - a version that saves battery power. In this case, the range is limited to 10 m, and the data transfer rate is 1 Mbps, but no more than 10 mA is consumed during transmission.

And now comes the next step: the Bluetooth Special Interest Group, which includes more than 8,000 companies, is preparing a version specification. Of course, you should not expect any revolutionary changes, but users mobile devices expect some important innovations. CHIP decided to find out some technical points.

Most of the innovations in Bluetooth 4.1 relate to interference protection. Bluetooth is now a standard component of smartphones and tablets; soon, LTE modules will also be introduced into these devices.

Unfortunately, Bluetooth uses the unlicensed 2.45 GHz frequency band (along with 2.6 GHz) as well as the LTE band in Russia and other countries. This can lead to mutual interference (see diagram). The problem is that the user cannot influence the LTE signal in any way.

Certain actions were required from Bluetooth developers to avoid interference. And that's exactly what was done in the new version.

To minimize interference, Bluetooth 4.1 will incorporate an LTE range filter. If an LTE transmitter interferes with data transmitted over Bluetooth, Bluetooth 4.1 will immediately respond to this

Sending and receiving data by the LTE module interferes Bluetooth operation. In version 4.0, losses reached 75% of packets. Bluetooth version 4.1 is not as sensitive to interference from LTE. The noise filter protects the radio module. In difficult cases, the channel switches automatically.

The so-called Bluetooth 4.1 adaptive switching system will look for another channel where there is less interference, transmitting and receiving data on a different frequency. If for Bluetooth 4.0 LTE interferes in 75% of cases, with Bluetooth 4.1 this figure drops to 25%.

Receiving and transmitting data without interference

Bluetooth Low Energy devices are especially popular these days. Especially for this power saving mode, version 4.1 has a new data transfer method that extends battery life.

Hard-core Bluetooth users are aware of the problem of disconnected connections. It often happened that if the user went to another room, the connection was interrupted. After that, I had to configure the connection manually.

Fewer disconnects with new Bluetooth

If two Bluetooth devices move out of range, the connection will be interrupted. With Bluetooth 4.0, devices must be back in range within 30 seconds to automatically connect. In version 4.1, this time is increased to three minutes.

With Bluetooth 4.1, manufacturers can set fixed intervals so that the user does not have to set up a new connection every time after disconnecting. Bluetooth 4.1 can work with an interrupted connection for up to three minutes - previously this figure was no more than 30 seconds.

The fact that you don't have to be connected to a computer to use Bluetooth demonstrates an innovation designed specifically for 3D glasses that work in conjunction with a TV. As a rule, this required connection with several devices at once, so the image on TVs often lagged behind. Now everything should work better.

Contactless Slave Broadcast in Bluetooth 4.1 is the second new feature that fans of 3D cinema will benefit from. The Bluetooth connection is only in one direction, the TV sends data at fixed intervals, the 3D glasses receive data but do not send any return connections to the TV.

Flexible connections with Bluetooth 4.1

The architecture of Bluetooth 4.1 connections functions in accordance with the Master-Slave principle. One device acts as a master (Master), and the second - as a slave (Slave). All devices can work both as masters and as slaves.

Thus, data from a fitness bracelet or heart rate monitor can now be transferred directly to a smartphone, which will then analyze it. Previously, direct interaction between a fitness bracelet and a smartphone was impossible.

Two Benefits bluetooth updates A: First, no need to worry about compatibility. Bluetooth 4.0 and Bluetooth 4.1 are absolutely compatible. A new chip for Bluetooth 4.1 is also not needed. Bluetooth 4.1 will be available through a Bluetooth 4.0 firmware update.

Experts also predict that Bluetooth 4.1 will support IPv6. Now this is not. Since the new version of Bluetooth fully supports IPv6, all Bluetooth devices will be assigned an IP address and will be able to access them over the Internet. So we can say that the Bluetooth revolution has already begun.

Bluetooth in comparison

Bluetooth has been around for 15 years, with new versions released every two years. Version 4.0 introduces a low power profile. Since the predecessors do not have it, protocols 4.0 and 4.1 are not backward compatible. In 4.1, it is planned to work on the IPv6 protocol.

		Bluetooth 4.0	Bluetooth 3.0	Bluetooth 2.x	Bluetooth 1.x
base speed	1 Mbps	1 Mbps	1 Mbps	1 Mbps	1 Mbps
Enhanced Data Rate (EDR)	3 Mbps	3 Mbps	3 Mbps	3 Mbps	No
high speed	54 Mbps	54 Mbps	54 Mbps	No	No
Range (max/min power)	100m/10m	100m/10m	100 m / no	100 m / no	100 m / no
Low Power Mode	Yes	Yes	No	No	No
Dual profile (simultaneous role as Slave and Master)	Yes	No	No	No	No
IPv6 support	getting ready	No	No	No	No
Pairing with NFC	Yes	Yes	Yes	Yes	No
128-bit AES encryption	Yes	Yes	No	No	No

Photos in the article: manufacturing companies

The need to install a bluetooth adapter for a computer arises when you need to quickly move information between different devices. For example, between a stationary PC and.

Content:

The principle of operation and setting up the bluetooth adapter for PC

The appearance of most adapters designed to connect to a computer or laptop (which also rarely supports bluetooth) resembles a small one. Some are even smaller.

And to boost the signal on these devices, a small antenna can be installed that adds 2-5 dBi. Built-in bluetooth adapters are boards that connect inside a PC (usually to a PCI slot) and sometimes provide a wireless connection using technology as well.

Rice. 2. Manual installation drivers for an adapter that is not automatically detected.

BlueTooth technology is based on radio communication and allows you to connect two devices to each other almost imperceptibly to the user. The advantages of using an adapter are:

The disadvantages of the device include a relatively small, compared with a wireless Wi-Fi connection, speed. In addition, most models transmit data over a short distance. Although when buying an adapter with an amplifier, you can increase the distance to several tens of meters - the result is impressive even for.

Device classification

Bluetooth adapters are primarily classified according to their range of action:

• old models, class 4, are able to connect two devices, the distance between which does not exceed 2-5 meters;
• devices of the 3rd class provide connections at a distance of 5 to 10 m;

Rice. 3. Standard Class 2 Bluetooth modules with a distance of up to 10m.

• The 2nd class of adapters allows you to connect if the distance between the computer and another gadget does not exceed 50 m;
• the first class, which is equipped with printers, modems and base stations, makes it possible to transfer data within a radius of 100 m from the adapter.

Using antennas that amplify the signal increases the distance. At the same time, devices of the same class provide a connection in different ways. various conditions. Since both the range and the stability of the connection depend not only on the characteristics of the adapter, but also on the configuration of the premises, and on the material of the enclosing structures.

Bluetooth adapter features

You can use Bluetooth USB adapters in the following situations:

• to transfer information from a mobile device to a computer or vice versa. This is especially useful if there are no devices to connect and if it is impossible to use Wi-Fi for this (a technology that is not supported on older phones);
• for wireless connection of two computers within the range of the bluetooth adapter;
• for connecting to a computer, digital camera, and other devices.

In most cases, the use Bluetooth technology instead of Wi-Fi or cable, increases the distance that connected devices can be. For example, you can connect two computers in this way, even if they are in neighboring rooms and even apartments.

And if you need to transfer data from an old model mobile phone (with a special connection cord format, like models or Sony Ericsson), this method may be the only available option. The only alternative is to buy a special cord, the cost is higher than that of an adapter.

Rice. 4. Cable for connecting Sony Ericsson phones with PC.

• check for the presence of the corresponding character on the keyboard;

Rice. 5. Keys that allow you to turn on the bluetooth module on your laptop.

• Open Device Manager and check for the presence of the module. The same option is also suitable for a stationary personal computer, although usually their owners are already aware of established boards and adapters.

After confirming the need to purchase a device, they proceed to its choice, focusing on three main parameters. The first is the protocol supported by the adapter. The second is the range of the device. And, finally, the third - the price, due to the class, and the manufacturer, and protection from external influences.

Device protocol selection

The presence of several generations of bluetooth adapters on sale complicates the choice of a suitable model. Moreover, according to the information on the pages of online stores, it is difficult to figure out which device can be considered new and which is already outdated.

Rice. 6. One of the outdated adapter models that can still be found on sale.

It is worth noting that the data transfer rate, connection stability, and price depend on the adapter protocol. The latest versions, 4.1 and higher, not only allow you to connect any device without connection problems, but also provide stable data transfer without interruptions and failures, and even consume less power.

In addition, when you leave the range of the adapter and return to it, the connection is restored automatically. And modern devices can support the connection of several gadgets at the same time.

Range selection

When choosing an adapter, one of the main factors is its range. Given that the increase in range is proportional to the increase in the price of the device, it is not necessary to buy a first-class model, the cost of which is noticeably higher. Especially when it comes to use at home, where the distance between devices rarely exceeds 10 meters.

For a home and a small office, class 2 or 3 adapters are suitable, as a rule, they do not have an antenna, and are in the price range up to 200-300 rubles. For premises big size it is advisable to choose models of the 1st class that support protocol 4.0 and 4.1 - in addition to a range of more than 50 meters, they will also provide a speed of at least 3 Mbps. Their cost can reach 1000 rubles.

Modifications of adapters with built-in antennas are even more expensive. Most often, they provide two types of wireless communication at the same time - both Bluetooth and Wi-Fi. Their cost can exceed 2000 rubles, but the functionality is much higher. With the help of such equipment, information will be guaranteed to be transferred to any device - to a laptop, and to a smartphone, and to another computer with a built-in adapter and supporting wireless technology.

Rice. 7. Bluetooth adapters with signal amplifying antenna.

Other Features of Choice

In addition to the range and protocol of the BlueTooth adapter, when choosing, pay attention to such characteristics as:

• type of connection to the computer;
• equipment manufacturer;
• functionality;
• strength;
• price.

The price range is important for those users for whom the speed of information transfer and range does not matter. To connect devices located in the same room, any device is enough, even with protocol 1.2 or 2.0. With the constant transfer of large files and a distance exceeding 10–15 meters, it is advisable not to save money, but to purchase an adapter that supports the technology Bluetooth transmission 4.0 or 4.1.

Durability matters if the device is constantly carried and installed on different computers or laptops. For the same situations, you need to purchase a gadget that connects to a USB port. If the instrument is intended to be used on only one computer, an in-board model can be selected. Moreover, such adapters can provide more and.

Popular manufacturers of bluetooth adapters are 3Com, 4World, Tracer, Broadcom, Atheros and GSM-Support. And among the brands, the range of which is presented budget models, it is worth noting the brands Trust and StLab.

The compatibility of adapters may also depend on the manufacturer - for example, devices from 3Com are equipped with their own drivers, which are not always detected automatically. Although most models from other companies do not even require tuning.

We choose a bluetooth adapter for the convenience of sharing your PC and digital devices. The functionality of the bluetooth adapter and its range.

Usb bluetooth adapter is a special device that supports the Bluetooth protocol, which allows you to connect your computer, which previously did not support this option, with any device with the appropriate settings to make it discoverable.

This device was designed to allow computers to connect wirelessly to each other, but has now become more affordable and versatile due to the reduction in size.

Therefore, it can now be used to connect a computer with any device that supports such an innovation.

At present bluetooth time available in phones, laptops, printers and even cameras. All this can receive and transmit information at a small distance from the computer.

Provided, if you, nevertheless, wanted to buy such an adapter, the only thing you need to decide is at what distance you want to make this connection.

Now these devices are capable of making a high-quality connection within a distance of 10-100 m. This directly depends on the power of the transmitter that is included in the adapter's equipment.

It is also possible to modify adapters with external antenna and other devices that allow you to increase the reception range of a stable signal. The Bluetooth adapter is connected directly to USB port computer.

With the help of a Bluetooth adapter, it is possible to carry out a number of manipulations with a cell phone - you can exchange data between your phone and a computer, make records available phone book, as well as send and receive SMS.

The Bluetooth adapter is different in that it allows you to transfer data from much more speed than data cables and IrDA. Most modern phones are equipped with Bluetooth. Therefore, you only need to set Bluetooth system adapter and configure the connection.

With the help of a Bluetooth adapter, your phone will be able to function as a modem. Moreover, the transfer of information will be carried out via the GPRS protocol. The range of Bluetooth adapters is able to fluctuate in the range of 10-150 m.

Models with a large reception radius are slightly more expensive. Bluetooth adapters are able to guarantee reception even when there are obstacles between the connecting devices.

It should be noted that Bluetooth adapters are used not only to connect a computer and a digital device, but also to establish a connection between a pair of computers. This connection makes it possible to exchange information and participate in many online games.

Given the decreasing cost of Bluetooth adapters, they are turning into the most attractive accessories for organizing a wireless connection.

Even more technologically advanced, perhaps, only the Wi-Fi protocol.

Reading descriptions of the characteristics of mobile phones, smartphones, tablets and other gadgets, we are constantly faced with different numbers Bluetooth versions - 2.1 + EDR, 3.0, 4.0. How are these protocols different, and do we need the latest version of Bluetooth? For starters, Bluetooth is a protocol for exchanging data over short distances. If we compare it with Wi-Fi, then its speed is lower, and the range is noticeably shorter, but there are pluses - lower power consumption and faster “pairing” of devices.

Let's move on to version numbers. The first version (1.0) of this protocol was born back in 1998, and at the moment it is so outdated that none of the modern devices use this version anymore.

The next version numbered 1.2 may still be found in some of today's devices. For example, some cheap Chinese headsets can still work with this version of the protocol. The exchange rate of the Bluetooth 1.2 protocol can reach 721 Kbps, there is already the possibility of quick pairing and there is support for the anonymity of devices on the network. With Bluetooth 1.2, many types of data can be transmitted, such as speech, files, service information, and so on.

A major change in the Bluetooth protocol was the emergence of EDR technology - Enhanced Data Rate (improved data transfer rate). Thanks to this technology, the exchange speed has increased to 3 Mbps (theoretically, but in practice the speed is about 1.5-2 Mbps). EDR technology is present in two versions of Bluetooth - 2.0 and 2.1. The difference between these versions is in various energy saving technologies. In version 2.1, an energy-saving technology (Sniff Subrating) was added, which reduced power consumption by several times. In addition, the security and speed of device identification has been improved, as well as the ability to update the encryption key without breaking the connection. Bluetooth 2.1 is the most widely used version of the standard. This version of the protocol is compatible with most devices on modern market – regular phones, navigators, media centers, wireless mice, headsets and other similar devices usually work with version 2.1 + EDR. So if you are currently watching a diploma on the site http://zachteno.ru/ and at the same time using a wireless Bluetooth mouse, then it most likely uses protocol version 2.1 + EDR.

In 2009 appeared new standard Bluetooth 3.0 in which there is high-speed (HS, High Speed) data transfer at speeds up to 24 Mbps. In practice, devices with Bluetooth 3.0 + HS have two modules on board at once - Bluetooth 2.1 + EDR (at a normal speed of up to 3 Mbps) and a module that transmits data using the 802.11 protocol (similar to Wi-Fi), which already provides high speed . At the same time, there is no direct compatibility with Wi-Fi, and the device requires a separate module to work with standard Wi-Fi networks.

In 2010, with the advent of the Bluetooth 4.0 protocol, the main drawback of HS technology, namely the relatively high power consumption, was eliminated. On the this moment all older smartphones support this particular version of the Bluetooth protocol. Most recent tablet models and many modern ultrabooks and laptops also have a Bluetooth 4.0 chip on board.

Thus, targeting a specific version of Bluetooth should only be in cases where any specific device can fully realize its functions only with a certain protocol. An example of such a device is some smart watch” that work in conjunction with a smartphone and display various information received from the smartphone on the screen. Otherwise, most peripherals support Bluetooth 2.1 + EDR and older versions of the protocol are not needed for such devices. If you need high-speed data transfer, then instead of supporting Bluetooth 3.0 or 4.0 on your devices, you might want to consider using Wi-Fi, since many modern models gadgets support Wi-Fi Direct in which the transfer speed is noticeably higher.

Hardly any technology has predicted demise more often than Bluetooth. That being said, it's impossible not to recognize the idea of ​​wireless as a success: Bluetooth 1.0 has been on the market for over 15 years, and Bluetooth has never been used in as many devices as it is now. All thanks to version Bluetooth 4.0, which now, however, seems rather slow.

Upgrade to 4.1

One billion Bluetooth devices are sold every year. But there are still few gadgets with Bluetooth 4.1. At the moment, the Huawei TalkBand B1 smart bracelet has been announced. Many modern chipsets, such as those in the OnePlus smartphone, will also be upgraded to 4.1.

Comes to replace Bluetooth Low Energy(or Bluetooth Smart) - a version that saves battery power. In this case, the range is limited to 10 m, and the data transfer rate is 1 Mbps, but no more than 10 mA is consumed during transmission.

And now comes the next step: the Bluetooth Special Interest Group, which includes more than 8,000 companies, is preparing a version specification. Of course, you should not expect any revolutionary changes, but mobile device users expect some important innovations. CHIP decided to find out some technical points.

Most of the innovations in Bluetooth 4.1 relate to interference protection. Bluetooth is now a standard component of smartphones and tablets; soon, LTE modules will also be introduced into these devices.

Unfortunately, Bluetooth uses the unlicensed 2.45 GHz frequency band (along with 2.6 GHz) as well as the LTE band in Russia and other countries. This can lead to mutual interference (see diagram). The problem is that the user cannot influence the LTE signal in any way.

Certain actions were required from Bluetooth developers to avoid interference. And that's exactly what was done in the new version.

To minimize interference, Bluetooth 4.1 will incorporate an LTE range filter. If an LTE transmitter interferes with data transmitted over Bluetooth, Bluetooth 4.1 will immediately respond to this

The sending and receiving of data by the LTE module interferes with Bluetooth operation. In version 4.0, losses reached 75% of packets. Bluetooth version 4.1 is not as sensitive to interference from LTE. The noise filter protects the radio module. In difficult cases, the channel switches automatically.

The so-called Bluetooth 4.1 adaptive switching system will look for another channel where there is less interference, transmitting and receiving data on a different frequency. If for Bluetooth 4.0 LTE interferes in 75% of cases, with Bluetooth 4.1 this figure drops to 25%.

Receiving and transmitting data without interference

Bluetooth Low Energy devices are especially popular these days. Especially for this power saving mode, version 4.1 has a new data transfer method that extends battery life.

Hard-core Bluetooth users are aware of the problem of disconnected connections. It often happened that if the user went to another room, the connection was interrupted. After that, I had to configure the connection manually.

Fewer disconnects with new Bluetooth

If two Bluetooth devices move out of range, the connection will be interrupted. With Bluetooth 4.0, devices must be back in range within 30 seconds to automatically connect. In version 4.1, this time is increased to three minutes.

With Bluetooth 4.1, manufacturers can set fixed intervals so that the user does not have to set up a new connection every time after disconnecting. Bluetooth 4.1 can work with an interrupted connection for up to three minutes - previously this figure was no more than 30 seconds.

The fact that you don't have to be connected to a computer to use Bluetooth demonstrates an innovation designed specifically for 3D glasses that work in conjunction with a TV. As a rule, this required connection with several devices at once, so the image on TVs often lagged behind. Now everything should work better.

Contactless Slave Broadcast in Bluetooth 4.1 is the second new feature that 3D fans will benefit from. The Bluetooth connection is only in one direction, the TV sends data at fixed intervals, the 3D glasses receive data but do not send any return connections to the TV.

Flexible connections with Bluetooth 4.1

The architecture of Bluetooth 4.1 connections functions in accordance with the Master-Slave principle. One device acts as a master (Master), and the second - as a slave (Slave). All devices can work both as masters and as slaves.

Thus, data from a fitness bracelet or heart rate monitor can now be transferred directly to a smartphone, which will then analyze it. Previously, direct interaction between a fitness bracelet and a smartphone was impossible.

Two advantages of Bluetooth upgrade: First, no need to worry about compatibility. Bluetooth 4.0 and Bluetooth 4.1 are absolutely compatible. A new chip for Bluetooth 4.1 is also not needed. Bluetooth 4.1 will be available through a Bluetooth 4.0 firmware update.

Experts also predict that Bluetooth 4.1 will support IPv6. Now this is not. Since the new version of Bluetooth fully supports IPv6, all Bluetooth devices will be assigned an IP address and will be able to access them over the Internet. So we can say that the Bluetooth revolution has already begun.

Bluetooth in comparison

Bluetooth has been around for 15 years, with new versions released every two years. Version 4.0 introduces a low power profile. Since the predecessors do not have it, protocols 4.0 and 4.1 are not backward compatible. In 4.1, it is planned to work on the IPv6 protocol.

		Bluetooth 4.0	Bluetooth 3.0	Bluetooth 2.x	Bluetooth 1.x
base speed	1 Mbps	1 Mbps	1 Mbps	1 Mbps	1 Mbps
Enhanced Data Rate (EDR)	3 Mbps	3 Mbps	3 Mbps	3 Mbps	No
high speed	54 Mbps	54 Mbps	54 Mbps	No	No
Range (max/min power)	100m/10m	100m/10m	100 m / no	100 m / no	100 m / no
Low Power Mode	Yes	Yes	No	No	No
Dual profile (simultaneous role as Slave and Master)	Yes	No	No	No	No
IPv6 support	getting ready	No	No	No	No
Pairing with NFC	Yes	Yes	Yes	Yes	No
128-bit AES encryption	Yes	Yes	No	No	No

Photos in the article: manufacturing companies

Every sound starts with a source. Today, there are many wireless protocols for transmitting sound. Some of them are much more interesting than Bluetooth, but have not yet received proper distribution. Today, almost all smartphones, laptops and tablets are equipped with Bluetooth, and equipping a device with its support with a USB output is a matter of five minutes.

Therefore, today we will limit ourselves to sound-reproducing devices using the “blue tooth” (the guide is quite suitable for choosing a Bluetooth speaker). This technology has quite long history and a lot of pitfalls, the existence of which is not always known to users.

The presence of a Bluetooth transmitter does not mean that the device can be used as a sound source for wireless audio equipment. Not every Bluetooth will allow you to listen to high-quality music without distortion. Not everyone is suitable for listening to files with a high bitrate and in lossless formats.

What to look for in order to listen to music wirelessly - whether it's just an MP3 or a high-quality rip from a vinyl record, we'll tell you in this article.

Let's start with the most important: this parameter directly indicates whether it is possible to listen to music using the device.

VersionBluetooth

IN modern devices most often you can find support for Bluetooth 3.0 or 4.0, in some top-end smartphones and other gadgets - 4.1. In this case, it may well turn out that the purchased headset supports connection only via protocol version 2.1. The adapters are backwards compatible, but the slowest protocol of the two works when connected.

Difference between protocol versions for regular user are minimal due to backward compatibility. The main thing that catches the eye is with each new version the power consumption of devices is reduced, and starting with 3.0, a second module has been added for high-speed data transfer at a speed of 24 Mbps.

Version 2.1 + EDR transmits data at a speed of no more than 2.1 Mbps. This is enough to play a low bitrate audio stream. It is recommended to use a Bluetooth version of at least 3.0 to play the audio video stream.

It must be taken into account that for full use device as a player, it is highly desirable to have Bluetooth version 4.0 and higher, or better - with reduced power consumption.

You can identify such an adapter thanks to the following categories.

ProfilesBluetooth

Profiles are a set of specific functions supported by devices. Of all those used in Bluetooth for listening to music, the following are interesting:

1. Headset Profile (HSP) required for headset-smartphone communication and wireless transmission of 64 kbps mono audio.
2. Hands Free Profile (HFP) also provides only mono transmission, but with higher quality.
3. Advanced Audio Distribution Profile (A2DP) necessary for the transmission of two-channel audio stream.
4. Audio/Video Remote Control Profile (AVRCP) provides control of the functions of playback devices (without it, even changing the volume of music is impossible).

A2DP is required for full listening to music. It not only ensures the transmission of the audio stream, but also manages the compression of the data before transmission.

However, even if both the transmitting and playback device (for example, a smartphone and wireless headphones) are equipped with Bluetooth 3.0 or 4.0 and support the required protocol, you need to pay attention to the codec that is used.

CodecsBluetooth

The most important thing for playing music using the A2DP protocol is the codec that compresses the audio stream transmitted to the headset. In total, there are currently three codecs:

1. Subband Coding (SBC)- codec used by default by A2DP and created by the profile developers. Unfortunately, SBC presses much rougher than MP3. And therefore, it is not suitable for listening to music.
2. Advanced Audio Coding (AAC)- a more advanced codec that uses other compression algorithms. Sounds much better than SBC.
3. AptX- here he is, right choice! At least because of the ability to transfer files to MP3 and AAC without additional manipulations and transcoding. This means no loss of sound. However, it is worth mentioning. There are several versions of aptX to play different bitrates. Each of them is designed for its own sound stream.

Version	Number of supported channels	Maximum sampling frequency, kHz	Quantization, bit	Maximum bitrate	Compression ratio
AptX	2	44,1	16	320 kbps	2:1
Enhanced AptX	2, 4, 5.1, 5.1+2	48	16, 20, 24	up to 1.28 Mbps	4:1
AptX Live	n/a	48	16, 20, 24	n/a	8:1
AptX Lossless	n/a	96	16, 20, 24	n/a	n/a
AptX Low Latency	n/a	48	16, 20, 24	n/a	n/a

»
The main features of the last two versions of the codec are the lowest possible delay in audio playback and reduced load on the processor when encoding. The Low Latency version allows you to achieve a delay of 32 ms between the source of the audio stream and the playback device. This will reduce the distortion introduced by the equipment when listening to music.

Thus, with certain preferences, you can choose a specific codec. If playback of a lossless stream is not expected, and a high audio delay is not critical, you should limit yourself to the standard aptX and not overpay for the device to support subsequent versions.

It is worth remembering that the required profile and codec must be supported by both the smartphone (or other audio stream source) and the headset itself (or Bluetooth speaker). Otherwise, the A2DP algorithm will automatically start using the SBC.

With Bluetooth, any two devices always work using the lowest version, simplest codec and protocol. So, if one of them does not support the necessary technology, you will not be able to fully enjoy the sound quality.

Listening to music for a long time requires support for Bluetooth version 3.0 or higher, aptX codec and A2DP profile. To listen to music at a high bitrate, support for the aptX Lossless codec is required - none of the others will do, since the music will be compressed when transferred to the playback device.

Data transfer technology short distances appeared back in 1994, when two engineers from Ericsson decided to do away with wires forever when exchanging data between mobile devices. This technology is called Bluetooth("Blue Tooth"). The technology got its name from Harold the First Blue-toothed, who was the king of Denmark and Norway, who became famous for uniting the Scandinavian tribes under his rule in the 10th century.

Communication standard description

Initially, the development was carried out at frequencies that are not subject to additional licensing. These are 79 channels operating at frequencies from 2402 MHz to 2480 MHz, which are specially allocated for the operation of medical and scientific equipment.

The exchange of information between the receiver and transmitters is carried out by constantly changing channels approximately 1600 times per second. Only the receiving and transmitting device knows which channel to switch to, the notification occurs through special identification keys. This method minimizes the possibility of interference and allows paired devices not to conflict with each other. bluetooth standard is one of the most secure ways to exchange information, because it is impossible to connect to a device without permission. The only problem with this type of communication is a very small range, but on the other hand, this also increases the level of security.

According to the power of radio transmitters, the standard is divided into three large groups or classes:

• Class 1 is used mainly in medical equipment, for which a transmitter with very little power is sufficient.
• Class 2 with medium power transmitters can be seen in modern mobile phones, tablets and other peripheral devices.
• Class 3 uses very powerful transmitters and finds its application in industrial plants, for example, to control individual machines or the entire production process as a whole.

Connection is possible not only between two devices. The number of simultaneously connected devices is limited to 71 devices, with one device acting as a master or master device, and all the others work as masters (slave). A device that works as a slave can, in turn, act as a master for those connected to it. So you can create a whole network called a piconet. No more than ten piconets can be combined at the same time.

Evolution of the standard

Since the introduction of the standard in 1994, the standard has been called Bluethooth 1.0. It was still a very raw product. It had a lot of security vulnerabilities due to the fact that it was necessary to transmit the device address in clear text. There were also difficulties with pairing devices from different manufacturers. bluetooth speed also left much to be desired. In version 1.1, it became possible to see the signal level and support for unencrypted channels was added.

Research was constantly going on, but the next bluetooth version 2.0 appeared only in 2007. has been significantly increased bluetooth speed, which reached almost 2.5 Mb / s, and in version 2.1 the power consumption parameters were significantly redesigned and reduced. Improved security and speed of device pairing.

In April 2007, it was presented bluetooth standard 3.0. together with the use of asynchronous multiprocessing technology, the data exchange rate was 24 Mb / s, but power consumption increased. The increase in power consumption did not give rest to developers, because for mobile devices this is a rather critical moment. After improvements at the end of the year, the general public was able to see Bluetooth 4 which is still in use today.

The main difference from previous versions this is a very low battery consumption. This is also achieved by the fact that the signal is not transmitted constantly, but only as needed, i.e. The transmitter is in a constant standby mode, and is activated only when necessary.

The connection between devices now occurs in 5 ms, and the distance between devices can now reach 100 meters within the line of sight. Degree of data encryption in bluetooth 4 happens on 128 bit algorithm. This standard has become the reference for connecting peripheral devices such as headphones, external speakers, smart watches and many others.

In various versions bluetooth baud rate next:

• 2 - up to 1 Mb/s;
• 0 - up to 3 Mb/s;
• 0 and v4.0 - up to 24 Mb/s.

Manufacturers are trying to design devices in such a way that they support various bluetooth version , for greater compatibility between devices.

Using bluetooth at home

Currently, the transfer of information using bluetooth is quite popular, and interest in the technology is constantly growing. There are many fields of activity where it has found its application:

• data exchange between two mobile phones;
• upload photos from a digital camera without using a wired connection;
• connecting a mouse, keyboard, printer, scanner and other peripherals to a computer or laptop;
• data synchronization between PC and mobile device;
• connecting a headset, smart watch and other devices to a mobile phone.

The imagination of developers about where you can use Bluetooth is limitless. New and new products supporting the work on this technology are constantly supplied to the market.