What is bluetooth and how to use it. What is a Bluetooth device? What is Bluetooth for. Bluetooth architecture diagram

For many, however, the most important transfer rates are important. Upcoming a new version   0 should be twice as fast as its predecessor. The latest version used in newest smartphones   and other mobile devices, was released almost two years ago.

So it's time to learn it in more detail. In the settings of the application, you choose Startup in the size of 2 megapixels, turn off your cell phone, press it more precisely, put it in your pocket and go to shooting. But the most important thing is that after a full-featured photo shoot you can barely recognize the battery both on the camera and on the mobile phone! The camera just needs a couple of times with the camera. No need to worry about having to repeat the pairing procedure each time you turn it on.

And one more functionality I really like. You can shoot without connecting to the “smart device”. Maybe you ask how long it will take? The camera is always "found" from the mobile, automatic download   the background image "does not require maintenance", and, most importantly, time battery life   hardly known. In practice, this can be used for different purposes and, accordingly, it can behave differently and be characterized by different properties.

The technology has many other applications that offer interesting features, although they are not well known. They are divided into layers, and this viewing angle is called the layer model. Imagine the composite layers of a dummy model, each of which contains its own protocols. Thus, the concrete profile can simply be represented as a broken vertical section through the layers of the model. Profiles define only those parts of the entire specification that are used for this service.

For end devices, profiles essentially determine what data and how it will be transmitted during communication. This basic profile is followed by another one that takes care of finding the services and functions that the device has recently found at its disposal. It allows two devices, usually telephones, to communicate directly with each other without any other network. As a rule, it is used to connect a computer and mobile phone to a dial-up Internet connection via a mobile phone.

The common object exchange profile, which is used to exchange common data objects between devices, is also widely used and important. There are three other profiles that many users use in practice. In addition to these base profiles, there are still thirteen new profiles, some of which are still under development. Let's take a closer look at other interesting profiles.

In other words, for example, a wireless mouse or keyboard with a computer or, mobile device. A typical use is, for example, the configuration of a remote mobile phone. This instruction is designed to adjust the volume, adjust the image, play or stop.

It is designed to connect the speakerphone to your phone. This profile is used for car calls, headphones, etc. Not everyone will want to use them, and not all of them are suitable for mobile phones, but it is good to know about these parameters. It is also important that phones and other devices that support only selected profiles do not make sense to talk about violations of the standard.

Bluetooth technology highlights

It depends on the manufacturer who decides to maintain the profiles. It remains the most widely used technology used for wireless data transmission over short distances. This article describes how this technology works. In this article, we will focus on the individual components of this technology and its future prospects. In the next article, we will look at our own communications and data security. The purpose of this group was to create a universal standard for the so-called wireless personal networks.

The name Blaatanda itself comes from the word "bla", which means "dark" in Czech and the word "tan", which in this case refers to the king or leader. The most important steps regarding the kernel standard are now available in advance as a technical specification. It was the first solid foundation for the first products sold - previous versions   suffered from a number of inaccuracies and errors. There are signs of compatibility, clear implementation of picot and unambiguous assignment of chapters or subordinate roles.

This announcement caused general surprise and is now being discussed live, especially in terms of the consequences of this decision for the future. In the list above, we did not note progress in application protocols. There are a number of them in this area. The structure of the protocol.

Instead of a complete and expensive implementation, manufacturers can integrate only the most important parts into the device. Necessity is only kernel protocols that should be part of each station. A common problem is the fact that this incomplete solution does not always guarantee the compatibility of the device.

The solution is called a service discovery protocol, one of the other mandatory protocols at this time. You can see the signals on the image. The physical layer is the frequency hopping method. Since there is a high probability of high channel distribution, it is the practice of the regulatory authority that uses a method in which a signal with a lower bandwidth is converted into a signal with a higher bandwidth.

Thus, work must be ensured with the highest number of mutually independent images with a higher spatial density. The method of calculating the frequency can be seen in the following two figures. The inputs for the kernel of choice in different modes of operation.

When choosing frequencies, of course, local rules and restrictions must be taken into account. This is not difficult because the world is essentially divided between two modes - the first mode of the 79-frequency jump is used in North America and Europe, the second mode with 32 frequency jumps is in Japan - previously used in France and Spain.

To support bidirectional traffic, a time-duplexed duplex method is used, in which the master can initiate transmission only at the beginning of an even-numbered lag and a slave device only at the beginning of an odd delay, as also shown in the following figure.

The choice of frequency of transitions during data transmission. The former are interpreted as positive deviations and zeros as negative deviations from the carrier frequency. The difference between these frequencies must be at least 115 kHz. Then the bandwidth and product time should be 0, 5, and the modulation index should be in the range from 0, 28 to 0.

Setting in the frequency jump method. One of the problems, however, is the common existence of several systems of the same protocol family, but not only this, perhaps more importantly, the question of the coexistence of systems with different protocol families. The issue of coexistence is the subject of numerous studies. The analyzes made by this group certainly deserve attention, but, unfortunately, the data are too general. The group, due to the pressure of industrial firms, could not develop more joint solutions, so it had to be limited only by analysis.

However, during the year, two aspects emerged that led to a change in status. However, it was only indicated that the Master could enter used or unused frequencies into the slave device. The corresponding implementation then remains on the basis that this decision will be made. In addition, the rule for frequency hops does not change, and the display functions are tuned to specific frequencies.

Bluetooth operation principle

Individual channels are selectively reduced by modifying the hop sequence. Channel maintenance is responsible for reassessing channel quality. These data also correspond to the results of modeling performed using other methods of frequency hopping.

At the data link layer level, basic network topologies, access mechanisms and addressing are described. In this way simple isochronous data streams are implemented, for example, in audio modules. If there is only a Master on the network, this is a picnic. In the case of a network in which the Master with one slave device is interconnected, and in the case of a point-to-point connection, the network is in the "Mono-slave" mode.

What is it for?

Any station can be configured as a slave on any picos and can operate in this mode. The same applies to a number of routing algorithms that were designed to manage large networks. In such levity, all communication is through the Master. Subsequent packets are transmitted at different frequencies. In normal mode, a frequency jump occurs at the beginning of each new delay. However, when transmitting packets that take from three to five such delays, the frequency does not change until the entire packet is transmitted.

Then the next packet is sent with a frequency that again matches the clock. These addresses serve both to uniquely identify the device when entering the network, and for the main device to calculate the transition sequence. Due to the small size of the address, it is also limited to seven devices that can connect to the network. The registration process takes some time only because the slave must be synchronized with the main jump.

Bluetooth Basics

The synchronization process consists of two stages. At the first stage, all available stations are viewed within the signal range and, of course, what are their addresses and clock statuses. The second stage is the contacting process and is used to establish the connection.