UMTS - what is it? UMTS technology. cellular

Cellular communication is currently developing only in one direction - improving the quality of communication and increasing the speed of data transmission. On the world market there is a continuous process of the appearance of progressive standards and technologies. In accordance with this, new designations and names appear. And one of them is UMTS. What is it, it is necessary to understand.

Prehistory

The global mobile market is currently the most profitable. Almost every citizen of any country takes part in it. But there is also a tough competition. There is a continuous improvement in mobile communication technologies. Leading manufacturers invest huge amounts in new development of equipment and components for mobile communication systems. UMTS technology has become one of such developments.

3G mobile networks

It is based on packet data transfer. The emergence of such networks is associated with an increase in demand for high-speed technology. Modern third generation networks are used in such areas:

• Videotelephone communication;
• Interactive data exchange in various multimedia formats;
• Transfer of large amounts of information and images;
• Work with intranets and the Internet;
• Broadcast multimedia information in asymmetric mode.

The issues related to the standardization of 3G networks are currently being addressed by the International Telecommunication Union. Now we should consider UMTS technology. What this, it becomes clear, if you understand its creation and use.

Creature

UMTS technology was developed by the European Institute for Standardization in the field of telecommunications specifically for European countries. Under this reduction, the following is concealed: a universal mobile telecommunications system. As a radio interface, WCDMA is used here. And it should be noted that these two concepts are completely different, which does not allow their use as synonyms.

The UMTS standard is often considered as a transitional option between 2G and 3G-4G technologies. That is, with the help of it, it is possible to make an easier transition to a new level of mobile communication development without any significant change in the equipment that exists at the moment. As a network backbone, GSM MAP is used here, and the combined radio technology is GSM / EDGE and WCDMA. The latter are built on existing GSM networks, but work in parallel. Switching the subscriber station between networks is carried out automatically.

The essence of technology

In UMTS (what this is and how it works, it will be clear below), two different methods of broadcasting the radio signal have merged. Ground transmitters use UTRA interfaces. Due to the 3GPP Releace 4 specification, there are media gateways, an alarm gateway and a switching center server. So it was possible to divide into MSC signaling information and user data. In addition, this specification contains a detailed description of the universal radio access base unit to the UMTS network. What is it? This mechanism allows you to achieve a data transfer rate of up to 2 megabits per second. Now there are eleven specifications of 3GPP.

UTRAN is designed to combine the base station and the radio network controller, and it is responsible for the operation of all radio frequency modules and channels in UMTS. RNC is a network controller that can be mounted directly in the equipment of the base station. The combination of these two elements, namely the base station and the controller corresponding to it, is called the network subsystem in the structural model of the UMTS network. Several similar subsystems can be used in one base unit.

Opportunities for work

3G UMTS allows the use of equipment from different manufacturers, since here the interface lu is used. The use of luR provides an opportunity to implement soft handover of the subscriber between several stations on which different equipment can be used. Cellular communication according to the UMTS standard is protected from interruptions of communication in motion, because it uses a soft handover. For example, when a car moves along a route with evenly installed base stations, when it is removed from one of them, communication with the client is transferred to the nearest to it. The connection is not interrupted abruptly, as happens in GSM networks. UMTS in this plan works much friendlier to the subscriber. Of course, this is only relevant for areas that are well-covered by the network. The lub interface was developed completely open especially to attract investment of equipment manufacturers in this field.

Network equipment

The blocks of the backbone network consist of traditional equipment, among which one can distinguish:

• Transcoder;
• Business register;
• Address register;
• GPRS support unit;
• Gateway for switching to other networks;
• A switching center for mobile communications;
• Base station controller.

The latter takes on the tasks of allocating the channel resource, switching channels, organizing the relay, collecting and transmitting telemetry to the control subsystem. The transcoder is tasked with encoding and decoding speech signals transmitted using compression. The address register provides a database of all subscribers of the cellular network of this operator. The guest register contains information about subscribers who are in the coverage area of the network.

Principle of UMTS operation

What is it, it became clear from the previous description, but how does such a network work, it is worth investigating. In the CN block, the most important operations are performed, which are reduced to the connection of the mobile station to the network, its further paging, cellular selection and localization of the subscriber, the implementation of incoming and outgoing calls, and relaying the subscriber between the base stations. CN is divided logically into two domains - CS and PS. The base station is responsible for processing radio signals, channel coding and speed adaptation, and much more. In addition, it controls the power in the internal circuit. Cellular UMTS can realize connection with various external networks, which are conditionally divided into two groups: with circuit switching and with packet switching. The first option is for telephone communication, and the second one is for connecting to the Internet. Since the switching center coordinates its work with fixed networks, it is entrusted with all the functions that are required for switching channels, and it is also responsible for managing the connection. The switching center performs the procedures that are required for handover and location registration.

additional characteristics

New generation networks are characterized by the presence of QoS function with a set of priorities: streaming, conversational, background and interactive. As already mentioned, when switching to 3G networks UMTS is used. That this was described in sufficient detail. It is important to note that the final implementation of such a transition requires replacement of both subscriber terminals and subsystems of base stations. In addition, it is required to replace most of the equipment used at the level of the core networks at the moment. The architecture of the network is significantly different from the presence of the switch division into two independent levels - switching and signaling processing with service control. This is all evidence that for the subsequent transition to next-generation networks, it will be necessary to upgrade the subsystems of base stations and subscriber terminals. New UMTS bands and the realization of all these goals will require the creation of electronic components and attracting huge investments.

How it works?

At the moment, several standards can be attributed to 3G, CDMA2000 and UMTS are the most widely distributed in the world. Both technologies are based on multiple access with code allocation of signals. With their help, it is possible to expand narrow signal bands in conventional cellular networks. Naturally, such an extension is designed to provide wireless broadband access to the Internet.

The scheme of operation of such networks is very simple: the subscriber unit communicates with the station of the cellular operator, if it supports such a standard and is closest. Cellular communication in this case operates on a much larger radius than Wi-Fi, so subscribers are not so much limited in space, using wireless Internet. UMTS bands allow you to comfortably use all the services provided. If a subscriber leaves the radius of one station, it falls into the range of the other, without loss of communication. Most often the frequency of UMTS is 2100 megahertz.

To work with such networks, you need special subscriber equipment, that is, smartphones that support 3G, USB modems, communicators, tablets and laptops equipped with built-in modules.

Payment for 3G is most often carried out in one of two ways: payment by traffic or subscription. In the second case, the subscriber has access to the Internet for a certain time, usually for a month. There are conditionally unlimited tariff plans that have a fairly large traffic quota, but it is usually difficult to spend a month.