Cellular communication is currently developing in only one direction - improving the quality of communication and increasing the speed of data transfer. There is a continuous process of emergence of progressive standards and technologies in the world market. In accordance with this, new designations and names appear. And one of them is UMTS. What it is, you should figure it out.
Backstory
The global mobile market is currently the most profitable. Almost every citizen of any country takes part in it. But there is also fierce competition. Mobile communication technologies are constantly improving. Leading manufacturers are investing heavily in new developments of equipment and components for mobile communication systems. UMTS technology has become one such development.
3G mobile communication networks
It is based on packet data transmission. The emergence of such networks is associated with an increase in demand for high-speed technologies. Modern third generation networks are used in suchareas:
- video telephony;
- interactive data exchange in various multimedia formats;
- transmission of large amounts of information and images;
- working with intranets and the Internet;
- broadcast multimedia information in asymmetric mode.
Issues related to the standardization of 3G networks are currently being handled by the International Telecommunication Union. Now it is worth considering UMTS technology. What it is will become clear if you understand its creation and use.
Creation
UMTS technology was developed by the European Telecommunications Standards Institute specifically for European countries. Under this abbreviation is hidden the following: a universal mobile telecommunications system. WCDMA is used as the radio interface. And it should be noted that these two concepts are completely different, which does not allow their use as synonyms.
UMTS is often seen 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 development of mobile communications without any significant change in the equipment that exists at the moment. GSM MAP is used as the network backbone, and combined GSM/EDGE and WCDMA technologies serve as the radio access network. The latter are built on top of existing GSM networks, but work in parallel. Switching of the subscriber station between networks is carried out automaticallymode.
The essence of technology
In UMTS (what it is and how it works, it will be clear later) two different methods of broadcasting a radio signal have been combined. Terrestrial transmitters use UTRA interfaces. The 3GPP Release 4 specification introduced media gateways, a signaling gateway, and a switching center server. Thus, it was possible to separate the signaling information and user data in the MSC. In addition, this specification contains a detailed description of the universal base unit for radio access to the UMTS network. What's this? This mechanism allows you to achieve data transfer rates up to 2 megabits per second. There are now eleven 3GPP specifications.
UTRAN is designed to combine the base station and the radio network controller, and it is also responsible for the operation of all radio frequency modules and channels in UMTS. The RNC is a network controller that can be mounted directly on the base station equipment. The combination of these two elements, namely the base station and the controller corresponding to it, in the structural model of the UMTS network is called the network subsystem. Several such subsystems can be used in one base unit.
Opportunities for work
3G UMTS allows you to use equipment from different manufacturers, as it uses the lu interface. The use of luR provides an opportunity to implement soft handover of a subscriber between multiple stations, which may use different equipment. cellularaccording to the UMTS standard, it is protected from disconnections in motion, because soft handover is used here. For example, when a car moves along a highway with evenly installed base stations, when moving away from one of them, communication with the client is transferred to the one closest to it. The connection is not interrupted by a jump, as happens in GSM networks. UMTS in this regard works much friendlier in relation to the subscriber. Of course, this is only relevant for areas with good network coverage. The lub interface has been designed to be fully open specifically to attract investment from OEMs in the field.
Network Equipment
The core network units consist of traditional equipment, among which we can distinguish:
- transcoder;
- business register;
- address register;
- GPRS support unit;
- gateway to other networks;
- mobile switching center;
- base station controller.
The latter takes on the tasks of allocating the channel resource, switching channels, organizing relay transmission, collecting and transmitting telemetry to the control subsystem. The transcoder is tasked with encoding and decoding speech signals transmitted using compression. The address register contains a database of all subscribers of the cellular network of a given operator. The guest register contains information about subscribers who are in the coverage area of the network.
How UMTS works
What is it, it has already become clear from the previous description, but how such a network works is worth understanding. In the CN block, the most important operations are performed, which come down to connecting a mobile station to the network, its further paging, cellular selection and localization of the subscriber, making incoming and outgoing calls, handover of the subscriber between base stations. CN is divided logically into two domains - CS and PS. The base station is responsible for radio signal processing, channel coding and rate adaptation, and much more. In addition, it controls the power in the inner loop. Cellular UMTS communication can implement connection with various external networks, which are conditionally divided into two groups: circuit-switched and packet-switched. The first option is for telephone communication, and the second option 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 circuit switching, and it is also responsible for connection management. The switching center performs the procedures required for handover and location registration.
Additional Features
New generation networks are characterized by the presence of a QoS function with a set of priorities: streaming, conversational, background and interactive. As already mentioned, UMTS is used in the transition to 3G networks. What it is has been described in sufficient detail. It is important to note that the final implementation of such a transition requires the replacementboth subscriber terminals and base station subsystems. In addition, much of the equipment currently used at the core level needs to be replaced. The network architecture is significantly different in that the switch is divided into two independent levels - switching and signaling processing with service control. All this is evidence that for the subsequent transition to new generation networks, it will be necessary to upgrade the subsystems of base stations and subscriber terminals. The new UMTS bands and the realization of all these goals will require the creation of electronic components and attracting huge investments.
How does it work?
At the moment, several standards can be attributed to 3G, CDMA2000 and UMTS are the most widely used in the world. Both technologies are based on Code Distribution Multiple Access. With the help of them, it is possible to expand the narrow bands of signals in conventional cellular networks. Naturally, such an extension is intended to provide wireless broadband access to the Internet.
The scheme of operation of such networks is very simple: the subscriber device communicates with the station of the cellular operator, if it supports such a standard and is closest. Cellular communication in this case operates at 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 the subscriber leaves the radius of one station, he falls into the radiusactions of another, while there is no loss of communication. The most common UMTS frequency is 2100 megahertz.
To work with such networks, special subscriber equipment is required, that is, smartphones that support 3G, USB modems, communicators, tablets and portable computers 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 rather large traffic quota, but it is usually difficult to use it up in a month.
