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Plugin modul 1-e

  1. 1. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 1 of 12 1 Introduction
  2. 2. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 2 of 12 1.1 UMTS - The New Standard...........................................................3 1.2 Current Trends (1/3) .....................................................................4 1.2 Current Trends (2/3) .....................................................................5 1.2 Current Trends (3/3) .....................................................................6 1.3 Demands on UMTS (1/2) ..............................................................7 1.3 Demands on UMTS (2/2) ..............................................................8 1.4 Standardization (1/2) ....................................................................9 1.4 Standardization (2/2) ..................................................................10 1.5 Stages of Development (1/2)......................................................11 1.5 Stages of Development (2/2)......................................................12
  3. 3. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 3 of 12 1.1 UMTS - The New Standard The abbreviation UMTS stands for "Universal Mobile Telecommunications System" and describes a standard which will enable the flexible and high data rate transmission of any kind of data over the air interface. This system is to be run in parallel with the existing 2nd generation digital GSM mobile systems. It is also called 3rd generation mobile communication.
  4. 4. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 4 of 12 1.2 Current Trends (1/3) As the information society enters the third millennium, new developments are beginning to emerge: 1. A trend towards integration: the three traditional fields of telecommunication technology - telecommunication, computer industry and multimedia services - will merge even further. 2. A trend towards convergence: the dividing line between these three branches, with their individual requirements for high speech transmission quality, high data rates and the provision of new applications will become blurred. 3. A trend towards globalization and mobility. In future, the mobile subscribers will be globally reachable under one number, and be able to use the available services without any limitations, no matter where they are in the world. 4. Existing 2nd generation mobile systems will reach their limits of capacity, while at the same time the users' need for mobile communication will increase.
  5. 5. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 5 of 12 1.2 Current Trends (2/3) In mobile communications, the general trend is towards high data rates. This is the result of new services being introduced on the basis of increasingly powerful computer technology, and the developments of corresponding applications. This will show in the applications that are being developed on the basis of UMTS. For example, multimedia applications for User Equipments, such as video telephony and video conferencing, will be offered to a greater extent. Also, the users will be able to surf the net with high data rates. A range of undreamt-of opportunities will open up to e-commerce suppliers. The term "m-commerce" is already established as a name for e-commerce via mobile phones. Mobile access to intranets and Local Area Networks will provide the users' access to data and company information whenever and from wherever they like.This could be useful to salespeople on the road, for example, who will be able to check if certain articles are in stock and place their orders on the spot.
  6. 6. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 6 of 12 1.2 Current Trends (3/3) Let's summarize the reasons for the introduction of a new system. The mobile users' increasing data volumes, together with the simultaneous increase in user numbers, are pushing the existing GSM mobile systems to their limits.These systems were originally intended exclusively for digital speech transmission. In addition to speech transmission, the new UMTS system has been designed for the whole range of mobile data services. It will meet the demands for fast and more flexible transmission of large amounts of data. In some cases, peak data rates of up to 2 Mbit/s can be achieved. The net performance will be comparable to the transmission capacity of fixed data networks.
  7. 7. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 7 of 12 1.3 Demands on UMTS (1/2) One user, one User Equipment and one subscriber number. Unlimited availability through global roaming, with optimum transmission of speech and data. The UMTS standard will make this vision come true. As the basis of future mobile telecommunication networks, it will bridge the gap between today's mobile radio networks and one universal multimedia network. The foundations for the mobile information society, the global village, have been laid.
  8. 8. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 8 of 12 1.3 Demands on UMTS (2/2) The UMTS network will transmit both speech and data. In cellular mobile radio, the air interface specifies the wireless transmission between the mobile equipment and the base stations. In GSM networks, the air interface is optimized only for speech transmission. Its low transmission capacity is insufficient for modern demands on wireless data transmission. Thus the basic requirements for the UMTS system are: UMTS must provide a powerful air interface for the transmission of speech and data in one system. To protect the network operator's previous investments, and to keep the costs for new equipment as low as possible, the new UMTS system will be based on and use the existing network infrastructure.
  9. 9. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 9 of 12 1.4 Standardization (1/2) The UMTS standard is important, because for the first time the rules for a global mobile radio network will be binding for everyone. This will make global roaming possible. The term UMTS was fixed by the European Telecommunication Standards Institute. In the context of the International Telecommunication Union (ITU) we speak of IMT-2000. In the global standardization process, the American National Standards Institute (ANSI) will make sure that the existing American Standards are taken into account. The Association of Radio Industry Business (ARIB) will make sure that the existing Asian guidelines are observed. The responsibility for the standardization lies with the 3GPP, or 3rd Generation Partnership Project, where network operators, producers and national regulation committees have bundled their activities.
  10. 10. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 10 of 12 1.4 Standardization (2/2) The basic demands we have already mentioned define the most important requirements of the UMTS standard. For the air interface, two things are particularly important: - The transmission frequencies must be allocated and the transmission method needs to be specified. - The new network should be based on existing networks as far as possible, and have unlimited access to them. The system interfaces for data transmission to the GSM networks and their GPRS enhancements, which will soon be introduced, are to be defined accordingly. Thus the UMTS system consists of two main components. An independent subnetwork for radio coverage, and the Core Network, which provides routing and switching. Now let us take a look at the basic UMTS structure.
  11. 11. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 11 of 12 1.5 Stages of Development (1/2) Let us start with the GSM network. The Base Station Subsystem (BSS) provides complete radio coverage. The Network Switching Subsystem (NSS) is used to switch the circuit- switched connections in the mobile radio network, and to forward them to the fixed data network. With the introduction of GPRS, the GSM networks are being enhanced for the transmission of higher data rates. The transmission capacity is increased by adapting the existing GSM air interface to the particular requirements of packet-switched data transmission, and by setting up a special GPRS network. In the next step, the UMTS standard will be implemented by setting up a subsystem for UMTS radio coverage, the UTRAN. With its reserved transmission bandwidths and its new transmission methods at the air interface, it will overcome the limitations that are characteristic of GSM. The subnetwork for transmission and switching, the Core Network (CN), is based on the two independent subnetworks we already know. The UTRAN is connected to the GSM and GPRS networks via its respective system interfaces, or InterWorking Units (IWU), as we call them.
  12. 12. UMTS Basics, Version 3.0  T.O.P. BusinessInteractive GmbH Page 12 of 12 1.5 Stages of Development (2/2) Let's have a look at the air interface. The air interface specified in the UMTS standard is called UTRA (Universal Terrestrial Radio Access) and uses CDMA technology. UTRA and CDMA will be described in detail in a separate chapter. At this point we will just look at their essential characteristics. In UMTS, specific frequency ranges between 1.9 and 2.2 Gigahertz have been planned for radio transmission. The required system capacity can only be achieved through the efficient use of this limited spectral resource. This is done with the help of the CDMA access method. Its outstanding features are its spectral efficiency, and its flexible transmission rates. The CDMA method will be implemented into two different transmission modes: the Wideband CDMA, or W-CDMA, is used with the FDD mode. It regulates the simultaneous flexible access of several subscribers to one FDD frequency pair. This means that one frequency band is used for sending and the other is used for receiving. The spacing between these frequency ranges is fixed. In TDD, which uses one frequency for both directions at different times, the TD-CDMA access method allows efficient subscriber access to the available timeslots.

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