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GSM Intro

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					  GSM

Introduction
         History of Mobile Communications
The beginnings:                                     Radio transmission
„archaic mobile communication”                      • 1873 Maxwell’s theory of electromagnetic waves
• Visual transmission (smoke / light)               • 1887 H. Hertz: experimental proof
• Audible transmission (drums, horns)               • 1895 Marconi: 1st wireless transmission
                                                    • 1901 1st transatlantic transmission
                                                    • 1903 Telefunken GmbH, AEG, Siemens + Halske
                                                    • 1906 1st speech and sound transmission
                                                    • 1909 1st radio broadcast
Electronic communication:                           • 1907 1st mobile transmission: radio station - train
„terrestrial network”
• Telegraph
     1st telegraph line 1843 Washington
• Telephone
     P. Reis 1861
     A.G. Bell 1876 World exhibition Philadelphia
              Single Cell Systems
• The first Mobile Telephone Service to offer duplex
  connections comparable to fixed network based
  telephone services started in 1946 as a car phone
  service in St. Louis, Missouri.
• Comparable mobile telephone services appeared in
  post-war Europe some years later.
        Cellular Mobile Radio Systems
• The breakthrough in capacity was achieved with the
  introduction of the Cellular Radio System in the late
  1970s/early 1980s.
• The coverage of the supply area of a mobile
  communication operator involves many radio cells with
  cellular radio systems, in which the aforementioned
  limitation of the available HF frequency range is neatly
  circumvented through the repeated use of the HF
  channels.
Single Cell Systems – Cellular Systems
     ‘1G’ Cellular Mobile Radio Systems
• Information transmission of first generation cellular
  mobile radio system takes place via analogue radio
  interface.
• These systems were tested in many countries in the end
  of the 70s.
    ‘2G’ Cellular Mobile Radio Systems
• A further and very significant innovation in mobile radio
  communications took place with the introduction of the
  second generation cellular mobile radio system (e.g.
  GSM) in the early 90s.
• Transmission via radio interface is now digital.
    ‘2G’ Cellular Mobile Radio Systems
• Along with a significant improvement of transmission
  quality and expansion of services, there has been a
  considerable increase in capacity.
• The increase in subscribers led to more convenient,
  lighter and less expensive equipment with a wide range
  of possibilities for use.
         Portable Mobile Equipment
• Mobile phones were first introduced in 1988. The
  weight of the equipment decreased from 1 kg to less
  than a 100 g within few years.
• At the same time, mobility clearly improved despite
  decreasing weight owing to improvements in
  rechargeable batteries.
GSM
         The GSM Recommendations
• The GSM Standard is a consistent and open standard
  for cellular mobile communication systems established
  by the ETSI.
• All aspects of the realization of the GSM Standard have
  been established in now more than 150
  recommendations (technical specifications).
         The GSM Recommendations
• At the same time the Recommendations are flexible
  enough for the different realizations of various vendors.
• The Recommendations are organized into 12 series
  according to different aspects.
• This structure reflects the structure of the PLMN (Public
  Land Mobile Network) system and its interfaces.
GSM Recommendation
           The Evolutionary Concept
• GSM Phase 1: (closed 1991) comprises all of the most
  important prerequisites for digital information
  transmission. Speech transmission is of the greatest
  importance here. Data transmission is also defined (0.3
  to 9.6 kbps). GSM Phase 1 comprises only a few
  supplementary services such as call forwarding and
  barring.
           The Evolutionary Concept
• GSM Phase 2: (closed 1995) Supplementary Services
  comparable to ISDN were included in the standard.
  Technical improvements have been specified, e.g. the
  Half Rate Speech. In Phase 2, the decision on future
  downward-compatibility with older versions is of high
  importance.
           The Evolutionary Concept
• GSM Phase 2+: Individual topics are discussed separately
  and the update is added to the GSM standard in Annual
  Releases. Main topics are new Supplementary Services as
  the ASCI services, the IN feature CAMEL and VHE are very
  important. Especially the introduction of features to
  achieve higher data rates, i.e. HSCSD, GPRS and EDGE has
  received much attention. GSM Phase 2+ thus paves the
  way to 3G (UMTS).
                   GSM Adaptations




          Frequency Range [MHz]           Useable HF channels   Application Area

          450.4 – 457.6 / 460.4 – 467.6
GSM400                                            35            Rural environment
          478.8 – 486 / 488.8 – 496
GSM900    890 – 915 / 935 – 960                  124            Worldwide except
E-GSM     880 – 905 / 925 – 960                  174            America
                                                                Worldwide except
GSM1800   1710 – 1785 / 1805 – 1880              374
                                                                America

GSM1900   1850 – 0910 / 1930 – 1990              299            America

GSM-R     876 – 880 / 921 – 925                   19            Railway systems
    PLMN - Public Land Mobile Network
• A PLMN is a terrestrial mobile communication network
  set up and run by public and private operators.
• It is used to provide public mobile communication
  services.

				
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posted:10/24/2011
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