Terminal pentru retelele numerice de transmsiuni

                                   CUPRINS
               Capitolul 1: Locul şi rolul terminalului în cadrul reţelei de
                                         transmisiuni (tipuri de terminale -
                          mesaje)..........................................1
                          Capitolul 2: Terminalul numeric de abonat (schemei
                                                   bloc)...................4
                                                              2.1 Prezentare
generală....................................................................
                                                              .............4
                                                               1 2.2. Schema
    bloc....................................................................
                                                   ........................6
                                     2.2.1 Elementele componente ale schemei
                                 bloc......................................8
                                              2.2.2 Interfeţele terminalului
               numeric.....................................................9
                    2.3 Moduri şi posibilităţi de configurare a terminalului
                                                     numeric..............11
    Capitolul 3: Conversia analog-numerică/numeric-analogică..............13
                                                                          1.
        Introducere.........................................................
                                               ...........................13
                                              2.   Modulaţia impulsurilor în
                  cod.....................................................14
                                            1. Cuantizarea formelor de undă,
                                       eşantionarea.......................14
                 2. Cuantizarea uniformă, cuantizarea neuniformă, comparaţie
                           între cele două metode de cuantizare, cuantizarea
                diferenţială................................................
                                                   .......................15
                                                              3.3  Modulaţia
Delta.......................................................................
                                                                     .....21
                                              3.3.1  Modulaţia delta liniară
                           (MDL)..........................................21
                          3.3.2  Modulaţia delta cu pantă continuu variabilă
                                                           (CVSD).........23
                                    3. Performanţele măsurate ale modulaţiei
                                                delta.....................31
                    4. Scheme bloc conform EUROCOM ID/1, IA8..............33
                                       1 Capitolul 4: Proiectarea interfeţei
                       utilizator.........................................38
                           4.1  Proiectarea amplificatorului pentru semnalul
                                           telefonic......................38
                                            4.2  Circuitul FX609 – descriere
                   generală...............................................40
                                            4.3   Proiectarea circuitului cu
             cuarţ........................................................42
           4.4  Schema de punere în evidenţă a caracteristicilor circuitului
                                                                 FX609....46
                                     4.5  Codarea de linie – coderul bifazic
                             condiţionat..................................48
                                               4.6  Circuitul de extragere a
           tactului.......................................................55
                       Capitolul 5:  Semnalizări utilizate între terminal şi
                                                   centrală...............62
                                                                1. Tonuri de
        supraveghere........................................................
                                                               ...........65
                                                             2.  Principiile
        semnalizării........................................................
                                                               ...........66
                                        3.  Diagrama de stări a terminalului
                           numeric........................................66
                   4.  Modul trafic.........................................
                                 .........................................69
                                                   5. Coduri interpretate în
           trafic.........................................................70
                                   6. Setări realizate în cazul conexiunilor
                                        elementare........................72
                                                              7.  Eliberarea
        conexiunii..........................................................
                                                                  ........75
                                                                    8.  Pre-
        emption.............................................................
                                                       ...................76
                                                                          9.
        Conferinţa..........................................................
                                                 ........... .............77
                                                   Capitolul 6: Concluzii şi
           recomandări....................................................80
                                                                       Anexe
                                                   Anexa 1: Servicii oferite
     abonatului...........................................................83
                          Anexa 2: Caracteristicile claselor 1, 2, 3 şi 4 de
                                          date............................86
  Anexa 3: Simulări codec delta liniar şi codec delta cu variaţie continuă a
pantei......................................................................
                                   .......................................94
                                                  Anexa 4: Scheme de reţea..
    .....................................................................100
                                     Schema bloc de principiu a terminalului
       Scheme electrice (interfaţa utilizator), cablaje şi planul de găurire
                                                          Diagrame de semnal
                                            Anexa 5: Prezentarea circuitului
                  FX609J.................................................108
 Anexa 6: Schema de măsură şi rezultatele experimentale obţinute.........114
Abrevieri...................................................................
                                        .................................118
Bibliografie................................................................
                                        .................................119
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VII