6781097077

GSM Networks: Protocols, Terminology, and Implementation

2.2.2    Functionality    17

2.2.3    Mobile Stations as Test Equipment    18

3    The Base Station Subsystem_19

3.1    Base Transceiver Station    19

3.1.1    Architecture and Functionality of a Base Transceiver

Station    20

3.1.2    Base Transceiver Station Configurations    22

3.2    Base Station Controller    25

3.2.1    Architecture and Tasks of the Base Station

Controller    26

3.3    Transcoding Ratę and Adaptation Unit    28

3.3.1    Function of the Transcoding Ratę and

Adaptation Unit    28

3.3.2    Site Selection for Transcoding Ratę and

Adaptation Unit    28

3.3.3    Relationship Between the Transcoding Ratę,

Adaptation Unit, and Base Station Subsystem    29

4    The NetWork Switching Subsystem_31

4.1    Home Location Register and Authentication

Center    32

4.2    Visitor Location Register    33

4.3    The Mobile-Services Switching Center    34

4.3.1    Gateway MSC    36

4.3.2    The Relationship Between MSC and VLR    36

4.4    Equipment Identity Register    37

5    The OSI Reference Model_39

5.1    Reasons for Standardization    39

5.2    Layering in the OSI Reference Model    40

5.3    Data Types of the OSI Reference Model    41

5.4    Information Processing in the OSI Reference

Model    42