Technical data

www.westermo.com Theoretical and general applications 7
Connection
......................................................................................................................................................................................................................... 70
Telecom modem language ............................................................................................................................................................................ 70
Error correction and compression ....................................................................................................................................................
70
Searching and file transfer .............................................................................................................................................................................. 70
Tomorrow’s highways
........................................................................................................................................................................................... 71
Leased lines
.........................................................................................................................................................................................................................
71
V.23 on a leased line .............................................................................................................................................................................................. 72
Westermo V.23 modem
...................................................................................................................................................................................
72
Using HyperTerminal (R)
....................................................................................................................................................................................
73–80
TDtool
...........................................................................................................................................................................................................................
76–77
AT-commands ......................................................................................................................................................................................................
78–80
Higher speeds
.....................................................................................................................................................................................................................
81–83
xDSL
.............................................................................................................................................................................................................................................
81
HDSL ........................................................................................................................................................................................................................................... 81
ADSL ........................................................................................................................................................................................................................................... 81
VDSL ............................................................................................................................................................................................................................................ 81
SDSL ............................................................................................................................................................................................................................................. 82
SHDSL ....................................................................................................................................................................................................................................... 82
G.703 ........................................................................................................................................................................................................................................... 83
GSM .......................................................................................................................................................................................................................................... 84–96
The history of GSM ....................................................................................................................................................................................
84–85
Architecture
.......................................................................................................................................................................................................................
85
Components in the network .................................................................................................................................................................... 86
Cell structures
.................................................................................................................................................................................................................
87
Radio transmissions between MS and BSS ...............................................................................................................
87–88
Services on the GSM network
...........................................................................................................................................................
89–92
Telephony
............................................................................................................................................................................................................................ 89
Circuit Switched Data
.......................................................................................................................................................................................
89
SMS
................................................................................................................................................................................................................................................
90
MMS .............................................................................................................................................................................................................................................. 90
Fax ...................................................................................................................................................................................................................................................
90
GPRS
................................................................................................................................................................................................................................ 91–92
Network security
................................................................................................................................................................................................... 92–95
GSM
..............................................................................................................................................................................................................................................
92
GPRS
............................................................................................................................................................................................................................................
92
Differences between GSM and GPRS ......................................................................................................................................... 93
Applications with GSM and GPRS
........................................................................................................................................ 93–95
GPRS classes
.....................................................................................................................................................................................................................
96
UMTS (3G)
.........................................................................................................................................................................................................................
96
ISDN
..................................................................................................................................................................................................................................... 97–104
What is ISDN
..................................................................................................................................................................................................................
97
Signalling
...................................................................................................................................................................................................................................
97
Connections
....................................................................................................................................................................................................................... 97