Operation Manual
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Appendix A: Technical Information on GSM Operation
English
Appendix A:
Information on the AVM Mobile ISDN-
Controller M2 in GSM Operation
This chapter provides technical background information
about the AVM Mobile ISDN-Controller M2’s GSM
operation. In addition to descriptions of the Controller’s
GSM operating modes, it also contains details about the
protocols implemented and the types of terminal
equipment that are compatible at the remote end.
A.1 The Four GSM Operating Modes
The Mobile ISDN-Controller M2 supports digital and
analog data connections and Group 3 telefax connections
to subscribers in ISDN or PSTN in accordance with the
CAPI 2.0 specification. The four operating modes
correspond to the different types of remote equipment
that Mobile ISDN users may dial up.
A.1.1 Mobile ISDN
The implementation of Mobile ISDN is defined in interna-
tional specifications (GSM API, GSM 07.08). The world’s
first implementation of this user-friendly technique consists
of the Mobile ISDN-Controller M2 at the GSM end and
the AVM ISDN-Controller B1 or AVM FRITZ!Card at
the ISDN end (see Chapter 4.2). If the AVM ISDN-
Controller B1 or AVM FRITZ!Card is installed at the
ISDN line called, then AVM’s Mobile ISDN protocol is
used, and operation of the Mobile ISDN-Controller M2 is
extremely simple: all CAPI 2.0 applications can then be
used effortlessly over GSM and ISDN—generally in the
same way as over ISDN alone. A very common application,
for example, is the remote access software NetWAYS/
ISDN used by a mobile workstation to dial in to AVM’s
NetWare MultiProtocol Router for ISDN or ISDN
Access Server for Windows NT using the ISDN-
Controller B1 (on a BRI line) or T1 (on a PRI).