Operation Manual

133
Appendix A: Technical Information on GSM Operation
English
Fig. 11 Mobile ISDN Stack, ISDN HDLC Application
At the mobile end, any suitable ISDN application based on
CAPI 2.0 can be used. The remote system must be
equipped with an AVM ISDN-Controller B1 or AVM
FRITZ!Card and a corresponding CAPI 2.0 application.
The B1 or FRITZ!Card performs the conversion from
asynchronous V.110 to synchronous X.75.
Glossary:
V.42bis: An ITU-T standard data compression protocol that can
increase the effective data rate over a connection by a factor of up to
four.
HDLC: The HDLC protocol family was developed for application over
synchronous links (i.e., without start and stop bits).
ISO 3309: The HDLC standard has recently been extended to include
an asynchronous or “start/stop mode”, so that HDLC can be used over
asynchronous links, such as the RS-232C port of a PC.
X.75: An ITU-T standard for error-corrected data communications
with HDLC framing over one ISDN B channel (64000 bit/s).
V.110 (also I.463): An ITU-T standard protocol; used to adapt an
asynchronous or synchronous serial data stream to the ISDN bit rate
of 64000 bit/s for transmission over an ISDN B channel.
L2R/RLP (Radio Link Protocol): Used as the data link layer of the
radio connection. Based on the HDLC protocol, L2R/RLP guarantees
a secured data connection to the cellular switch.
Application, e.g.
NetWAYS/ISDN
with PPP over ISDN
CAPI 2.0
B1=0 (HDLC)
B2=1 (Transparent)
B3=0 (Transparent)
ISO 3309
L2R
RLP
Bfa
L2R
Air Transmission
RLP
S
0
ISDN Line
S
0
V.110
ISO 3309
Mobile Station with AVM
Mobile ISDN-Controller M2
and HDLC Application
ISDN Station with
AVM ISDN-Controller B1
Mobile Switching Center
(MSC)
V.110
CAPI 2.0
B1=0 (HDLC)
B2=1 (Transparent)
B3=0 (Transparent)
Application, e.g.
ISDN Access Server
with PPP over ISDN