
Chapter 19: Wireless Wide-Area Networking
Dial-up Data Connections
Psion Mobile Devices Developers Guide
198
15. Type the AT command ATE1 followed by ENTER to enable command echo, which will allow you to
see the subsequent commands you type.
The terminal window is now connected to the modem, allowing you to enter AT commands. When you are
finished entering commands, close the terminal window.
19.4.3 Dial-up Data Connections
The following dial-up connections are available through the WWAN driver:
•GSM Networks
•UMTS Networks
• CDMA Networks
• iDEN Networks
19.4.3.1 Dial-up Data in GSM Networks
Not all GSM networks support dial-up data connections to land-line modems (e.g. Rogers in Canada has
never supported dial-up data connection, Microcell Fido in Canada discontinued dial-up data connection
support a few years ago). For those networks that support dial-up data connections no additional configura-
tion should be required for a connection to an analog modem at 9.6 kbps.
Some networks allow faster dial-up connections at 14.4kbps. The AT command “+CBST=14,0,1” has to be
added in the WWAN UI settings of the Wireless Manager GUI, under Properties > Configure… > Call
Options > Extra Settings to enable this mode.
The even faster High Speed Circuit Switched Data (HSCSD) mode available on a few networks is not
supported by any of the modems in Psion products.
For ISDN lines, the situation is more complex. Some ISDN modems may accept analog connections as
above, while others require the protocols V.110 or V.120 to be used. These also require an additional
AT command.
If an ISDN modem requires the X.75 or HDLC protocols, then no connection is possible. Also, many GSM
networks do not support V.120 (e.g. Vodafone D2 in Germany) and only the Audiovox RTM-8000 and CMCS
NTN-000 support V.120.
For more details on ISDN connections see D. Živadinovic, M. Winkler, Des Surfers Bastelstunde in c't 7/2001,
page 228 (in German).
For more details on GSM AT commands see Digital cellular telecommunications system (Phase 2+);
Universal Mobile Telecommunications System (UMTS); AT command set for 3G User Equipment (UE), 3GPP
TS 27.007 version 5.4.0 Release 5, ETSI, 09/2003.
The following table summarizes the required AT commands.
19.4.3.2 Dial-up Data in UMTS Networks
In general, UMTS modems should not be used for dial-up data connections.
Only the UMTS networks in Japan allow dial-up data connections. As a consequence, for modems that
support both GSM and UMTS dial-up connections are not possible once the modem has switched to UMTS
(which it will do whenever UMTS is available and no dial-up connection is already active).
Land-line modem Speed Extra Settings
analog 9.6kbps
analog 14.4kbps +CBST=14,0,1
ISDN V.110 9.6kbps +CBST=71,0,1
ISDN V.110 14.4kbps +CBST=75,0,1
ISDN V.120 9.6kbps +CBST=39,0,1
ISDN V.120 14.4kbps +CBST=43,0,1
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