User guide

COM – Serial Interface 4.4
53
CSD or High-Speed GPRS Data Connection to Internet
To connect to the Internet, install the faxmodem driver from the EasyGate CD-ROM
first. Another possibility is to use the GSM provider’s installation wizard in case it
supports the SIEMENS GSM module installed in EasyGate (SIEMENS MC39i, MC55,
MC56 or MC55i). GPRS/faxmodem driver can be found on installation CD. The path to
the driver is \\data\EasyGate\Modem driver\. Driver’s filename is mdm2n_vx.x.inf
where x.x stands for the version of the driver.
The installation wizard usually configures the telephone connection of the network too.
If you use manual installation, you have set it properly. Ask you GSM provider for
Internet connection instructions because they can be different for each provider
(especially the telephone number to be dialed, DNS, etc.). It is necessary, for
example, to set the APN in modem extra settings in the GPRS mode:
Example: at+cgdcont=1,"IP","internet.t-mobile.cz"
Caution
 GSM providers mostly specify the *99# number to be dialed for GPRS
connection in their instructions. SIEMENS GSM modules require the
*99***1# format.
CSD or GPRS Data Connection?
The maximum CSD transmission rate is 14400 bps. GSM connection is reserved for
the whole time of connection and calls are charged according to the connection time.
The CSD mode can provide data connection of two PCs.
EasyGate is equipped with GSM modules providing GPRS class 10 (4+2 timeslots),
which means that it is able to transmit data into a PC at the rate of 85600 bps and at
half the rate towards the GSM network. The GPRS cannot be used for connection of
two PCs. It can only provide connection with an APN – e.g. the Internet. Most GSM
providers charge GPRS connections according to the volume of data transmitted or by
a lump sum and so the GPRS is suitable for long-time connection with occasional data
transmissions.
SMS Sending and Receiving
It is possible to send and receive SMS units using appropriate AT commands. There
are a number of PC programs that are based on this principle. Install SW designed for
SIEMENS GSM modules (SIEMENS mobile telephone SW can also be used). You can
send and receive SMS even during EasyGate voice calls.
Combination of COM Traffic with Voice Calls
As already mentioned, SMS transmission can be made even during telephone calls.
The SMS program is only blocked temporarily during outgoing call establishing and
incoming call ringing.
The same applies to PCManager monitoring. A message announcing that EasyGate is
blocked is displayed during voice call establishing.
No voice call can be made during CSD data connection.