GSM SMS refers to the process when SMS messages are sent from PC via one or more
attached GSM device with the help of an SMS gateway software. GSM SMS is ideal for
sending and receiving fewer than 15 000 SMS messages per day, since the capacity of
one GSM modem is about 6-10 SMS per minute.
SMS over GPRS
GSM SMS is available by using a suitable GSM device (phone or modem) attached to the
computer with a phone-to-PC data cable. For information about suitable phones, check out
the GSM devices page. The GSM device has to
be equipped with a SIM card that charges (preferably) low rates for SMS messages.
With this setup you can use a computer program (SMS gateway) to
send and receive SMS messages. In this case, the SMS gateway software uses the attached device
to communicate with the GSM network. If a message is sent out by the gateway running
on the computer, it is first sent to the attached GSM device. Then the GSM device
transmits it to the SMS Center (SMSC) of the GSM service provider, using a wireless
When a message is received, the GSM device stores the message in its memory or on the
SIM card, and sends a notification to the SMS gateway. When the program receives
this notification, it retrieves (reads) the message from the respective memory cell,
and then deletes the message from the device to make room for the next incoming message.
The advantage of using a cellular modem is that you do not need Internet connection
for SMS messaging. Sending an SMS message using a cellphone takes about 5-6 seconds.
Receiving takes about the same time. Good SMS softwares allow you to attach more
than one device to your PC and to use them simultaneously
to increase capacity.
As a cellular network, GSM allows mobile phones to connect to it when searching
for cells in its proximity. The cell network is created through antennas that
transmit radio signals by way of dedicated carrier frequencies (850 MHz, and
1900 MHz in Canada and the United States; 900 MHz, or 1800 MHz in other
countries) with a coverage area of 35 km, or 22 miles.
How to connect the GSM modem to the PC