Sierra Wireless AirCard 710, Руководство пользователя, Страница: 12 / 53

AirCard 710 Wireless Network Ca r d - U s e r G u i d e
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General Packet Radio Service (GPRS). Like Internet
connections over cable modems, digital subscriber lines
(DSL), or high-bandwidth corporate connections, GPRS
connections do not consume an entire data circuit—they
break up their data into small chunks called
packets,
which
share data circuits with other packetsfrom other users,
and find their way across the network to be reassembled at
their destination. Such connections are known as
packet-
switched data.
The Internet is a packet-switched network.
To connect to the Internet or your corporate network in
packet mode, you simply insert the AirCard 710 PC Card,
click a few buttons, and launch your network software—
such as a web browser, e-mail client, file transfer applica-
tion, or other program. A packet mode connection behaves
as an “always on” connection—you do not need to dial up
each timeyou connect. Since GPRS efficiently shares radio
and network resources with other GSM users, wireless ser-
vice providers typically charge for packet mode data by
the amount ofinformation transmitted, not by connection
time, so you can remain connected indefinitely.
In general, packet mode service is more economical, faster, and
more convenient for most users. However, since it requires
service providers to install GPRS technology at each cellular
radio tower, it is not available everywhere that GSM coverage
is. (For information about service providers and GSM
coverage, see “Choosing a GSM Wireless Service Provider ” on
page 8.)
Since the AirCard 710network card supports both circuit and
packet modes, it provides all the advantages of GPRS packet
data where it is available, while allowing you to use circuit-
switched connections where GPRS has not yet been imple-
mented. The benefits to you are that you can use the AirCard
network card in anyarea that has 1900MHz GSM coverage
(assuming there are no account restrictions)and you will be
able to takeadvantage of the fastest possible data transmission
speed.
Connection Speed
The speed ofyour wireless network connection depends on a
number of factors, including:
•
Whether you have a circuit mode (CSD) or packet mode
(GPRS)dataconnection.
•
How your service provider has configured its GSM data
network.
•
How many people are using GSM data and voice services
in your current area.