Sierra Wireless AirCard 710, Руководство пользователя, Страница: 11 / 53

Introduction
Rev B Oct. 2001 3
AirC
ard
710
Ba
sic
s
Note: More information about
GSM networks is available on
the GSM Development Group
web site, www.cdg.org.
A Network Card, a Modem, and
a Phone
The AirCard 710 wireless network card operates in three
different modes, depending on the services you need to use
and their availability in your current area:
Network Card (Packet Mode) Where
packet mode
service is
available (see the next section), the AirCard 710 wireless
network card is a true network card that works just like the
network cards familiar to most corporate computer users (such
as Ethernet andToken Ring cards).
Modem (Circuit Mode) When acting as a modem (in
circuit
mode
), the AirCard 710 network card allows you to dial up any
other modem (such as an Internet service provider for dial-up
Internet access)or receive faxes.
Phone (Voice Mode) You can also connect a handset to the
AirCard 710 network card and use it as a phone in
voice mode
.
In this mode, your computer acts like a mobile phone handset,
but with some different and often more flexible features. See
the chapter “GSM Voice Connections” on page 45.
How Circuit Mode and Packet Mode Data
Connections Differ
While the AirCard 710’s voice mode works much like a mobile
telephone, there are several differences between thecard’s two
data modes:
•
Circuit mode connections
(also known as
circuit-switched data,
or CSD) require the AirCard network card todial a
telephone number and make a connection like a traditional
computer modem, using the GSM digital cellular network
just as traditional modems use telephone wires. They work
just like voice phone calls: the connection between your
AirCard network card and the other modem consumes a
complete
circuit
on the telephone network, which remains
open as long as the connection is open.
When you are finished with a CSD call, as with a voice call,
you disconnect from the network. Wireless service provid-
ers typically charge for circuit mode connections by con-
nection time—perminuteor per second,just like voice
calls. You are charged whenever you areconnected, even if
you are not transmitting any data.
•
Packet mode data connections
, on the other hand, allow the
AirCard network card to connect instantly to the GSM
network with a few mouse clicks, using a protocol called