Sony Ericsson T300 ユーザーズマニュアル
T300/T302
White Paper, August 2002
23
Modem and AT
commands
commands
The T300/T302 contains a complete GSM/GPRS
modem. This provides data and e-mail
communication, as well as Internet/intranet
access, for a connected PC, PDA or handheld
device. Once the PC/PDA is connected to the
phone using infrared, and the appropriate
software is installed, the modem in the phone
works in a similar way to a PC Card modem, or an
external modem.
modem. This provides data and e-mail
communication, as well as Internet/intranet
access, for a connected PC, PDA or handheld
device. Once the PC/PDA is connected to the
phone using infrared, and the appropriate
software is installed, the modem in the phone
works in a similar way to a PC Card modem, or an
external modem.
In the T300/T302, AT commands are used for:
•
controlling the data communication
between the PC and the remote service
between the PC and the remote service
•
configuring and requesting settings and
behaviours in the phone, from a connected
PC or PDA
behaviours in the phone, from a connected
PC or PDA
GSM data communication
The built-in data capability turns the phone into a
modem when connected to a PC/PDA. The T300/
T302 offers the user data connection anytime,
anywhere, unmatched by fixed telephone
networks. Each GSM channel is divided into eight
repeating time slots. A normal GSM voice or data
call is circuit switched, and only one time slot is
used for each call. The data speed is therefore
limited to 9,600 bps. For more information, see
modem when connected to a PC/PDA. The T300/
T302 offers the user data connection anytime,
anywhere, unmatched by fixed telephone
networks. Each GSM channel is divided into eight
repeating time slots. A normal GSM voice or data
call is circuit switched, and only one time slot is
used for each call. The data speed is therefore
limited to 9,600 bps. For more information, see
“Built-in GSM data modem technical data”
on page 62
on page 62
.
High Speed Data gives a faster speed
High Speed Data (HSCSD) increases speeds for
circuit switched data by allowing the phone to
use a coding scheme with a high capacity, and to
use two time slots for receiving data. The
download speed is increased to up to 28,800
bps. The speed for sending data is limited to
14,400 bps. The data rate can be increased
several times by the use of rate adaption,
interworking with ISDN. This also provides
additional features, such as quick call set-up
capability.
circuit switched data by allowing the phone to
use a coding scheme with a high capacity, and to
use two time slots for receiving data. The
download speed is increased to up to 28,800
bps. The speed for sending data is limited to
14,400 bps. The data rate can be increased
several times by the use of rate adaption,
interworking with ISDN. This also provides
additional features, such as quick call set-up
capability.
GPRS enables constant connection
and high speed
and high speed
With GPRS, the connection is maintained
“constantly”, and data is transmitted in packets.
Pricing of GPRS can be dependent on the actual
use of bandwidth, which means very low cost
when no data is sent or received, while the phone
remains connected. When transmitting large
amounts of data, bandwidth can be increased
automatically to allow faster transmission speed,
up to 64,200 bps download speed.
“constantly”, and data is transmitted in packets.
Pricing of GPRS can be dependent on the actual
use of bandwidth, which means very low cost
when no data is sent or received, while the phone
remains connected. When transmitting large
amounts of data, bandwidth can be increased
automatically to allow faster transmission speed,
up to 64,200 bps download speed.
AT commands support
This section outlines the AT commands
supported by the T300/T302. The information
here can be of use for advanced users, to
indicate the possibilities they have to:
supported by the T300/T302. The information
here can be of use for advanced users, to
indicate the possibilities they have to:
•
develop new communications software
•
add the T300/T302 to an application’s list
of compatible modems
of compatible modems
•
adjust the settings of their mobile tele-
phone and modem
phone and modem
The modem in the T300/T302 supports the
V.25ter command set, which is the standard
communication set used by modems.
V.25ter command set, which is the standard
communication set used by modems.
The T300/T302 is compatible with industry de
facto extensions, ETSI 07.05, 07.07 and 07.10.
facto extensions, ETSI 07.05, 07.07 and 07.10.
Overview of AT command functions
AT commands are used to configure the mobile
telephone, to request information about the
current configuration or operational status of the
mobile phone, and to test availability and request
the range of valid parameters, when applicable,
for an AT command.
telephone, to request information about the
current configuration or operational status of the
mobile phone, and to test availability and request
the range of valid parameters, when applicable,
for an AT command.
The built-in modem can be set to any one of three
modes of operation. These are:
modes of operation. These are:
Off-line command mode
The command mode for entry of AT commands,
when the device is first turned on.
when the device is first turned on.
On-line data mode
Allows “normal” operation of the built-in modem,
for exchanging data or facsimiles with a remote
modem.
Allows “normal” operation of the built-in modem,
for exchanging data or facsimiles with a remote
modem.
On-line command mode
For sending AT commands to the built-in modem
while remaining connected to a remote modem.
while remaining connected to a remote modem.