Sony Ericsson T630 Benutzerhandbuch

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White Paper
 T630/T628
35
October 2003
Take advantage of full user control in the data 
connections menu, establishing multiple 
descriptions and accessing advanced settings 
for GPRS.
Interruption of GPRS data account
When the user is browsing with a T630/T628 the 
GPRS connection will be automatically discon-
nected when an incoming call is received. This is 
the default behaviour. However, it is possible for 
operators to customize the phone in such a way as 
to ensure that the user is asked if they wish to 
remain connected when an incoming call is 
received. 
Modem and AT commands
The T630/T628 contains a complete GSM/GPRS 
modem. This provides data and e-mail communi-
cation, as well as Internet/intranet access, for a 
connected PC, PDA or handheld device. Once the 
PC/PDA is connected to the phone using a cable, 
Bluetooth wireless technology or 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 T630/T628, AT commands are used for:
controlling the data communication between 
the PC and the remote service
configuring and requesting settings and behav-
iours 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 T630/
T628 offers the user data connection anytime, any-
where, unmatched by fixed telephone networks. 
Each GSM channel is divided into eight repeating 
time slots. A normal GSM voice or data call is cir-
cuit switched, and only one time slot is used for 
each call. The data speed is therefore limited to 
9,600 bps.
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.
GPRS enables constant connection and 
high speed
With GPRS, the connection is maintained “con-
stantly”, 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 85,600 bps 
download speed.