Sony Ericsson T612 Benutzerhandbuch

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White Paper
 
T610/612
23
Bearer type characteristics
The T610/612 accesses WAP services over IP. IP can be 
provided either over GSM Data or GPRS, depending on 
network services.
Typical differences which distinguish the bearer types 
are listed below.
GPRS access
The connection is maintained “constantly”, with data 
transmitted in packets, and transmission capacity being 
used by the application in use on an as-needed basis.
Higher transmission speed than with GSM Data or SMS 
access.
Pricing of GPRS can be dependent on the actual use of 
bandwidth, which means the user is charged for the vol-
ume of data transmitted, rather than the duration of the 
connection.
When transmitting large amounts of data, bandwidth can 
be increased automatically to allow faster transmission 
speed.
Ideal for complex pull services, browsing, data transfer, 
provisioning, pager services, messaging services, info 
services, push initiations.
GSM data access
Circuit connection of data calls, which means that the 
phone is connected during the entire WAP session.
Pricing is comparable to that of data calls in the network.
Gateway characteristics
A WAP Gateway provides Internet/intranet as well as 
WAP services to the mobile browser. A Gateway is 
identified by an IP number, depending on access type.
End-to-end gateway navigation
The WAP 2.0 supports E2E (End-to-End) Gateway 
navigation, making it possible for example for a bank to 
redirect its clients from the Internet gateway to its own 
gateway.
Security using the WAP
For certain WAP services, such as banking services, a 
secure connection between the phone and WAP gateway 
is necessary. An icon in the display of the T610/612 
indicates when a secure connection is in use. 
The T610/612 is based on the WAP 2.0 (WML 1.3) 
specification suite, in which security functionality is 
specified by a technology called Wireless Transport 
Layer Security (WTLS). The WAP protocols for 
handling connection, transport and security are 
structured in layers, with security handled by the WTLS 
layer, operating above the transport protocol layer. 
WTLS classes define the levels of security for a WTLS 
connection:
WTLS class 1 – encryption with no authentication.
WTLS class 2 – encryption with server authentica-
tion.
WTLS class 3 – encryption with both server and cli-
ent authentication.