PIONEERPOS AT Commands G24-LC - Manual (Page 38)

Improved OEM Features
1-8 G24-L AT Commands Reference Manual April 15, 2008
Technical Description
Figure 1-1, “System Overview,” on page 1-5 displays the system overview which comprises the
following links and layers:
Physical layer links:
• The terminal is connected to the G24-L using a physical RS-232 connection.
• The G24-L is connected to the GGSN using a GPRS link.
• The GGSN is connected to the Internet via some sort of physical connection (usually
telephone or cable).
Point-to-point layer links:
• AT command protocol is used to transfer data between the terminal and the G24-L.
• After authentication, the G24-L is linked to the GGSN using PPP protocol.
• The GGSN is connected to its Internet service provider using some protocol.
TCP / UDP layer:
• The G24-L can transfer data with the WEB using either TCP/IP or UDP/IP protocols.
• The protocol stacks in the terminal or in the OEM must be managed when using TCP/IP or
UDP/IP protocols. The G24-L software can manage these stacks internally. This enables the
G24-L to relieve the terminal from the job of managing these protocols.
Note: Currently, the embedded TCP/IP feature may be used only for mobile-initiated
connections. The embedded. TCP/IP feature cannot listen on a port for incoming
connections.
Audio
Overview
The audio (digital and analog) feature in the G24-L module involves three main issues: path
(routes the current input and output devices), gain (volume management) and algorithm. For
more information, refer to
“Audio” on page 3-155 .
Features and Benefits
The following algorithm related features are provided:
Sidetone
Sidetone reduces the microphone audio input that is routed to the selected speaker so that the
person speaking can hear himself or herself talking. This creates a slight echo because the speaker