Technical Description; Audio; Overview - Motorola G24 Guide Developer's Manual

Improved OEM Features
•
Up to four simultaneous protocol connections.
•
Ability to pass data via the protocol stack using AT commands (command mode). This
relieves the terminal from switching the RS232 to "binary mode" and back to "command
mode".
•
Ability to use UDP and TCP simultaneously.
•
No need for protocol support from the terminal - only data sending and receiving.
•
Reduced memory utilization. The G24 manages the protocol stack and therefore saves
terminal memory.
•
Ability to open TCP connections, secured with SSL/TLS.
•
Ability to receive the incoming TCP connections.
•
Ability to accept IP connections only if the IP belongs to a defined IP white list.

Technical Description

Figure 1-1, "System Overview," on page 1-5
following links and layers:
Physical layer links:
•
The terminal is connected to the G24 using a physical RS-232 connection.
•
The G24 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.
•
After authentication, the G24 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 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 software can manage these stacks internally. This enables the
G24 to relieve the terminal from the job of managing these protocols.
Note:

Audio

Overview

The audio (digital and analog) feature in the G24 module involves three main issues: path (routes
the current input and output devices), gain (volume management) and algorithm. For more
information, refer to
1-10
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" on page
AT Commands Reference Manual
displays the system overview which comprises the
3-229.
December 31, 2007