VEGA INSYS Modem GPRS 5.0 - Manual (Page 85)

INSYS GPRS 5.0 serial GPRS General
85
Note
The transmitted amounts of data consist of the sum of application
user data and the TCP packet data. The information from the TCP/IP
packets also represents a network load and will add to the total
costs.
For the entire data amount it is also important to select parameters
adjusted to the application to form TCP packets. These parameters
consist of:
The maximum set block value (default: 512 byte) (see
AT**TCPBLOCK)
The maximum waiting period (AT**TCPAGG).
8.2 Network Design
The GPRS system is intended as additional service within the scope of the GSM
system. The GPRS data exchange (GPRS = General Packet Radio Services) runs
packet-oriented, based on the Internet Protocol (IP).
The following figure shows the basic design, where the application has to provide
the TCP/IP/PPP stacks. This is required when using the standard GPRS functional-
ity of the INSYS GPRS 5.0 serial.
Mobile application
PPP/IP
GPRS Bearer
IP
GPRS Bearer
Router
(GGSN)
IP IP
application server
TCP
IP
GPRS Net radio components and internal GPRS net
IP
GPRS engine
Application
remote site
GSM/GPRS
Engine
TCP
PPP/IP