Developing Modem Applications
80-99208-1 Rev. D 5-3
• Data flows to and from the modem over-the-air, using the
Globalstar satellites and Gateway s connected to the
Internet (for packet data) or to the PSTN (for
asynchronous data).
• A host application (server) manages remo te sites (DTEs);
for example a host application might manage data from
numerous remote oil or gas wells.
Figure 5-1. DCE - DTE Application Components
Satellite
Globalstar
Gateway
Server
GSP-1620
Modem
SCADA Terminal
Control Port
(modem AT commands)
Data Port
DTEDCE
Tx
Rx
Host
Outdoor Antenna
Internet (for PPP data)
or
PSTN (for async data)
(running your
application software)
(Host application managing remote DTEs)
Interface Port
(Data or AT commands)
Remote