User's Manual

SATELLINE-3AS
User Guide, Version 2.2
47
7.3 Detailed description of Message Routing
7.3.1 Source Mode Routing
The above figure represents a network containing four (4) radio modems. Each radio modem is
given a unique address (0…3). A terminal device has been attached to the three of the four
radio modems and they communicate with each other using terminal addresses X, Y and Z,
respectively. Radio modem 0 and terminal device X together constitute the base station of the
network and all routing information of the network has been programmed into this base station.
When the terminal device X transmits a packet to (e.g.) terminal Y, radio modem 0 will detect
the address Y from the data received through the serial port. From the routing table a route 1,2
can be found to which the radio modem also adds its own address to define the route for return
data. Radio modem 1 repeats the packet and radio modem 2 removes the address information
from the received data packet thereby transferring only the original data to the serial interface.
The address information received together with the packet is reversed (2,1,0) and saved to be
used in the transmission of subsequent reply packets.
0
1
3
2
X
Y
Z
System Modem
Y1, 2
Z1, 3