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// SATELLAR MANUAL // RADIO UNIT // USER GUIDE // V. 1.8
6. Data transmission
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received correctly. This kind of situation cannot be solved with priority settings but needs a more com-
plicated handshaking procedure, which is explained in chapter 6.6.2. Priority settings help the important
messages get through but must be used carefully keeping in mind that the stations set to priority RX may
not be within each others’ radio coverage.
6.3 Basic mode with repeater
Basic mode with repeater is used to extend the radio coverage by adding one RU operating in this mode
between two basic mode RUs as described in the Figure 6.2.
Figure 6.2 Basic repeater mode
RU ‘C’ stores all the data it receives and then forwards it to the radio path. There are no station addresses
in the RU, i.e. the DTE, which just sent data gets it back after a while from the repeater station. Therefore
the DTE must be able to disregard these messages.
6.4 Source routing
Source routing is supported with FSK-radio.
When two or more repeaters are used it is necessary to use addresses to route the data. This is because
otherwise the repeaters would send the same messages to each other again and again in the network.
When using source routing the radio stations are forwarding only the data that belongs to them, not all the
data they hear in the network. The name source routing comes from the fact that only one station in the
network can be used as an entry point, the source, for the routing data. This station is called a master and
the other stations are slaves. Network topology is created with SATEL NETCO Design stack and sent to the
master station, which then includes the routing data in the messages to the slave stations. The following
picture clarifies the situation.
