SATEL-EASy+
User guide
Version 1.33
34
Full Error Check
In this mode the radio modem waits until the end of the reception and checks the whole
received message before forwarding it to DTE. The additional time delay compared to No Error
Check is roughly the time needed to transfer the user data message over the serial line.
6.5.2 SATELLINE-3AS mode
CRC-8 Partial
Verifies the data in small blocks and they are delivered to DTE as sub messages after validating.
Once an error is detected, the rest of the message is ignored. In practice, if the error appears in
the middle of the message, the first part is forwarded to DTE and the data in erroneous sub-
message and after that will be lost. The CRC-8 partial is equivalent to the "Error checking ON" in
SATELLINE-3AS and SATELLINE-EASy models.
CRC-16 Full and CRC-8 Full check
Adds checksum characters accordingly at the end of the user data message. At the reception
end the receiver receives first the whole package and if the checksum matches the data
message is forwarded to the serial port.
! CRC-8 Partial and CRC-8 Full check activate an internal control on the radio link. These
checksum types can’t be viewed in the serial line data flow.
CRC-16 Full check adds the checksum to data. It is possible include the checksum into the
received data in the serial line by setting the CRC16 Full check to OFF state at the receiving
radio(s).
In typical use case, if checksum is preferred in the system, it is recommended to use the
CRC-16 Full check -mode and set the parameter equally to the radios in the same radio
network. Additional data transfer delay will be added approximately according to the data
packet size to the total transfer delay.
6.6 Air Encryption
The product encrypts the data that is transmitted on the air interface with the listed encryption
techniques:
• AES128
• AES256 (DRM Feature – see chapter 15.1)
Data security is often a concern when using radio communication. Bit encryption (CTR-mode)
on the air-interface ensures privacy in the radio network. The principle of encryption in the radio
path is to collect a certain amount of data to a shift register and manipulate it according to a
certain rule. Every data packet is encrypted individually. Depending on the encryption type, the
process of encryption adds 5-10ms delay in the data flow to each sent data packet (<5
characters in AES128 and <10 in AES256) and must be avoided in the cases where low latency is
the most important requirement.
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