3-out-of-6 code

The 3-out-of-6 code is a coding method that is used in radio transmission to achieve reliable parities. For this purpose, the level fluctuations at the receiving end must be kept as low as possible.

In the 3-out-of-6 code, four-bit long source symbols are converted into 6-bit long code words. This means that one third of the codeword, namely 4 out of 6, is inefficient. On the other hand, the generous conversion avoids uncertainties in the transmission.

The 3-out-of-6 code is used, among other things, in the wireless version of the M-Bus, the Wireless M-Bus. In the wireless meter bus, the 3-out-of-6 coding maps useful bit sequences on specially selected sequences, whereby fixed bit sequences are used for the radio transmission.