In this project I have also used the RF (Radio Frequency) Modules to transfer data from Encoder to Decoder wirelessly. For wireless communication we always require a Tx (transmitter) and Rx (receiver). Image below shows you both of them:
These modules are really simple to deal with. They just require a VCC (+5V), GND (0V) and the DATA connection. Some of them require ANTENA (ANT) connection as well.