SDR - Software Defined Radio implements most or all radio associated operations at software level as oposed to hardware level.
Bithium has developed a GNU radio based SDR wireless audio solution for surround systems using the Opus codec. It uses the 863 - 865MHz band.
The devised approach is software configurable to allow other services to run in parallel. Embedded versions of the solution are possible by using a generic high-speed microcontroller and low-cost FPGA. This has also been demonstrated in the Amalia-Sophie project.