So, I was searching the market for what my wireless headphone options were and got quite disappointed.
As it seems, wireless used is either IR, RF (on the FM/UHF band) and Bluetooth (also 2.4Ghz seemingly working in the router's norm).
IR ... needs line of sight, small range...
RF... prone to interferences
Bluetooth... small range
2.4GHz... some reviews said they interfered with the home wireless routers