NEED HELP IN WIRELESS INTERCOM

I have a circuit Full duplex intercom

http://www.redcircuits.com/Page78.htm

but i have some problems regarding the circuit because we need a modify the said circuit to be WIRELESS FULL DUPLEX INTERCOM but we don't know what are the right modification needed for this

Please we need some HELP to make the WIRED FULL DUPLEX INTERCOM to WIRELESS FULL DUPLEX INTERCOM

Thank you for your time