Virtual wire and 2 frequencies for full duplex cmn

I have a pair each of RX-BI and TX-CI. I want to know whether a transmitter and receiver can be used on each side specifying different frequency for each pair to achieve a full duplex communication. If YES, please let me know how the frequencies of 315/433.92 MHz can be selected. My knowledge in RF and antennas is very limited. The data sheet talks about antenna lengths of 22.6(for 315 MHz) and 17.2(for 433.92 MHz). So, is it enough to just provide 2 pairs of different antennas. Also, please confirm my understanding that the 'antenna' can be just a strip of wire of the particular length.

My knowledge in RF and antennas is very limited.

That probably means you can't do the project. In a ham radio setup at these frequency you can get away with a spacing of 1.5MHz between the transmitter and the receiver. However you need a good notch filter set at the transmit frequency in the antenna path of the receiver. This is because the strong transmitted signal will make the receiver insensitive. These filters are hard to make and even harder to adjust. I used some cavity filters about the size of pint milk bottles for the filters when I did this for a ham radio repeater I made in the 70s.

I am extremely sorry for not adding the specifications. I started my RF comm study using the 'virtual wire lib':

In this document, the transmitter and receivers used are: RX-BI and TX-CI. datasheets:

I read that the RX component is marked 435MHz and the TX component is marked as hybrid- 435/315MHz.

So then it might only be possible if I could use an acknowledgement based communication.

Has any one used this particular RX and TX components in a full duplex mode?

Now, if you transmit and receive at different times

then it wouldn't be full duplex communications but only half duplex.

and at right angles to each other (to minimize cross-feed.)

This is only effective if the antenna are separated by at least a wavelength, otherwise you are into the near field interaction and that is quite messy. If you do implement this then the transmitter / receiver pair must share the same orientation.