Full duplex shared frequency radio?
This isn't trivial for a number of reasons, but it is possible.  Part of the problem is that the receiver has to have a huge dynamic range to be able to receive the 1W signal and the tiny signal from afar just above the noise floor, and understand both without losing data.

One system that can help, though, is to remove the transmitted signal from the antenna before the receiver:



Some research points out that this can be made to work.

However, the point is that what you're asking is possible, but it's very difficult to do well.