You need to develop a protocol for a communication system and make some simulations about throughput vs self-interference, collision probability, average waiting time in the network.
As discussed before, assumption is that VUE1 cannot join NET.A or it has a message to send, which cannot wait to long to find a transmission opportunity. Hence, it will transmit to RSU over RSU's dedicated downlink channel, and RSU equipped with FD technology, will receive its message, and will broadcast it to all surrounding cars. This solution will mitigate the hidden node problem, will decrease waiting time in dense networks, and will result in higher overall throughput of the whole system.
You should develop a protocol through which this FD reception and transmission is performed. RSU may have a near perfect self-interference cancellation. Transmission power of RSU is considerably more than that of VUE1, which means other vehicles (e.g. those in NET.A) will be able to receive RSU's signal correctly when VUE1 is transmitting at the same time.
You can assume Tout be the timeout for a VUE's message. It means that VUEx's message (a normal or an emergency message) should be broadcasted to surrounding vehicles within Tout, and if not, that message will be expired or will not be helpful enough. In a vehicular network, average waiting time for a VUE before transmission can be found. It depends on the number of VUEs in the network. So in a dense network, it could be more than Tout. In your protocol VUE1 (or any other VUEs in NET.A) will wait for Tout to find a transmission opportunity. If not successful, then it will switch to transmitting to RSU in order to avoid message loss. You can show in your simulations how this protocol will decrease the average waiting time, and how it will affect the success rate for transmission of normal or emergency messages.
When a VUE is transmitting over dedicated channel for vehicular network, as there is no interference, transmission throughput would be Tr0. However, when it is going to transmit over RSU's downlink channel, due to residual self-interference on RSU's receiver, the achievable throughput would be Tr1 which is less than Tr0, provided that transmission power of VUE is constant in both cases. You can show in your simulations how Tr1 is affected by residual self-interference, and what would be the overall throughput of the network, when VUE1 and another VUE in NET.A are both broadcasting at the same time (over different channels).
For simulation scenario you may use qpsk or bpsk (with or without coding) modulation, bandwidth can be 10 or 20MHz acc. to standards. You may use different power levels, but remember that RSU's power should be much more than that of VUEs'. For waiting times, you can refer to IEEE802.11 legacy standard and find the average waiting time which is a variable of number of users.
You may find the probability that two VUEs try to transmit at the same time to RSU (probability of collision) and compare it with probability of collision in a conventional network, when there is no transmission through RSU.