### Related Work  
The incorporation of NOMA with FD is a challenging yet promising approach for the 6G technology. The idea of combining NOMA with FD can improve the SE and the combination will also help in managing the drawbacks of each technology. Regarding the hardware progression in the propagation and digital and analogue domains [3], several studies have been put forward for the combination of both promising techniques. Table 1 shows the comparative study of the existing FD-NOMA literature. The existing literature explores the advantages of FD and NOMA. For maintaining a balance between FD and Half-Duplex (HD) [8], the transmission switching mode from HD to FD and vice versa is one of the common approaches of communication. Beamforming is another successful approach for NOMA and FD. It can improve the data rate of a particular user with power allocation management [9]. It also provides a better ergodic sum-rate than HD [10]. However, the HD outperforms FD at high Signal-to-Noise-Ratio (SNR) in terms of outage probability and in the delay-tolerant transmission [8; 10]. There are several approaches for successful implementation for NOMA and FD with high data rate [9] and ergodic sum-rate [10] including beamforming. Cognitive Radio-based NOMA (CR-NOMA) with femtocells is a good strategy for the deployment of NOMA using pairing techniques of the near and far users [11] and for the improvement of system overall performance. A communication system is based on several layers, each layer has different requirements of security due to multiple connected objects in the beyond 5G [12]. Physical Layer Security (PLS) is one of the main concerns in a smart system. This literature focuses on the PLS. For PLS there are two types of eavesdropper/s (Eve) that cause threats to security; active and passive. It can be amongst the trusted intended user or an outsider. Several existing algorithms are obliging for tackling the issues of PLS, however, due to the advancement of technology, the security threats are also getting advanced. The enactment of technology everywhere including; banks, buildings, security systems, houses, schools, accounts, industries and transportation makes everything vulnerable. One of the possible ways of handling security issues of jamming and eavesdropping for a hybrid eavesdropping (passive eavesdropping on the transmission source and the reactive jamming on legitimate users) of FD-NOMA is by exhausting eavesdropper by increasing its decoding complexity [13]. After the development of a numerous algorithms [12; 13; 14], the security of a wireless communication system still needs improvement. In the traditional communication system, each device is capable of dual communication with a transmission and a reception task called HD communication. In HD, the channel is shared between the dual tasks, with orthogonal (different) time slots or orthogonal frequency bands (out-of-band FD mode). FD allows a device to broadcasts and receives the signals in the same frequency band and time slot [15]. There are two types of FD: the Out-of-Band FD (OBFD) (which is a kind of HD) and the In-Band FD (IBFD) where the transmission and reception of the signal take place at the same time slot and frequency band. In terms of network capacity, system reliability, sum rate and other theoretical aspects IBFD is superior to conventional HD [3].