# Interference Mitigation Strategies in Beyond 5G Wireless Systems: A Review
## 3 Classification and Evolution of Interference Management Strategies in B5G Networks
### Classification and Analysis of Interference Management Strategies in B5G Networks
#### 3.2.1 Device to Device  
In cellular networks, D2D communication is a new concept. Instead of traveling the signal through the core network, user equipment (UEs) is allowed to communicate using a direct link [66]. In a sparse area, D2D attempts to use the physical range of the transmitting devices to increase the signal for mobile devices. D2D communication can work together with cellular networks to complement each other. In terms of energy and spectrum, resource sharing between D2D and cellular communication is a crucial factor to be considered when designing D2D [67; 68; 69]. Content privacy and strong anonymity are the main advantages obtained from D2D. These are given because it is not the responsibility of the central storage to store the information exchanged. D2D communications are also capable of improving delay, throughput,  
Figure 3: Evolution of IMI strategies across 4G, 5G, and B5G networks, highlighting shift from static rule-based methods to intelligent, adaptive solutions. fairness, and EE [70; 71]. In addition, the performance of D2D is dramatically enhanced by improving the spectrum reuse (SR) and system throughput (ST) due to direct traffic routing [72; 73]. Offloading the cellular traffic is achieved by switching the path from infrastructures to direct transmissions [74; 75]. Figure 4 illustrates a typical D2D communication scenario within a dense SC network in B5G. It highlights the coexistence of D2D and cellular links, which introduces cross-tier interference challenges that must be addressed through efficient POC and RA schemes [76]. An essential issue that needs to be solved is the interference that underlies D2D contact with the cellular world. To deal with this issue, the mutual interference between D2D links and cellular links in HetNets of B5G technology needs to be managed in such a way that the UDNs must take place in the future network. UDN is a strategy in the B5G communication system. It consists of SCs which are capable of improving the coverage of the network and the capacity of the system [77]. In these SCs, the FR creates severe interference between SC links, macro cell links, and D2D links which is a critical topic when using the D2D and UDN [78]. While D2D communication offers substantial gains in SE and offloading, its real-world implementation faces challenges such as SR conflicts with licensed cellular bands and difficulty in managing interference in uncoordinated dense deployments. Moreover, POC  
Figure 4: D2D communication interference in B5G networks. in D2D is constrained by hardware limitations on UE power transmission (PT) and the need to comply with regional spectrum regulations. An effective IMI system is required to enhance the network's overall efficiency. In the past few years, researchers proposed various IM schemes that aim to minimize interference in D2D communication systems. [PERSON] et al. [75] proposed a Q-learning-based RA strategy for D2D communication networks, enabling efficient mode selection (MOS) under varying interference conditions. Their simulation results demonstrated improved SE and reduced interference levels, showcasing the potential of AI-driven resource adaptation in dense cellular environments. In [76], the authors analyzed D2D communication systems with energy harvesting (EH) over \(\kappa\)-\(\upmu\) shadowed fading conditions. Their work introduced a power distribution mechanism that enhances EE while controlling interference, particularly in environments with fluctuating signal conditions. [PERSON] et al. [79] investigated the potency of two POC methods to minimize D2D interference. The first of them is focused on the level of fixed power or uses no POC to manage the transmitter's power level. In the second method, adaptive POCs for two distinct systems are used. They concluded that both methods of POC led to network efficiency enhancement. In [80], the authors exploited the interference user level under multicasting circumstances.