In a cellular network, Device to Device (D2D) communication faces a number of difficulties, including interference and slow upward and downward linking between device connectivity with base stations. Utilizing optimum frequency spectrum reuse (OFSR), these two issues can be overcome. In order to prevent D2D communication devices on the Evolved Node B (eNB) and cellular user transmitters from interfering with D2D receiver, OFSR is a mechanism where the user reuses the frequency of another cell. The study looks at the problem of spectrum sharing between D2D and cellular communications in a cellular network. Under this network spectrum rationalization, D2D links may access the spectrum that a mobile network operator manages. Each D2D link has the choice of acquiring a sub-band for exclusive usage or gaining access to the sub- bands used by cellular users. Spectrum can also be shared by D2D lines that only use a particular sub-band. One to one hundred (1-100), one to two hundred (1-200), one to three hundred (1-300), and one to four hundred (1-400) users each made up a group (1-400). The system equations were used to represent the network information, such as link gains, noise levels, signal-to-interference- and-noise ratios, and the devices' selected communication mode. Simulations that incorporate D2D communication as an additional communication channel are utilized to demonstrate performance bounds for the cellular system based on the derived equations. When compared to resource allocation technique, the simulation result demonstrates that OFSR has less interference. As can be observed from the simulation results, the throughput in the down link is higher than the throughput in the uplink.