The changes in network services, technology and in the regulation has led a new era for the innovation of the network with the birth of the Next Generation (NextG). Also NextG is afflicted by the problem of growing demand for the spectrum, but it is possible a more efficient use of the spectrum thanks to more bands and technologies. The current model of distribution of the spectrum assigns the rights of the spectrum in frequency bands allocated to certain categories of services with the aim of avoiding interference. In this regard, two main sharing concepts are introduced: Underlay Approach (UWB), Overlay Approach (Cognitive Radio). Using a CR is possible to observe the spectrum, to find which frequencies are free and then to implement the best communication shape and to check that the interference is maintained at the minimum. The target of this work is to equalize the total distribution of the allocated radio spectrum resources among more interfering devices that work in the same geographical area. One of the intelligent principles, considered to the use of spectrum in addition to the FSU Algorithm based on SINR and Interference Threshold Approach, is the Spectrum Load Balancing, that is derived from the idea of water-filling. The goal is support the distributed QoS and in this manner will make an improvement in the spectrum efficiency.