Abstract—The interference graph is an important input factor for efficient frequency channel allocation. This paper proposes the interference graph creation technique for frequency channel allocation. The indoor femtocell networks in multi-floor buildings are used for the study area with frequency channel allocation criteria consideration. The performance of network service is analyzed. There are the areas covered by the signal from femtocell base station and the interference signals from femtocell base station and signal quality in service areas. The simulation-based results of the proposed technique can support frequency channel allocation to each femtocell base station. It can finely detect interference link between femtocell base stations. Moreover, the performance of the studied femtocell networks in terms of signal quality and throughputs is increased, compared to other creating interference graph techniques in the literature review.