WiMAX (Worldwide Interoperability for Worldwide Microwave Access) is based on the IEEE 802.16 standard for Metropolitan Area Networks (MAN). There are several ways of quantifying the performance of a broadband system. This paper will address pressing issues of WiMAX system, which is interference. The manuscript focuses on the effect of number of channels per sector. The authors derive simulation results for the interference taking into account the number of channels per sector. Different channels allocation strategies are analyzed and their performances are compared.