This chapter illustrates the basic technical issues of Worldwide Interoperability for Microwave Access (WiMAX) base stations. It introduces the concept of orthogonal frequency-division multiplexing (OFDM) and orthogonal frequency-division multiple access. The chapter explains the frame structure of WiMAX and discusses the design parameters of different subcarrier permutation methods. It explains the quality of service classes in WiMAX and the concept of the media access control scheduler. The chapter discusses the concept and the design parameters of fractional frequency reuse (FFR) technique. WiMAX technology supports line-of-sight and non-line-of-sight conditions using the OFDM technique. The frame in WiMAX can be represented as the frequency-division duplexing mode or time-division duplexing mode. WiMAX base stations are deployed in cellular networks where different frequency reuse factors can be used. The FFR technique plays an important role in cellular network deployment, as it supports universal frequency reuse with a slight reduction in spectral efficiency.