This thesis addresses both real-time and non-real time supports of communication services in a broadband fixed wireless network with Probing Process. In such a network, each cell is divided into multiple sectors, each of them served by a sector antenna colocated with the base station (BS), and user terminals use directional antennas mounted on the rooftops and pointed to their respective BS antennas. With the use of directional antennas to suppress interference, the Probing Process is proposed to improve data packet transmission without information exchange and coordination among base stations. The Probing Process detects available slots unused by other sectors to provide a higher capacity in sectorization cells. To support real time and non-real time traffic and efficiently implement Probing Process in FDD method, the base station (BS) adopts a demand-assignment channel access protocol named Prioritized Access with Centralized Polling Control that shares the bandwidth for different requests of real-time and non-real time users. The simulation results presented in this thesis show the quantitative improvement for voice traffic and data traffic with Probing Process.