Abstract Worldwide Interoperability for Microwave Access (WiMAX) defines different data delivery services that can be used in order to satisfy Quality of Service (QoS) requirements such as flexibility and efficiency. In this paper a new distributed Master-Slave model was introduced to compare the Performance between the centralized and distributed Network models in order to support QoS in fixed WiMAX with respect to throughput, delay and application response time parameters, to enhance the services that are provided to the end users. The design has been evaluated using the simulation tool OPNET modeler 16.0. The results obtained from the two models shows significant increase in the network throughput and drastic decrease in network delay and application response time. The results in scenario1 of two models shows the throughput increases from 50,000bit/sec to 100,000bit/sec, delay decrease from 0.0060/sec to 0.0040/sec and application response time decrease from 0.80/sec to 0.58 which greatly enhances the QoS performance.