  Mobile WiMAX (Worldwide Interoperability for Microwave Access) is being
touted as the most promising and potential broadband wireless technology. And
the popularity rate has been surging to newer heights as the knowledge-backed
service era unfolds steadily. Especially Mobile WiMAX is being projected as a
real and strategic boon for developing counties such as India due to its
wireless coverage acreage is phenomenally high. Mobile WiMAX has spurred
tremendous interest from operators seeking to deploy high-performance yet
cost-effective broadband wireless networks. The IEEE 802.16e standard based
Mobile WiMAX system will be investigated for the purpose of Quality of Service
provisioning. As a technical challenge, radio resource management will be
primarily considered and main is the costly spectrum and the increasingly more
demanding applications with ever growing number of subscribers. It is necessary
to provide Quality of Service (QoS) guaranteed with different characteristics.
As a possible solution the scheduling algorithms will be taken into main
consideration and the present well known algorithms will be described. In this
paper, we have highlighted the following critical issues for Mobile WiMAX
technologies. This paper specifically discussed about the below mentioned in
detail. - QoS Requirements For IEEE 802.16 Service Classes, Achieving efficient
radio resource management. - Deficit Round Robin (DRR) Scheduling algorithm. -
Modified Deficit Round Robin (MDRR) scheduling algorithm's attributes,
properties and architecture. System Model And Scenarios Using OPNET Modeler
Software. - Simulation Limitations And Constraints.
