Cross Layer Scheduling in WiMAX QOS for Disaster Management

How a base station assigns free resource slots to BE service class is depending on the available channel bandwidth after all the other classes have been served. Generally, it is known that the performance of BE is always the worst and provides the lowest level of quality compared to all other classes. However, if somewhat unexpected natural disaster strikes or an environmental catastrophe occurs, when the major communication infrastructure has been destroyed, it is possible that the only available Quality of Service (QoS) service is BE. Under this condition, users or, particularly, a rescue team will not have any other options but to use the only available service class for any types of applications including voice communications or even video communications. Based on that scenario, we have performed simulations using OPNET modeler simulation tool to evaluate the rtPS and BE performance with particular focus on video conferencing/streaming and also data transfer applications. Simulation results show that in certain situations, a user with BE QoS could provide better throughput compared to a user with rtPS. In addition, we also propose a cross layer scheduling mechanism by assigning the video conferencing/streaming application to BE service class and file transfer application to the rtPS service class.  The results obtained indicate that for certain combinations of users and QoS, BE service class demonstrates a higher throughput than rtPS. This scenario can be practically applied by a rescue team in any disaster management operations apart from normal teleconference service

End-to-end QoS model for mobile WiMAX systems

This paper defines an end-to-end QoS functional model for mobile WiMAX systems and investigate several technical issues. Our main contribution is to analyze the end-to-end QoS variations in mobile WiMAX systems according to the QoS functions. We discuss the strong and weak points of QoS related functions, which can be affected by the network architecture, and propose the design examples of a service class mapping function. To evaluate the end-to-end QoS, we implemented an end-to-end performance analysis simulator of mobile WiMAX using OPNET. Simulation results show that the uplink application layer throughput is about 70 percent of the uplink physical layer throughput. �� 2011 IEEE