Dynamic QoS-based optimized video transmission in WiMAX networks

User's requests have increased from one to many different services at the same, thus increasing the demand for bandwidth from the service provider. Since bandwidth available is limited, the network has to either optimize the data from the input or to efficiently allocate the resources. An important problem in a WiMAX network is finding a suitable technique to improve the bandwidth available to the network as well providing QoS to large number of users. High bandwidth consuming services such as video services demand its required bandwidth to provide high quality of service (QoS), thus an adaptive modulation technique is proposed to provide QoS at reduced rates by measuring the channel state. A QoS-based scheduling architecture is also proposed to provide the guaranteed QoS requirements to the users. This architecture includes optimization at physical layer, QoS differentiation and scheduling at medium access control (MAC) layer, dynamic bandwidth allocation at MAC layer and admission control. Results have shown good throughput and delay characteristics for large number of users.