الفهرس 
A proposed scheduling scheme in OFDMA WiMAX Network
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Abstract
The wireless channel provides frequency diversity caused by multi path propagation and temporal diversity due to the movement of obstacles or users. In addition, a multiuser channel provides multiuser diversity because of the statistical independence of the individual users{u2019} fading processes. Exploiting this diversity by scheduling users on favorable resources is one of the major opportunities to increase the system capacity. Network providers face the problem of delivering services to users with strongly varying channel quality. System capacity needs to be traded off against user satisfaction, requiring fairness metric to be considered in the resource allocation process. Traffic scheduling in packet - based networks is a mechanism responsible for determining the transmission order of packets from different competing flows. At a given scheduling instant (that is, a timeslot), the traffic scheduler tries to maximize the system performance in terms of different QoS requirements such as delay, loss rate, throughput, and utilization of limited radio resources using the status of the server and packets waiting at buffers