Implement Real-time Transmission Mechanism for VBR Stream under 802.16 Wireless Networks

In this paper variable rate control strategies for real-time VBR stream service over IEEE 802.16 broadband networks are investigated. This is done in the context of real-time streaming using variable bit rate technology. A data rate control mechanism is derived for the case where the downlink channel provides real time polling bandwidth allocation service and remains traffic rate parameter constant. The paper show that the common queuing scheduling algorithms have some fairness bandwidth allocation problems for real time polling on Wimax system (IEEE 802.16) MAC layer. That is said, Wimax system are using VBR real-time polling service resulted to additional access latency jitter and bandwidth allocation disorder for transmitted variable data rate of VBR stream, when the base station regular time interval polling to SSs for contention bandwidth request period. However, This scheduling algorithm opposed to solve SSs contented bandwidth resource problem, depending on real-time polling service (rtPS) quality of service function under ranging response non-contention polling period, as adopted fairness bandwidth allocation max-min algorithm only time constraint condition to transmit real-time multimedia video on 802.16 wireless broadband environment. In addition, for analysis of vedio stream capacity, we utilize NS2 simulation, and show that the rtPS by fairness Max-Min algorithm can support to service more multimedia stream users compared with the others rtPS scheduler algorithms, respectively.