Fair loss-rate scheduling algorithm for WiMAX network

• Main Authors: Ching-Ting Yang, 楊景婷
• Other Authors: Hann-Tzong Chern
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/8xb97j

碩士 === 國立臺灣科技大學 === 電子工程系 === 105 === IEEE 802.16 is a standard for wireless communication network. It has the advantages of high transmission rate, long transmission distance and supporting various kinds of multimedia services such as voice and video. To ensure the Quality of Service (QoS) of different application, the service flows are classified into five classes. The five classes of service flows can be summarized as real-time and non-real time. If the waiting time is over the maximum latency of a real-time packet, it will be discarded. In this paper, we will propose a fair loss-rate scheduling algorithm for WiMAX network, to improve the loss-rater of real-time packet. First, in the beginning of the scheduling, the deadline of each real-time packet will be checked. If the deadline time is over the system time, the packet will be discarded. If the deadline time will be over before next frame starts, the packet will be considered as emergency packet. The emergency packet will lose if it is not scheduled in this frame. Since loss-rate is a significant QoS parameter, the emergency packets of different classes should be scheduled fairly. The allocation of emergency packets for ertPS class should be adjusted according to the loss-rate of rtPS service flows. Otherwise, the loss-rate of rtPS class will not be accepted since it has lower priority. At the final round, we will use Weighted Fair Queue algorithm to allocate the packets of all service flows until all available bandwidth is allocated or all packets are scheduled. With this algorithm, the loss rate is well controlled for all real-time service flows.