A Dynamic Bandwidth Request Algorithm based on Traffic Loading for Best-Effort in IEEE 802.16 Networks

• Main Authors: Chen-Hua Cheng, 鄭振華
• Other Authors: Wen-Shyang Hwang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/77508244439233444591

碩士 === 國立高雄應用科技大學 === 資訊工程系 === 98 === In WiMAX network, first the SSs send bandwidth request before transmitted data, the SSs transmitted packet in data transmission period after the BS allocated uplink bandwidth. The IEEE 802.16e standard defined five QoS class, BE (Best-Effort) can only used contention slot to send bandwidth request, how to reduce the collision rate and utilize remaining QoS class bandwidth effectively is an important issue. In contention resolution scheme, when more and more SSs send bandwidth request, throughput and fairness greatly reduced as a result of the collision rate increased rapidly, therefore this thesis focused in the increased SS environment how adjust the number of bandwidth requests in the frame to improve the collision rate and throughput. This thesis consists of two steps: First, configured SS for three level initial back window (Initial Backoff Window ;Wmin) and backoff frame duration according to traffic loading. Second, turn reserved bit in the IEEE 802.16 Generic MAC Header into a More Data bit collocate Maxmin Fair Scheduling with dynamic configuration to improve network utilization and fairness. The simulation results show the proposed algorithm in the increasing number of SS can effectively improve the collision rate, throughput and fairness.