Study of Pre-Allocating TCP ACK Traffic in WiMAX ULMAP

• Main Authors: Peng-Yu Chen, 陳鵬宇
• Other Authors: Pei-Wei Huang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/62612738309651572093

碩士 === 大葉大學 === 資訊工程學系碩士班 === 97 === In the IEEE 802.16e, the access right of the uplink bandwidth must be requested by subscriber stations （SS）. The base station （BS） receives the requests from subscriber stations and grants suitable bandwidth to subscriber stations. According to this request-grant procedure, subscriber stations must request the uplink bandwidth from base station in order to transmit the ACK of the received data. This procedure introduces the delay of the transmission of TCP ACK. The transmission of following TCP data packets are postponed and will cause the inefficiency of transmitting the TCP’s packets in the IEEE 802.16e network. In this thesis, we propose a method to cope with this problem. The proposed method grants the uplink bandwidth for TCP-ACK to SS in advance. Hence, SS can transmit TCP-ACK immediately when receiving TCP-DATA. The base station inspects SS’s transmission activity. If there are TCP-DATA in the downlink transmissions, BS will allocate the bandwidth of TCP-ACK in corresponding ULMAP（Uplink Map） block directly. SS needs not to request bandwidth for TCP-ACK. Thus, SS do not wait for the delay of BS’s permission before transmitting the TCP-ACK. According to simulation results the proposed scheme improves the performance of the transmission by eliminating the response time of requesting the bandwidth of TCP- ACK.