期刊名称：International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)
印刷版ISSN：2278-1323
出版年度：2017
卷号：6
期号：4
页码：518-522
出版社：Shri Pannalal Research Institute of Technolgy
摘要：In this paper, we study the determination of down-link (DL) and uplink (UL) channel split ratio for Time Division Duplex (TDD)-based IEEE 802.16 (WiMAX) wireless networks. In a TDD system, uplink and downlink transmissions share the same frequency at different time intervals. The TDD framing in WiMAX is adaptive in the sense that the downlink to uplink bandwidth ratio may vary with time.At physical layer WiMax uses orthogonal frequency division multiple access technique in wireless communication. OFDM delivers a wireless signal much farther with less interference. Cyclic Prefix (CP) is used to combat intersymbol inter-ference (ISI) and intercarrier interference (ICI) introduced by the multipath fading channel.WiMax provides high-speed data access to the Internet where the transmission control protocol (TCP) is the core transport protocol.In particular, we investigate the dependence of the aggregate throughput and goodput of TCP on factors such as DL:UL ratio, Cyclic Prefix, frame duration, modulation and coding scheme and offered loads. It finds that these factors affect TCP performance by exacerbating the bandwidth asymmetry inherent to the MAC layer and cyclic prefix inherent to the Physical layer.
关键词：IEEE 802.16; Media Access Control (MAC); MAP; TCP throughput & goodput; Cyclic Prefix; Frame duration; DL:UL ratio.
