Design and analysis of an ARQ scheme for broadband wireless access

Abstract

This paper presents design and analysis of an Automatic Repeat reQuest (ARQ) scheme for enhancing the throughput and reliability of broadband wireless access systems. The impact of ARQ is emphasized in terms of early error recovery, particularly when Internet data applications and the TCP protocol are considered over a point-to-multipoint fixed wireless system. A selective repeat type ARQ scheme is designed through simulation experiments by modeling the entire network protocol stack as well as the wireless channel. The system-wide impact of ARQ is investigated in terms of reduced end-to-end delay, increased throughput and SNR gain, together with the overhead costs. ARQ performance is further studied for enhanced features, Segmentation and Reassembly (SAR) and Bitmap Compression, with an effort to reduce the overhead costs, the extent of which depends on the nature of the errors. Extensive and realistic modeling of all interacting layers and design based on this modeling distinguishes this work from others. The designed ARQ scheme and its performance provide valid implications for WiMax technology and applications.