Broadband Wireless Access (BWA) Networks: A Tutorial Kuowei Hwang and V Rao Vemuri University of California, Davis {kuowei, rvemuri}@ucdavis.edu Abstract Explosive innovations are sweeping the telecommunications industry worldwide as appetite for bandwidth keeps growing unabated. Several reasons are contributing to this trend: (a) growth of the Internet and Internet-based applications, (b) increased dependence of digital transmission even for analog applications, and (c) a global trend toward deregulation. Nowhere is this trend more marked than in the so-called last mile local loop bottleneck. The rapid rise in the popularity of Web-based applications is driving industry to build the infrastructure needed to bring high bandwidth, or "broadband," communications to the home. A fixed broadband wireless access (BWA) system is being offered to the public as a choice for the last mile of access. This paper discusses the niche occupied by BWA systems and presents a tutorial introduction to physical and medium access control layers, and the radio link protocol requirements. 1. Introduction Everything is going wireless [1, 2]. IEEE 802.11, BlueTooth, 3G, WAP, C/TDMA, IEEE 802.16, BWA, LMDS, MMDS, and so on are dotting the wireless landscape. What are all these acronyms? In short, BlueTooth is a wireless LAN for short-range communications within a 30 ft radius distance. IEEE 802.11 can achieve larger range of 300 ft, depending whether inside a building or outside. IEEE 802.11b, the currently available wireless local area network (WLAN), has 11 Mb/s data rate. IEEE 802.11a and 802.11g are expected to provide up to 50 Mb/s. They all work in ISM (Industrial, Scientific, and Medical ) band. IEEE 802.16 addresses broadband wireless access (BWA). In North America, Europe and other areas of the world, a widespread demand for low- cost broadband access to new Internet protocol (IP) services is fueling a BWA revolution. These developments strongly suggest that the BWA revolution is real and that fixed BWA technologies will establish deep roots in the telecommunications industry. Figure 1 shows the different types of broadband technologies used today for large scale network. The growing acceptance of fixed BWA is not only a function of its ability to supply increased bandwidth to large, under-served customer segments and the limited availability of fiber -optic cable but reflects important advantages as well. These advantages include rapid market entry, reduced access expense, modularity permitting flexibility and scalability; lower infrastructure costs due to ability to gradually build- up to meet evolving demand; and the cost--effectiveness of pointto--multipoint (PMP) architectures.