nd system capacity, reliability and robustness, seamless connectivity, reduced access latencies, etc. In this chapter we discuss the current status of broadband wireless access technologies and the efforts that are made by prominent standardization organizations to materialize the vision and to fulfill the objectives for the next generation of broadband radio access systems. Presently, the most important activities in this area are conducted by the Institute of Electrical and Electronics Engineers and 3rd Generation Partnership Project. These two organizations have historically contributed to the devel- opment and advancement of fixed and mobile broadband systems such as the IEEE 802.16, IEEE 802.11, IEEE 802.3, and the UMTS family of standards. Both organizations have already taken significant steps toward the next generation of fixed and mobile broadband wireless access technol- logies also known as IMT-Advanced systems. There is a great amount of commonality and similarity between the latest generations of wireless access system standards that started with similar system requirements and has further continued with similar functional blocks, protocols, and baseband processing, resulting in the notion of ultimate convergence in the 4th or later generations of broadband wireless access technologies. An attempt will be made to provide the background information and justification for this viewpoint throughout this chapter, while adhering to a systematic and structured approach. 1.1 MOBILE BROADBAND WIRELESS ACCESS TECHNOLOGIES Wireless broadband technologies provide ubiquitous broadband access to mobile users, enabling consumers with a broad range of mobility and a variety of wireless multimedia services and appli- cations. Broadband wireless access technologies provide broadband data access through wireless media to consumer and business markets. The most common example of broadband wireless access is Mobile WiMAX. DOI: 10.1016/B978-0-12-374964-2.10001-3 Copyright © 2011 Elsevier Inc. All rights reserved. CHAPTER 