maps, work items, and specifications, receiving, reviewing, and acting upon reports from working groups. 1.4 INTRODUCTION TO 3GPP STANDARDS The original scope of 3GPP was to produce technical specifications and technical reports for 3G mobile systems based on evolved Global System for Mobile communication (GSM) core networks [35] and the radio access technologies that they support; i.e., Universal Terrestrial Radio Access (UTRA) with both FDD and TDD duplexing modes. The scope was subsequently amended to include the mainte- nance and development of GSM technical specifications and technical reports, including evolved radio access technologies; e.g., General Packet Radio Service (GPRS) and Enhanced Data rates for GSM 1.4 Introduction to 3GPP standards WiMAX Forum Working Groups Marketing Working Group Promotes the WiMAX Forum, its brands and the standards (MWG) which form the basis for worldwide interoperability of BWA systems. Global Roaming Working Group Ensures the availability of global roaming service for (GRWG) WiMAX networks in a timely manner as demanded by the marketplace Maintains existing OFDM profiles, develops additional fixed Evolutionary Technical Working OFDM profiles, and develops technical specifications for the Group (ETWG) evolution of the WiMAX Forum's OFDM based networks from fixed to nomadic to portable, to mobile Certification Working Group Handles the operational aspects of the WiMAX Forum Certified (CWG) program Application Working Group Defines applications over WiMAX that are necessary to meet core (AWG) competitive offerings and that are uniquely enhanced by WiMAX Creates higher level networking specifications for fixed, nomadic, Network Working Group portable and mobile WiMAX systems, beyond what is defined in the (NWG) scope of IEEE 802. 16REV2 Regulatory Working Group Influences worldwide regulatory agencies to promote (RWG) WiMAX-friendly, globally harmonized spectrum allocations Service Provider Working Group Gives service providers a platform for influencing BWA product and (SPWG