4-based systems and mobile WiMAX is used to describe IEEE 802.16-2009 or IEEE 802.16m based systems. The WiMAX Forum further develops higher-level networking specifications for mobile WiMAX systems beyond that defined by the IEEE 802.16 air interface standard (see Chapter 2). The combined effort of the IEEE 802.16 Working Group and the WiMAX Forum help define the end-to-end system solution for a mobile WiMAX network. A certification profile is defined as a particular instantiation of a system profile (i.e., a predefined set of parameters extracted from the system profiles) where the operating frequency, channel bandwidth, and duplexing mode are also specified. The WiMAX equipments are certified for interoperability according to a particular certifi- cation profile. Furthermore, Protocol Implementation Conformance Specification (PICS) is a ques- tionnaire to be completed by vendors that specifies which features have been implemented in the product for conformance testing [14]. Release 1.5 of the mobile WiMAX system profiles, based on the latest revision of the IEEE 802.16 standard [8], provides a short-term migration of WiMAX systems that include additional features relative to Release 1.0, such as FDD support and Time Division Duplex (TDD) enhanced operation, new band classes, support of multicast and broadcast and location-based services, and femto-cells [33]. Release 1.5 systems are fully backward compatible with Release 1.0. The WiMAX Forum is currently working toward Release 2 of mobile WiMAX system profiles based on the IEEE 802.16m standard whose completion is expected in 2011 [34]. Figure 1-6 illustrates the organization of the WiMAX Forum and provides a brief description of the charter of each working group. The WiMAX Forum working groups operate under a Technical Steering Committee (TSC). The TSC functions include overseeing technical development of WiMAX Forum specifications and certifications, ensuring integrated, timely and predictable technical programs within WiMAX Forum, planning and approving road