tivated [3]. The Generic Packet CS (GPCS) is a network layer protocol-agnostic packet convergence sub-layer that supports multiple network protocols over IEEE 802.16 air interface. The GPCS provides a generic packet convergence sub-layer. This layer uses the MAC SAP and exposes a SAP to GPCS applica- tions. The GPCS does not redefine or replace other convergence sub-layers. Instead, it provides a SAP that is not protocol specific. With GPCS, packet parsing occurs above GPCS. The results of packet parsing are classification parameters provided to the GPCS SAP for parameterized classification; however, upper layer packet parsing is left to the GPCS application. With GPCS, the upper layer protocol that is immediately above the IEEE 802.16 GPCS is identified by a parameter known as GPCS protocol type. The GPCS protocol type is included in service flow management primitives and connection establishment messages. The GPCS defines a set of SAP parameters as the result of upper layer packet parsing. These are passed from upper layer to the GPCS in addition to the data packet. The SAP parameters include SFID, the MS MAC Address, data, and length. The GPCS allows multiplexing of multiple layer protocol types (e.g., IPv4, IPv6, and Ethernet) over the same IEEE 802.16 MAC connection. It is outside the scope of the GPCS protocol to specify how the upper layer multiplexes and de-multiplexes multiple protocol data packets over an IEEE 802.16 connection or service flow [3]. In multimedia streaming applications, the overhead of Internet Protocol (IP) [15], User Datagram Protocol (UDP) [16], and Real-time Transport Protocol (RTP) [17,18] payload headers are 40 bytes for IPv4 (or 60 bytes for IPv6 [19]). For voice-over-IP, this corresponds to approximately 60% of the total amount of encoded voice data (e.g., the RTP payload of 3GPP Adaptive Multi-Rate 12.2 kbps full-rate codec consists of 33 bytes [20]). Such large overheads may be tolerable in wired links where capacity is often not an issue, but are excessive for wireless systems