service flow ID). METROPOLITAN AREA NETWORKS DOWNLINK UPLINK frame Broadcast Half Duplex Terminal #1 Full Duplex Capable User Half Duplex Terminal #2 Figure 13.9 Burst FDD framing with IEEE 802.16. TDM Portion Broadcast TDMA Portion Control DIUC a DIUC b DIUC C DIUC 0 DIUC d DIUC e DIUC f DIUC g Burst Start Points DL-MAP UL-MAP Figure 13.10 IEEE 802.16 FDD downlink subframe. Table 13.1 IEEE 802.16 Modulation Rates and Channel Sizes Channel Width Symbol Rate QPSK Bit Rate 16-QAM Bit Rate 64-QAM Bit Rate (MHz) (Msymbols/sec) (Mbps) (Mbps) (Mbps) 134.4 The ATM convergence sublayer provides support for VP (virtual path) switched con- nections and VC (virtual channel) switched connections. This sublayer also supports end-to-end signaling of dynamically created connections such as SVCs (switched vir- tual connections) and soft PVCs (permanent virtual connections). There is ATM header suppression as well as full QoS support. The packet convergence sublayer provides initial support for Ethernet, IPV4 and IPV6. Here there is payload header suppression that is generic plus IP-specific with full QoS 13.6 IEEE 802.16 STANDARD MAC Message SDU 1 SDU 2 MAC PDUs PDU 1 PDU 2 PDU 3 PDU 4 PDU 5 Burst FEC 1 FEC 2 FEC 3 MAC PDUs Preamble FEC block Figure 13.11 A typical MAC PDU transmission. Generic MAC Header Payload (optional) CRC (optional) Figure 13.12 MAC PDU format. support. We can expect possible future support in this sublayer for PPP (point-to-point protocol; see RFC 1661), MPLS (multi-protocolo label switching), and others. MAC addressing specifies a 48-bit address capability for the subscriber station (SS) and 48-bit base station (BS) ID that is not a MAC address. There is a 24-bit operator indicator. There is also a 16-bit connection ID (CID) that is used in MAC PDUs. MAC PDUs are transmitted in PHY bursts. A single PHY burst can contain multiple concatenated MAC PDUs. The PHY burst can also contain multiple FEC (forward error correction) blocks. The MAC PDUs can span FEC block boundaries. The transmission convergence lay