in the Feedback Polling IE. When sent as unsolicited feedback, the legacy MS can either send the feedback header on currently allocated UL resource or request additional UL resource by sending an indication flag on the fast-feedback channel or the enhanced fast-feedback channel, or by sending a bandwidth request ranging code [1]. The feedback header with and without the CID field are illustrated in Figure 6-9. The feedback header with the CID field is used when the UL resource used to send the feedback header is requested through bandwidth request ranging; otherwise it is without the CID field. In Figure 6-10, the CID Inclusion CHAPTER 6 The IEEE 802.16m MAC CPS (Part I) MSB of Header Content (3 Bits) (11 Bits) LSB of Header Content MSB of CID (8 bits) (8 Bits) LSB of CID Header Checksum Sequence (8 Bits) (8 Bits) Header Content (19 Bits) Bandwidth Request Bandwidth Request Uplink Transmit Power (19 Bits) (11 Bits) (8 Bits) Incremental/Aggregate Bandwidth Request (BR) Bandwidth Request with Uplink Transmit Power Report Bandwidth Request Feedback Type Preferred CQI (11 Bits) (7 Bits) (3 Bits) Period (3 Bits) Reserved (4 Bits) DCD Change Indicator (1 Bit) FBSS Indicator (1 Bit) Bandwidth Request and Carrier to Interference plus Noise (CINR) Report Channel Quality Indicator Channel (CQICH) Allocation Request Preferred Uplink Maximum Uplink Transmit Power Transmit Power DIUC Index Bandwidth Request Power Saving Class (8 Bits) Headroom in dB (11 Bits) (6 Bits) (3 Bits) (6 Bits) Power Class Activation (1 Bit) Reserved (1 Bit) Reserved (1 Bit) Physical Channel Report Bandwidth Request and Uplink Sleep Control Report ARQ Block Serial Number/ Reserved MAC SDU Serial Number (11 Bits) (8 Bits) ARQ Block Serial Number (BSN) or MAC SDU Serial Number (SN) FIGURE 6-8 Legacy Type I MAC signaling header structures [1] 6.3 MAC signaling headers Table 6-3 Type Field Encodings for Legacy MAC Signaling Header Type I [1] MAC Header Type (HT) Description of the Fields Ob000 Incremental Bandwidth Request (BR) The amount of requested res