tains the remaining system information for maintaining communication with the BS. The contents of the superframe header components are shown in Table 9-14. Table 9-14 Contents of Superframe Header [2] Superframe Header Component Periodicity (ms) Parameters Size (Bits) Description P-SFH LSB of Superframe Number Four least significant bits of superframe number. S-SFH Change Count The value of S-SFH change count associated with the S-SFH SP1, SP2, or SP3 IE transmitted in this superframe. S-SFH Size Extension S-SFH Number of Repetitions The transmission format (repetition factor) used for S-SFH (1, 3, 6). S-SFH Scheduling Information ObOO: S-SFH includes SP1 IE; 0b01: S-SFH includes SP2 IE; Ob10: S-SFH includes SP3 IE; Ob11: No S-SFH. S-SFH SP Change Bitmap The change of S-SFH SP1, SP2, or SP3 IE associated with the S-SFH change count: 0b000: No change in SP1-SP3; 0b001: SP1 has changed; 0b010: SP2 has changed; Ob100: SP3 has changed. S-SFH Applying Offset This one-bit flag informs the MS of the S-SFH change count that is considered for applying the system parameters in the S-SFH SPx IEs. If the S-SFH applying offset is set to "0," the MS uses the system parameters of S-SFH SPx IEs associated with the current S-SFH change count. Otherwise, if the S-SFH applying offset is "1," the MS uses the parameters associated with previous S-SFH (Continued) Table 9-14 Contents of Superframe Header [2] Continued Superframe Header Component Periodicity (ms) Parameters Size (Bits) Description change count. If the S-SFH contents associated with previous S-SFH change count is not available, the MS will acquire the relevant S-SFH contents by decoding the S-SFH sub-packets at their corresponding scheduled timing. S-SFH SP1 MSB of superframe number Remaining bits of superframe number except those already in P-SFH. LSB of 48-bit BS MAC ID Twelve least significant bits of (BS-ID) BS-ID. Number of UL ACK/NACK Channel numbers represented by Channels per HARQ Feedback the two bits (0, 1, 2, 3) are as Region follows: For 5 MHz band, 6, 12, 18