ledgement to confirm the change of sleep mode configuration. If the BS accepts the change of sleep mode configuration, the BS sends an MAEH extended header as acknowledgement. The BS may modify the terminal's sleep cycle setting. In this case, the BS replies with a sleep control header including a different SCID to the Sleep Control This header is used to carry control Configuration of FID (4 bits) is flow identifier and is set to 0b0001. signaling related to sleep operation sleep mode Type (5 bits) denotes the MAC signaling header by a BS or an MS. In the case where operation type. this header is used to respond to a parameters previously used sleep control header, Length (3 bits) indicates the length of the signaling header in bytes. the MS or the BS are required to set the Sleep Control Header Sub-type (3 bits): response indication flag to 1 and to use Ob000 = Listening Window control; the same sub-type as the previously 0b001 = Resume Sleep Cycle Indication; received sleep control header. If the BS- 0b010 = Sleep cycle configuration switch; initiated request and an MS-initiated 0b011 = Sleep Cycle control; request occur concurrently, the BS- 0b100 = Multi-Carrier Listening Window control. initiated request takes precedence over Response Indication flag (1 bit). the MS-initiated request. Listening Window End or Extension flag (1 bit). Last frame of Extended Listening Window (7 bits) indicates the frame that extended listening window is terminated. Scheduled Sleep Cycle Interruption flag (1 bit). Start Frame Offset for Scheduled. Sleep Cycle Interruption (7 bits) denotes the number of frames in the future from the frame containing this header in which the scheduled sleep cycle interruption will occur. SCID (4 bits) corresponding to the new sleep cycle setting. Start Frame Offset for new sleep cycle configuration (3 bits) are the least significant bits of the frame number in which sleep cycle setting is to be applied. Next Sleep Cycle Flag (NSCF) (2 bits). New Initial Sleep Cycle (6 bits) is used when the curren