hronous HARQ re-transmission (i.e., a HARQ scheme where the transmissions/re-transmissions are scheduled at predetermined fixed time intervals) is used for uplink persistent allocations. The UL Basic Assignment A-MAP IE is transmitted to signal control information for HARQ re-transmission. For transmissions where HARQ is enabled, an ACK or NACK is transmitted to acknowledge the success or failure of decoding of data burst. If an ACK or NACK for the data burst is detected in the assigned HARQ feedback channel, the BS would assume that the DL Persistent A-MAP IE is correctly received by the MS. If the initial data burst identified by the UL Persistent A-MAP IE is successfully decoded in HARQ period, the BS assumes that the UL Persistent A-MAP IE is correctly received. If no ACK or NACK is detected in the HARQ feedback channel, the BS assumes that the MS has not received the DL Persistent A-MAP IE and the same DL persistent allocation can be re-transmitted. In the case of de-allocation of persistent allocations in the DL/UL, the BS transmits a HARQ feedback allocation in the DL/UL Persistent A-MAP IE. This allocation is used to identify the HARQ channel in which the ACK for the DL/UL Persistent A-MAP IE signaling the de-allocation is transmitted. In the absence of an ACK, the BS will assume that the MS has not received the DL/UL Persistent A-MAP IE, and will re-transmit the DL/UL Persistent A-MAP IE that signaled de-allocation. If no ACK or NACK is detected in the HARQ feedback channel, the BS will assume that the MS has not received the UL Persistent A-MAP IE and re-transmit the same UL Persistent A-MAP IE. 6.10.2 Group Resource Scheduling The Group Resource Allocation (GRA) is a scheduling mechanism that allocates resources to multiple users as a group, in order to reduce the control overhead. The users are grouped according to the commonality of channel conditions and operational parameters, such as modulation and coding scheme, MIMO mode, HARQ burst size, and resource size. A bitmap is used to represent differen