| 摘要 |
A ARQ actions taken in the data link layer control (DLC) in a wireless communications system for data transmission is implemented by using the HiperLAN/2 protocol that has a selective retransmission process to complete bitmaps when there are errors in data unit transmissions. More particularly it pertains to adaptive allocation of ARQ feedback bandwidth to economize on the use of bandwidth. This is achieved by informing the scheduler of the status of received and non-received data units at the receiver to allow adaptive ARQ feedback bandwidth during data transmission. The information about the status of data units at the receiver is provided by the ABIR flag contained in the ARQ feedback message. If there are many unacknowledged messages of,data units, the ABIR flag is set and the scheduler increases bandwidth to accommodate the traffic of retransmitted messages that were omitted. When the situation has returned to normal, that is, there are minimal messages waiting to be retransmitted the ABIR flag is set to null and no added bandwidth is assigned. This technique can be used also to find the lowest level of bandwidth by decreasing bandwidth until there is a backup in traffic of retransmissions and increasing bandwidth at that time.
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