| 摘要 |
A method for preventing a stall condition in a terminal of a mobile communications system uses a timer to limit how long data blocks are stored in a reordering buffer. The method includes receiving a data block over a wireless link, determining whether a preceding data block has not been received, storing the received data block in the reordering buffer if a preceding data block has not been received, and then outputting the received block from the buffer when the timer expires. Whether or not a preceding data block is missing is determined based on a comparison of transmission sequence numbers. In other steps of the method, succeeding data blocks are output from the buffer based on expiration of a second timer period. The periods of the timer are advantageously controlled to prevent a wrap-around of transmission sequence numbers with respect to data blocks stored in the buffer. If desired, the data blocks may include MAC-hs protocol data units. By limiting the amount of time any one data block stays in the buffer, a stall condition is advantageously prevented. As a result, transmission efficiency and the reliability of received data is substantially improved. The method is ideally suited for use in a medium access layer of a high-speed downlink packet access (HSDPA) mobile communications system, although other uses are contemplated. <IMAGE> |
