Method and apparatus for operating a timer for processing data blocks
A timer for processing data blocks is proposed for a receiver of a mobile communications system. If the timer is not running, the timer is started based a data block. The data block has a sequence number higher than a sequence number of another data block that was first expected to be received. If the timer is stopped or expires, the timer is based on a highest sequence number of a data block among data blocks that cannot be delivered to a higher entity. The timer can be used to prevent a stall condition in mobile communications.
1. A method of operating a timer for processing data blocks by a terminal in a communications system, the method comprising:
storing, by the terminal, a first data block with a sequence number in a buffer;
starting, by the terminal, the timer based on the sequence number of the first data block, wherein the sequence number of the first data block is higher than a sequence number of another data block that was expected to be received; and
when the timer expires, starting, by the terminal, the timer based on a sequence number of a second data block, wherein the second data block has a highest sequence number among data blocks that are stored in the buffer.
2. The method of claim 1 , wherein the first data block stored in the buffer is processed by a data link layer of the terminal.
3. The method of claim 1 , wherein no additional timer is started in the terminal if the timer is running.
4. The method of claim 1 , wherein the timer is used for re-ordering operation at a sub-layer of the terminal.
5. The method of claim 1 , further comprising:
while the timer is running, determining, by the terminal, whether to deliver at least one received data block to an upper layer in an ascending order when the first data block is stored in the buffer.
6. The method of claim 5 , further comprising:
when the timer expires, deliver, by the terminal, any data block that can be delivered to the upper layer in an ascending order.
7. The method of claim 5 , wherein the upper layer is a radio link control (RLC) layer of the terminal, and wherein the RLC layer operates in an acknowledged mode (AM).
8. The method of claim 5 , wherein the upper layer is a radio link control (RLC) layer of the terminal, and wherein the RLC layer operates in an unacknowledged mode (UM).
9. A terminal in a communications system, the terminal comprising:
a buffer configured to store data blocks with a sequence number; and
a processor coupled to the buffer and configured to:
start a timer based on the sequence number of a first data block, wherein the sequence number of the first data block is higher than a sequence number of another data block that was expected to be received;
when the timer expires, start the timer based on a sequence number of a second data block, wherein the second data block has a highest sequence number among data blocks that are stored in the buffer.
10. The terminal of claim 9 , wherein the upper layer is a radio link control (RLC) layer of the terminal, and wherein the RLC layer operates in an unacknowledged mode (UM).
11. The terminal of claim 9 , wherein the first data block stored in the buffer is processed by a data link layer of the terminal.
12. The terminal of claim 9 , wherein no additional timer in the terminal is started if the timer is running.
13. The terminal of claim 9 , wherein the timer is used for re-ordering operation at a sub-layer of the terminal.
14. The terminal of claim 9 , wherein the processor is further configured to:
while the timer is running, determine whether to deliver at least one received data block to an upper layer in an ascending order when the first data block is stored in the buffer.
15. The terminal of claim 14 , wherein the processor is further configured to:
when the timer expires, deliver any data block that can be delivered to the upper layer in an ascending order.
16. The terminal of claim 14 , wherein the upper layer is a radio link control (RLC) layer of the terminal, and wherein the RLC layer operates in an acknowledged mode (AM).
17. The terminal of claim 14 , wherein the upper layer is a radio link control (RLC) layer of the terminal, and wherein the RLC layer operates in an unacknowledged mode (UM).