Method for reporting reception result of packets in mobile communication system
Disclosed is a bitmap structure which enables the size of a bitmap field containing reception result information to be significantly reduced while fully performing its acknowledgment function. To this end, a message region for recording indicators, which enables reception success or failure for the maximum allowable SN level packets treatable by block ACK to be confirmed, is assigned. A message region for recording only the reception results for unsuccessfully received packets is also assigned. A receiving party confirms the unsuccessfully received packets through the indicators, and retransmits the unsuccessfully received packets. Also, a transmitting party provides the number of SN level packets and the maximum number of fragmentation packets to the receiving party. The receiving party determines an optimized bitmap configuration scheme, and transmits the reception results for the respective fragmentation packets to the transmitting party based on the determined bitmap configuration scheme.
1. A method for configuring a Block Acknowledgement (BA) frame in a wireless communication system for acknowledgement by a receiver of a data transmission from a transmitter, the method comprising:
receiving—by the receiver a Block Acknowledgement Request (BAR) frame in the data transmission from the transmitter;
determining by the receiver an overall size of a bitmap for the BA frame from the BAR frame configured to acknowledge the data transmission;
configuring by the receiver the BA frame of the response to include the bitmap having the determined overall size;
transmitting by the receiver the configured BA frame to the transmitter,
wherein the bitmap of the BA frame includes bits representing reception results of packets of the data transmission received from the transmitter.
2. The method as claimed in claim 1 , wherein the overall bitmap size is determined by the receiver to be:
Overall bitmap size=ceiling [ m×n/ 8]octets
where ceiling [x] denotes a minimum integer from among integers exceeding ‘x’, the variable ‘m’ is a number of consecutively received packets-, and the variable ‘n’ is a number of fragmentation packets,
wherein the variable ‘m’ and the variable ‘n’ are determined from the BAR frame.
3. The method as claimed in claim 2 , wherein the bitmap of the BA includes a plurality of individual bitmaps for the consecutively received packets and a size of each individual bitmap corresponding to each of the consecutively received packets is determined as n bits.
4. The method as claimed in claim 3 , wherein a number of bits out of the overall bitmap size are padding bit, the number of padding bits being calculated by the following equation:
ceiling [m×n/8]×8−m×n.
5. The method as claimed in claim 1 , wherein each bit of the bitmap for the block acknowledgement is set as ‘1’if a corresponding packet is successfully received, and is set as ‘0’ if reception of the corresponding packet has failed.
6. The method as claimed in claim 1 , wherein information about bitmap size is included in a control field of the BAR frame.
7. The method as claimed in claim 1 , wherein the BAR frame includes bitmap size related information used by the receiver in determining the overall size of the bitmap.