Apparatus and method of block acknowledgements with reduced recipient state information
An apparatus and method for block acknowledgements with reduced recipient state information are described. In one embodiment, the method comprises the storing of a receive state for a block of frames received during a transmission opportunity (TXOP) with an on-chip state memory. Once stored, an immediate block acknowledgement, including the receive state information, may be transmitted to an originator according to a block acknowledgement request (BAR) received during the TXOP. In the embodiments described, the BAR is received during the TXOP in which the block of data frames were transmitted to a recipient. In one embodiment, the recipient is free to discard the receive state information to free space within the on-chip system memory by requiring the originator to maintain the receive state information of blocks of data frames transmitted during TXOPs. Other embodiments are described and claimed.
1. A method comprising:
storing receive state information within a state memory for a block of frames received during a transmit opportunity (TXOP), including:
comparing a transmission identifier (TID) and a transmitter address (TA) of a received data frame to a TID and a TA of the receive state information,
updating the receive state information for the received data frame if the TID and TA of the receive state information match the TID and TA of the received data frame,
generating additional receive state information if the TA of the received data frame matches a TA of the receive state information and the TID of the received data frame does not match the TID of the receive state information, and
otherwise, discarding the receive state information, and generating new receive state information for the TID and TA of the received data frame;
transmitting a block acknowledgement (ACK) including the receive state information according to a block acknowledgement request (BAR) received during the TXOP; and
discarding the receive state information subsequent to completion of the TXOP.
2. The method of claim 1 , wherein discarding the receive state information further comprises:
receiving a block of frames during a next TXOP;
generating new receive state information for the block of frames received during the next TXOP; and
deleting the receive state information for the block of frames received during the TXOP.
3. The method of claim 1 , further comprising:
releasing a continuous sequence of frames beginning from a starting sequence number (SSN) of the received BAR.
4. A method comprising:
storing receive state information within a state memory for a block of frames received during a transmit opportunity (TXOP):
transmitting a block acknowledgement (ACK) including the receive state information according to a block acknowledgement request (BAR) received during the TXOP, including:
receiving the BA during the TXOP,
comparing a transmission identifier (TID) and a transmitter address (TA) of the BAR to a TID and a TA of at least one block ACK (BA) bitmap,
shifting the BA bitmap according to a starting sequence number (SSN) of the received BAR if the TA and TID of the BA bitmap match the TA and the TID of the received BAR,
transmitting the BA bitmap to an originator, and
transmitting a null BA bitmap to the originator if the TA and the TID of the received BAR do not match a BA bitmap of a recipient; and
discarding the receive state information subsequent to completion of the TXOP.