Block acknowledgement

= Block Acknowledgment =

It is a feature in IEEE 802.11-2007 Standard and 802.11n Draft to allow acknowledgement of a group of frames instead of a single frame (as previously used in 802.11a/b).

There are mainly two commands to establish a Block Acknowledgement agreement:

ADDBA: To establish a BlockAck agreement.

DELBA: To turn down a BlockAck agreement.

Once the agreement has been established, there are two types of Block Acks:

1. Immediate BlockAck

2. Delayed BlockAck

The frames used in these agreements are:

BAR (Block Acknowledgement Request)

To request an acknowledgement to the recipient station, confirming that has received a block of frames.

and BA (Block Acknowledgement) response

The confirmation from the recipient station, stating which frames have been received, this is explicitly mentioned in a matrix (part of the BAR) call the "bit map".

As the time of writing, current version of 802.11n unapproved standard (D3.01) includes a new type ob BlockAck called "HT Immediate BlockAck".

External links

* [http://grouper.ieee.org/groups/802/11/Reports/tgn_update.htm Status of the project 802.11n] IEEE Task Group TGn

References