30
Field
Description
secondary bandwidth. When data is being transmitted, it
can act as 40MHz bandwidth, and it can also acts as 20
MHz bandwidth independently. In this way, the data rate
is doubled.
Aggregation
MSDU
(A-MSDU)
Enable or disable A-MSDU.
MSDU is the aggregation of multiple MSDUs by using
certain method and the multiple MSDUs forms a greater
load. MSDU can be considered as Ethernet message.
Usually, when AP or wireless client receives MSDUs from
protocol stack, the MSDUs will be marked with the
Ethernet message header (also called A-MSDU
Subframes). Before sending them out, the A-MSDU
Subframes need to be transformed into the message
format of 802.11 one by one.
A-MSDU aggregates multiple A-MSDU Subframes and
encapsulates them to be an 802.11 message. In this way,
PLCP Preamble, PLCP Header, and 802.11 MAC
overhead that are needed to send an 802.11 message
decrease. At the same time, the acknowledge frames
also decrease, and the efficiency for sending message is
improved.
Auto Block
ACK
Enable or disable Auto Block ACK.
In order to insure the security of the data transmission,
802.11n protocol requires that if client receives a uincast
frame, it should immediately send back an ACK frame.
After the receiver of A-MPDU receives A-MPDU, it needs
to process every MPDU. In that case, it sends out ACK
frames to every MPDU. Block Acknowledgement is used
to reduce the number of the ACK frames by using an
ACK frame.
Decline BA
Request
Enable or disable Decline BA Request.