D-Link Unified Access System DWS-3000 Series User Manual page 159

Table 55. QoS Settings
Field
cwMin
(Minimum Contention
Window)
cwMax
(Maximum Contention
Window)
TXOP Limit
Description
This parameter is input to the algorithm that determines the initial
random backoff wait time ("window") for retry of a transmission.
The value specified in the Minimum Contention Window is the upper
limit (in milliseconds) of a range from which the initial random backoff
wait time is determined.
The first random number generated will be a number between 0 and the
number specified here.
If the first random backoff wait time expires before the data frame is
sent, a retry counter is incremented and the random backoff value
(window) is doubled. Doubling will continue until the size of the
random backoff value reaches the number defined in the Maximum
Contention Window.
The value specified in the Maximum Contention Window is the upper
limit (in milliseconds) for the doubling of the random backoff value.
This doubling continues until either the data frame is sent or the
Maximum Contention Window size is reached.
Once the Maximum Contention Window size is reached, retries will
continue until a maximum number of retries allowed is reached.
Station EDCA Parameter Only (The TXOP Limit applies only to
traffic flowing from the client station to the access point.)
The Transmission Opportunity (TXOP) is an interval of time when a
WME client station has the right to initiate transmissions onto the
wireless medium (WM).
This value specifies (in milliseconds) the Transmission Opportunity
(TXOP) for client stations; that is, the interval of time when a WMM
client station has the right to initiate transmissions on the wireless
network.
8 Configuring Advanced Settings
Configuring QoS 159