USRobotics Instant802 APSDK manual Enabling/Disabling Wi-Fi Multimedia

Professional Access Point Administrator Guide

Field

Description

cwMin	This parameter is input to the algorithm that determines the initial random
(Minimum Contention Window)	backoff wait time for retry of a transmission.
	Select a value from the list. The value selected for cwMin 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 in cwMin.
	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 dou-
	bled. Doubling will continue until the size of the random backoff value reaches
	the number defined in the Maximum Contention Window.
	For more information, see “Random Backoff and Minimum / Maximum Conten-
	tion Windows” on page 146.
cwMax	Select a value that is higher than cwMin.
(Maximum Contention Window)	The value specified for cwMax is the upper limit, in milliseconds, for the dou-
	bling 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.
	For more information, see “Random Backoff and Minimum / Maximum Conten-
	tion Windows” on page 146.
Max. Burst	AP EDCA Parameter Only. The Max. Burst Length applies only to traffic flowing
(Maximum Burst Length)	from the access point to the client station.
	This value specifies, in milliseconds, the Maximum Burst Length allowed for
	packet bursts on the wireless network. A packet burst is a collection of multiple
	frames transmitted without header information. The decreased overhead
	results in higher throughput and better performance.
	Valid values for maximum burst length are 0.0 through 999.9.
	For more information, see “Packet Bursting for Better Performance” on
	page 147.

Enabling/Disabling Wi-Fi Multimedia

By default, Wi-Fi MultiMedia (WMM) is enabled on the access point. With WMM enabled, QoS prioritisation and coordination of wireless medium access is on. With WMM enabled, QoS settings on the Professional Access Point control downstream traffic flowing from the access point to client station (access point EDCA parameters) and the upstream traffic flowing from the station to the access point (station EDCA parameters).

Disabling WMM will deactivate QoS control of station EDCA parameters on upstream traffic flowing from the station to the access point

With WMM disabled, you can still set some parameters on the downstream traffic flowing from the access

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