Motorola WR850GP manual Acknowledgement, Edca AP, Client Parameters

Section 3 Configuration

Field	Description
No-	Enables No-Acknowledgment operation in WMM, entrusting that
Acknowledgement:	the WR850 and clients can share prioritization settings without
(ADVANCED)	the need to transmit acknowledgement messages.
	Disabling acknowledgement messages can free up wireless
	network capacity but can increase opportunities for errors if
	strong wireless connections are not established between the
	WR850 and all WMM-enabled clients.
	• Selecting On entrusts that prioritization can occur without
	acknowledgement messages.
	• Selecting Off mandates acknowledgement messages.
	FACTORY DEFAULT: Off
EDCA AP and	WMM uses a protocol called Enhanced Distributed Channel
Client Parameters:	Access (EDCA) to prioritize traffic on the wireless network.
(ADVANCED)	EDCA requires that wireless devices assign each intended
	transmission a priority, within an Access Category (AC).
	WMM defines 4 Access Categories:
	• Voice, to give voice traffic the highest priority, since it has
	the least tolerance for delays and/or loss of data.
	• Video, to give video a higher priority than other traffic,
	and optimize real-time video display.
	• Best Effort, for legacy devices, and/or any other traffic
	sensitive to delays (e.g., general Internet surfing).
	• Background, for lowest priority traffic with limited
	sensitivity to delays (e.g., printing).
	EDCA manages queues of transmissions within each of these
	ACs, allocating “slots” of time (or “transmit opportunities”) to
	each, based on three prioritization settings, set per AC:
	• Arbitrary Inter-Frame Space Number (AISFN), a
	minimum number of “slots” a transmission will wait in
	between transmission opportunities.
	• Contention Window (CW), a minimum and maximum
	number of “slots” randomly added to the AIFSN, in order
	to minimize conflicts between transmissions.
	• Transmit Opportunity Limit (TXOP limit), the length of
	time allocated to a transmission one it reaches the top of
	a queue. For example, video is typically given larger
	TXOP limits because it is more data-intensive.
	The WR850 manages EDCA prioritization across the network.
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