Users Guide

130 | Configuration Reference Dell PowerConnect W-AirWave 7.4 | Configuration Guide
1. Select Profiles > SSID > EDCA Station in the navigation pane.
2. Select the Add button to create a new EDCA Station profile, or click the pencil icon to edit an existing
profile. Complete the settings as described in Table 34:
Table 62 Profiles > SSID > EDCA Station Profile Settings
Field Default Description
General Settings
Folder Top Set the folder with which the profile is associated. The drop-down menu displays all
folders available for association with the profile.
Name Blank Name of the EDCA STA profile.
Best Effort
Arbitrary Inter-frame
Space Number (1-15)
3 WMM is an extension to the Carrier Sense Multiple Access with Collision Avoidance
(CSMA/CA) protocol’s Distributed Coordination Function (DCF).
The collision resolution algorithm responsible for traffic prioritization depends on the
following configurable parameters for each AC:
 arbitrary inter-frame space number (AIFSN)
 minimum and maximum contention window (CW) size
Minimum Contention
Window (Exponent) (0-15)
4
Maximum Contention
Window (Exponent) (1-15)
10
Transmission Opportunity
Slots in 32 μsec Units
0 For each AC, the backoff time is the sum of the AIFSN and a random value between 0
and the CW value. The AC with the lowest backoff time is granted the opportunity to
transmit (TXOP). Frames with the highest priority AC are more likely to get TXOP as
they tend to have the lowest backoff times (a result of having smaller AIFSN and CW
parameter values). The value of the CW varies through time as the CW doubles after
each collision up to the maximum CW. The CW is reset to the minimum value after
successful transmission.
In addition, you can configure the TXOP duration for each AC.
Background
Arbitrary Inter-frame
Space Number
7 WMM is an extension to the Carrier Sense Multiple Access with Collision Avoidance
(CSMA/CA) protocol’s Distributed Coordination Function (DCF).
The collision resolution algorithm responsible for traffic prioritization depends on the
following configurable parameters for each AC:
 arbitrary inter-frame space number (AIFSN)
 minimum and maximum contention window (CW) size
Minimum Contention
Window (Exponent)
4
Maximum Contention
Window (Exponent)
10
Transmission Opportunity
Slots in 32 μsec Units
0 For each AC, the backoff time is the sum of the AIFSN and a random value between 0
and the CW value. The AC with the lowest backoff time is granted the opportunity to
transmit (TXOP). Frames with the highest priority AC are more likely to get TXOP as
they tend to have the lowest backoff times (a result of having smaller AIFSN and CW
parameter values). The value of the CW varies through time as the CW doubles after
each collision up to the maximum CW. The CW is reset to the minimum value after
successful transmission.
In addition, you can configure the TXOP duration for each AC.
ACM No Define whether or not admission control mandatory (ACM) is to be supported on APs
configured with this EDCA profile.