3.8
Wireless
Ubee Interactive
50
DDW3612 Subscriber User Guide
•
July, 2010
3.8.7
Additional Information - WiFi MultiMedia (WMM)
WMM QoS is a part of the IEEE 802.11e QoS enhancement to certified WiFi wireless
networks.
On wireless access points without WMM QoS, all traffic streams are given
the same access priority to the wireless network. If the introduction of another traffic
stream creates a data transmission demand that exceeds the current network
capacity, then the new traffic stream reduces the throughput of the other traffic
streams. A WMM QoS capability in a network may assign access categories (ACs) to
various streams of packets. The assigned AC of a stream of packets may depend on
the packets' priority, for example, as assigned by an application, and may be referred
Power Save Support
Select On or Off to turn on or off power savings. WMM Power
Save increases the efficiency and flexibility of data transmission.
Specifically, the wireless client device can "doze" between
packets to save power, while the wireless access point buffers
downlink frames. The application chooses the time to wake up
and receive data packets to maximize power conservation
without sacrificing Quality of Service.
EDCA-AP Parameters
Enhanced Distributed Channel Access - Access Point. In this
area of the screen, four Access Categories (ACs) are listed to
prioritize wireless network traffic. Refer to the next row below.
AC-BE
AC-BK
AC-VI
AC-VO
The Wi-Fi Multimedia feature prioritizes traffic according to four
access categories (ACs):
AC-BE
—Best Effort, medium throughput and delay. Most
traditional IP data is sent to this queue.
AC-BK
—Background, high throughput. Bulk data that requires
maximum throughput and is not time-sensitive is sent to this
queue (for example, FTP data).
AC-VI
—Video
AC-VO
—Voice
CWmin/CWmax/AIFSN
For each AC, set the following fields:
CWmin/CWmax
AIFS—Interframe Space
Back off Counter
TXOP (b) Limit
(usec)/TXOP (a/g) Limit
(usec)/Discard Oldest
First
Enter a TXOP limit. Each AC is assigned a Transmit Opportunity
(TXOP). A TXOP is a bounded time interval during which a
station can send as many frames as possible (as long as the
duration of the transmissions does not extend beyond the
maximum duration of the TXOP). If a frame is too large to be
transmitted in a single TXOP, it should be fragmented into
smaller frames. The use of TXOP reduces the problem of low
rate stations gaining an inordinate amount of channel time in the
legacy 802.11 DCF MAC. A TXOP time interval of 0 means it is
limited to a single MSDU or MMPDU.
EDCA STA Parameters
These settings are used for receiving terminals.
CWmin/CWmax/AIFSN
TXOP (b) Limit
(usec)/TXOP (a/g) Limit
(usec)
Refer to the rows above for definitions of these fields.
Apply
Click to save all changes.
19216811.live