3Com OfficeConnect 3CRWDR200A-75 User Manual page 58

58 C 5: R C
HAPTER OUTER ONFIGURATION
Figure 36 WMM Screen
Typically, voice and video traffic types are delay-sensitive, but are tolerant
of some frame losses.On the other hand, data traffic type is
delay-tolerable, but requires loss-free transmission. So you may adjust
theses parameters with regard to the characteristics of these types of
data to better manage your network flow.
AC (Access Category): It uses 4 different ACs, from high to low:
VO:Voice, VI: Video, BE:Best Effort, BK: Background
AIFS (Arbitrary Interframe Space): An Interframe Space for different
Access Category
TXOP (Transmission Opportunity): WMM (Wireless Multimedia)
Transmission Opportunity: defined by IEEE 802.11e, the TXOP is the
interval of time when a particular STA (station) has the right to initiate
transmissions.
ACM (Admission Mandatory): Advertised in the EDCA parameter set
element to indicate the admission control is required for each of the ACs.
EDCA AP Paramenters:
Theses values of AIFS, CWmin, and CWmax are announced by the AP via
beacon frames. The AP can adapt these parameters dynamically
depending on the network conditions. Basically, the smaller AIFS and
CWmin, the shorter the channel access delay for the corresponding