3Com WX2200 3CRWX220095A Switch User Manual

Overview 313
Power Tuning
By default, the switch evaluates the scan results for possible power
changes every 300 seconds (5 minutes), and raises or lowers the power
level if needed.
If RF Auto-Tuning determines that a power change is needed on a radio,
MSS ramps the power up or down until the new power level is reached.
Ramp-up or ramp-down of the power occurs in 1 dBm increments, at regular
time intervals. The default interval is 60 seconds and is configurable. The
power ramp amount (1 dBm per interval) is not configurable.
Channel Tuning
By default, the switch evaluates the scan results for possible channel
changes every 3600 seconds (1 hour). MSS uses the following parameters
to determine whether to change the channel on a radio:
Presence of active sessions.
By default, If the radio has active sessions, MSS does not change the
channel. If the radio does not have any active sessions, MSS uses the
remaining parameters to determine whether to change the channel.
Received signal strength indication (RSSI)
Amount of noise on the channel
Packet retransmission count, which is the rate at which the radio
receives retransmitted packets.
Utilization, calculated based on the number of multicast packets per
second that a radio can send on a channel while continuously sending
fixed-size frames over a period of time.
Phy error count, which is the number of frames received by the MAP
radio that have physical layer errors. A high number of Phy errors can
indicate the presence of a non-802.11 device using the same RF
Received CRC error count. A high number of CRC errors can indicate
a hidden node or co-channel interference.
The thresholds for these parameters are not configurable.
RF Auto-Tuning also can change a radio’s channel when the channel
tuning interval expires, if a channel that has less disturbance is detected.
Disturbance is based on the number of neighbors the radio has and each
neighbor’s RSSI.