3com WXR100 3CRWXR10095A User Manual

Page of 728
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 
spectrum.
„
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.