RLX2-IHx Series ♦ 802.11a, b, g, n
Appendix C - RLX2-IHx 5 GHz Radio DFS Support
Industrial Hotspots
User Manual
ProSoft Technology, Inc.
Page 202 of 248
9
Appendix C - RLX2-IHx 5 GHz Radio DFS Support
Some channels in the 5 GHz band are shared with radar and must adhere to
Dynamic
Frequency Selection
(DFS) rules. If the radio detects the presence of radar on its
operating frequency, it must automatically change to another frequency.
Note: This applies only to radios that can operate at frequencies in the 5 GHz band.
9.1
DFS Radio Operations
If radar is detected on an operating channel, transmissions must cease within the
required
Channel Closing Transmission Time
, and must move to a new channel within
the required
Channel Move Time
. Before transmitting on a new DFS channel that has
not been previously checked for radar, the RLX2-IHx series radio must monitor the
channel for the
Channel Availability Check Time
before transmitting. Operations cannot
return to a channel where radar was detected for at least the
Non-Occupancy Period
.
The values for these parameters are noted in the table below:
Parameter
FCC Value
ETSI Value
ETSI Value
5.600 to 5.650 GHz
(Channels 120, 124, &
128)
Channel Availability
Check Time
60 seconds
60 seconds
10 minutes
Channel Move Time
10 seconds (12 seconds
for "long pulse" radar
10 seconds
10 seconds
Channel Closing
Transmission Time
200 milliseconds (plus
up to 60 milliseconds
over 10 seconds)
1 second
1 second
Non-Occupancy Period
30 minutes
30 minutes
30 minutes
If a Master radio detects radar, it issues a channel change announcement to all Client
and Repeater radios in the network. It then moves to a new channel within the
Channel
Move Time
. (Typically, this move time is 500 milliseconds or less.) If the selected
channel was not previously checked for the presence of radar, the Master radio must do
so for the
Channel Availability Check Time
before it can begin to transmit. If the newly-
selected channel is not a DFS channel, or if the channel was previously monitored for
radar since the radio was powered on, transmissions can begin immediately.
During the
Channel Availability Check Time
, a radio blinks all three amber Signal
Strength LEDS approximately once per second. If radar is detected on the new channel
during the
Channel Availability Check Time
, the Master radio selects another channel
and begins the process again.