User's Manual

Chapter 4 - Operation and Administration Sector Menu
BreezeMAX Extreme 176 System Manual
 Radar Detected Time: The last date and time at which the test results
indicated a presence of radar activity on this frequency, or N/A if the
frequency was not tested since last reset. The frequency is considered as
Unavailable for selection by the DFS mechanism if the elapsed time since the
Detected Time is not higher than Channel Non Occupancy Period.
Last Clear Channel Test: The last date and time at which the test results indicated
that there is no radar activity on this frequency, or N/A if the frequency was not
tested since last reset. The frequency is considered as Available for selection by
the DFS mechanism if the elapsed time since the Last Clear Channel Test is not
higher than Startup Test Valid Period.
4.7.2.2.2.2 DCS
The DCS (Dynamic Channel Selection) mechanism is designed to find the most
suitable channel for operation, i.e., the channel with the least interferences.
When the BS is turned on (startup) the DCS is triggered to select one of the best
channels at the current time. The selection is based on Noise and Interference (NI)
level measurements performed in all defined channels by the built-in spectrum
analyzer. DFS (if applicable) will be triggered after the channel selection (for
verification of the channel). A channel that is considered by the DFS mechanism
as Unavailable (see “DFS” on page 170) will not be selected by the DCS
mechanism.
If the Random Channel Selection parameter (see “Random Channel Selection” on
page 102) is set to Disable, the channels to be included in the DCS mechanism
will be those included in the Usable Frequencies List. If the Random Channel
Selection parameter is set to Enable, the unit will select randomly channels from
the relevant frequency band.
In configurations with two sectors, the DCS mechanism will avoid selection of the
channel used by the other sector.
During normal operation (on-going status), spectral efficiency detectors triggers
the DCS mechanism to seek for a new channel when channel conditions cause
performance degradation below a certain level.
Upon channel selection, the DCS is in charge of tracking the channel during
ongoing operation. During channel tracking, the DCS collects the uplink and
downlink RSSI and SNR of MSs served by the BS and calculates the average SNR
according to RSSI ranges. This enables the DCS to track the channel's conditions
according to the actual deployment and conditions, without any need for external
calibration/definitions. The DCS compares the on-going conditions with the
conditions at the initial selection point. If the conditions degraded below a certain
threshold, the channel selection procedure is triggered again.