Verint Nextiva S1100, Руководство пользователя

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G: DFS and False Radar Detection
76 Verint Video Intelligence Solutions
To avoid false radar detection caused by an adjacent channel, the signal level of an
potential interfering device on the first adjacent channel must not exceed -50 dB, -36 dB on
the second channel, and -32 dB on the third channel; for example, if you use channel 100,
104 is the first adjacent channel, 108 the second channel, and 112 is the third channel.
The design of wireless systems in a DFS context becomes difficult because not only can the
master devices cause an interference, but the clients and slaves on an adjacent channel can
also generate interferences that can cause false radar detection. There should be a reduced
number of cells available to limit the amount of possible false radar detections; it is strongly
suggested to limit the number of colocated cells to six.
The new features that help reduce the possibility of false detection events are:
„
Half Channel Selection
This new parameter of the command line interface (CLI) eliminates the possibility of
using adjacent channels. Enable this feature on all masters (S3100, S1100-R) in a new
installation to avoid the potential conflict of having two masters on adjacent channels.
By default this feature is disabled.
If this option is enabled, the channel list becomes:
100(DFS), 108(DFS), 116(DFS), 124(DFS), 132(DFS), 140(DFS), 254(Auto DFS/TPC)
The full channel list is:
100(DFS), 104(DFS), 108(DFS), 112(DFS), 116(DFS), 120(DFS), 124(DFS), 128(DFS),
132(DFS), 136(DFS), 140(DFS), 254(Auto DFS/TPC)
In the CLI: Wireless Communication > Advanced Wireless Setup > DFS/TPC Adjacent
Channel Removal
„
Slave Radar Detection Management
A new CLI parameter allows you to disable radar detection on slave or client devices,
therefore reducing the number of nodes that can detect radars. In a typical DFS
environment, the slave or client can detect a radar and alert its master to change the
frequency channel. This situation can cause a major problem because it increases the
number of nodes that can detect radars.
The default value is Disabled, meaning that the slave/client does not detect radars; in
this case, the slave/client EIRP is reduced from 30 to 23 dBm.
In the CLI: Wireless Communication > Advanced Wireless Setup > Enable Radar
Detection on Slave
„
Manual Channel Selection
You can now select the initial frequency channel that will be used by the master, with
SConfigurator or the CLI. This new feature does not disable radar detection on master
devices. This process will still take place and if a radar is detected, the device will go
through the regular DFS process (stop transmission on the channel, block this channel
for 30 minutes, and select a new channel in the available channel list).