Verint Nextiva S1100, Руководство пользователя

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F: Separation Between Devices Using Adjacent Channels
68 Verint Video Intelligence Solutions
If using adjacent frequency channels in a non-DFS environment, you should respect
guidelines relative to the minimum separation between device antennas, to avoid
interference.
To reduce radio interference possibilities between two adjacent channels, you should ensure
that the maximum margin between the emission of the two wireless cells is 25 dB. To meet
this objective, perform a site survey and apply minimum distance guidelines.
Performing a Site Survey
The difference in signal level between two adjacent cells must be less than or equal to
25 dB. If this margin is higher than 25 dB, there will be too much interference in the two
adjacent wireless cells. To calculate this margin, you need to perform a site survey; for
more information, see page 45. Here is an example of a 25 dB margin between channels 8
and 9 in the 4.9 GHz band:
Consider the following setup in the 4.9 GHz band with 5-MHz bandwidth, where Cell B uses
channel 6 and you are trying to add Cell A on channel 3 (adjacent to channel 6):
To determine if this setup is feasible, you need to conduct a site survey on device A1 (the
master device in Cell A), then calculate the margin between the two cells. During the site
survey, device A1 will find the other five devices. With the provided signal levels, you need
to check if S2 - S1 <= 25 dB, where:
„
S1 is the lowest signal level in the wireless cell of the device performing the site survey
(A1 in the example).
„
S2 is the highest signal level in the adjacent cell (Cell B in the example).
Interference between the two channels
Cell B Cell A
A3
A2
B3 B2
A1 B1