Cambium Networks PMP 450 AP, Планирование и руководство по установке

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Chapter 3: System planning Radio Frequency planning
Page
3-23
When selecting one of the LTE Frame Configuration options from the Co-located LTE Frame
Configuration Option drop-down menu, a shift is applied to the Cambium PMP frame in order to
correctly line up with the selected LTE frame.
Frame parameters
After following the steps described above, the Cambium PMP and the LTE APs are synchronized, and
their frame length is the same.
Next, the frame parameters have to be selected in order to avoid any overlap between one AP
transmitting and another receiving.
Figures X and Y shows one example of frames that do not interfere and one example of frames that do
interfere. In both Figures the downlink time and the uplink time of the two APs are not identical.
In Figure X there is no overlap between one AP transmitting and another AP receiving, and the two APs
can be co-located.
In Figure Y however, AP1 is still transmitting when AP2 is already receiving. This creates interference at
the AP2’s receiver and the APs cannot be co-located with these parameters.
Figure X Example of APs that can be co-located
Figure Y Example of APs that cannot be co-located
Once the LTE Frame Configuration is selected from the drop-down menu, the LTE downlink and uplink
times are defined.
The Cambium PMP frame times are determined by the following configuration parameters:
• Channel Bandwidth: amount of spectrum allocated for communication in the sector
Options for the Channel Bandwidth in the 3 GHz band are 5 MHz, 7 MHz, 10 MHz, 15 MHz, 20
MHz, 30 MHz and 40 MHz.