Cambium Networks PTP 450 Series, Configuration Manual

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Chapter 1: Configuration Configuring radio parameters
Page
1-150
•
does not increase the power of transmission from the AP.
• can reduce aggregate throughput.
For example, with a 20 MHz channel and 2.5 ms frame, every additional 2.24
miles reduces the data air time by one symbol (around 1% of the frame).
Regardless of this distance, the SM must meet the minimum requirements
for an acceptable link. The parameters have to be selected so that there is
no overlap between one AP transmitting and another AP receiving. A co-
location tool is provided to help with selecting sets of parameters that allow
co-location.
The default value of this parameter is 2 miles (3.2 km).
Downlink Data Specify the percentage of the aggregate throughput for the downlink
(frames transmitted from the AP to the subscriber). For example, if the
aggregate (uplink and downlink total) throughput on the AP is 90 Mb, then
75% specified for this parameter allocates 67.5 Mb for the downlink and 22.5
Mb for the uplink. The default for this parameter is 75%. This parameter must
be set in the range of 15% - 85%, otherwise the invalid input will not be
accepted and the previously-entered valid setting is used.
Note
In order to prevent self-interference, the frame configuration
needs to align which includes Downlink Data, Max Range and
Contention slots. For DFS regions, the maximum Downlink % for
a 5.4 GHz radio is 75% only.
Contention Slots This field indicates the number of (reserved) Contention slots configured by
the operator. The SM uses reserved Contention slots and unused data slots
for bandwidth requests. See
Contention slots on page 1-209 .
Broadcast Repeat
Count For PMP systems broadcast packets are not acknowledged. So, they are sent
at the lowest modulation rate 1X. This setting adds an automatic
retransmission to broadcast packets to give SMs that have poor signal a
higher chance to get the packet.
Contention Slots
This field indicates the number of (reserved) Contention slots configured by
the operator. The SM uses reserved Contention slots and unused data slots
for bandwidth requests. See
Contention slots on page 1-209.
Auto Contention This parameter allows the operator to enable or disable Auto Contention.
EIRP This field indicates the combined power level at which the AP will transmit,
based on the Country Code. It also includes the antenna gain and array gain.
SM Receive Target
Level Each SM’s Transmitter Output Power is automatically set by the AP. The AP
monitors the received power from each SM, and adjusts each SM’s
Transmitter Output Power so that the received power at the AP from that
SM is not greater what is set in this field. This value represents the
transmitted and received power (combined power) perceived on the SM.
Adjacent Channel
Support For some frequency bands and products, this setting is needed if AP is
operating on adjacent channels with zero guard band.