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PMP 400/430 and PTP 200/230 Series Configuration and User Guide
pmp-0042 (March 2014)
Page 69 of 98
Guard Band
One difference between a PMP 450 deployment and a mixed PMP 450 – PMP 430 deployment using the
interoperability feature is that in a PMP 450 deployment, adjacent sectors can operate with adjacent
frequencies, while in a mixed PMP 450 – PMP 430 deployment using the interoperability feature a guard
band is needed. The guard band is equal to 5 MHz between two adjacent 20 and 10 MHz channels, and it is
equal to 2.5 MHz between two adjacent 5 MHz channels.
The interoperability feature will typically be used in two possible scenarios: for upgrading a PMP 430
network to a PMP 450 network, or for adding PMP 430 SMs to a Greenfield PMP 450 deployment.
Upgrade of a PMP 430 network to a PMP 450 network:
During network planning of a PMP 430 network, the recommendation is not to use
adjacent channels on adjacent sectors, but to leave a 5 MHz guard band between
adjacent channels when used on adjacent sectors. If the 5 MHz guard band is already
present between adjacent channels, than this is a sufficient guard also between a PMP
430 channel and a PMP 450 channel, so the upgraded PMP 450 sector does not need
additional guard bands.
Add PMP 430 SMs to a Greenfield PMP 450 deployment:
In a Greenfield PMP 450 deployment there is no requirement for guard bands between
adjacent channels, so it is possible that the network was deployed with adjacent channels
on adjacent frequencies. If PMP 430 SMs are added to the sector, it is necessary to
update the network planning in order to leave a gap of 5 MHz between two adjacent 20 or
10 MHz channels, and a gap of 2.5 MHz between two adjacent 5 MHz channels when
operating on adjacent sectors.
Stranded SMs
If some PMP 430 SMs are turned off during the upgrade process, they will require a truck roll to be
upgraded to Release 12.2, because they will not be able to connect to the PMP 450 AP without running
R12.2 software.
Cyclic Prefix
Since the PMP 450 AP supports CP=1/16 only, the upgraded PMP 430 SMs in interoperability mode also
support CP=1/16 only. The PMP 430 SMs will automatically be defaulted to CP=1/16 when connected to a
PMP 450 AP; the other CP values can be selected when registering to a PMP 430 AP.
Channel Bandwidth
For the PMP 430 SMs to connect to the PMP 450 AP in interoperability mode, the PMP 430 bandwidth
selected in the GUI needs to match the PMP 450 AP bandwidth. The PMP 430 SM does not support the
band scan feature, and initial scanning only uses the selected bandwidth.
Color codes
When the operator replaces a PMP 430 AP with a PMP 450 AP it is recommended that they use the same
color code.