Technology And Benefits; Nlos Benefits And Limitations - Cambium Networks PMP 400 Series Configuration And User's Manual

Networks, bridges
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PMP 400/430 and PTP 200/230 Series Configuration and User Guide
Name
Universal GPS (UGPS)
 Provides network synchronization for
smaller networks where CMM may not
be cost effective. The UGPS provides
synchronization for one or two modules
so that even remote areas at the edge
of the network can operate with
synchronization for improved
performance.

Technology and Benefits

The radio automatically selects QPSK (Quadrature Phase Shift Keying), 16-QAM (Quadrature Amplitude
Modulation), or 64-QAM based on RF environment to provide 1X, 2X, and 3X operation, respectively. This
provides 3 speeds and a throughput of over 45 Mbps aggregate (sum of up plus down when configured for
20 MHz channel bandwidth) compared to FSK Canopy products with 2 speeds and a throughput of up to 14
Mbps.
The OFDM radios feature lower receive sensitivity, FEC (Forward Error Correction), and higher antenna
gain, all of which combine to provide longer range within regulatory-specified EIRP (Equivalent Isotropic
Radiated Power).
Details on performance are listed in
The PMP 400 and PTP 200 Series radios use an OFDM physical layer with 10 MHz channels and 256 sub-
carriers while the PMP 430 Series radios use an OFDM physical layer with configurable channel bandwidth
of 5, 10 or 20 MHz. The PTP 230 Series radios use an OFDM physical layer with configurable channel
bandwidth of 10 or 20 MHz. A PMP 400 Series 5.4 GHz radio with 10 MHz channels will interoperate with a
PMP 430 Series 5.4 GHz radio configured with 10 MHz channel bandwidth and 1/4 cyclic prefix. However;
due to the different carrier and modulation schemes between these OFDM radios and FSK Canopy radios,
the two do not interoperate over the air. For example, a PMP 430/400 Series 5.4 GHz OFDM SM cannot
connect to a 5.4 GHz FSK AP.

nLOS Benefits and Limitations

In addition to providing LOS (Line-of-Sight) connectivity, use of OFDM technology can provide nLOS (near
Line-of-Sight) connectivity and sometimes NLOS (Non-Line-of-Sight) connectivity:
LOS: the installer can see the AP from the SM and the first Fresnel zone is clear.
nLOS: the installer can see the AP from the SM, but a portion of the first Fresnel zone is blocked.
NLOS: the installer cannot see the AP from the SM and a portion or even much of the first Fresnel
zone is blocked, but subsequent Fresnel zones are open.
For examples of LOS, nLOS and NLOS links, see
pmp-0042 (March 2014)
Model or Part Number
Table 8
on page 37.
Figure 15.
Typically use with
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A
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Page 28 of 98

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