User's Manual

PMP 400/430 and PTP 200 Series Canopy User Guide
Supplement
Issue 4 0 – DRAFT 6 November 2009 Page 19 of 64
• 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.
Figure 13 shows examples of LOS, nLOS, and NLOS links.
Figure 13: LOS, nLOS, and NLOS
Whereas multi-pathing degrades a link in some technologies (FSK, for example), OFDM can
often use multi-pathing to an advantage to overcome nLOS, especially in cases where the
Fresnel zone is only partially blocked by buildings, “urban canyons”, or foliage. OFDM tends to
help especially when obstacles are near the middle of the link, and less so when the obstacles
are very near the SM, AP, or BH.
However, attenuation through walls and trees is substantial for any use of the 5.8 GHz, 5.4 GHz
or 4.9 GHz frequency bands. Even with OFDM, these products should not be expected to
penetrate walls or extensive trees and foliage.
2.2 APPLICATIONS
Applications for the PMP 58430/54400 and PTP 54200 Series systems include
• High throughput enterprise applications
• nLOS video surveillance in metro areas
• Extend networks into urban areas
• Extend networks into areas with foliage
Applications for the PMP 49400 and PTP 49200 Series systems include
• High throughput licensed network for government applications
• Municipal network - nLOS video surveillance in metro areas
• Disaster relief network
• Data service network - extend licensed networks into areas with foliage