User Manual

Canopy 900 MHz AP and SM User Guide
Issue 1, Draft 1 June, 2004 Page 10 of 16
Figure 2: Highlights of 900 MHz AP Configuration Page
2.5 Range of 40 Miles LOS, Significant Foliage Penetration NLOS
Description
The Canopy 900 MHz modules have a Line-of-Sight (LOS) range of 40 miles (over 64 km), and substantial
Non-Line-of-Sight (NLOS) range. NLOS range is dependent on foliage, topography, obstructions, and
other RF engineering considerations. The physics of longer-wavelength 900 MHz, the power allowed by
regulatory authorities, and the low Canopy Carrier-to-Interference (C/I) ratio combine to support service
over these increased LOS and NLOS ranges.
While the expected typical range in real-world conditions is 40 miles, the AP can be set for a range up to
120 miles (over 190 km) to accommodate long shots with very clear Fresnel zone (possibly due to high
tower or mountain top location) and quiet RF environment.
Setting the range higher tells the software to have a slightly longer switchover time between transmit and
receive to accommodate longer air delay. This reduces the slots per frame available for data, which reduces
aggregate throughput at the AP. However, the predictability of Canopy point-to-multi-point throughput
continues. All SMs served by an AP set to a given range continue to have the same throughput regardless
of their distance from the AP.
The 900 MHz modules complement the other frequency bands offered. The 900 MHz modules can be used
to cover a larger area, albeit with lower throughput, than the other frequency bands. Depending on specific
operator requirements, they can be used to penetrate foliage, have greater range, or add additional
subscribers or additional overall throughput to a tower that is maxed out or can’t use another frequency
band due to interference or tower rights issues.
Operation
Set the Max Range parameter on the AP Configuration page to the distance of the furthest planned SM
from the AP cluster, as shown in Figure 2: Highlights of 900 MHz AP Configuration Page.