10
| NETWORK COMPONENTS | GEOKON
12:
FIGURE 12:
Mesh Network Topology
Each transmission from logger to gateway or logger to logger is considered one
"hop". Examples of hops are shown in figures above and below. Up to four hops
can be made between a logger and the gateway. With the ability to hop comes
the ability for the gateway to communicate with loggers that have not
established direct radio contact. GeoNet devices can operate around buildings
or other barriers using hops.
13:
FIGURE 13:
Working Around Obstructions via Hops
FRESNEL ZONE
The Fresnel zone is the geographic area between the sending antenna and the
receiving antenna. Objects in the Fresnel zone can cause reflections of the
transmitted signal. When these reflections arrive at the receiving antenna, they
may be out of phase with the signal that took a straight-line path, and this can
weaken the straight-line signal.
For optimum performance,
GEOKON
recommends creating as much vertical
space as possible between the straight-line path and obstacles, including the
ground.
The Fresnel zone must be at least 60% obstruction-free to ensure optimal
wireless communication. The figure below illustrates the Fresnel zone.
1 Hop
S = Gateway
N = Logger (1, 4, 8, ADR)
= Data Path
1 Hop
Cell
Ethernet
USB/RS-232
1 Hop
Obstruction
1 Hop
1 Hop
1 Hop
1 Hop
1 Hop
1 Hop
