Mine Site Technologies NS50, User Manual, Page: 25 / 126

2.6 Determining Distances between Wireless Network Switches
Line of Sight Distances
In line of sight, each NS50 has a maximum wireless range of 300 metres (984 feet) using high gain
directional antennas. NS50 units are generally installed with a 100 metre (328 feet) overlap of the radio
field as shown in
Figure 8: Wireless channel layout and distances . This ensures sufficient coverage
between NS50 units.
NS50 units within range of each other must be configured with different Wi-Fi channels. By default every
fifth channel is used (channels 1, 6 and 11) to prevent signal overlap, minimising the possibility of
inter-modulation or interference.
Figure 8: Wireless channel layout and distances
Distances Around Curves
The wireless range of a NS50 decreases when going around curves. In this case, NS50 units need to be
installed closer together to provide sufficient coverage. Distances between NS50 units will vary depending
on the drift and tightness of the curve. They are installed closer together on a tight curve.
Use the following steps to estimate the distance between NS50 units:
1. Install one NS50 unit at the beginning of the curve.
2. Install the second NS50 unit between 20 metres (65 feet) to 40 metres (130 feet) from the end of the
curve.
3. Install and align antennas.
4. Perform a RF signal strength test by walking from the first NS50 to the second NS50.
5. If the strength test records levels of:
• -80dBm to -65dBm, the NS50 units are spaced for optimal coverage.
• -81dBm to -100dBm, move the second NS50 closer (at 10m intervals), and conduct another RF
signal strength test.
• -64dBm to -10dBm, move the second NS50 further away, and conduct another RF signal strength
test.
NS50 User Manual 25 Revision A
Network System Design