Introduction to Wireless Networks
- 3.0 Implementing a Wireless Link
3.1 Stages
3.2 Radio Path Obstacles
3.0 Implementing a Wireless Link
3.1 Stages
Common stages for implementing a wireless network are:
- Site survey
- Link budget calculation/terrain modeling
- Trial/implementation
- Testing/commissioning
Some of the main issues to be considered are:
- Data rate required
- Link distances
- Natural high points
- Obstacles
- Spectrum congestion
- Cabling issues
- Access
3.2 Radio Path Obstacles
Typically the biggest challenge in a radio link is achieving good line of site between the two antennas. Figure 7 shows the "no obstacle radius" for 2.4GHz and 5.8GHz at different distances.
Hills and vegetation are normally the biggest obstacle to achieving these sort of clearances. In practice, short 2.4GHz links will often work through small amounts of vegetation although packet loss frequently increases once the vegetation gets wet.
The best solutions for improving radio paths is normally to use higher towers or repeaters at midpoints.
Figure 7: No Obstacle Radius
Other Considerations
All masts, antennas and equipment must be solidly attached. Wind loading can create very high forces on exposed structures.
<-- back to "2.0 Choosing an Antenna"
<-- back to "1.0 Introduction to Wireless Networks"
