Tsunami MP.11a Antenna Installation Guide
Figure 6. Clearance Factor Diagram
CALCULATIONS
Availability of the microwave path is a prediction of the percent of time that the link operates without producing an excessive bit error rate (BER) due to multipath fading. In the absence of direct interference, availability is affected by the following:
▪Path length
▪Fade margin
▪Frequency
▪Terrain (smooth, average, mountainous)
▪Climate (dry, temperate, humid)
Depending upon the type of information carried over the link and the overall network design redundancy, you may want to design for a specific availability rate. For example, if the data or voice traffic carried by the radio is critical, the link can be designed for a very high availability rate (for example, 99.999% or 5.3 minutes of predicted outage per year).
Availability can be improved by increasing the fade margin either by making the path shorter or by using the higher gain antennas in conjunction with lower loss transmission line (using a higher quality transmission line, shortening the length, or both).
Chapter 2. Determining Range and Clearance | 20 |
CPN 65756B | Issue Date: August 2003 |
