System Performance Values
Rx Threshold(RSSI)The Rx Threshold is the setting that determines where the Coverage is shown during overlay creation. We suggest you set the value to the minimum signal you require during an install. This value and the Strong signal margin will determine where the Strong and weak colors are displayed in your Coverages and Multi Maps.
Required Reliability %This is an important variable in your coverage calculations. This percentage adds additional statistical loss based on distance and frequency to get to a more reliable link. For WISPs, the default value of 70% usually is a good number. The longer the link, the more statistical loss is added. For point to point links, we advise turning this value up to 90% to add a bit more statistical loss and further pad your link budget requirements.
Strong Signal MarginThe Strong Signal Margin is what TowerCoverage.com considers strong vs. weak signal. The Strong Signal Margin is the Rx above the minimum threshold. The default color values are: green for a strong signal and red for a weak signal. On your coverage map, the red areas will be the Rx Threshold to your Strong Signal Margin and the green areas will be your Strong Signal Margin and above.
For Example: You already set your Rx Threshold to -70. Now you set the Strong Signal Margin to 5 dB. On your coverage map using the default color values you will have red colored areas and green colored areas. The red areas will be between -70 and -65. The green areas will be anything considered strong, or greater than -65. Now, if you adjust the Strong Signal Margin to 10 dB, then red on the coverage map will show areas between -70 and -60 and green will be anything better than -60.
OpacityThis value determines how bold the colors of your coverage are. 50% will allow you to easily see the features of the map under the coverage.
Rendering QualityRendering Quality determines the pixelation of the coverage map. There are three options here for the Rendering Quality. Typically “High Resolution” is fine for most coverage maps, however, if you have a lot of of hills and trees you may want to get the maximum resolution out of the data sets provided. In areas outside of the USA, the high resolution map will return virtually the same results as the maximum since the resolution of the land cover and terrain data is lower than within the USA.
The rendering quality on a Multi Map is determined by the size of the area that map covers. The larger the area, the lower resolution in which it displays.
Use Land CoverThis tells the site whether or not to take your Land Cover settings into account in the calculations. See also Land Cover for more information.
Land CoverThis tells the site which Land Cover settings to take into account in the calculations. If you have created a custom setting and want to utilize it, you would select it here.
Use Two RaysTwo rays are used for multi-path calculations. Most WISP use radios that cannot do multi-path reflections, so this option is turned off by default. If your radio system can use multi-path reflections then, you may want to turn this value on.
Create ViewshedThe view shed option sets all land cover density values to 10000, or their maximum value. This means that as soon as a signal attempts to go through any type of land cover, it will result in a loss so great that the signal will not travel through it. This creates a view shed; but unlike other systems, the views held here take into account land cover values, such as tree heights etc. If you are using radio systems in frequencies in 5 GHz or larger, in most cases, trees will attenuate the signal to an unusable level. Some customers would prefer not to see any locations where trees would have an impact on service. If that is the case, the view shed option is what they would use.
For WISP operations, we recommend that any frequencies above 2.4 GHz should use the view shed option, as those frequencies at the power levels we use, will stop the transmitted signals. 2.4 GHz and under has decent foliage penetration, so leaving the view shed off for these frequencies is recommended.