COMPUTE METHOD PARAMETERS BY ITU-R REC. 530
In addition to the microwave radio link specific parameters for fixed service (like digital hop type, modulation, speed, time between failures, etc.), there are other parameters specific to the compute method proposed by ITU-R Rec. 530.
Xirio allows the user to choose calculation type and method, as well as what attenuations to take into account in the digital hop.
•Compute Method. ITU-R Rec. 530 provides for fading probability calculation. There is a method for short time and another for more time.
•Attenuation by gases. The tool can be or set manually to obtain water vapor density value of the recommendation based on the ends coordinates. The button allows the user to obtain this calculated value automatically.
•Precipitations. You can manually set or configure The tool can be set to obtain the rainfall value of the recommendation based on the ends coordinates. The button allows the user to obtain this calculated value automatically.
•Discard unavailability due to rainfall less than 0.001%. ITU-R Rec. 530 is not valid for calculated unavailability values less than 0.001% of time. Thus the user can choose to eliminate this calculation in some cases.
•Gross margin for rain calculation. If this option is activated, digital hop reports will obtain a gross rainfall margin that will determine the available reception margin in continuous rain conditions. This margin is informative since it will not be used for quality and unavailability calculation.
•Attenuation by reflections. If this option is activated, calculation will take into consideration possible reflections from the path. The user can specify the path type where is the reflection or can indicate if the tool automatically obtains it from the morphographic layer if that one has been established in the study. The "Maximum roughness factor" can be set to consider a reflection, with a typical value of 3.