Transmission Design Warning and Error Messages
The following are the possible error messages and explanations that are encountered in the Transmission Analysis module.
Equipment Error Messages
"Missing <Antenna Use> Antenna Gain at Site 1 or 2"
An antenna gain is required in order to complete a reliability calculation. The Antenna Use can be for any of the antenna types TR,DR,TX,RX,or TH. Clicking on the antenna graphic will allow the user to enter the gain or select an antenna from the index.
"Missing transmit power at Site 1 or 2"
The transmitter power is required in order to complete a reliability calculation. Clicking on the radio graphic will allow the user to enter the power or select a radio from the index.
"alpha1 or bits per block out of range"
"Missing receiver threshold at Site 1 or 2"
"Dispersive fade margin not used at site 1 or 2 for selective fading"
"Equipment signature not used at site 1 or 2 for selective fading"
"Missing antenna XPD at Site 1 or 2 for XPIC operation"
"Missing noise floor at Site 1 or 2"
"Missing C/I ratio for ITU XPD calculation"
A required value for the ITU P.530 XPD calculations. This value is normally supplied when a radio file is loaded. If not using a radio file, the value can be entered manually.
"Missing residual BER data for SDH radio at site 1 or 2"
"ATPC option not specified in radio data"
Multipath Calculation Error Messages
"One or more parameters are outside the valid ranges for ITU-R P.530-18"
The ITU-R P.530-18 formula for predicting the percentage of time that a given fade depth is exceeded, is derived from multiple regressions on fading data. The ranges for the values used in the formula are defined in Rec. ITU-R P.530-18. Pathloss limits the values to these ranges. This warning is displayed when one or more of these values is outside the valid range.
"Negative thermal fade margin at Site 1 or 2"
"Negative multipath flat fade margin at Site 1 or 2"
"Negative effective fade margin at Site 1 or 2"
"Data throughput availability < 99.95"
"Same start and end sites selected"
"Intervisible terrain range is less than 50% of profile"
"Zero antenna height at site 1 or 2"
"Zero diversity antenna height at site 1 or 2"
"EIRP exceeds FCC 101 limits at site 1 or 2"
"Fade Occurrence Factor outside valid range"
"Frequency must be in the range 54-108 or 174-216 or 470-806 MHz"
"Frequency out of range for antenna at site 1 or 2"
"Frequency out of range for tx lines at site 1 or 2"
"Frequency out of range for radio at site 1 or 2"
"Receive signal greater than maximum value at site 1 or 2"
Rain Calculation Error Messages
A rain calculation consists of the two basic parts:
- Calculate the rain rate (millimeters / hour) which will produce an attenuation equal to the link fade margin.
- Determine the fraction of time that this rain rate is exceeded i.e. the probability of an outage due to rain.
- Rain affects both directions of transmission simultaneously and is a function of frequency, path length and polarization.
The following errors and warnings are possible with ITU and Crane rain attenuation calculations.
"Rain Calculation Frequency limits exceeded (1 - 100 GHz)"
Rain calculations have an upper of 100 GHz and a lower limit of 1 GHz. Turning off the Rain calculation by clicking on the rain cloud and setiing Rain Calculation to Off will suppress this error.
"Rain outage probability > 50% at site 1 or 2"
"Missing 0.01% rain rate"
ITU rain calculations require a 0.01% rain rate. This value can be read from the ITU data files or manually entered. ITU-R P530 Rain Data Entry Form
"ITU Rain extrapolation failed at site 1 or 2"
Normally Pathloss interpolates the required rain rate from the rain statistics file. When this data is outside the range of the data in the file, Pathloss attempts to extrapolate the the curve to obtain a value. If the this value is too far outside this range on the high end (smaller percentages of time) this warning may appear. In essense, this message conveys that rain fading will not be an issue and it can be ignored.
"Rain rate extrapolated at low end at site 1 or 2"
Normally Pathloss interpolates the required rain rate from the rain statistics file. When this data is outside the range of the data in the file, Pathloss attempts to extrapolate the the curve to obtain a value. If the this value is too far outside this range on the low end (larger percentages of time) this warning may appear.
"Rain probability is outside the ITU range of 1% to 0.001% at site 1 or 2"
The ITU-530 rain calculation is valid for percentages of time in the range of 1% to 0.0001%. If the calculated rain probability is outside this range then the above warning will be displayed. The rain probability is based on fade margin and the .01% rain rate. On many practical links, this range will be exceeded especially on short links with high fade margins.
"Rain does not affect performance at site 1 or 2"
"Zero rain rate at site 1 or 2"
"Negative rain flat fade margin at Site 1 or 2"
"The required ALU rain data files are not available"
Path Parameter Errors
"Site coordinates are required for this calculation"
Coordinates are required to establish the path center coordinates. The path center is required to calculate many of the values required for reliability calculations. Examples include DnDh, Geoclimatic factors, rain rates, and terrain roughness. Path Profile Data Entry Form - Common Parameters
"Missing path length"
A path length is normally calculated from the site coordinates. If no site coordinates are provided, a path length can be entered manually in the Path Data window. A path length is required to calculate free space loss and atmospheric losses due to water vapor and oxygen. Path Profile Data Entry Form - Common Parameters
"Missing frequency"
A frequency is required for all calculations. The frequency must greater than 20 Mhz.
"Missing terrain roughness"
Terrain roughness is a required entry for the Vigants Barnett multipath algorithm. Terrain Roughness Calculation.
"Missing climatic factor"
A Climatic factor is a required entry for the Vigants Barnett multipath algorithm. Path Profile Data Entry Form - Vigants Barnett
"Missing C factor"
A C factor is a required entry for the Vigants Barnett multipath algorithm. Path Profile Data Entry Form - Vigants Barnett
"Missing KQ factor"
"Missing frequency exponent"
"Missing distance exponent"
"Missing path inclination"
"Missing grazing angle"
"Missing geoclimatic factor"
"Missing latitude / longitude"
"Missing area roughness"
"Missing P(dN/dH)"
"Missing average annual temperature"
"Frequency is out of range"
Diversity Errors
"Zero diversity antenna spacing at Site 1 or 2"
A non-zero value is required for the vertical separation of space diversity antenna.
"No diversity receive signal at Site 1 or 2"
"No main-div gain diff at Site 1 or 2"
"Cannot use angle diversity with hybrid diversity"
"Require frequency diversity with hybrid diversity at site 1 or 2"
"Diversity antenna spacing is greater than 200 wavelengths at site 1 or 2"
"Non selective space diversity improvement < 1 at site 1 or 2"
"Selective space diversity improvement < 1 at site 1 or 2"
"Space diversity improvement < 1 at site 1 or 2"
"Non selective frequency diversity improvement < 1 at site 1 or 2"
"Selective frequency diversity improvement < 1 at site 1 or 2"
"Frequency diversity improvement < 1 at site 1 or 2"
"Selective quad diversity improvement < 1 at site 1 or 2"
"Quad diversity improvement < 1 at site 1 or 2"