Support & Learning Portal

Usage

This guide is applicable to the Tachyon Networks online link calculator tool.

Input the target distance between your AP and client, and results will automatically be updated at the bottom of the form.  You can then choose different values for channel and target modulation in order to determine if your link is possible, and how robust it is under rainy conditions, given the selected parameters.   

Please keep in mind that there are no inputs for AP and client site elevation and location as all 60 GHz links must have no obstructions along the path of the link.

Inputs

The access point is statically set to the TNA-301 model, and the station is the TNA-302 model.

Target distance

Enter the target distance, in meters, between the AP and client devices.  

Channel

Select the AP and client's 60 GHz channel.  Keep in mind that the higher channels will be less affected by oxygen absorption and will produce a higher expected RSSI, as well as an increased signal budget.

Target modulation

Select the target datarate/modulation that you wish to achieve on the links between the AP and clients.  This value should be the rate you're targeting under ideal (e.g. dry) environmental conditions.  As rain levels affect the quality of the link, the radios will modulate down to a lower datarate in order to keep the link connected, assuming you don't have MCS rates set to a fixed value in the configuration.

Results

After inputting your target link distance, and adjusting other link parameters, results will be updated in the RESULTS section of the page. 

Rx sensitivity

Rx (receive) sensitivity is the lowest signal at which a connection is possible for the given channel width and target modulation.  

Expected RSSI

This is the expected RSSI you should expect to see on this link under dry environmental conditions (e.g. no rain fade).  

Signal budget

The signal budget value is the difference between the link's expected RSSI and receive sensitivity.  The higher the signal budget, the more robust your link will be due to tolerance of rain fade.

Coverage area

This is the approximate coverage area of an AP given the target distance.  

Other details and messages

If your expected RSSI value is less than the receive sensitivity value for the specified modulation, then you'll see a message in red informing you that a connection at the specified modulation and with the specified channel parameters is not possible for the given target MCS rate, but note that it still could be possible at a lower MCS rate.

If the expected RSSI is greater than receive sensitivity, then you're left with a "signal budget", which allows rain fade to take place without bringing the link down.  The amount of rain that can be tolerated depends on the budget amount, type of rain, and link distance.  

Below the main results, you'll see a message with a weather icon telling you the rain rate (in mm/hr) that your link can withstand at MCS1 without going down.

General purpose calculators

The calculators at the bottom of the page can be used for any 60GHz-based hardware platform.

Rain rate to attenuation calculator

Input a rain rate in mm/hr and the results table will show the loss per channel (dB/km) due to rain fade. Upper channels will have slightly more loss than the lower channels. 

Signal budget to rain rate calculator

Input your link's signal budget and distance, and the results table will show the max rain rate per channel that the link can withstand @ MCS1 before it drops, provided for each channel.

References

Estimated max distance between TNA-301 and TNA-302

Note: these max distances assume a modulation rate of MCS1, and do not take attention due to rain into account.

Rain fade table