By Aileen Ryan, RAIN Alliance President & CEO, and Josef Preishuber-Pflügl, RAIN Alliance Head of Regulatory Affairs

We’ve been asked this question many times following the deadline of September 20.  Thanks to all our members and your partners and customers who listened, read our analysis, and filed comments. We are pleased that nearly 2000 comments have been filed with the FCC, with the vast majority against the proposed rule-making.

Now it is up to the FCC to review all the comments and decide on the next steps. There is no specific timeline that the FCC must adhere to.

In the meantime, NextNav filed reply comments that dispute some of the RAIN Alliance and AIM analysis, and we want to set that record straight.

1. Assumed antenna heights and propagation models (e.g. losses through buildings)

NextNav’s reply comment disputes the antenna heights and propagation models assumed in our analysis. Interference power depends on many factors.  In the continued absence of any firm data provided by NextNav, we estimated antenna heights and propagation models in our preliminary interference analysis and arrived at an interference power level of ‑80dBm (0.01nW).

Despite their dispute of the assumptions made in our analysis, footnote 143 of NextNav’s filing confirms the interference power metric of ‑80dBm:

  • … the nominal power of the [NextNav]  downlink 5G signal can be at ~-80 dBm for a good signal. 

Thus, as our analysis states, wherever a NextNav mobile has good coverage with NextNav’s proposed base station, an interference power level that will cause issues with a RAIN system has to be expected.

2. Signal power from a RAIN tag

Footnote 143 of NextNav’s filing states:

  • … the received signal power of the RFID signal [from an RFID tag into an RFID Reader] can be better than ~-30 dBm for one way communication and -40 dBm for two-way communication using passive technology.  

RAIN is different from many other RF systems, and the signal power of a tag signal into a reader rarely, if ever, exceeds -30dBm (1000nW) and infrequently exceeds -40dBm (100nW).  Based on input from RAIN industry experts who have worked with this technology for many years, the RAIN Alliance preliminary analysis assumes a signal power of ‑70dBm (0.1nW). This is between 1,000 (one thousand) and 10,000 (ten thousand) times weaker than NextNav’s wildly inaccurate statement. Such a level of inaccuracy from NextNav is deeply concerning in such an important document.

We have no doubt that the FCC will understand that the RAIN technology calculations, which were created and peer-reviewed by the experts on RAIN, are accurate for RAIN implementations and not be blinded by misrepresentation.

Stay tuned as this story evolves!