The battle of the 26 GHz band: Facts vs Myths

Yesterday, I wrote a piece which estimates the increase in deployment cost of 5G in the 26 GHz band in case the power restrictions (as proposed by DoT at the behest of ISRO) gets implemented. The article concluded a significant increase in costs (16 times compared to that of no restrictions)- killing the 26 GHz band and in turn 5G in India. The purpose of this note is to evaluate the merit of the DoT's stance and to analyse whether the same is aligned with larger interest of the nation.

DoT's Submission to WRC

The following is an extract of DoT's submission to WRC dated 6th Oct 2019.

3. the operation of IMT within the frequency band 24.25-27.5 GHz shall protect the existing and future SRS/EESS earth stations;

4 the operation of IMT within the frequency band 24.25-27.5 GHz shall protect the existing and future FSS earth stations;

5 that administrations shall apply the following condition for the frequency band 24.25-27.5 GHz:

When deploying outdoor base stations, it shall be ensured that each antenna normally transmits only with the main beam pointing below the horizon and the antenna shall have mechanical pointing below the horizon except when the base station is only receiving. The antenna pattern shall comply with Recommendation ITU-R M.2101. In addition, IMT base stations shall comply with the TRP limits given in Table 1:

Facts

1. ISRO has existing EESS (Earth Exploration Satellite Service) for which it has already settled with the industry for a 23 Km isolation zone. Hence proposed power limits are totally unnecessary.
2. India does not have any SRS services (Space Research Services) in the 26 GHz band, and anything even planned in future will not need 7 dBw power restrictions. They will need some isolation of certain radius, just like S.No 1. Hence, proposed power limits are totally unnecessary for this case.
3. FSS earth stations (receivers) are not permitted by ITU in this band, they are permitted only in 17 GHz band. As regards FSS uplink, it does not require 7 dBw power restrictions, as the satellite receivers (which are at risk of interference from 5G BTS) are located at 36,000 to 41,000 Kms. Hence, the proposed power limits for this case are totally unnecessary.
4. ISRO has plans for only ISS (Intersatellite services) in this band, that too only 350 MHz (10% of the total band) between 27 to 27.5 GHz. It seems the 7 dBw power restriction proposed is meant to protect this service. But the DoT's submission to ITU does not refer to the ISS service at all while they seek the 7 dBw power restriction for the 5G BTS. Also, by seeking such protections they have destroyed the complete band, that too when ISRO has no ITU filings for using 90% of the 26 GHz band. Amazing!

Conclusion

From the above, it is clear that DoT's submission to ITU has factual inconsistency/inaccuracies. The same neither protects the interest of ISRO (as the submission did not even mention the ISS service for which it is seeking protection) nor that of the nation (since its proposal ends by blocking the whole band for no reasons whatsoever). Such levels of inconsistency/inaccuracy present all of us Indian in poor light at international forums, and therefore harmful to the interest of the nation at large.

(Views expressed are of my own and do not reflect that of my employer)

PS: Find the list of other relevant articles in the embedded link.