5G Spectrum: Space Department Getting Its Science Wrong

At a time when the European Commission has adopted spectrum in the 26 GHz for 5G across the block to enable fibre optic-like connectivity for users of mobile telephony and also new opportunities for indoors and industrial IoT, India’s department of space (DoS) wants this band to be blocked totally for 5G services.

The DoS has written to the department of telecommunications (DoT) that they exclusively want spectrum in the bands of 26 and 28 GHz for themselves. Their rationale is to ensure interference-free operations of the satellite services to be launched in future in these bands. But it looks like that blocking 5G for the Indian operators in the 26 and 28 GHz bands will not diminish the risk of interference to the DoS satellites, as they are already facing interference from Japan and Russia’s mobile system in the 2.5 GHz band, which is similarly poised.

DoS satellites operating in the 2.5 GHz band (widely used globally for mobile technology), are at a higher elevation when viewed from India, but due to the curvature of the Earth, they are at a lower elevation when viewed from other countries.

As a result, when radio frequency waves emanating from the BTS of these (Russia or Japan) countries skid the surface of the earth, they shoot straight at the Indian satellites which have their receivers tuned in this band.
However, being at higher elevation, these satellites are not facing any interference from the BSNL’s WiMAX services deployed in the 2.5 GHz band, as signals emanating from these BTS are pointing towards the surface of the earth and not to these satellites.

The DoS will face a similar issue in the 26 and 28 GHz band, as these will be widely used internationally for 5G. And even if the Indian operators are prevented from rolling out 5G services locally in these bands, the Indian satellites will continue to face interference from 5G deployments in other countries, just like they are facing in the 2.5 GHz band.

The DoS has raised the issue of interference in the 2.5 GHz band with DoT and internationally, but did not get any relief. Therefore, if DoS wants its satellites not to face any interference it should move their plans to some other band where no 5G is planned to work globally, as only then they can guarantee an interference free operation.―Financial Express