The department of telecommunications (DoT) has rejected the department of space’s (DoS) demand that 25 MHz of spectrum in the 3.5 GHz band (3.400-3.425 GHz), which is a 5G band, be reserved for it so that mobile signals do not interfere with satellite signals.
The DoS wanted this quantum of spectrum to be reserved for its Navic constellation maintenance and not be put up for auctions for the mobile operators. After consultations with the Telecom Regulatory Authority of India (Trai), the DoT has now decided that a large chunk of spectrum like 25 MHz on a pan-India level need not be reserved for DoS. Instead, a small protection zone of 25-km radius anchored around the earth stations for Navic satellite will be sufficient to prevent the 5G systems from interfering with the satellite signals.
Earlier, DoS had vetoed this suggestion, saying that it needed an isolation zone of 1,400-km radius to ensure an interference-free operation. If the DoT’s position finally prevails over DoS, in the forthcoming auctions mobile operators will be able to get a contiguous chunk of 5G spectrum.
The rationale put forward by DoS for reservation of 25 Mhz spectrum was that it is developing a domestic Global Positioning System (GPS). In this direction, it has already launched its Navic satellite but the services are yet to start. The earth stations for managing the synchronisation of clock signals from the satellite system have been located at places like Hassan, Bhopal, Jodhpur, and Shillong.
The problem with the reasoning of the DoS was that while it talked about protection from interference within the border by creating an isolation zone of 1,400 km, it overlooked the fact that problems would arise from neighbouring countries like Pakistan, China, Myanmar, Bhutan, Bangladesh, Nepal, and Sri Lanka, all of which fall within the 1,400-km radius of the locations where the earth stations have been set up. All these countries will sooner or later launch 5G services in the 3.5 GHz band and they are under no obligation to fall in line with DoS’s demand of respecting the 1,400-km protection zone. In such a scenario, the domestic GPS system will be vulnerable to interference from the mobile networks in neighbouring countries, impacting the very efficacy and security of the system.―Financial Express