Telcos write to govt on 5G in airports, say no interference with spectrum used by aircraft altimeters

Leading telcos have written to the government arguing against the temporary ban on deploying 5G services in and around airports on the grounds that the 5G bands used by carriers did not interfere with airwaves used by aircraft altimeters.

A senior industry executive said that telcos have highlighted the technicalities to the telecom department in a communication sent by the industry association earlier this week, where telcos have also sought that they be allowed to restart the services.

“We’ve written to the government because there’s no evidence to suggest that there is any such interference, more so because the bands that are being used are not the same,” the executive said.

The Directorate General of Civil Aviation (DGCA) had raised concerns over the interference of 5G C-Band or 3.3GHz to 3.6GHz spectrum band with plane radio altimeters back in September. Following inter-ministry discussions, the department of telecom issued directions to Bharti Airtel, Vodafone Idea and Reliance Jio end of November that carriers cannot install 5G base stations in the 3.3-3.6 Ghz band within 2.1 kilometeres from both ends of a runway and 910 meters from the central line of the runway.

The DoT also directed the propagation power should be reduced in base stations already installed within 540 meters of the defined areas. The department also directed downward tilting of 5G base stations so that 5G emissions do not interfere with radio altimeters. The ministry of aviation had also asked that telcos should create buffer zones as the 5G bands could interfere with aircraft altimeters.

Industry executives said that the impact of the directions was quite pronounced since 5G services had to be stopped in high density areas in key metros close to the airports and including the airport area as well. For instance, 5G services were either stopped or severely compressed in the Lutyen’s Delhi due to proximity to the Safdarjung airport, and similar closures had to be done in Hyderabad and Bangalore.

“A significant amount of coverage compression has taken place,” a second executive said.

Experts said that interference between the 5G bands used by both carriers – 3.3-3.5 Ghz and 700 Mhz -- should not be a concern since the bands were separate with adequate buffers. The bands are much lower than the band used by airline altimeters which starts from 4.2Ghz.

However, Airtel which recently announced the launching of 5G services in five airports including Bengaluru, Nagpur, Patna, Pune and Varanasi, had to shut down its base stations temporarily following the orders, while adjacent areas also suffered unavailability of 5G services. Reliance Jio has launched in 66 locations since October this year, it is yet to cover airports or adjacent areas.