A government panel led by Principal Scientific Adviser Ajay Kumar Sood has been assigned the task of resolving the issue surrounding the rollout of 5G services in and around airports, as per an Economic Times report. The focus of these discussions will be on concerns related to aircraft and passenger safety.

A broader panel has been constituted to “address the 5G matter”, sources told the paper. This decision comes in the wake of the lack of consensus on timelines for replacing obsolete aircraft radio altimeters, a crucial device providing vital altitude information during landings in low visibility conditions.

Concerns Linger

While discussions between the Directorate General of Civil Aviation (DGCA), the Department of Telecommunications (DoT), telecom companies, airline operators, and aircraft manufacturers have been ongoing, the issue has remained unresolved for over a year.

A radio altimeter operates in a bandwidth of 200 MHz in the frequency band 4200 MHz to 4400 MHz. Despite the DoT auctioning spectrum in the 3300-3670 MHz band for 5G, concerns persist about interference due to the wider frequencies caught by the current outdated altimeters in aircraft.

As per preliminary estimates, around 500 Boeing aircraft and approximately 300 Airbus aircraft in India may require a retrofit.

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 start from 4.2Ghz.

Temporary 5G Site Installation Restriction at Airports

As a temporary measure in November 2022, the DoT barred mobile operators from installing any 5G sites in the 3,300-3,670 MHz band within 2.1 km of airport runways. This was done to avoid potential interference with aircraft radio frequencies and was intended to be in place only until the replacement of aircraft altimeters.

However, leading telcos have now complained the continued halt on upgrades has caused them revenue losses. In September they urged the Ministry of Civil Aviation (MCA) to direct the DGCA to issue a deadline for all airlines operating in India to replace outdated radio altimeter systems.

“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. After the government’s directions, 5G services had to be stopped in airports and high-density areas in key metros close to airports. 5G services were either stopped or severely compressed in 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.

Meanwhile, aircraft manufacturers Boeing and Airbus have also stressed the need for a permanent solution around 5G connectivity at airports. They said that decisions regarding purchase orders for altimeters by airlines and DGCA were crucial, the report added.

Earlier the manufacturers had conveyed that altimeters would be available for countries outside the United States only after December 2023. The delay in airlines placing purchase orders has further escalated the issue.