Issues related to 5G | Timeline

“Explained: The concern over 5G and flight safety” – Indian Express – 21st Jan 22

What is the issue?

Air India and several other airlines have cancelled flights to the US. They are worried that the 5G roll-out there may affect aircraft and passenger safety, a concern raised by Boeing and Airbus in the past.

Federal Aviation Administration (FAA) and aircraft makers warned that accurate functioning of radar altimeters in some aircraft may be affected by the 5G radio frequencies.

How do flight radar altimeters help in safe flight operations?

For all airborne vehicles an aircraft, spacecraft, or even a missile an altimeter is crucial to gauge the altitude and the distance covered.

Airlines take off and land using autopilot systems, which use data from radar altimeters to determine the altitude of the aircraft. Hence, they are a crucial part of flight operations for pilots, particularly while seeking to make low-visibility landings in poor weather conditions. (Not using auto-pilot would lead to more fuel consumption and higher costs for airlines)

Altimeters are of three main kinds: barometric, laser, and radio or radar altimeters.

Most commercial passenger and cargo aircraft use a combination of all these altimeters along with Global Positioning System (GPS).

They are used to determine their path, as well as factors such as height above sea level, presence of high-rises, mountains, and other obstacles, and the likely flying time.

The radio or radar altimeter is a very small, low-power radar system that operates in the 4.2-4.4 GHz frequency microwave C-band.

The high frequency of these altimeters enables aircraft makers to install small antennae that produce powerful signals that can be relayed quickly and accurately.

Why is there concern about radar altimeter interference specifically in the US?

The situation is critical in the US, which auctioned 5G bandwidth in 2021 in the 3.7-3.98 GHz on the C-band spectrum range.

This band is very close to the 4.2-4.4 GHz range in which radio or radar altimeters operate.

According to industry experts, there are chances of interference of the two bands as telecom service operators, in order to extract the full value of 5G and give customers the best experience, push operations to the highest band possible.

Altimeters too, need to operate at higher frequencies in order to get the most accurate readings possible.

“Technology tangle: On 5G services and flight disruptions”, “Why 5G roll-outs are disrupting flights to the US” – The Hindu and Livemint – 20th Jan 22

What are the steps taken by US regulators?

US regulators left about a 200 MHz buffer between the altimeters’ frequency and the 5G C-Band frequency. However, some airplanes like the Boeing 777 are using some older radio altimeters, which are finding it difficult to function in this buffer. So some US telcos have temporarily deferred the 5G roll-out.

Can this impact India’s 5G roll-out?

India’s 5G auctions are expected to include spectrum bands of 3.3GHz -3.6GHz, which means the C-Band may not be operational, at least in the near future.

Additionally, aircraft equipment is manufactured globally, with certain standards. The FAA tests will likely lead to standards for altimeters and applied internationally. Once a standard is known, it can be implemented in all aircraft.

“The controversy over inclusion of the mm wave band in 5G auctions” – The Hindu – 15th Jan 22

News: Telecom regulatory Authority of India (TRAI) had asked for Industry’s view on various contours of 5G roll out in India. This plan of TRAI also included the idea of adding millimetre (mm) wave band of 24.25-28.5GHz in the auction of 5G spectrum.

Satcom Industry association-India (SIA) which represents the interests of the communication satellite ecosystem in India has voiced concerns over inclusion of millimetre (mm) wave in 5G auction.

What is the mm Wave band?

This is a particular segment of radio frequency spectrum that ranges from 24-100 GHz.

It has short wavelength and is very appropriate to deliver at high speed and lower latencies. The current available networks work optimally well on the shorter wavelengths, but they don’t work well on the parameter of speed, which is needed for 5G.

So for 5G to work at its full potential, and speed up the mm wave band is very essential.

What are the concerns voiced by the SIA regarding its inclusion in 5G spectrum action?

According to SIA, this particular band has been reserved for the satellite based broadband services as per ITU (International telecommunication union)’s directive. The 5G roadmap of European Union also follows this directive.

If excess spectrum is provided, it could pose a downside risk of bands going unsold or underutilised.

Also, the mm wave band is very critical for the satellite communication industry, and it is very essential to ensure that 5G operations do not interfere with their current operations.

How can this negatively impact the satellite communication Industry?

Recently, internet is being provided by the satellite based communication service providers apart from the fibre optic based systems.

So the satellite communication industry is trying to keep the mobile telephony companies out of their competition for the band.

The Industry body also noted that the 330 MHz spectrum in the 3.3-3.67 GHz band is enough to satisfy India’s mid-band 5G needs while ensuring a competitive auction.