dallas – The proliferation of new generation commercial wireless communications (5G) and 5G antennas has raised concerns about interference with aircraft operations when landing at airports. But what is 5G technology?
5G is the fifth generation mobile network technology following 4G-LTE and is being developed by the International Telecommunication Union (ITU-R) and the Designed by Generation Partnership Project (3GPP). Collaborating over the Internet to deliver immersive experiences, telepresence, connectivity at scale, and advance the Internet of Things (IoT) with faster data rates.
5G can reach data speeds of up to 20 Gbps and user experience of up to 100 Mbps, has lower latency compared to 4G, supports a density of 1 million devices per 1 Km2, and can support high-speed data communication up to 500 Km/ Enabling hr mobility. – High speed trains and flying drones.
5G technology services are provided using the UHF (ultra high frequency), SHF (very high frequency) upper bands, and EHF (extremely high frequency) lower bands of the radio frequency spectrum. 5G frequency ranges are 1-4 GHz, 6-24 GHz, 30 GHz, and 40 GHz.
Since the commercialization of 5G in April 2019, more than 89 countries, including Tanzania, have invested in, tested, deployed and launched 5G network services across various radio frequency ranges.
For example, the European Union and South Korea use the bands 3.4-3.8 GHz and 3.42-3.7 GHz, respectively, and the United States uses the band 3.7-4.2 GHz.
Risk of interference with aircraft radar altimeters due to 5G radio frequencies
A radar altimeter, also known as a radio altimeter or low-range radar, is a critical piece of equipment that enables and enhances a variety of safety and navigation functions in civilian, commercial, and military aircraft by measuring and displaying ground clearance. . Provides situational awareness to the crew during various stages of flight and instrument approaches.
Radar altimeters operate in the 4.2-4.4 GHz band spectrum allocation of the Aeronautical Radionavigation Service (ARNS) and their information forms part of the Terrain Awareness and Warning System (TAWS), Traffic Warning and Collision Avoidance System (TCAS). Masu. , wind shear detection system, flight control system, automatic landing system (including autothrottle and automatic landing flare and rollout), automatic flight guidance and control system (AFGCS), and electronic centralized aircraft monitoring (ECAM) system.
A 2020 study by the Radio Technology Commission for Aeronautics (RTCA) found that 5G base stations and user equipment onboard aircraft operating in the 3.7-4.2 GHz frequency band (currently deployed in the United States) Both may pose a risk of harmful interference. Radar altimeters (operating in the 4.2-4.4 GHz range) are applied to all types of aircraft and have far-reaching safety implications and implications for aviation operations.
Radar altimeter interference from 5G radio signals can cause radar altitude information to be lost or worse, false radar altitude information to be unintentionally generated.
Impact on the US aviation industry
The Federal Communications Commission (FCC) is auctioning off the 3.7-3.98 GHz band of its allocated 3.7-4.2 GHz frequency band to carriers AT&T and Verizon, and some local airports will also be included in the network rollout. Ta.
Because this frequency band is close to the operating frequency of radio altimeters, 4.2-4.4 GHz, interference can affect safety in the aviation industry.
As a result, the Federal Aviation Administration (FAA) has imposed restrictions on aircraft operations, causing delays, diversions, and cancellations for passenger flights at airports equipped with 5G and during bad weather.
Turkish flight TK1951 crashes due to radar altimeter failure
On February 24, 2009, Turkish Airlines (TK) flight TK1951, operating a Boeing 737-800 and carrying 135 souls, departed from Istanbul (IST), Turkey, and arrived at Amsterdam Airport Schiphol, the Netherlands. AMS) after stalling while landing at the same airport. 400 feet due to radar altimeter failure and pilot error.
A radar altimeter failure caused the autothrottle control system to reduce idle power during approach. The crew realized this too late and were unable to take appropriate steps to increase thrust and recover the aircraft before it stalled and crashed.
The plane broke into three pieces on impact, killing nine passengers and crew, including all three pilots.
Possibility of 5G and radar altimeter coexisting
Aviation safety and 5G can coexist, but stakeholders must work together to find and install permanent solutions. Possible solutions include:
Radar altimeter update
Future radar altimeter designs will need to be improved to increase their immunity to radio frequency interference in the 3.7-3.98 GHz band by updating the Minimum Operational Performance Standards (MOPS).
The altimeter must then be certified with additional performance requirements for RF interference rejection. As a step toward resolving this issue, the FAA approves a new, more robust and reliable radar altimeter that is resilient and uses proprietary digital signal processing (DSP) technology to eliminate interference with 5G C-band radio signals. Did.
5G power level and antenna height reduction
All countries deploying 5G are likely to impose some restrictions on the use of radar altimeters to protect them from harmful interference. This may include lowering both the power level of 5G transmissions and the height of antennas near airports and along approach and landing routes.
5G transmission may also be limited to antennas pointing to the sky or near public helipads. These measures ensure that 5G can operate further away from the aviation environment and limit the directional tilt of 5G antennas.
Sufficient spacing for 5G frequency bands from radar altimeter
The ITU standard specifies an appropriate margin of 6dB requirement from the radio altimeter operating frequency limit to eliminate the possibility of radio interference from other radio frequency services.
When selecting and managing the frequency spectrum for 5G, countries must ensure the necessary spacing between frequency uses to eliminate the possibility of interference.
For example, the European Union and South Korea have chosen 5G frequency bands far from radio altimeter frequency limits and have not encountered any cases of interference in their operations.
Regarding 5G restrictions around airports
Experts have advised countries to limit the deployment of 5G near airports unless viable solutions are in place to mitigate radar altimeter interference from 5G signals.
When Canada approved 5G in the 3.45-3.65 GHz frequency band, restrictions were placed near 26 airports to ensure aviation safety.
For more information on civil aviation spectrum protection and aircraft safety systems, please see IATA’s Aviation and 5G and 5G and Aviation Safety documents.
Featured Image: Michael Rodback/Airways
