New 5G Mobile Signal - Threats To US Flights?

[pritch]

maybe the C band issue a states one, should be fine flying VFR on a nice day, wouldnt fancy an approach IMC with an altimeter that may give false readings.

According to wireless testing firm Rohde and Schwarz, the C-band is all frequencies between 4 and 8GHz. When US wireless geeks talk about C-band, though, they're talking about 3.7 to 4.2GHz—and specifically, in this case, the range from 3.7 to 3.98GHz.

[LOU LOU DISNEY]

See Emirates have cancelled flights to Orlando & 7 other US destinations because this.

[pritch]

What we're being told

5G NETWORK – AVIONICS INTERFERENCE ISSUES
What:

5G high-speed telecommunication networks are being slowly rolled out across the world. It’s a fast, high-density information streaming medium that operates in the 3.4-4.0 MHz frequency range. It is short range and is susceptible to attenuation by buildings and trees, which necessitates a vast network of antennae. The associated infrastructure is both resource intensive and very expensive, so 5G implementation is going to be slow.

So What:

Most Radio Altimeters (RADALT) work in the 4.2-4.4 MHz band. The Radio Technical Committee for Aeronautics has conducted an assessment of 5G in the frequency band 3.7-3.98 MHz (Oct 2020) and found the potential for harmful interference to aviation RADALT systems. The RADALT is a mandated critical aircraft safety system used to determine an aircraft’s height above terrain or water (e.g. maritime environments). RADALT equipment can be directly integrated into several aircraft systems and functions for various flight profiles. These can include: Terrain awareness, aircraft collision avoidance, wind shear detection, flight controls, auto-land, auto-hover and transition up/down systems in rotary aircraft. Interference could lead to malfunctions in aircraft systems and a potential loss of situational awareness during critical phases of flight. Both 5G enabled portable electronic devices and ground-based antennae have the ability to compromise RADALT equipment.

Mitigations:

Worldwide testing and evaluation has been limited thus far; various nations are looking into potential 5G flight safety issues; Canada, Japan, and the USA are introducing guard bands of between 0.2 and 0.7 MHz either side of the 4.2-4.4 MHz RADALT frequency band. Canada is introducing both exclusion and protected zones around major airports and heliports that have auto-land systems (CAT I, II and III). Ground-based antennae will be tilted downwards and transmission power levels reduced. Uncrewed airborne operations (e.g. drones/RPAS) will not be permitted in the 3.45-3.65 MHz band. Individual aircraft types will require testing and certification with regard to exposure to 5G signals; this will be a time consuming and expensive process. Transport Canada will be producing maps showing 5G zones, allowing crews to plan to avoid them in the low level environment. ICAO is liaising with aircraft manufacturers to decide the best way ahead to mitigate this issue. In the interim, operators are reminded to remain vigilant regarding their aircraft behavioral characteristics and report any undesirable or objectionable aircraft behaviors observed during manual or automated RADALT systems operations.

Useful websites:

Map of Exclusion Zones and Protection Zones (SRSP-520) - Spectrum management and telecommunications
Blanclirio Yoo Toob channel put out an interesting video yesterday. Basically the FAA rescinded the 5G NOTAM as the rollout of the system has been delayed by two weeks. It would have severely restricted operations at 80 or so airports in CONUS by not allowing the use of CAT I/II/III and RNP approaches in poor weather.