The aviation industry has stated its belief that 5G services may potentially adversely impact radio altimeters used to assist with landing aircraft.
AMTA says it is disappointed the aviation industry has chosen to play out issues regarding altimeters and potential 5G interference in the public domain, despite failing to engage in the ACMA Technical Liaison Group (TLG) on this matter.
AMTA further says the aviation industry has yet to provide sufficient evidence in support of its claims that 5G services will interfere with radio altimeters, and that it has not provided any detail on the technical specifications and performance characteristics of altimeters in service after multiple requests for them to do so.
Despite this, AMTA says the aviation industry continues to use emotive language and to assert without evidence that aircraft safety is at risk from 5G services that may use the 3.4 to 4.0 GHz bands. AMTA says the approach is only stoking public fear about a problem that has not been substantiated and is an unhelpful approach.
The issue was first raised by US aviation industry group RTCA in an October 2020 study. Before, the US FCC had found that the technical rules and the guard band between 5G and radio altimeters were “sufficient to protect (aviation) services in the 4.2-4.4GHz band.”
The GSMA report says “RTCA avoided giving detailed, non-aggregated deployment information on radio altimeter models currently being used and only some anonymised information was provided publicly by RTCA’s research partner in late 2021.”
AMTA head of spectrum and network infrastructure Chris Coughlan said, “The aviation industry in Australia has likewise refused to provide detailed specifications of radio altimeters in service in Australia to the ACMA TLG.”
The GSMA report further states key studies used by the aviation industry in support of their demands for interference mitigation measures from the mobile sector are “based on highly pessimistic, overprotective and theoretical operational scenarios that together would not occur in live radio network implementations”.
“The mobile industry stands ready to mitigate any real issues that the aviation industry can factually demonstrate," Coughlan said. "However, at this time the aviation industry is refusing to share any detailed technical information so that a wider audience of radio experts can examine the real data and assess the probability of any potential hazards."
AMTA says it is important to start with the facts and evaluate the evidence scientifically, not speak of worst-case scenarios with hidden assumptions.
AMTA notes Japan has implemented mitigations and only in the 4 - 4.1GHz band, near airports. This band is not intended for 5G use in Australia, and AMTA says this is an additional guard and evidence that Australia has over-achieved on the Japanese levels of mitigation. AMTA says the aviation industry has "conveniently failed" to mention the Japan example.
In fact, AMTA says it's likely to be the case the aviation industry's worst-case scenario applies to old technology that already should have retired years, if not decades, ago. AMTA is aware of updated altimeters with superior filtering capabilities and says the aviation industry would be wiser considering acquiring these if they remain concerned about 5G impacts.
AMTA further states no examples of interference have been shown in any market, with all the examples cited by the aviation industry being equipment failures. The examples actually serve to underpin AMTA's concern that outdated equipment should be replaced by the aviation sector to ensure the ongoing safety of air personnel and passengers, they say.
“The Government agencies in Australia such as the ACMA and CASA are fact-based bodies that rely on clear evidence and science in establishing risk. The aviation industry has yet to contribute to this fact-based process, instead resorting to emotive rhetoric which may only serve to deny Australian businesses and consumers of the benefits of 5G services around airports," Coughlan said.