Japan solves 5G airliner conundrum: Keep mobe masts 200m from airport approach paths. That's it

(And maintain a guard band.) US airliners melt down as rest of world moves on


American aviation regulators have banned the use of autoland at some of their country's airports as the local debate about 5G phone mast emissions and airliners continues – while Japan claims to have solved the problem a year ago.

This morning Emirates, the largest airline of the United Arab Emirates, declared it was suspending flights to nine US airports as mobile network operators in the States said they were suspending their planned switch-on of 5G services. It follows Japan's All Nippon Airways (ANA), Japan Airlines and Air India, according to the Daily Mail.

Yet in Japan itself the solution was straightforward, with local scientists telling the International Civil Aviation Organisation last year: "To avoid the blocking of radio altimeters, the location of the high-power 5G base station should be avoided within 200m from the approaching route of aircraft."

In the US things are rather different, however.

"Boeing has announced flight restrictions on all airlines operating the Boeing 777 aircraft, and we have cancelled or changed the aircraft for some flights to/from the US based on the announcement by Boeing," an ANA spokesman told the Mail. We have asked Boeing for comment.

The US-specific problem occurs because the so-called C-band of frequencies set aside for 5G by spectrum regulators is closer to a safety-critical aviation band than in the rest of the world, as previously reported. US aviation trade unions and the Federal Aviation Administration (FAA), the sector's safety regulator, fear that radio emissions at the top of the C-band's 3.98GHz frequency could bleed over into the 4.2-4.4GHz band used by airliners' radio altimeters.

Disrupting radio altimeters potentially prohibits the use of automatic landing capabilities, as used during bad weather when pilots can't see the airport.

The Reuters newswire reported this morning that Verizon and AT&T will not switch on 5G services at some base stations near airports, though others have reportedly been flashed up already.

Meanwhile The Drive, a car news website with an aviation 'n' military side hustle, reported an airline pilot as saying: "We will be limited to Category 1 approaches… Cities such as Seattle, Eugene, Portland, San Francisco, and Spokane, which are notorious for low visibility and low ceilings will experience days of interrupted travel."

Meanwhile, in Japan

Mobile market analyst John Strand of Strand Consulting claimed in a briefing note issued today that the dispute is all about who pays for radio altimeter upgrades to conclusively exclude 5G interference, accusing the FAA of not carrying out proper testing to validate its precautionary principle-driven bans on radalt-dependent approaches being flown by airliners.

"Instead," wrote Strand, "the FAA has colluded with various aviation trade associations (pilots, airlines, and aircraft) in the hope that they can get the mobile industry to cough up $100m or so to pay for altimeter upgrades."

No source was given for the $100m figure. Strand compared the US situation with Japan, though erroneously claimed the Japanese 5G spectrum allocation overlaps the lower end of the radio altimeters band. NTT Review, a technical magazine produced by local telco NTT Docomo, stated the relevant Japanese 5G allocations are 3.6-4.1GHz and 4.5-4.6GHz. These are closer to the radio altimeter band (4.2-4.4GHz) than in the US, yet there hasn't been a similar outcry from Japan about 5G interference with airliners.

As Gartner analyst Bill Ray previously pointed out to The Register, the question is whether radio altimeters' RF filters are good enough to exclude bleed-through interference from 5G transmitters. To that end, local studies in Japan appear to have found a solution to the problem: don't build masts under runway approach paths and make sure there's enough guard band (unused spectrum) in between the frequencies in use.

Japan's Electronic Navigation Research Institute (ENRI) published a study (.docx, 21 pages) on 5G interference with radio altimeters and submitted its findings to the International Civil Aviation Organisation in March last year. Its practical tests included experiments carried out on Rockwell Collins and Honeywell radio altimeters, both companies being major suppliers to airframers such as Boeing and Airbus.

"In the last evaluation we need at least 60MHz of [guard band] to avoid the blocking to the radio altimeters," said ENRI, adding: "400m of separation distance from the point beneath the aircraft might be needed to make the compatibility in case of the maximum envelope pattern."

The Japanese scientists made their finding after ensuring beam-forming antennas were pointed earthwards so the centre of directional high-power pulses can never be transmitted above the horizontal.

All these findings support UK and EU regulators' stances on 5G and airliners, which is broadly "no problems seen, no problems anticipated." Their US colleagues ought to be taking notes from the rest of the world. ®


Other stories you might like

  • New York City rips out last city-owned public payphones
    Y'know, those large cellphones fixed in place that you share with everyone and have to put coins in. Y'know, those metal disks representing...

    New York City this week ripped out its last municipally-owned payphones from Times Square to make room for Wi-Fi kiosks from city infrastructure project LinkNYC.

    "NYC's last free-standing payphones were removed today; they'll be replaced with a Link, boosting accessibility and connectivity across the city," LinkNYC said via Twitter.

    Manhattan Borough President Mark Levine said, "Truly the end of an era but also, hopefully, the start of a new one with more equity in technology access!"

    Continue reading
  • Cheers ransomware hits VMware ESXi systems
    Now we can say extortionware has jumped the shark

    Another ransomware strain is targeting VMware ESXi servers, which have been the focus of extortionists and other miscreants in recent months.

    ESXi, a bare-metal hypervisor used by a broad range of organizations throughout the world, has become the target of such ransomware families as LockBit, Hive, and RansomEXX. The ubiquitous use of the technology, and the size of some companies that use it has made it an efficient way for crooks to infect large numbers of virtualized systems and connected devices and equipment, according to researchers with Trend Micro.

    "ESXi is widely used in enterprise settings for server virtualization," Trend Micro noted in a write-up this week. "It is therefore a popular target for ransomware attacks … Compromising ESXi servers has been a scheme used by some notorious cybercriminal groups because it is a means to swiftly spread the ransomware to many devices."

    Continue reading
  • Twitter founder Dorsey beats hasty retweet from the board
    We'll see you around the Block

    Twitter has officially entered the post-Dorsey age: its founder and two-time CEO's board term expired Wednesday, marking the first time the social media company hasn't had him around in some capacity.

    Jack Dorsey announced his resignation as Twitter chief exec in November 2021, and passed the baton to Parag Agrawal while remaining on the board. Now that board term has ended, and Dorsey has stepped down as expected. Agrawal has taken Dorsey's board seat; Salesforce co-CEO Bret Taylor has assumed the role of Twitter's board chair. 

    In his resignation announcement, Dorsey – who co-founded and is CEO of Block (formerly Square) – said having founders leading the companies they created can be severely limiting for an organization and can serve as a single point of failure. "I believe it's critical a company can stand on its own, free of its founder's influence or direction," Dorsey said. He didn't respond to a request for further comment today. 

    Continue reading
  • Snowflake stock drops as some top customers cut usage
    You might say its valuation is melting away

    IPO darling Snowflake's share price took a beating in an already bearish market for tech stocks after filing weaker than expected financial guidance amid a slowdown in orders from some of its largest customers.

    For its first quarter of fiscal 2023, ended April 30, Snowflake's revenue grew 85 percent year-on-year to $422.4 million. The company made an operating loss of $188.8 million, albeit down from $205.6 million a year ago.

    Although surpassing revenue expectations, the cloud-based data warehousing business saw its valuation tumble 16 percent in extended trading on Wednesday. Its stock price dived from $133 apiece to $117 in after-hours trading, and today is cruising back at $127. That stumble arrived amid a general tech stock sell-off some observers said was overdue.

    Continue reading
  • Amazon investors nuke proposed ethics overhaul and say yes to $212m CEO pay
    Workplace safety, labor organizing, sustainability and, um, wage 'fairness' all struck down in vote

    Amazon CEO Andy Jassy's first shareholder meeting was a rousing success for Amazon leadership and Jassy's bank account. But for activist investors intent on making Amazon more open and transparent, it was nothing short of a disaster.

    While actual voting results haven't been released yet, Amazon general counsel David Zapolsky told Reuters that stock owners voted down fifteen shareholder resolutions addressing topics including workplace safety, labor organizing, sustainability, and pay fairness. Amazon's board recommended voting no on all of the proposals.

    Jassy and the board scored additional victories in the form of shareholder approval for board appointments, executive compensation and a 20-for-1 stock split. Jassy's executive compensation package, which is tied to Amazon stock price and mostly delivered as stock awards over a multi-year period, was $212 million in 2021. 

    Continue reading
  • Confirmed: Broadcom, VMware agree to $61b merger
    Unless anyone out there can make a better offer. Oh, Elon?

    Broadcom has confirmed it intends to acquire VMware in a deal that looks set to be worth $61 billion, if it goes ahead: the agreement provides for a “go-shop” provision under which the virtualization giant may solicit alternative offers.

    Rumors of the proposed merger emerged earlier this week, amid much speculation, but neither of the companies was prepared to comment on the deal before today, when it was disclosed that the boards of directors of both organizations have unanimously approved the agreement.

    Michael Dell and Silver Lake investors, which own just over half of the outstanding shares in VMware between both, have apparently signed support agreements to vote in favor of the transaction, so long as the VMware board continues to recommend the proposed transaction with chip designer Broadcom.

    Continue reading

Biting the hand that feeds IT © 1998–2022