back to article BT in tests to beam down 5G coverage from the stratosphere

BT is helping to test out antenna technology for a company planning to deliver 4G and 5G coverage from high-flying aircraft. The system is intended to provide connectivity in remote areas that are not well served by terrestrial networks. The project, which has received funding from Innovate UK – Britain's "innovation agency …

  1. hoola Silver badge

    Possibly a sensible solution

    5G has the potential to make fixed lines redundant for many Internet users.

    The advantages I see on this are:


    It can be solar powered

    Does not clutter up space with cube-sats

    Launch costs and environmental impact must be less than lobbing stuff into LEO.


    Lower altitude so possibly more vulnerable

    1. Anonymous Coward Silver badge

      Re: Possibly a sensible solution

      I can imagine that they'll next start to explore a laser mesh system to link the various drones to a single downlink, then at some point they'll realise that they're just duplicating the work of starlink but at a lower altitude.

      Wouldn't it be easier for His Muskiness to deploy the tried-and-tested satellite hardware onto the drones rather than this company starting from scratch?

      Also, given the current world situation, it'd be far too easy for foreign powers to disable communications over a wide area by taking out a slow aircraft. Far easier than targeting hundreds of cell towers.

      Nope, to me this whole thing stinks of VC funding with no real prospect of a useful product at the end of it. Much like the penguin, it'll have wings but won't fly.

      1. abetancort

        Re: Possibly a sensible solution

        Easy to shutdown but even easier to restore service.

        Letting too much power in the hands of Musk is dangerous as we have seen in his handling of Twitter’s acquisition. It’s time someone showed that there could be competition in Starlink’s turf.

    2. lglethal Silver badge

      Re: Possibly a sensible solution

      I agree that this is potentially a solution, but some of what you have written is really not right.

      Cheap - long term this is unlikely to be cheaper than a dedicated satellite. You need at least 3 aircraft (1 in flight, 1 in refit/maintenance, 1 spare (in case maintenance runs long)), you need to conduct regular maintenance of them (easily the most expensive part of any aircraft's life cycle), you need to constantly fuel them. A Satellite needs to launch once. It's an expensive launch, but that's it. Only ongoing cost is maintaining station, which means a small amount of time connected to a ground station. Significantly cheaper than an aircraft. So over the lifetime of the product, I'd guess they come out about the same. Admittedly, I'm talking about a proper Telcom satellite, not a Starlink swarm of satellites, which admittedly, they get expensive fast due to needing a dedicated ground station (or multiple stations) and lots of launches!

      Solar Powered - they've already said hydrogen powered. Hydrogen can be produced cleanly, but generally it's not. It's usually made from cracking fossil fuels, as that's easier and cheaper, than Hydrolysis. Hopefully, that changes in the future, but I wouldnt bet on it.

      Does not clutter up space with cube-sats - Telcom sats are not cube-sats, they tend to be big old things that sit in a Geo-sync orbit. The reason being, you want them sitting above the spot of land you want them monitoring. Put them in any other type of orbit, and they have to, well, orbit the Earth, so they'll be moving off station regularly. That's why the likes of Starlink need vast swarms in order to cover the whole sky effectively. And to piss off the Astronomers, of course...

      Enviromental Impact, would be interesting to see. A single Rocket launch versus continually burning low levels of hydrogen for months on end. I'd almost suspect that the launch if done with a standard LOx/LH2 Rocket would be less environmentally damaging (as the output is mainly water vapour). Kerosene rockets, would be closer.

      As for your lower altitude possibly being more vulnerable disadvantage. There's no "possibly" about it. Atmospheric winds are not something to sneeze at. Even in relatively benign areas, they arent exactly friendly. In Space, your main issue is Cosmic Rays, and those can be relatively well accounted for through hardening, and data monitoring.

      For me, probably the biggest advantage of the A/C version is that, it is childs play to upgrade them. Once you launch a satellite, it's there and it's done. If the tech upgrades or changes a year down the line, too bad. An A/C system like this can upgrade by simply swapping out the modules. That massively extends the life of the project...

      1. Roland6 Silver badge

        Re: Possibly a sensible solution

        > You need at least 3 aircraft

        What isn’t being mentioned is flight / on-station time.Expect this to be hours rather than days or weeks, which means each flying “base station” will need a permanent ground crew.

        The only real use I see for this is for temporary networks, but can this be deployed to say the Caribbean, mid Pacific etc. in a matter of hours?

        1. Richard 12 Silver badge

          Re: Possibly a sensible solution

          They're claiming one week on-station.

          Which seems like the very upper end of feasibility, assuming the weather is clement and the jet stream isn't anywhere near.

          When the wind doth blow, it's going to burn through the fuel much faster. Or land, leaving no service at all.

          This really doesn't feel like a feasible option for long-term use. To me it's a "cell is down, this will cover until the tower is fixed" option.

      2. quartzie

        Re: Possibly a sensible solution

        There are at least two issues with geosynchronous satellites you mentioned.

        1. They're out of reach of regular cell phones (4G/5G)

        2. The delay involved precludes them from being used for phone service (120ms one-way due to orbital altitude 36000km)

        I'm not saying that starlink-on-a-plane IS the solution, but geosynchronous satellites are most certainly not.

      3. jmch Silver badge

        Re: Possibly a sensible solution

        Re solar-powered - I believe that there was an experimental solar-powered aircraft that could in theory keep aloft indefinitely, but I guess it only needs to power its own propellers and electronics, and a bunch of comms equipment would increase both weight and power needed. I suspect the reason for hydrogen power is that they can't get it to work as reliably with solar.

      4. Potemkine! Silver badge

        Re: Possibly a sensible solution

        burning low levels of hydrogen for months

        2H2 (g) + O2 (g) → 2H2O (g) + energy

        Where's the pollution?

        Even if in the atmosphere this could produce some nitrogen oxides, this is not necessarily a bad thing as nitrogen oxides degrade methane in the atmosphere.

    3. steviebuk Silver badge

      Re: Possibly a sensible solution

      "5G has the potential to make fixed lines redundant for many Internet users."

      It was marketed as that but never happened because its hyped bollocks.

      1. Richard 12 Silver badge

        Re: Possibly a sensible solution

        Actually, it has done that for many users.

        Mostly those who rent in large cities.

        1. Stork Silver badge

          Re: Possibly a sensible solution

          I thought 4G did that for some.

    4. J. R. Hartley

      Re: Possibly a sensible solution

      RIP LOHAN :'(

      Never forgotten.

    5. anonymous boring coward Silver badge

      Re: Possibly a sensible solution

      "5G has the potential to make fixed lines redundant for many Internet users."

      A, small, pipe dream.

  2. Flak

    Google Loon (but with wings?)

    I have no doubt that the technology will work following some testing, but the question for me is around commercial viability.

    1. John Robson Silver badge

      Re: Google Loon (but with wings?)

      The problem is that various areas of many countries don't have the terrain and population density to make ground based towers cost competitive.

      If this is anywhere near as good as they think it is (and I imagine there could be some interesting upload RF issues to deal with) then it could provide "good enough", or even better, coverage to those areas.

      And with enough of the area covered by a single platform then the capex and opex might be worthwhile.

      I assume they're running a fuel cell to power the base station(s) as well as the propulsion system...

      1. Andy The Hat Silver badge

        Re: Google Loon (but with wings?)

        It supports standard smartphones do doesn't require more base stations for users and I would assume it can transmit/receive directly to/from existing cell infrastructure, perhaps with an extra dish or two installed across a wide area. It may be possible that there's no signal shadow and it uses a single central system for all uplink - eg Madley

      2. katrinab Silver badge

        Re: Google Loon (but with wings?)

        If you looked at the numbers, you might conclude that Scotland was a country that doesn't "have the terrain and population density to make ground based towers cost competitive".

        But, the thing about the uninhabited mountain areas that make up most of the country's land area is that they are uninhabited. Nobody lives there. The average person in Scotland lives in a place with the same population density as the average person in England, rounded to 1 decimal place. Those places have phone lines, phone towers, etc, exactly the same as they do in England.

        So if you were to put one of these plane things up in the Scottish Highlands, you are going to reach a few farmers, rock climbers, and so on, but not that many people in the overall scheme of things. Nobody in Glasgow or Edinburgh is going to be interested in it.

        1. Anonymous Coward
          Anonymous Coward

          Re: Google Loon (but with wings?)

          That's often the view of governments (UK and Scottish), who struggle to see much outside London or Edinburgh/Glasgow*. But there's a lot happening in rural Scotland. Not only do people live there, but a surprising number of people also work there and need good comms. Some parts of the Scottish highlands already have good cell access (sometimes better than congested cities) - it's often good broadband that is lacking.

          *I moved from the south of England to live and work in NE Scotland >40 years ago; I'm against Scottish independence, mainly because I think the desire is based on emotion rather than logic. For many of us outwith the Central Belt, Holyrood is no closer than Westminster. I also think both sides of the split would feel a lot of pain. </political rant>

          Back to topic, I would much prefer they try this concept than any support of the inner space vandalism that is currently being done. We're polluting the surface and now looking for ways to do the same in orbit...

          1. katrinab Silver badge

            Re: Google Loon (but with wings?)

            Sure there is more to Scotland than just Glasgow and Edinburgh; but most of Scotland's land area is just bare rock that very likely no human has ever visited. There are some places in England like that, but a far smaller proportion of the total land area.

            Looking at the latest numbers:

            Remote rural population in the UK as a whole is 7.9%, in Scotland it is 5.8%.

            Accessible rural in UK is 9.3%, in Scotland it is 11.2%

            Urban population in UK is 82.9%, in Scotland it is 82.9%

            So, urban population in Scotland is the same as the UK to the nearest 1 decimal place, it is 0.05% higher in Scotland.

            Rural population is also the same, but remote rural in the UK as a whole is actually higher.

    2. wiggers

      Re: Google Loon (but with wings?)

      The commercial viability is really what is being tested. Hard to tell until they try it.

      1. Michael

        Re: Google Loon (but with wings?)

        It would allow 99% coverage and not coverage by population as is stated now. This allows government to mandate coverage that allows emergency services to access data services anywhere. It allows new services that could collect remote data if only there was coverage.

        It would allow the entire rail network to be covered ensuring remote monitoring would work and reduce the likelihood of fatal crashes. There are many industries that want to use data services in remote locations. You don't need population densities toake use of the data services.

        1. John H Woods Silver badge

          Re: Google Loon (but with wings?)

          Emergency services would benefit even from low bandwidth comms. I've always found the mobile-phone-that-can-send-satellite-texts quite an intriguing idea.

  3. Zolko Silver badge

    sloppy journalism

    with a wingspan of 60 meters (196 feet)

    that would be 0.2982 Furlong. Or around 10 giraffes. Geez, can't you properly do your job ? How are we supposed to correctly represent such dimensions if you insist on using weird units !

    1. Will Godfrey Silver badge

      Re: sloppy journalism

      Well feet I understand, but what are these meters?

      Knowing BT, I guess they are parking meters!

    2. anonymous boring coward Silver badge

      Re: sloppy journalism

      But how many double decker busses parked in an Olympic size swimming pool?

  4. Pete 2 Silver badge

    Text only

    > 500 individually steerable beams, and is able to provide data speeds of up to 150Mbps across an area as wide as 15,000 square kilometers

    So should we assume the marketing dept. got hold of this and that the coverage is really 300kbits/sec per beam (per cell) multiplied by 500 beams = 150Mbit/sec

    With each beam covering 30 sq km, any / all users would have to share that bandwidth between them. And that's if the 5G signal can penetrate clouds (of the meteorological kind)

    1. hoola Silver badge

      Re: Text only

      I think that the main point is that this is a way to deliver services to areas where masts are not viable due to the cost, terrain and population density.

      The actual number of simultaneous connections may not be that high.

  5. Peter Mount

    Even areas near existing masts don't get coverage

    Where I am I get 4G easily - don't have a 5G phone but near by Maidstone does have it so that's even close. However if I go to my local Pub, which is a 10 minute walk from home I rarely get anything better than 2 or 2.5G let alone 3 or 4G, sometimes nothing at all. The nearest masts are about 1.5 miles away in several directions.

    Somehow I don't see that part of Kent getting any improvements from this - this would only work for the wildest areas.

    The plus side is that I can have a few pint's without people being able to get in contact other than the Pub's WiFi (if that even works)

  6. Will Godfrey Silver badge

    Never mind commercial viability...

    What about the environment?

    What effect will this have on wildlife - in particular, birds?

    How are the aircraft fueled and powered?

    What ground support systems will need to be maintained?

    If this is some form of glorified repeater, what kind of base station would be needed?

    1. LogicGate Silver badge

      Re: Never mind commercial viability...

      Where this thing is supposed to fly, there are no birds.

      Expect some spiders to get smashed (those buggers can fly really high), and little else.

      If you worry about the environment (as you should), then this is not the item to start with.

      Stop mowing your lawn and plant a wildflower mixture instead.

      Also, the number of units flying will be so low, that the impact is a rounding error compared to everything else we are doing.

    2. Sgt_Oddball

      Re: Never mind commercial viability...

      For fuel, its on hydrogen... As the article mentions.. Several times.

      At any rate it looks to be easier to deploy than the current mobile cell towers (basically a flatbed truck with a bunch of server racks, a radio mast, a generator and four wheel drive to go up the side of a mountain).

      I wonder if the private cell network system could also be run through this?

  7. David Pearce

    Looks like someone chose hydrogen without thinking about its abysmal energy density. Those high pressure tanks are heavy

    1. LogicGate Silver badge

      Unless they go liquid hydrogen, and minimize the insulation so that the boiloff-rate equals the consumption.

    2. John Robson Silver badge

      Or maybe they thought about it - and decided that it was worth it.

      It's unlikely that they've got this far without considering the fuel storage.

  8. Mishak Silver badge

    All they need to do here...

    Is raise the height of a local mast by a few metres so that the signal gets over the hill to the 200+ properties that are in its shadow.

  9. xyz Silver badge

    The rendering makes it look like...

    Mickey Mouse, so it probably is.

  10. Anonymous Coward
    Anonymous Coward

    Isn't this a repeat?

    This is one of those ideas that get wheeled out every 5 years and then withers away without any result. Ignore it already!

    Obviously the designers forget about high speed atmospheric winds.

    I admit I only scanned the article, it seemed so much of a rehash. Did they try to say they'd be so high up they'd be above any "atmospheric disturbance"? Did they say how high that would actually be? With wings and propellers no less. Great fun.

    1. Paul Crawford Silver badge

      Re: Isn't this a repeat?

      A linked article says 60,000 feet, so similar to Concorde and the likes of U2 spy-planes, etc. That will avoid a lot of turbulence, but not jet-stream. I suspect propellers might struggle at that altitude but I don't know if variable-pitch designs would be economical for take off and for simply maintaining altitude, after all it is not really *going* anywhere fast, aside from fighting jet stream.

      1. Richard 12 Silver badge

        Re: Isn't this a repeat?

        Jet stream is really quite fast, of course.

        240 knots is quite significant.

  11. 080

    Never mind 5G, could we possibly have 4G or even 3G within 10 miles of Cardiff, not exactly the sticks.

    1. Will Godfrey Silver badge

      But, but, that's the wet country!

      All the rain saturates the air 'waves' and makes them so heavy they sink to the ground.

  12. yetanotheraoc Silver badge

    parse error -- exciting applications

    "to validate some very exciting applications for mobile and fixed wireless access coverage" ... Exciting => Invest! Fund me!

    Meanwhile back here on planet Earth, I want my wireless coverage with the least excitement possible. If there's anything exciting going on in the *applications*, it should be entirely independent of how the wireless is delivered.

  13. Anonymous Coward
    Anonymous Coward

    Ho Hum !!!

    Will not happen in a month of Sundays .... as the saying goes !!!

    Test it all you like but BT will not fund such a service ..... but will be more than welcome to be paid to test it though !!!


  14. captain veg Silver badge

    This is not the only technology being considered for delivering a wireless service to...

    "remote or hard-to-reach areas"

    It's the UK we're talking about here. Certain fringe-right politicians insist that the islands are somehow already full. How hard, then, can it be to run some fibre out to all of them?

    "SPL's antenna uses phased array tech featuring 500 individually steerable beams, and is able to provide data speeds of up to 150Mbps"

    150Mbs. So already ten years out of date.

    Spain has a much lower population density, and yet standard fibre delivers 300Mbps or more.

    In France I can have 1.2Gbps for a very reasonable monthly fee.

    I'm currently in Andorra. Basic, universal broadband is 300Mbps. Everyone here is up a mountain. How remote or hard-to-reach do you want?


    1. Paul Crawford Silver badge

      Re: This is not the only technology being considered for delivering a wireless service to...

      The "hard" part of running fibre is money. Years of insufficient investment, no government strategy beyond letting the markets decide, and some pointless voucher schemes that BT/Openreach would get based on promises they never get round to delivering.

      Basically the same reasons so much else of the UK lags behind the EU and South Korea, etc.

      I think only the USA is worse in terms of good internet service for all among developed countries, for much the same reasons.

  15. Jim84

    Blimps vs fixed wing

    Blimps that fly by varying their buoyancy might turn out to be a better bet for communications or ISR than unmanned fixed wing aircraft:

    1. Paul Crawford Silver badge

      Re: Blimps vs fixed wing

      They still need engines for station-keeping against jet stream, etc.

  16. Anonymous Coward
    Anonymous Coward

    This big ball of shit we live on has mass and gravity so at what point could you have something connected to the ground by a cable that the alternate forces would come into play keeping something in position?

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