Starlink's Portability mode lets you take your sat broadband dish anywhere* Starlink customers who've been itching to take their dish on the road can finally do so – for a price. The Musk-owned satellite internet service provider quietly rolled out a feature this week called Portability which, for an additional $25 per month, will allow customers to take their service with them anywhere on the same …
Why ?
What does it matter where the dish is ? There is a dish, with a paid subscription. You should be able to lob it on the roof of the car and drive around with it. The cubestats are moving at thousands of miles an hour anyway, a few more dozen shouldn't have any kind of impact.
Although there are technical limitations related to the number of subscribers each ground station can support my guess is that the principle concern is scalpers.
I hope that when laser links can connect you to any ground station, there are plenty of satellites to provide bandwidth and there is no waiting list for terminals then the restrictions will disappear. There is a possibility that competition with Kuiper will end Starlink restrictions - in 2050 - if Jeff can manufacture engines.
Scalper in this case is probably Musk.
So pay an extra $25 a month, or leave your dish at home. No putting it on your yacht, truck, job or campsite. At least not without paying for a 'premium' roaming service.
Or there may be some regulatory restrictions, ie operator license is only for fixed endpoints. Which is probably true for some countries, but Inmarsat managed portability with BGAN kit, widely used by reporters.
Starlink was clearly advertised for use in fixed locations only. There were regulatory restrictions as well as technical, both of which have been relaxed over time.
Inmarsat is a contraction international marine satellite. They started by obtaining licenses for mobile use because most ships do not remain at fixed locations. Back when I worked with their kit ('80s), the satellites were referred to as Atlantic, Pacific and Indian (as in ocean). They have expanded since then, but their main target as always been mobile, with the size of that mobile reducing over time. The kit I worked on would have capsized some of the boats customers hoped could get a satellite phone/fax.
Yup. As a young telecomms sprog, I remember getting excited at the prospect of an STM-1 satellite connection. Would have needed roof loading capable of supporting a 15m dish, and cost a fair chunk of a geostationary satellite.
But as sales would say, it'd be technicaly feasible.
Even though I'm an excellent shot, I do miss sales sometimes. I did get to have some fun looking at naval applications, like the cunning mounts hiding under domes. Including whether those could be installed on swaying skyscrapers. Also been puzzled about cultural differences, ie VSAT solutions for DR were far more common in the US than Europe. Conclusion was the US is more used to things like hurricanes & tornados, so pulling a spare dish out of stores restores service faster than waiting for cable restoration.
You aren't comparing like with like. Inmarsat uses satellites in geostationary orbit 22,000 miles away. There is only a dozen of these satellites spread around the earth so they are expensive what with high contention and limited bandwidth. Starlink satellites are in low earth orbit constantly moving over the sky. That means that regardless of where you are on earth (barring the poles), you're going to have a multitude of satellites overhead. You could be in the middle of the ocean, a desert, a city, anything with a clear line of sight and there will be one overhead.
Now it may be that the 1st generation of Starlink terminal (dish and box) isn't so great if you mount it to a boat because it is not gimballed & motorised. But if you're stationary in a marina, a campsite, or a cabin in the woods then there is absolutely no reason the existing dish shouldn't function exactly as it does at home - lock onto a passing satellite, handshake, authenticate, internet happens. Any additional charge imposed for "roaming" is nothing to do with any technical issue, it's merely a cashgrab.
In any particular place or time there will be up to about one useful Starlink satellite overhead. There may be others near the horizon, but they are not licensed to transmit at that angle and if they tried it would be with reduced signal strength and cause interference with the actual useful one.
Until recently, Starlink satellites needed to be in range of a ground station to do anything useful. Ground stations were built according to demand and demand in the middle of an ocean was limited. The more modern satellites can also communicate with each other via laser links. When not in range of a ground station they can route traffic via laser to another satellite that is.
Mobile use is a new feature based on new satellites and new licensing. It was not offered before because it either would not work, would not work reliably or would reduce access by other paying customers.
Charging extra for mobile use is not a particularly good reason to pile on hate for Elon. There are plenty of much better reasons. I will start you off with FundingSecured's latest cryptocurrency pump and dump via twitter.
"In any particular place or time there will be up to about one useful Starlink satellite overhead"
That is not true, at least where I'm located, I have at least 6-8 usable satellites in view.
Users in very high latitudes have very few satellites at the moment (the bulk of the current constellation is at a 53° inclination).
Users at low latitudes will have lower densities of usable satellites than my situation (also did to the inclination).
If you're curious about how many satellites you could see from your location, check out starlink.sx. It's an unofficial site that tracks the satellites and other info.
AFAIK, Starlink still requires that your active satellite requires access to a ground station. They have launched some satellites with laser links, but no confirmation that they're active yet.
Mobile (roaming) use has been possible for some time (I think the reddit username is tuckstruck for a guy who has been RVing around the US and Canada with Starlink). The feature was semi-official until this week.
There's an error in the article, Starlink does allow you to transfer service to another party. There are some caveats, of course. I don't think the ability to transfer was available at launch.
OOh, that's quite interesting.
When you initially look at, you think there are loads of Starlink Sats up there...
What is clear thought is that when zooming in, there really aren't. Looking at the UK now, there are perhaps 3 or 4 over the UK in reality.
Where I am currently in Croatia.... not even that much.
Is one 'dot' one Satellite, or does it represent a small cluster?
I was thinking about the middle of the ocean use of starlink when there was an article about some US domestic airlines signing up for Starlink.
I think Starlink may not be able to be used in the middle of the ocean currently. I understand current Starlink sats can't communicate with each other, and they need to communicate with ground stations.
Once they have the sats which can communicate with each other (via laser as I understand), then lack of ground stations in the middle of the ocean will not be an issue.
> there is absolutely no reason the existing dish shouldn't function exactly as it does at home
If there was no difference at all where you operate your dish, why would Starlink be severely limiting their sales by having wait lists for some areas and not others?
Move your dish from a rural area to a dense city and you'll quickly find the limits of the capacity of those satellites overhead. Once you want to talk to the internet, the location and capacities of the ground stations needs to be taken into account as well. You're also only talking about a change in longitude. Changes in longitude will alter how many satellites are overhead.
Because you're moving into an area with OTHER folks with a paid subscription, and they shouldn't suffer because you're trying to snaffle their bandwidth.
It's not first-come, first-served. You get what's left over. ""Starlink prioritizes network resources for users at their registered service address."
Also, there may simply not be satellites in view. Granted, with the metric assload of satellites they're putting up that's probably not an issue, but they need to put in in the fine print anyway.
People moving around with their satellite dish are most likely moving to places with less contention, not more. e.g. someone driving out of a city to go on a camping trip. I very much doubt it makes any difference to contention in those sparsely used areas.
And if there were some potential for abuse then I'm quite certain that Starlink could stop it with a reasonable usage policy, e.g. roamers only get 30 days in a year or more aggressive bandwidth throttling.
Unless they are parked in a trailer park with another 100 trailers, most of them having starlink dishes.
Or a campsite with most campers having their own dishes.
I guess it will work better when you go to places which are out of the way and not well known.
They are not cubestats, and they are not built to support mobile. You'll have to wait a couple of years for AST to get their sats up, and then sell a kidney before they will let you connect to them with your 5G phone.
If you take enough Starlink dishes to the same location, they will run out of bandwidth. E.g. if you have a few thousand people turn up for a festival, and they are all camping in a field with their dishes, then there's no way Starlink can provide enough bandwidth. In that case, they quite reasonably prioritize the fixed dishes rather than the roaming ones. E.g. that means that the people in the village near the campsite can continue to work from home using their Starlink connections.
Regarding moving: One of the problems is Doppler shift. If a radio transmitter and a radio receiver are moving towards each other, then the receiver will see a higher frequency than the transmitter is actually transmitting. Similarly a lower frequency if they are moving away. This means that a moving dish will see different satellite frequencies than it expects, and will probably fail to decode them. This happens even at typical car speeds.
It is possible to correct for Doppler. And they must be doing that to account for the satellite movement. However, they likely design their correction system with the expectation that the ground stations were not moving.
Another problem is that I believe that the ground stations shape the transmissions to go to the satellite. If they are aiming off to one side, and you drive around a bend, suddenly they are not pointing at the satellite any more. It is possible to fix this, with the right sensors on the base stations. But since Starlink are selling a fixed service, there is no reason for them to incur the cost of those sensors.
Regarding doppler shift in a car:
Speed of light = 1 billion Km/hour
Speed of Car = 100 Km/hour
Speed of Car as fraction of Speed of Light = 0.0000001
Not saying you are wrong, but the channels to Starlink must be pretty narrow for doppler shift to be a problem.
"Yes but if the baud rate is high enough, a small shift like that could alter the timing of symbol reception at either end"
Shouldn't do, as the receiver will be constantly adapting to keep synchronisation with the transmitted carrier. It has to do that to account for drift between the transmit and receive clocks, but also to account for the Doppler shift in the transmit carrier due to the satellites orbital motion. Gut feeling is that Doppler induced by moving the ground segment even in a fast car is not going to be significantly more than that induced by the satellite orbit. As others have said here, the more challenging aspect to operating a dish on the move is keeping it pointed.
I think they already have this solved cos they have started Starlink for aircraft.
https://www.theregister.com/2022/04/22/starlink_lands_first_aviation_customer/
And since aircraft tend to fly alot faster compared to road vehicles, I doubt even a car racing at 200kmh will be a problem.
Not to mention according to the article, they currently restrict you from using it in a moving vehicle, so it's not an issue anyway.
Not really.
Aircraft can *also* travel above oceans, which have waves. Extremely reflective surfaces over scales of several hundred square kilometers, with random fading characteristics due to Doppler on the sea state. Aero terminals have to be qualified against several sea states from Calm, to Hurricane Atlantic.
Aircraft bank at large angles, so even though the antenna is “on the top” of the aircraft, some antenna sidelobes do reflect off the sea. And since the reflective surface is up to 13km distance, that corresponds to an extremely large delay spread - for 4G we usually talk about delay spreads of a couple of microseconds, while for aero it’s 100 microseconds, which drives some unique challenges for equalisers and signal design.
Aircraft don’t turn “quite slowly”. The *vector acceleration* on a commercial jet is up to 4m/s2 maintained for a couple of minutes. That’s a huge Doppler change. The “normal” way to handle Doppler for fixed satcoms to LEO satellites, is to pre-compensate from the known orbital position of fast-moving spacecraft, and GPS location of terminal. Unfortunately, the maths just doesn’t quite work for aero, because the vector direction of the aircraft changes faster than the reaction time of the GPS and gyro units; if you crunch through the error budgets, you’ll find it’s the acceleration multiplied by the loop response time that kills you. So the receivers on both aircraft, and ground infrastructure must dynamically estimate Doppler open-loop, a rather different receiver structure.
I don’t really understand your point about ATC separation. Satellite regions/beams are huge, on the order of hundreds of kilometres. The whole of Europe is only probably a dozen beams.
Speed of Car as fraction of Speed of Light = 0.0000001
And that is only true if the satellite is right at the horizon and the car is moving in a straight line exactly to or from that point on the horizon. As the satellites are usually a fair bit above the horizon, that fraction is usually a lot smaller, down to zero if the satellite is in a direction that is perpendicular to the course of the car (like but not necessarily limited to straight above).
> the channels to Starlink must be pretty narrow for doppler shift to be a problem.
It's common in modern digital signaling method for doppler shift at mere car speeds to be a problem. Even multipath interference off moving objects can be a problem:
https://www.tvtechnology.com/opinion/receiving-atsc-30
It's not a technical limitation. Remember that they've recently signed up a couple of airlines to provide in-flight internet service. Airplanes travel quicker than cars!
It'll just be down to bandwidth allocation, and the chance to extract more money is a side benefit.
One is a small problem, that was not designed for, and is uncorrected.
The other is a big problem, that was accounted for in design, and is corrected for.
That's the difference. Whether the first problem is so small that it shouldn't actually be a problem, I have no idea.
If Starlink can't cope with a thousand people camping in a field then how would it cope with many tens of thousands in a mid size city? This isn't an excuse.
As for doppler shift, this is already a thing. The satellites are constantly moving towards or away from you. It might be a technical limitation of the 1st gen terminal that it's not designed for trucks / boats but that has nothing to do with roaming per se.
I don't think they're aiming for tens of thousands of people in a city - they will generally have much better, faster, cheaper alternatives.
For ~25% the cost I get substantially lower ping (single digit ms), five times higher download and upload. But then I live in a reasonably densely populated area.
We know that movement is NOT an issue... As the same starlink sats are capable of keeping comms at full speed with jets. They tested it with military aircraft and have just signed a deal with Hawaiian air ( https://www.itpro.co.uk/network-internet/wifi-hotspots/367475/spacex-starlink-signs-first-in-flight-wi-fi-deal ).
It is more of an issue with regulatory approval for 'mobile' stations. I am waiting for starlink on a boat. The 'maritime' permissions are currently for (if I recall correctly) under 10 mobile maritime stations (as a test). The movement is a regulatory not a technical issue.
Well, an aero sat terminal normal cost price $30k for a cheap one, $250k for one appropriate to a commercial jet.
If Elon is selling you the same terminal for the $1k you’re paying for your home Starlink terminal, then you’re getting an exceptionally good deal.
Suggest you buy the home terminal capable of aero terminal functionality ASAP at a saving of a smidge under a quarter of a million dollars. Before Elon notices what a doofus he’s been.
Don't most festivals work with telcos to have transportable cell sites installed? If enough concerts/ball games are held in one place, venue owners often provide free space for multiple telcos to install cell sites.
Someone has to pay for the Twitter purchase and it ain't gonna be Elon. Cough up the unadvertised $25 a month or complain on Twitter. Until he takes that over fully, of course, then fuggetaboutit.
Pub O'Clock
There are more and less congested regions of the earths surface. Obviously, Starlink are going to allow new subscribers in the less congested regions, but will have to cap capacity in the more congested regions.
The fact that the satellites are moving is irrelevant. At any one time, there is a maximum of X satellites above each location to provide service.
As to the mobility angle, I think you are thinking about the Doppler, no that also makes a difference. 7km/s for line-of-sight does cause Doppler, but in a pretty trivial way to compensate. But as soon as you are driving through areas, you need to think about reflected signals and that means compensating for Rayleigh fading. It’s a very,very different problem.
Sigh. No, it’s very different. Engineering modems to be able to cope with mobile (fast-fading multipath) is complicated. Mind-bogglingly complicated and expensive. Total global R&D is about $30bn *per year*, for a decade, of which probably a third or more goes on solving just that one problem.
Elon is *launching* thousands of spacecraft. Plus building those spacecraft. Plus designing the modems on those spacecraft. His total available R&D spend for modems is maybe at best 2% of what 4G cost. How much are you expecting him to add engineering effort on, for a use case that doesn’t exist yet, and that *you don’t even want to pay a single cent for*. I can tell you how much engineering he did on that use case: he allocated exactly as many dollars as you are prepared to pay for it, on top of the Fixed case. Zero.
It’s no use whingeing “but the Fixed scenario is already expensive”. Yes. Yes it is. It has to pay for thousands of spacecraft, more by a factor of ten than have been built in the history of humanity. What were you expecting?
They won't. Trust me.
Pass me those two green fire extinguishers that we found in the basement. We may have a "fire" in the think tank. Yes the one with the sticky door. I blame the airtight seal. Halon - I mean the random contents of those old green extinguishers is heavier than air and can be squirted through a gap in the ceiling tiles...
This is, ultimately, why you need competition. Though I should not really have to remind anyone that any services even remotely comparable to starlink in terms of capability - portable or not - did not come at the decidedly low cost that starlink does.
If you're buying into it today you're either a specialised user, or an early adopter; and as such can expect early adopter costs for a while yet.
Eventually there will be too many competitors and you'll see a swathe of mergers and consolidations. Why should wireless telecomms be any different to any other cycle of the same nature!
Sirius Radio uses geostationary satellites. I was able to pick it up in my hire car even in the Northern state of Vermont. Any forestation or tall building would block it though. With LEO satellites, surely there was potential for a global in-car radio platform, with such strong coverage that only tunnels would block. I'm wondering if that's retrofitable to Starlink satellites via a software upgrade. If not, it's a lost opportunity.
This thought has occurred to me because I'm in a part if the UK where FM and DAB rarely work at all, due to hills and valleys.
Are you assuming that LEO satellites just will have more power density to ground than GEO?
If so, that’s wrong. It *may* be sometimes correct, but there are too many other factors to make it a useful guide. Distance is not the only measure.
First off, a typical GEO is about 10x larger than a typical LEO, which means 10x solar panel size, which means 10x electrical power budget.
Second, GEO satellites can have truly massive antenna dishes, 10-15m+, which goes most of the way to mitigating the orbital distance penalty.
Third: at each power level, you have to work with power amp technologies and modules that actually exist and can be procured, not just extrapolating off the end of a graph.
Fourth, cost,cost,cost
There simply isn’t any way to definitively decide whether GEO or LEO has the advantage, other than doing a full costed system study end-to-end. When I were a lad, in the first 5-10 years of being a satellite design engineer, I was convinced that if one could only understand it at a deep enough level, you’d be able to intuit it from first principles. After twenty years in the industry, and personally being involved in, and then running, over a dozen system studies, I accepted the brutal truth. There’s no shortcut. You’re going to need to do the detailed work, and it will take ten experienced engineers a couple of months to calculate the right answer.
Not assuming, wondering. And you've added some food for thought. Then again, while GEO radio works with a relatively simple car antenna, something Starlink-based would presumably used a scaled-down phased array panel that's flush with the car roof. The signal gain would be very significant and likely to lift it into usability even with low power LEO satellites. Yes it's early days right now and the economics don't stack up at this minute, however the tech is advancing so fast that the same Starlink satellites will still be up there once viability arrives.
Hence I was wondering, how reconfigurable those birds are.
And I thought it was a new shiny thing Musky was doling out, until, i saw he wanted me to pay 25 somethings a month towards his twitter fund.
A) People use Starlink where there is no other option.
B) i have tried registering coordinates as a service address on the app and it isn't having any of that, so I have to use my house address.
C) i know a lot of the RV crowd use starlink because they could just park up and do whatever RV types do online. They will not be happy.
All in all, suddenly, i feel dirty.
Your "C" option would be the only reason I might sign up, but paying an extra 25 a month for a lower service guarantee tier just because I love in an RV/caravan and have no fixed address? I'd do better buying a cellular hot spot. All the same technical problems, but no upcharge to roam and a lower initial buy-in.
As people have said, I don't think the "don't use it while mobile" is a technical limitation; it's a matter of the current satellites talking to a ground station or two at a time, the laser link planned between sats is not operational yet (not sure if the current sats actually have lasers or not for that matter.) So you have areas of the earth where overhead sats are out of range of any ground station; and areas where visible sats will have high traffic going through them. They presently allow or disallow new signups in an area based on that.
I think this rule is REALLY to let people know they don't want them paying like $135 a month and using it as a replacement for a mobile hotspot in their car... otherwise you'd probably have a crush of RVers using it. (Note, RV'ers are US equivalent of caravaners.) The RV parks tend to be out in the sticks so it'd probably be fine while they're parked. But if they left it running during the day, they'd be driving on the interstate (highways) between nightly stops, which will invariably go through densely populated cities (where the sats are probably maxed out.) I suppose they do not want to encourage that kind of usage.
So that just means no sale, Elon. Anyone paying extra for the roaming service will rightly have the expectation that paying extra will mean the service will work as well on the road as it does at home. But paying extra to be back of the line? No thanks. Either the extra spend guarantees roaming works as well away from home as it does as home, or don't charge extra for roaming with the understanding that roaming service is a lower priority than those at their home address, and is not guaranteed to work at all.
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