I hope it will still be possible to receive a BPS timing signal privately and anonymously with ATSC 3 like one can with GPS. ATSC 3 has the Dedicated Return Channel because marketers “““need””” to spy on every-fucking-thing we do: https://www.atsc.org/wp-content/uploads/2024/04/A323-2024-04...
“Conventional linear TV services alone (albeit ultra-high-definition) may not be sufficient to sustain the terrestrial broadcasting business which requires a large amount of highly coveted spectrum resources. Intelligent media delivery and flexible service models that maximize the network Return on Investment (ROI) is of paramount importance to the broadcasting industry in the new era.”
That's a lot of fancy words to say ‘we're doing this because it makes us more money’ lol
“Recent studies have shown that interactivity between media customers and service providers and between users themselves will be one of the most important features in the next-generation media service. In this document, this unique opportunity is addressed by defining a Dedicated Return Channel (DRC) system for the next-generation broadcasting system.”
Yeah... and that's one of the most innocuous new "features" in ATSC 3.0.
Almost everything I've seen (besides BPS, and maybe HDR if you're one of the few who has a really good home theater setup) is a benefit for broadcasters and advertisers, and a bit worse for consumers (especially requiring new hardware/decoders... and sometimes persistent Internet connections!).
Same feeling here. ATSC 3.0 with DRM and persistent Internet requirements tells me this is going to be the downfall of OTA television. I can see ATSC 4.0 being a discounted ISP subscription paired with some OTA location checks via BPS.
At NAB someone asked one of the ATSC folks what would happen if the key is compromised and someone didn't connect a receiver to the Internet. The answer was "the receivers have many built in public keys. They should last the lifetime of the device."
Concerning because they could have a situation like with some 4K blu ray discs, your hardware becomes obsolete because DRM requires that cat and mouse game...
But what even is the business case here? I get the idea of encrypting pay TV, but isn't the entire point of free broadcast TV that it's... free?
It would be a different story if the DRM were available ubiquitously, e.g. in the way that arguably Widevine is for online streaming (but certainly not broadcast TV). Are rightholders that afraid of unauthorized out-of-market rebroadcasts that they'd rather obliterate their reachable market with stunts like that?
> But what even is the business case here? I get the idea of encrypting pay TV, but isn't the entire point of free broadcast TV that it's... free?
This should be a big clue that the spying is the point, and all the DRMs of the world are justification for spying instead of the other way around. Total Information Awareness is the path to completing the Great Work.
Yeah, if I squint and think back to the reasoning from previous generations of tech like this it’s that they don’t want people to be able to make bit-perfect recordings to save and share. By putting DRM on the broadcast stream they’re trying to make sure that it’s only usable as a one-time broadcast.
>When a SoC is compromised and the key is leaked from the TEE, all models of that device with the key are now untrusted for Level 1.
Has this actually happened? Especially for "appliances" like set-top boxes or blu-ray players, as opposed to something like a tablet which are presumably easier to hack.
This is so user-hostile that I don't believe there will be any adoption. It will have to be shoved down the throat of those who use broadcast, which are overwhelmingly older and more remote.
ATSC first generation will probably outlive this DRM-driven abomination.
It's not like anyone's gonna ask them. Networks will just label this as ${network name}'s HYPER NEXT GEN 10G TV EXPERIENCE (HNG TV), market the shit out of it, and offer free ESPN on it, tack on some Paramount HBO Supermax Plus for $0.99/year and throw in a half-decent Smart TV as a sign-on bonus, and adoption will skyrocket.
TV networks in the US are a living proof that, with enough marketing spend and a pinch of confusion in the offer structure, you can sell people on anything. Half the time you can just offer sportsball access and people will switch.
It's how previous versions of broadcaster overreach happened, and why Smart TVs succeed despite their shortcomings.
Or, the manufacturers will lose patience with slow adoption, the mess that is widevine DRM (what? Your TV isn’t based on Android? No, you can’t have DRM!), and customers really not caring because basically none of the broadcasts make the visual picture substantially better right now, so there is no incentive to move.
That’s what happened to LG [0]. They dropped ATSC 3.0 tuners. I’m sure this cost them precisely 0 sales as the industry incompetence destroys the broadcast industry.
Remember during the switch to digital TV, when marketers convinced half the population that they needed to buy a new "digital antenna" to keep viewing the same channels?
I came to the same conclusion when I saw a whole armada of new TVs from every manufacturer in the eve of any World Cup. Plus TVs tailored for football has a special mode called "sports" which make football arguably look/feel better.
> TV networks in the US are a living proof that, with enough marketing spend and a pinch of confusion in the offer structure, you can sell people on anything. Half the time you can just offer sportsball access and people will switch.
The cratering market values say otherwise. Few people under 40 even care about “TV”, and live sports distribution contracts (and the associated gambling) are the only thing holding it up.
I too used to think TV is dead and no one is paying for cable anymore, but every now and then I keep hearing it's still alive and well, and that's always in association with some big sportsball events; I can believe that their customers nowadays are almost entirely sports fans, but then the pull they have with that segment is still strong. In my mind, the term "ESPN" registers as "something to dangle in front of US customers to get them to buy some TV plan".
False, the majority of under 40 are still watching "TV" but just through intertube streaming. netflix, apple TV, amazon, and so on, all except apple have ads too.
The post I responded to mentioned TV networks, not TV. In a thread discussing over the air TV, I took that to mean linear programming sold by CBS (soon to be Skydance), NBC (Comcast), ABC (Disney), and Fox (also Disney, I think), and the CW (Nexstar).
The crux of the matter being that even if OTA channels didn’t track people’s location, it wouldn’t matter since OTA itself going the way of the dodo.
You're not wrong, but don't forget about the upgraded modulation and coding schemes. That might actually help consumers on the edge of coverage receive broadcasts and will definitely be an improvement over creaky 8vsb
I live in an area that is on the edge of coverage and has lots of hills. On ATSC 1.0, CBS is hard to pick up. Frequently unwatchable - which means unreliable for sports. I picked up an HDHomerun Flex 4K a few years ago. Basically the same week that ATSC 3.0 went live.
For a few weeks it was glorious. I had no problem picking up CBS (it was broadcast from the same antenna as ATSC 1.0 - so it was the modulation that was helping out). And then, after a little over a month. Whack! No more CBS. They turned on DRM. They are still the only network that in my area with DRM. Ughh.
Under the previous administration I filled a few issues about this from a public safety perspective - I live in with the FCC an area with unreliable power. During severe weather, we often lose Internet and power (which knocks out cable TV too). Requiring working internet to watch TV to monitor the progress of a tornado in your area seems stupid and dangerous. Unfortunately, nothing happened then regarding the issue and given the way that Brendan Carr is taking the FCC, I don’t think there will be any progress on this.
I’ve had a couple of the original, the prime, extend, and now the Flex 4K. They’ve all been terrific devices. The extend was a little wonky because transcoding goes wonky on bad signals, but generally great.
They’re all a huge improvement over older cards like the pcHDTV or the really old Hauppauge WinTV PVR 250 that I fought with for Freevo and MythTV so long ago. The switch to Channels was a huge quality of life improvement too.
>During severe weather, we often lose Internet and power (which knocks out cable TV too). Requiring working internet to watch TV to monitor the progress of a tornado in your area seems stupid and dangerous.
Radio can work, but again, I’m on the edge of reception areas and the hills make picking up FM and AM inconsistent.
In the event of a truly severe weather event (the ones where they hit the alert to make every cell phone go off), the visuals provided by television are hugely helpful.
> "That's a lot of fancy words to say ‘we're doing this because it makes us more money’ lol"
You say that as if they're using lots of words to obfuscate that fact, but the quote you pasted has them saying entirely directly "maximize the network Return on Investment", which is just normal business terminology (and only one word more than your "it makes us more money"!)
Obviously this has no impact on whether that's a good or bad thing, I'm just pointing out that they weren't using a lot of words to hide that fact.
The utilization of an expanded lexicon, replete with polysyllabic and sesquipedalian terminology, engenders an ostensibly enhanced verisimilitude and an amplified capacity for rhetorical suasion in the articulation of one's propositional assertions.
"Return on investment" isn't using uncommon words to try to be hard to interpret, it's a standard business term in English-speaking countries.
The fact that it seemed like its intention was to obfuscate is just a sign that you're not familiar with basic business terminology, nothing more.
(And there's no shame in that, nobody knows the common phrases in every area of society, if you've never taken any business classes nor been involved in running a business there's no reason you should know it - but that doesn't mean people who use those words are trying to hide what they mean.)
Edit: and unsurprisingly it's therefore also frequently seen on HN:
In case you're only accidentally missing the point and not just being an asshole: I would expect most people to have heard the term ROI before. I would not expect most people to understand the ways in which a bi-directional data path can turn into money. I definitely wouldn't expect most people to understand that it will involve compromising their privacy to spy on their viewing habits in a way that the last 100 years of broadcast television has no precedent for.
My apologies for failing to guess that when you complained they used too many fancy words to hide that the reason is to make more money, you actually weren't objecting to their use of a simple phrase acknowledging their goal of making more money and you were actually thinking about everything else they said rather than that.
> Recent studies have shown that interactivity between media customers and service providers and between users themselves will be one of the most important features in the next-generation media service. In this document, this unique opportunity is addressed by defining a Dedicated Return Channel (DRC) system for the next-generation broadcasting system.
Wow, that's one of the best uses of corporate-speak euphemism I've seen. Everybody who reads it knows what it really means, but if you just don't say it, it's fine. Recent studies indeed!
I just realized the BPS is there to augment the return channel. Not only can the advertiser figure out what you are watching, but also where you are located.
Wi-Fi geolocation has been around for a while now and is very accurate too, so if TV/receiver manufacturers choose to reveal your location to advertisers (whether out of their own greed or because it's required to receive ATSC 3.0 DRM keys), they can already do so without any problem.
Thanks to the beamforming that's central to modern Wi-Fi and 5G cellular standards they can even see through your walls using the backscattered energy of the steered beam, like an airport security scanner for the entire planet:
Wait, to be clear, this 'dedicated return channel' is just for TVs to broadcast back to the station that they're watching the adverts? I thought ATSC 3.0 was going to rely on IP backhaul for that. Actually broadcasting back seems... impractical at best.
I mean, let's keep in mind, even ATSC 1.0 had really awful reception issues; compared to analog NTSC where there was enough redundancy that you could just tune into a garbage station from way too far away and see something. Now imagine trying to make that already unreliable channel bidirectional. I just really hope all the return channel stuff is optional, because it sure as hell isn't going to work without way more stations broadcasting on more channels, and OOPS you've reinvented LTE.
Back in the late 90s when Ireland was starting to think about digital terrestrial TV a system called DVB-RCT was considered. Basically your receiver could also transmit back to the television transmitter. The system could handle thousands of concurrent connections, albeit each one had very low bandwidth - around 1Kbp/s in peak time.That was considered good enough for very basic interactivity and for authorising PPV purchases etc.In quieter hours or in areas were there were fewer receivers that bandwidth would be much higher, but in reality that would be rare.
In the end the company that the governement selected to start the rollout of DTT went bust and I don't think the system was used anywhere else. The developer of the technology abandoned it in 2006 as other connection methods (broadband/mobile data) were preferred.
Ironically there's no redundancy in NTSC. There are layers of information and they degrade downward until you have just a black and white picture with no sound.
In ATSC there is two types of forward error correction on the digital bitstream. The problem it faces is it sits in the same channel allocations as NTSC while having to deliver significantly more information than NTSC. That and the actual digital modulation used is not as ideal for receivers to capture.
You can digitize and lossily compress an NTSC signal significantly without losing much detail; that's why I call it redundant. Compression removes redundancy.
In ATSC the tradeoff between compression and error correction is such that a noisy channel is far more likely to cut out or otherwise be unusable than it would have been in NTSC.
I would think that the expectation is for the common option to be IP backhaul based on embedded LTE/5G modems. Having a separate communication scheme is probably more of a hedge for super rural areas that don't have LTE/5G or other IP coverage, especially as that is where broadcast TV will have more staying power.
“The fundamental record that captures consumption information is called a Consumption Data Unit (CDU). For a streaming A/V channel, each CDU identifies a reporting interval during which a service is accessed. Such a CDU includes the service identifier, the time the service access started and the time the service access ended. If any Applications are active during the report interval, it also records when the Applications are active (whether on a primary device or a “second screen”, companion device), including the Application Identifier, the time the Application started being active, and the time it stopped being active.”
“For services, events logged into a CDU shall correspond to all usage intervals of no less than 10 seconds and may correspond to shorter usage intervals. For Application activity, events logged into a CDU shall correspond to all usage intervals of no less than 5 seconds and may correspond to shorter usage intervals. The precision and accuracy of start times and end times in the CDUs should be within 1 second.”
The payload schema is a 4651-byte JSON structure, so I would imagine that a response-payload fitting this schema would be same-order-of-magnitude size. With 10-second granularity that works out to roughly a half-kilobyte-per-second data rate, and according to the DRC spec the maximum payload size of one DRC message is 2048 bytes.
It will also report when you play something back from a DVR:
“Component.SourceDeliveryPath – Delivery path used for or the source of the content component indicated by the parent Component element.
SourceDeliveryPath.type –
0 – Broadcast delivery (content component is delivered by broadcast)
1 – Broadband delivery (content component is delivered directly by broadband by broadcaster)
2 – Time-shift-buffer source (content source is local time shift buffer)
3 – Hard-drive source (content source is local hard drive)
4 – Delivery via direct connection (HDMI)
5 – Alternate IP delivery (content component is delivered via intermediary)”
Honestly that sounds pretty congruent with thinking about the spec from the position of the authors. Like what is the difference between "local time shift buffer" and "local hard drive" if it isn't some contractual authorization aspect they're pushing? Especially when you think that this standard is going to be deployed on TVs that will likely be displaying video from other sources than just broadcast.
OP is falling about the spec incorporating usage monitoring.
5G was designed with a very public and explicit goal for IoT of allowing many more devices to connect than 4G could, and more conveniently. Nothing unexpected or user-harming, and nothing new as 4G was already used for IoT.
Yeah at my work we still get a lot of the old 5G propaganda. "It's groundbreaking for IoT". Beh screw that it's just the successor to 4G. A bit faster and more flexible. The rest is just stupid marketing. There's nothing it can do that 4G couldn't, only slightly less efficiently.
The one thing that was really new was support for super high density environments with mmWave. That would have been ideal for stadiums etc. With regular tech the networks get overwhelmed. mmWave offers more cells in a tiny area. But here in Europe that's been given up for good. Phones don't even come with mmWave antennas anymore.
When EE launched 5G in the UK, they took out a full page ad with a massive headline saying simply "A real crowd pleaser"
One of the best adverts for a long time - if you knew about the technical advantages of 5G, it had a real double meaning.
If you knew 90s British dance music, it had a further humourous double meaning promoting the telco (an oblique reference to The Shamen's Ebenezer Goode)
> an oblique reference to The Shamen's Ebenezer Goode
That didn’t even cross my mind and Rich West (Mr. C) is a friend of mine and I know the song well. I, of course, get the reference now it has been pointed out, but you’re right that it’s pretty damn oblique!
This is a clickbait article. More towers mean that existing triangulation somewhat more accurate, and "anyone with access" is the cellular service provider.
5G does not always result in more towers, it just supports closer towers for better performance.
"Anyone with access" to Google or Apple data also knows exactly where you are. "Anyone with access" to <social media app of choice> knows exactly where you are. "Anyone with access" to police databases know exactly where you drove. "Anyone with access" to VISA/Mastercard data knows exactly where you've shopped. "Anyone with access" to Find my data will know exactly where your phones, headphones, and other trackable items are at any point in time.
This isn't a complaint about 5G, but about cellular anonymity which has never existed.
We should create technology that deliberately feeds trash data to marketers, in mind-boggling volumes. Drowning the signal in a biblical flooding of noise.
We should make things so useless and annoying for them, as they did for us.
Apparently there are two options: An existing Internet connection, or actually receivers transmitting back to the broadcast tower – which sounds crazy, but the specification [1] says it can work over up to 100 kilometers with line-of-sight...?
Then again, thanks to modern modulation techniques, digital steering etc., battery-powered smartphones can talk to satellites 36 thousand kilometers away these days as well, so maybe this is just a thing now? The spec also does mention receive repeaters for complicated non-line-of-sight propagation scenarios.
Note that this blog post (and the associated video) were a quick off-the-cuff thing while I was on the NAB show floor—I have been talking to a few of those involved in the testing at NIST, Sinclair, and Avateq (among others), and will hopefully have a lot more in a follow-up.
Right now it's in the experimental stage, with only 6 towers total deployed (only 5 were operational during NAB, and only one in Nevada... so timing, not navigation yet).
The ultimate plan—which is probably dependent on how well ATSC 3.0 rolls out (which has plenty of hurdles[1])—is to encourage broadcasters to add on the necessary timing equipment to their transmitter sites, to build a mesh network for timing.
That would allow the system to be 100% independent of GPS (time transfer could be done via dark fiber and/or ground-satellite-ground directly to some 'master' sites).
The advantages for BPS are coverage (somewhat) inside buildings, the ability to have line of sight nearly everywhere in populated areas, and resilience to jamming you can't get with GPS (a 100 kW transmitter signal 10 miles away is a lot harder to defeat than a weak GPS signal hundreds of miles away in the sky).
The demo on the show floor was also using eLoran to distribute time from a site in Nevada to the transmitter facility on Black Mountain outside Vegas, showing a way to be fully GPS-independent (though the current eLoran timing was sourced from GPS).
[1] ATSC 3.0, as it is being rolled out in the US, doesn't even add on 4K (just 1080p HDR), and tacks on 'features' like 'show replay' (where you tap a button and an app can stream a show you're watching on OTA TV through the Internet... amazing! /s), DRM (at stations' discretion, ugh), and 'personalized ad injection' (no doubt requiring you to connect your TV to the Internet so advertisers can get your precise location too...). Because ATSC 3.0 requires new hardware, consumers have to be motivated to buy new TVs or converter boxes—I don't see anything that motivates me to do so. I feel like it may be a lot like the (forever ongoing) HD Radio rollout.
I bought an atsc 3 tuner, and the experience turned me off of OTA tv. Since then, things managed to get worse as when I was poking around, DRM wasn't in use, but now it is.
I was hoping to get better fidelity between the roughly 2x bitrate per channel, and the video codec update. And probably overly optimistically was hoping the 1080p feed source was progressive so there wouldn't be a deinterlacing step.
Otoh, local broadcasters use an audio codec I can't easily use, integration with mythtv is poor, and there's no sign anything is going to get better soon.
Maybe if I had a tv with an atsc 3 tuner, live tv would be an option, but I'm not buying a tv for that.
ATSC 1.0 took a while before gathering momentum, so maybe that's going to be the same here, and in another few years, it might make sense to consider a transition. OTOH, maybe the writing is on the wall and OTA broadcasting will die on this hill. I was an OTA enthusiast, but between ATSC 3 being terrible, and the reallocation of spectrum that means cellular base stations sometimes overwhelm my pre-amp, it's not much fun anymore. (I have a filter post-pre-amp but it'd be better if I got on the roof to put it pre-pre-amp, but roofs are scary) Maybe I'm just getting curmudgeonly though.
Why is US ATSC 3.0 so bad? It is nearly a decade since it was South Korea have it deployed and operational. The standard itself is no longer "next gen". Brazil's TV 3.0, also uses ATSC 3.0 is so much better in every aspect.
Even if someone mandate it as requirement for TV sold next year all the tech inside are at least 10 years old ( HEVC ? ) . Not to mention the roll out time. Do Americans only watch Cables and Netflix? And not Free to Air TV? Which is what I belief what most of the worst still do to a larger extend other than Internet streaming.
They might as well look into the standards before putting a mandate into it.
Broadcast TV modernisation is trapped between a load of enemies.
To the north, competition from a huge installed base of last-gen technology, which is mostly good enough.
To the south, streaming services, youtube and cable. These let people watch whenever they want (nobody has VCRs any more) and they've offered 4k for over a decade.
To the east, the industry's dumb decision to build the 'next gen' technology atop a patent minefield, and load it with DRM. So if you manufacture this tech, you can face huge surprise bills because in implementing the spec you've unknowingly infringed on some nonsense patent.
And to the west, the commercial reality that showing someone an advert in 4K isn't any more profitable than showing the advert in 1080p. If you're a broadcast TV station when you up your quality everything gets more expensive but you don't make any extra money. So why bother?
> If you're a broadcast TV station when you up your quality everything gets more expensive but you don't make any extra money. So why bother?
In a functioning, competitive market, the answer to this is "Customers choose a competing broadcast TV station with higher quality." Unfortunately what we have is far from that.
Yes. Satellite dishes also provide service like cable does, a number of "basic" channels included plus options for "premium" channels that cost extra. The basic channels include the broadcast networks for one's geographic area.
They're not that popular but there are similar bundles available over the Internet, YouTube TV is one.
All the national broadcast networks have Internet options, Hulu has shows from multiple networks, Paramount+ has CBS. Both also have shows made for cable & satellite channels and Internet-only programming.
There's a lot more than Netflix too, Amazon Prime, AppleTV+, Disney+, Max, and many others.
Live sports kept people signed up to cable & satellite for a long time, I think now there are Internet options (and probably exclusives, I don't watch sports).
Be aware that the cable tv infrastructure is also the main Internet service provider, many people are like me, paying the cable company for home Internet but not for TV (my plan does include a legally mandated minimum TV service and a TV box but I only have it because it's cheaper than Internet alone for some reason).
Broadcast TV after the digital rollout was so bad many people just stopped watching TV. Picking it up is such a hassle it's simply not worth the effort for some ad laden TV.
At the time of the switchover in the early 2000s I lived about 40 miles from a major metropolitan area, Minneapolis, which is pretty close in US terms. We spent hundreds of dollars on different antennas (indoor and outdoor) and signal boosters and what not and it was simply never reliability.
In 2008 I moved to my current location, three miles outside of downtown Minneapolis. Again I tried a number of antennas and still found operation to be anything but reliable. I gave up and began just watching Netflix.
The people who live close enough to the broadcasts to pick it up have easy access to cable TV. The people who live in the countryside who used to depend on it can't pick it up. There's just no place for the TV system we were given.
> Broadcast TV after the digital rollout was so bad many people just stopped watching TV.
That is the first time I've heard that. Everything I've heard has been positive - people amazed that others aren't doing it. Are there any numbers on user satisfaction?
I used it myself once or twice and it worked simply with antennas that were relatively cheap (<$50 iirc). Maybe there was a problem in Minneapolis?
> The people who live close enough to the broadcasts to pick it up have easy access to cable TV.
Cable is expensive for many people and broadcast is free, of course. (Also, Broadcast is more private, for now.)
> I used it myself once or twice and it worked simply with antennas that were relatively cheap (<$50 iirc). Maybe there was a problem in Minneapolis?
I don’t know about Minneapolis is particular, but 40 miles is far enough that it gets tricky, and in my Canadian city, I’m close to the towers as the crow flies, but in the RF shadow of a huge hill - so I’d actually get better reception if I was further away from the broadcast towers.
I live in downtown Chicago and get tons of channels, despite no line of sight due to buildings in the way. Though they tend to go out when the El passes by.
> The demo on the show floor was also using eLoran to distribute time from a site in Nevada to the transmitter facility on Black Mountain outside Vegas, showing a way to be fully GPS-independent (though the current eLoran timing was sourced from GPS).
There's been a consistent call by many people that there needs to be a diversity of options for navigation and timing:
Well... and there's the electricity grid which can be used for timing needs accurate enough to a single second, and in Europe there's DCF77 [1] which can not just be used as a 2*10^-12 seconds-accurate timing standard but also a frequency standard.
Did you actually mention what BPS actually stands for in the article? I read the whole thing and don't recall reading that. Yes, I'm capable of searching and finding the information myself, but in an article about something something esoteric like this, explaining the acronym would be useful.
Edit: Broadcast Positioning System for anyone that didn't figure it out.
How does it solve for time without location? With GPS location and time are one solution to an equation with 4 unknowns (x,y,z,t). Without location you won't know the time delay between you and the transmitter.
High-power, and ideally authenticated, alternatives to space-based GNSS are desperately needed, given the sharp uptick in jamming and spoofing incidents in many places.
In a true "end of history" moment, the US and other NATO members discontinued both of their ground-based systems (which are inherently harder to jam due to their much higher transmission power, since transmitters are not power limited) – Omega in the late 1990s and Loran-C in the early 2010s – in favor of GPS, while Russia kept their equivalent functional, and China completed an eLoran network last year.
Add to that the FAA's reduction of their ground-based VOR/DME station network that lets planes navigate when GPS is unavailable...
GPS jamming, and much more concerningly spoofing, will probably quickly come within reach of non-nation-states and smaller groups of all kinds, and ultimately individual actors, and that can't possibly end well for civil aviation if robust countermeasures don't become available very soon.
The reason that dead reckoning was inaccurate was because of clock and vector inaccuracies. Looking at the advances in clockpieces and gyroscopes (both of these has benefitted over the optical revolution) over the years, I am not shocked that dead reckoning is back in vogue.
Dead reckoning is also inaccurate due to unknown winds. Even if you take off with the best available forecast, it’s often wrong by 5mph+. After three hours your position is off by 15 miles. That’s not remotely good enough for most aviation purposes.
Dead reckoning based on heading and time alone, but if you have a good INS it's not affected by wind only by accuracy of the gyroscopes/sensors.
Current systems drift by about 0.5 miles per hour. And that's normal commercial grade systems, I'm sure the military has an option for better systems if they need them.
As t0mas88 said, you don't rely on the measured speed of the aircraft/ship, you rely on gyroscopes (which are much more resistant to external factors), and both clocks and gyroscopes have improved signifcantly (clocks are now better than cesium atoms - read about atomic clocks) and so are gyroscopes (again, optical gyroscopes that are miles better than mechanical ones).
Missels are expensive. Jammers can be farther away than a cheap drone can reach.
Jammers often move. Your missle often cannot manovure well enough to hit. jammers often turn off - if you missle is detected they turn the jammer off and move it. They are often running more than one jammer so getting one to turn off isn't going to matter.
Plus aircrafs can use Earth gravity map. Sensors became accurate enough to detect minuscule changes in gravity strength to position aircraft to few hundred meters.
True, but both very hard to do in a system that's deployed to space and (heavily regulated) avionics part of aircraft that get upgraded very infrequently, to say nothing of the billions of other civilian receivers.
A university of Texas research group demonstrated more than ten years ago that they could spoof GPS in the vicinity of an automatically navigating UAV, and force it to land at a point of their choosing. This has been within the reach of garage hackers for a long time.
Gets trickier when you're using dGPS. And you need at least 2 antennas/receivers to know direction of arrival. Beamforming in the direction(s) of the expected satellite(s) seems to help a lot with e.g. starlink. But you'll need a phased array and a beamformer.
GPS jamming, and much more concerningly spoofing, will probably quickly come within reach of non-nation-states and smaller groups of all kinds, and ultimately individual actors
You don't need ATSC 3.0 to do this kind of thing! The short-term stability of the oscillators they use for commercial DTV transmission is apparently good enough that just having one local reference to compare GPS vs. each TV station's phase (and distribute that data) can produce a pretty good positioning system. Rosum was doing this back in 2005: https://www.tvtechnology.com/news/tv-signals-used-for-geopos...
ATSC 3.0 channels (there are some already) are encrypted. So no more free-to-air, no open standards, no more open source viewers. Watch TV using Kodi? VLC? Not anymore.
I’m trying to understand if this depends on something specific to FM or TV signals, or if it’s more of a protocol-level idea (i.e., any time-synced, known-location transmitters would work).
If it’s not intrinsic to FM, why not use existing cellular towers to do this? They’re everywhere, and phones already receive broadcast messages (like Amber Alerts) even without a SIM (I think) — so it feels like this could be done without needing new radios.
What makes this more accurate than cell tower triangulation today? Is the limitation in timing sync across towers, or something else in how cell networks are structured?
And for indoor use — how does this handle multipath? Reflections from walls or even atmospheric bounce seem like they’d throw off timing accuracy, similar to what messes with GPS in dense areas.
If planning/designing a timing system like this using existing antenna,
why wouldn't you choose to use cellular base stations? The cellular
network reaches most places with overlapping coverage and carries network time. The lowest cellular frequencies are adjacent the upper broadcast TV channels.
Aren't modern cellular receivers what we call software defined radios? They
can choose which channels to receive.
This sounds interesting but it most likely will only be of use in populated areas where there is enough signal overlap from broadcast towers. You’ll still need GPS in the countryside and on water.
At least in Europe, when broadcasting went digital (DVB-T), a lot of cities started being covered by single frequency network transmission, which specifically leverages different transmitter locations transmitting the same signal to decrease dead zones.
Due to how OFDM works, I suppose the idea here is to intentionally send a heterogeneous signal on a few non-overlapping subcarriers (for single-frequency networks) or on different transponders at different locations (since single frequency networks aren't as common in the US due to how broadcasting evolved there, although ATSC 3.0 apparently also allows single frequency networks).
The OP link is a blog post, which includes links out to the primary resources (much more in depth than the BPS landing page). The video is a byproduct of my conversations at NAB, and both are just preliminary... I've been working on a more in depth look at GPS and BPS (and other alternatives).
I'm fighting through a cold so granted my reading comprehension is way down but at least in my diminished state I was reading through that and was baffled ...
I'm sure the average reader who deals with broadcast signal electronics knows what's going on here but I just walked away from it confused. It looks like terrestrial broadcasters sending out time codes for triangulation?
I have that in my Hyundai Kona. It's fascinating to hear what's on those stations. I can't imagine simultaneous listenership numbers ever breaking 100.
Every time I show someone I first have to introduce the concept of it existing. And these are technical people.
I'm surprised that broadcast TV is used as a basis for this. It's not a topic with which I'm familiar, but I would have guessed that it was only slightly more popular than Fax and that it would have faded out is most of the world.
Good cable and connectors can set you back by several thousand dollars.
Another domain where that is true involves logic analyzers. A few years ago, on a bit of a lark, I bought a (used) fairly high-end Keysight logic analyzer. The kind of thing that cost like $20,000 or more when it was brand new. But I got a sweet deal on it, so I bought it. Only... it came with no test leads. And then I started shopping for the leads.
Yikes.
I forget the exact numbers now, but as best as I can recall, the leads came in 64pin sets, where the device supported up to 4 test lead sets, for 256 total channels. And just one of the 64pin test lead sets cost something like $1500. So a full set would cost another $6000 on top of the device itself. I think that was about what I paid for the analyzer itself in the first place!
Now I don't regret buying it and in truth I never needed to use 256 channels anyway, so I only bought 1 of the test lead sets so far. But yeah... test leads / cables /etc. for high bandwidth / low latency / high frequency applications get pretty damn expensive.
I've got a rack of equipment that sometimes requires a special calibration where I need to lug over a signal generator. Of course the only ones we have available that go to the necessary frequency weigh like 50lbs. I've recently been eyeing a little gadget that costs about 1/10 or 1/20 the cost of the Keysight units, interfaces using USB oe Ethernet, and is about the size of a deck of cards. The accuracy isn't perfect on its own but that's what a 10MHz ref clock is for. It's amazing how far tech has come and it's amazing how much we are still paying for these dinosaur pieces of test equipment.
But concepts are translatable to other technologies, for example mobile phone network signals (even without decrypting it) which in most populated areas can have hundreds frequencies by itself.
there are literally literally thousands of radio signals around us which can be used for various unintended / non-cooperative purposes. also not only ground based signals, satellites are transmitting all kinds of signals towards earth, some for communication, some for remote sensing / earth observation.
Or not only is it possible to use non-cooperative signals for timing, but also for passive radar. For example DVB-T - you receive bounces/echoes of signal from airplanes, drones and measure its characteristics.
Good community is around GNURadio, they have all kinds of enthusiast and profesional usecases, explorations, videos, ...
Or just simple 30$ RTL-SDR + laptop, you can sit next to road and listen for tire pressure monitoring sensors data, they contain unique ids, so you can know when postman enters your street...
(some of those thousands signals can be dependent on GPS too...)
it is possible to listen to small part of spectrum thru receivers which enthusiasts connected to internet, without buying anything for example -http://kiwisdr.com/public/
but "high performance signals" are not in frequency range of those radios. but it is possible to hear ham radio, aviation, military, maritime, not only voice but weather fax, other digital signals, all sorts of timing signals...
I want to like this — I think having ground-based alternatives to GPS and other space-based PNT systems is a very good thing! But after reading the paper at https://www.nab.org/bps/Broadcast_Positioning_System_Using_A... and other BPS information on the NAB's website, I think the NAB is being wildly optimistic about BPS:
• ATSC 3.0's physical layer can already transmit GPS time in a way that receivers could get it back out. What BPS brings to the table is a requirement and specification for accurately and consistently filling in the physical layer preamble fields containing the time data, along with a new physical layer pipe (think "low-level data stream") that contains additional information about the transmitter and, optionally, its neighboring transmitters.
• BPS is capable of producing time fixes when the receiver only has a lock on one source. This isn't surprising at all — GPS receivers can do the same thing. But either type of receiver with only one source would see a clock offset proportional to the path delay, which it wouldn't be able to compute and back out without knowing its position.
• BPS is only designed for 2-D position fixes. While that's a reasonable design decision (the vertical position error would be massive), it also makes BPS less useful for the NAB's "indoor positioning for first responders" use case, especially in areas with multi-story buildings.
• The need to receive and process/decode multiple, most likely non-adjacent 6 MHz channels for positioning increases receiver complexity and cost.
• The NAB claims that 1 kilometer of separation between two BPS transmitters is "sufficient for useful position determination." I don't buy it, especially in the face of poor transmitter geometry.
• They note that 16 TV stations in the New York City area broadcast from One World Trade Center, so for the purposes of BPS, they're effectively one station. This kind of transmitter colocation is incredibly common, both in urban areas (ten TV stations broadcast from Sutro Tower in San Francisco) and in more rural areas (six TV stations in the Roanoke-Lynchburg DMA broadcast from towers within ~1 mile of each other on the ridgeline of Poor Mountain). Even if every ATSC TV station became an ATSC 3.0 w/ BPS transmitter, bad transmitter geometries would destroy BPS's position accuracy in lots of markets.
• What's the business case for broadcasters? BPS won't be free for broadcasters to implement, and there doesn't seem to be a path to it generating revenue except for a hand-wavy "maybe one day televisions will be able to determine their locations without Internet connections using BPS, and then broadcasters can do location-targeted advertising with those TVs!"
My uncharitable take is that BPS will never be a usable standalone PNT system. A timing system in the "rebroadcasts GPS" sense? Maybe. Standalone positioning? No way. Broadcasters implementing BPS (or ATSC 3.0 at all) without being forced to by the government? I don't see it.
My uneducated guess is government funding, plus becoming part of a new "essential backbone" infrastructure, thus guaranteeing incentives to stay operational for a longer period of time.
tldr; BPS is Broadcast Positioning System. Same principle as GPS: a known waveform is used to triangulate position and time. Advantage: indoor available, less easy to jam/spoof due to high tx power of broadcasting stations. BPS can be added to ATSC 3.0 Next Gen TV signal which is rolled out since 2019 in the US.
Current planning is public availability in 2027-2029.
A good gov presentation with an overview and technical details is here [1].
Hmm it's just a turn of phrase. I would bet you $100 that no more than 0.001% of the population have heard of BPS. I hadn't. That's functionally "nobody".
The title is still clickbait given the reason nobody has heard of it is that it barely exists and is not useful yet.
Also, it smelled a bit like wishful thinking to assume the high precision clock would not be driven by GPS on real world deployments. I know some cell towers synchronize via PTP, but a great many others use GPS as their time source.
For anyone who deploys GPS-based timing systems at scale, having more sources of precise time is a huge boon. (Some companies pay many millions for dark fiber just to have a redundant time source).
Holdover can only help so much, if there's a persistent jamming effort, it can wreak havoc on many time-critical systems.
A alternative, but only for timing and as GPS supplement. Unless you’re in a place where you can pick up 4 ATSC transmitters at different locations you won’t get position or navigation with it.
So if you can get more than 3 different TV stations you should be good. Most stations don’t share transmission towers, AFAIK.
There are places, especially in the mountains where you don’t get the requisite number of towers, but large portions of the US will, and the required signal to noise ratio is better than to decode regular TV signals, so you have a larger area covered than for TV.
well i do not share your "enthusiasm" do not forget those systems used twitter,google,amazon,microsoft infrastructure, so those private companies build it first...
It's a little unclear to me from reading the Wikipedia page; is it fully functional today, and worldwide? It'd be cool if my phone showed me which systems it was using at any time, but I have chosen The One True Apple Way so I don't think that'll come any time soon
If you're on Android there's an app, GPS Test that shows you a chart with all the signals it's picking up with different symbols for each system and a filter too. My phone is currently picking up 5 GPS, 4 GLONASS, 8 Galileo, and even 3 Beidou sat signals (I'm in Western Europe).
Also you should be able to look up your phone specifications to see what GNSS services it's capable of using on GSMArena
Edit:oh I missed that you're on Apple so that app is useless for you. Still might be of some use to others though.
your phone ai can recognize dogs in your photos, and militaries have all kinds of aerial survey, satellit photos of your house, so do they really need to use external radio signals, or is it enough for them to use fully internal system with just cameras and khadas mind 2 ?
I hope it will still be possible to receive a BPS timing signal privately and anonymously with ATSC 3 like one can with GPS. ATSC 3 has the Dedicated Return Channel because marketers “““need””” to spy on every-fucking-thing we do: https://www.atsc.org/wp-content/uploads/2024/04/A323-2024-04...
“Conventional linear TV services alone (albeit ultra-high-definition) may not be sufficient to sustain the terrestrial broadcasting business which requires a large amount of highly coveted spectrum resources. Intelligent media delivery and flexible service models that maximize the network Return on Investment (ROI) is of paramount importance to the broadcasting industry in the new era.”
That's a lot of fancy words to say ‘we're doing this because it makes us more money’ lol
“Recent studies have shown that interactivity between media customers and service providers and between users themselves will be one of the most important features in the next-generation media service. In this document, this unique opportunity is addressed by defining a Dedicated Return Channel (DRC) system for the next-generation broadcasting system.”
Yeah... and that's one of the most innocuous new "features" in ATSC 3.0.
Almost everything I've seen (besides BPS, and maybe HDR if you're one of the few who has a really good home theater setup) is a benefit for broadcasters and advertisers, and a bit worse for consumers (especially requiring new hardware/decoders... and sometimes persistent Internet connections!).
Same feeling here. ATSC 3.0 with DRM and persistent Internet requirements tells me this is going to be the downfall of OTA television. I can see ATSC 4.0 being a discounted ISP subscription paired with some OTA location checks via BPS.
There is 1 provider for ATSC3 DRM (which is already rolling out in major markets): Google Widevine.
There is 1 operating system for ATSC3 DRM: Android.
There are several SoCs that can be used for "Level 1 Widevine".
When a SoC is compromised and the key is leaked from the TEE, all models of that device with the key are now untrusted for Level 1.
I think people should just be aware of the state of play.
At NAB someone asked one of the ATSC folks what would happen if the key is compromised and someone didn't connect a receiver to the Internet. The answer was "the receivers have many built in public keys. They should last the lifetime of the device."
Concerning because they could have a situation like with some 4K blu ray discs, your hardware becomes obsolete because DRM requires that cat and mouse game...
Wow, and all that to encrypt hours of ads with a few minutes of the 20th rerun of some show in between...
When you can't innovate, financialize.
But what even is the business case here? I get the idea of encrypting pay TV, but isn't the entire point of free broadcast TV that it's... free?
It would be a different story if the DRM were available ubiquitously, e.g. in the way that arguably Widevine is for online streaming (but certainly not broadcast TV). Are rightholders that afraid of unauthorized out-of-market rebroadcasts that they'd rather obliterate their reachable market with stunts like that?
> But what even is the business case here? I get the idea of encrypting pay TV, but isn't the entire point of free broadcast TV that it's... free?
This should be a big clue that the spying is the point, and all the DRMs of the world are justification for spying instead of the other way around. Total Information Awareness is the path to completing the Great Work.
Yeah, if I squint and think back to the reasoning from previous generations of tech like this it’s that they don’t want people to be able to make bit-perfect recordings to save and share. By putting DRM on the broadcast stream they’re trying to make sure that it’s only usable as a one-time broadcast.
Free as in beer. See what happened to Aereo.
>When a SoC is compromised and the key is leaked from the TEE, all models of that device with the key are now untrusted for Level 1.
Has this actually happened? Especially for "appliances" like set-top boxes or blu-ray players, as opposed to something like a tablet which are presumably easier to hack.
This is so user-hostile that I don't believe there will be any adoption. It will have to be shoved down the throat of those who use broadcast, which are overwhelmingly older and more remote.
ATSC first generation will probably outlive this DRM-driven abomination.
So atsc 3 won't work unless you have some continuous "i'm user xyz watching this channel at time x.y.z" going back to the broadcaster?
Why would anyone use atsc 3? It's not free over the air, you can't spoof it?
It's not like anyone's gonna ask them. Networks will just label this as ${network name}'s HYPER NEXT GEN 10G TV EXPERIENCE (HNG TV), market the shit out of it, and offer free ESPN on it, tack on some Paramount HBO Supermax Plus for $0.99/year and throw in a half-decent Smart TV as a sign-on bonus, and adoption will skyrocket.
TV networks in the US are a living proof that, with enough marketing spend and a pinch of confusion in the offer structure, you can sell people on anything. Half the time you can just offer sportsball access and people will switch.
It's how previous versions of broadcaster overreach happened, and why Smart TVs succeed despite their shortcomings.
Or, the manufacturers will lose patience with slow adoption, the mess that is widevine DRM (what? Your TV isn’t based on Android? No, you can’t have DRM!), and customers really not caring because basically none of the broadcasts make the visual picture substantially better right now, so there is no incentive to move.
That’s what happened to LG [0]. They dropped ATSC 3.0 tuners. I’m sure this cost them precisely 0 sales as the industry incompetence destroys the broadcast industry.
[0]: https://www.theverge.com/2023/9/30/23897460/lg-drops-atsc-3-...
Remember during the switch to digital TV, when marketers convinced half the population that they needed to buy a new "digital antenna" to keep viewing the same channels?
I came to the same conclusion when I saw a whole armada of new TVs from every manufacturer in the eve of any World Cup. Plus TVs tailored for football has a special mode called "sports" which make football arguably look/feel better.
That kind of pumping makes me sad and sick.
It's being marketed as "NEXTGEN TV" so not far off.
> TV networks in the US are a living proof that, with enough marketing spend and a pinch of confusion in the offer structure, you can sell people on anything. Half the time you can just offer sportsball access and people will switch.
The cratering market values say otherwise. Few people under 40 even care about “TV”, and live sports distribution contracts (and the associated gambling) are the only thing holding it up.
I too used to think TV is dead and no one is paying for cable anymore, but every now and then I keep hearing it's still alive and well, and that's always in association with some big sportsball events; I can believe that their customers nowadays are almost entirely sports fans, but then the pull they have with that segment is still strong. In my mind, the term "ESPN" registers as "something to dangle in front of US customers to get them to buy some TV plan".
False, the majority of under 40 are still watching "TV" but just through intertube streaming. netflix, apple TV, amazon, and so on, all except apple have ads too.
That's not really "TV", though (at least unless you'd also consider people buying a film or show on VHS or DVD "television").
The post I responded to mentioned TV networks, not TV. In a thread discussing over the air TV, I took that to mean linear programming sold by CBS (soon to be Skydance), NBC (Comcast), ABC (Disney), and Fox (also Disney, I think), and the CW (Nexstar).
The crux of the matter being that even if OTA channels didn’t track people’s location, it wouldn’t matter since OTA itself going the way of the dodo.
You're not wrong, but don't forget about the upgraded modulation and coding schemes. That might actually help consumers on the edge of coverage receive broadcasts and will definitely be an improvement over creaky 8vsb
I live in an area that is on the edge of coverage and has lots of hills. On ATSC 1.0, CBS is hard to pick up. Frequently unwatchable - which means unreliable for sports. I picked up an HDHomerun Flex 4K a few years ago. Basically the same week that ATSC 3.0 went live.
For a few weeks it was glorious. I had no problem picking up CBS (it was broadcast from the same antenna as ATSC 1.0 - so it was the modulation that was helping out). And then, after a little over a month. Whack! No more CBS. They turned on DRM. They are still the only network that in my area with DRM. Ughh.
Under the previous administration I filled a few issues about this from a public safety perspective - I live in with the FCC an area with unreliable power. During severe weather, we often lose Internet and power (which knocks out cable TV too). Requiring working internet to watch TV to monitor the progress of a tornado in your area seems stupid and dangerous. Unfortunately, nothing happened then regarding the issue and given the way that Brendan Carr is taking the FCC, I don’t think there will be any progress on this.
I have an older HDHomerun - it's great! Most of the 3.0 stations in my area are already encrypted so I haven't bothered to upgrade
I’ve had a couple of the original, the prime, extend, and now the Flex 4K. They’ve all been terrific devices. The extend was a little wonky because transcoding goes wonky on bad signals, but generally great.
They’re all a huge improvement over older cards like the pcHDTV or the really old Hauppauge WinTV PVR 250 that I fought with for Freevo and MythTV so long ago. The switch to Channels was a huge quality of life improvement too.
>During severe weather, we often lose Internet and power (which knocks out cable TV too). Requiring working internet to watch TV to monitor the progress of a tornado in your area seems stupid and dangerous.
Just listen to radio?
Radio can work, but again, I’m on the edge of reception areas and the hills make picking up FM and AM inconsistent.
In the event of a truly severe weather event (the ones where they hit the alert to make every cell phone go off), the visuals provided by television are hugely helpful.
Deaf?
For anyone who wants to know about ATSC 3.0 the Antenna Man channel covers over the air (OTA) stuff in the US:
* https://www.youtube.com/watch?v=cw3W7MoafR4
* https://www.youtube.com/@AntennaMan/videos
ATSC 3.0 allows for DRM/encryption as the parent comment mentions.
> "That's a lot of fancy words to say ‘we're doing this because it makes us more money’ lol"
You say that as if they're using lots of words to obfuscate that fact, but the quote you pasted has them saying entirely directly "maximize the network Return on Investment", which is just normal business terminology (and only one word more than your "it makes us more money"!)
Obviously this has no impact on whether that's a good or bad thing, I'm just pointing out that they weren't using a lot of words to hide that fact.
The utilization of an expanded lexicon, replete with polysyllabic and sesquipedalian terminology, engenders an ostensibly enhanced verisimilitude and an amplified capacity for rhetorical suasion in the articulation of one's propositional assertions.
"Return on investment" isn't using uncommon words to try to be hard to interpret, it's a standard business term in English-speaking countries.
The fact that it seemed like its intention was to obfuscate is just a sign that you're not familiar with basic business terminology, nothing more.
(And there's no shame in that, nobody knows the common phrases in every area of society, if you've never taken any business classes nor been involved in running a business there's no reason you should know it - but that doesn't mean people who use those words are trying to hide what they mean.)
Edit: and unsurprisingly it's therefore also frequently seen on HN:
https://hn.algolia.com/?q=return+on+investment
https://hn.algolia.com/?q=ROI
In case you're only accidentally missing the point and not just being an asshole: I would expect most people to have heard the term ROI before. I would not expect most people to understand the ways in which a bi-directional data path can turn into money. I definitely wouldn't expect most people to understand that it will involve compromising their privacy to spy on their viewing habits in a way that the last 100 years of broadcast television has no precedent for.
RADIO ON INTERNET
My apologies for failing to guess that when you complained they used too many fancy words to hide that the reason is to make more money, you actually weren't objecting to their use of a simple phrase acknowledging their goal of making more money and you were actually thinking about everything else they said rather than that.
Shorter, Milchick!
> Recent studies have shown that interactivity between media customers and service providers and between users themselves will be one of the most important features in the next-generation media service. In this document, this unique opportunity is addressed by defining a Dedicated Return Channel (DRC) system for the next-generation broadcasting system.
Wow, that's one of the best uses of corporate-speak euphemism I've seen. Everybody who reads it knows what it really means, but if you just don't say it, it's fine. Recent studies indeed!
I just realized the BPS is there to augment the return channel. Not only can the advertiser figure out what you are watching, but also where you are located.
Wi-Fi geolocation has been around for a while now and is very accurate too, so if TV/receiver manufacturers choose to reveal your location to advertisers (whether out of their own greed or because it's required to receive ATSC 3.0 DRM keys), they can already do so without any problem.
Thanks to the beamforming that's central to modern Wi-Fi and 5G cellular standards they can even see through your walls using the backscattered energy of the steered beam, like an airport security scanner for the entire planet:
https://arxiv.org/pdf/2301.00250.pdf
https://people.csail.mit.edu/fadel/papers/wivi-paper.pdf
Wait, to be clear, this 'dedicated return channel' is just for TVs to broadcast back to the station that they're watching the adverts? I thought ATSC 3.0 was going to rely on IP backhaul for that. Actually broadcasting back seems... impractical at best.
I mean, let's keep in mind, even ATSC 1.0 had really awful reception issues; compared to analog NTSC where there was enough redundancy that you could just tune into a garbage station from way too far away and see something. Now imagine trying to make that already unreliable channel bidirectional. I just really hope all the return channel stuff is optional, because it sure as hell isn't going to work without way more stations broadcasting on more channels, and OOPS you've reinvented LTE.
Back in the late 90s when Ireland was starting to think about digital terrestrial TV a system called DVB-RCT was considered. Basically your receiver could also transmit back to the television transmitter. The system could handle thousands of concurrent connections, albeit each one had very low bandwidth - around 1Kbp/s in peak time.That was considered good enough for very basic interactivity and for authorising PPV purchases etc.In quieter hours or in areas were there were fewer receivers that bandwidth would be much higher, but in reality that would be rare.
In the end the company that the governement selected to start the rollout of DTT went bust and I don't think the system was used anywhere else. The developer of the technology abandoned it in 2006 as other connection methods (broadband/mobile data) were preferred.
Ironically there's no redundancy in NTSC. There are layers of information and they degrade downward until you have just a black and white picture with no sound.
In ATSC there is two types of forward error correction on the digital bitstream. The problem it faces is it sits in the same channel allocations as NTSC while having to deliver significantly more information than NTSC. That and the actual digital modulation used is not as ideal for receivers to capture.
You can digitize and lossily compress an NTSC signal significantly without losing much detail; that's why I call it redundant. Compression removes redundancy.
In ATSC the tradeoff between compression and error correction is such that a noisy channel is far more likely to cut out or otherwise be unusable than it would have been in NTSC.
I would think that the expectation is for the common option to be IP backhaul based on embedded LTE/5G modems. Having a separate communication scheme is probably more of a hedge for super rural areas that don't have LTE/5G or other IP coverage, especially as that is where broadcast TV will have more staying power.
This is my understanding as well. You can see the usage-reporting scheme and data structure here: https://www.atsc.org/wp-content/uploads/2024/04/A333-2024-04...
“The fundamental record that captures consumption information is called a Consumption Data Unit (CDU). For a streaming A/V channel, each CDU identifies a reporting interval during which a service is accessed. Such a CDU includes the service identifier, the time the service access started and the time the service access ended. If any Applications are active during the report interval, it also records when the Applications are active (whether on a primary device or a “second screen”, companion device), including the Application Identifier, the time the Application started being active, and the time it stopped being active.”
“For services, events logged into a CDU shall correspond to all usage intervals of no less than 10 seconds and may correspond to shorter usage intervals. For Application activity, events logged into a CDU shall correspond to all usage intervals of no less than 5 seconds and may correspond to shorter usage intervals. The precision and accuracy of start times and end times in the CDUs should be within 1 second.”
The payload schema is a 4651-byte JSON structure, so I would imagine that a response-payload fitting this schema would be same-order-of-magnitude size. With 10-second granularity that works out to roughly a half-kilobyte-per-second data rate, and according to the DRC spec the maximum payload size of one DRC message is 2048 bytes.
It will also report when you play something back from a DVR:
“Component.SourceDeliveryPath – Delivery path used for or the source of the content component indicated by the parent Component element.
SourceDeliveryPath.type –
0 – Broadcast delivery (content component is delivered by broadcast)
1 – Broadband delivery (content component is delivered directly by broadband by broadcaster)
2 – Time-shift-buffer source (content source is local time shift buffer)
3 – Hard-drive source (content source is local hard drive)
4 – Delivery via direct connection (HDMI)
5 – Alternate IP delivery (content component is delivered via intermediary)”
> 5 – Alternate IP delivery (content component is delivered via intermediary)
Ok, this is entirely paranoid conspiracy theory rumblings at this point, but why does this sound like a way to catch unlicensed rebroadcasters?
Honestly that sounds pretty congruent with thinking about the spec from the position of the authors. Like what is the difference between "local time shift buffer" and "local hard drive" if it isn't some contractual authorization aspect they're pushing? Especially when you think that this standard is going to be deployed on TVs that will likely be displaying video from other sources than just broadcast.
Just like 5G, which provides unexpected connectivity for IoT devices.
Search for "miot" or "mmtc"
There is zero relation there.
OP is falling about the spec incorporating usage monitoring.
5G was designed with a very public and explicit goal for IoT of allowing many more devices to connect than 4G could, and more conveniently. Nothing unexpected or user-harming, and nothing new as 4G was already used for IoT.
Yeah at my work we still get a lot of the old 5G propaganda. "It's groundbreaking for IoT". Beh screw that it's just the successor to 4G. A bit faster and more flexible. The rest is just stupid marketing. There's nothing it can do that 4G couldn't, only slightly less efficiently.
The one thing that was really new was support for super high density environments with mmWave. That would have been ideal for stadiums etc. With regular tech the networks get overwhelmed. mmWave offers more cells in a tiny area. But here in Europe that's been given up for good. Phones don't even come with mmWave antennas anymore.
When EE launched 5G in the UK, they took out a full page ad with a massive headline saying simply "A real crowd pleaser"
One of the best adverts for a long time - if you knew about the technical advantages of 5G, it had a real double meaning.
If you knew 90s British dance music, it had a further humourous double meaning promoting the telco (an oblique reference to The Shamen's Ebenezer Goode)
> an oblique reference to The Shamen's Ebenezer Goode
That didn’t even cross my mind and Rich West (Mr. C) is a friend of mine and I know the song well. I, of course, get the reference now it has been pointed out, but you’re right that it’s pretty damn oblique!
I never knew 'Eezer, but do pass on my thanks to Rich for some brilliant tunes from my younger years!
NEVER underestimate the layered entendre game in the UK.
> Nothing unexpected or user-harming, and nothing new as 4G was already used for IoT.
https://www.fastcompany.com/90314058/5g-means-youll-have-to-...
This is a clickbait article. More towers mean that existing triangulation somewhat more accurate, and "anyone with access" is the cellular service provider.
5G does not always result in more towers, it just supports closer towers for better performance.
"Anyone with access" to Google or Apple data also knows exactly where you are. "Anyone with access" to <social media app of choice> knows exactly where you are. "Anyone with access" to police databases know exactly where you drove. "Anyone with access" to VISA/Mastercard data knows exactly where you've shopped. "Anyone with access" to Find my data will know exactly where your phones, headphones, and other trackable items are at any point in time.
This isn't a complaint about 5G, but about cellular anonymity which has never existed.
We should create technology that deliberately feeds trash data to marketers, in mind-boggling volumes. Drowning the signal in a biblical flooding of noise.
We should make things so useless and annoying for them, as they did for us.
I might have missed it just skimming, but what's the physical method they are planning to use for return channel?
Apparently there are two options: An existing Internet connection, or actually receivers transmitting back to the broadcast tower – which sounds crazy, but the specification [1] says it can work over up to 100 kilometers with line-of-sight...?
Then again, thanks to modern modulation techniques, digital steering etc., battery-powered smartphones can talk to satellites 36 thousand kilometers away these days as well, so maybe this is just a thing now? The spec also does mention receive repeaters for complicated non-line-of-sight propagation scenarios.
[1] https://www.atsc.org/wp-content/uploads/2024/04/A323-2024-04...
I just used bullshit remover : “Conventional TV ain't enough. Need new tech to make more money. Gotta maximize that ROI, yo.”
So you got that right.
Note that this blog post (and the associated video) were a quick off-the-cuff thing while I was on the NAB show floor—I have been talking to a few of those involved in the testing at NIST, Sinclair, and Avateq (among others), and will hopefully have a lot more in a follow-up.
Right now it's in the experimental stage, with only 6 towers total deployed (only 5 were operational during NAB, and only one in Nevada... so timing, not navigation yet).
The ultimate plan—which is probably dependent on how well ATSC 3.0 rolls out (which has plenty of hurdles[1])—is to encourage broadcasters to add on the necessary timing equipment to their transmitter sites, to build a mesh network for timing.
That would allow the system to be 100% independent of GPS (time transfer could be done via dark fiber and/or ground-satellite-ground directly to some 'master' sites).
The advantages for BPS are coverage (somewhat) inside buildings, the ability to have line of sight nearly everywhere in populated areas, and resilience to jamming you can't get with GPS (a 100 kW transmitter signal 10 miles away is a lot harder to defeat than a weak GPS signal hundreds of miles away in the sky).
The demo on the show floor was also using eLoran to distribute time from a site in Nevada to the transmitter facility on Black Mountain outside Vegas, showing a way to be fully GPS-independent (though the current eLoran timing was sourced from GPS).
[1] ATSC 3.0, as it is being rolled out in the US, doesn't even add on 4K (just 1080p HDR), and tacks on 'features' like 'show replay' (where you tap a button and an app can stream a show you're watching on OTA TV through the Internet... amazing! /s), DRM (at stations' discretion, ugh), and 'personalized ad injection' (no doubt requiring you to connect your TV to the Internet so advertisers can get your precise location too...). Because ATSC 3.0 requires new hardware, consumers have to be motivated to buy new TVs or converter boxes—I don't see anything that motivates me to do so. I feel like it may be a lot like the (forever ongoing) HD Radio rollout.
I bought an atsc 3 tuner, and the experience turned me off of OTA tv. Since then, things managed to get worse as when I was poking around, DRM wasn't in use, but now it is.
I was hoping to get better fidelity between the roughly 2x bitrate per channel, and the video codec update. And probably overly optimistically was hoping the 1080p feed source was progressive so there wouldn't be a deinterlacing step.
Otoh, local broadcasters use an audio codec I can't easily use, integration with mythtv is poor, and there's no sign anything is going to get better soon.
Maybe if I had a tv with an atsc 3 tuner, live tv would be an option, but I'm not buying a tv for that.
ATSC 1.0 took a while before gathering momentum, so maybe that's going to be the same here, and in another few years, it might make sense to consider a transition. OTOH, maybe the writing is on the wall and OTA broadcasting will die on this hill. I was an OTA enthusiast, but between ATSC 3 being terrible, and the reallocation of spectrum that means cellular base stations sometimes overwhelm my pre-amp, it's not much fun anymore. (I have a filter post-pre-amp but it'd be better if I got on the roof to put it pre-pre-amp, but roofs are scary) Maybe I'm just getting curmudgeonly though.
Why is US ATSC 3.0 so bad? It is nearly a decade since it was South Korea have it deployed and operational. The standard itself is no longer "next gen". Brazil's TV 3.0, also uses ATSC 3.0 is so much better in every aspect.
Even if someone mandate it as requirement for TV sold next year all the tech inside are at least 10 years old ( HEVC ? ) . Not to mention the roll out time. Do Americans only watch Cables and Netflix? And not Free to Air TV? Which is what I belief what most of the worst still do to a larger extend other than Internet streaming.
They might as well look into the standards before putting a mandate into it.
Broadcast TV modernisation is trapped between a load of enemies.
To the north, competition from a huge installed base of last-gen technology, which is mostly good enough.
To the south, streaming services, youtube and cable. These let people watch whenever they want (nobody has VCRs any more) and they've offered 4k for over a decade.
To the east, the industry's dumb decision to build the 'next gen' technology atop a patent minefield, and load it with DRM. So if you manufacture this tech, you can face huge surprise bills because in implementing the spec you've unknowingly infringed on some nonsense patent.
And to the west, the commercial reality that showing someone an advert in 4K isn't any more profitable than showing the advert in 1080p. If you're a broadcast TV station when you up your quality everything gets more expensive but you don't make any extra money. So why bother?
> If you're a broadcast TV station when you up your quality everything gets more expensive but you don't make any extra money. So why bother?
In a functioning, competitive market, the answer to this is "Customers choose a competing broadcast TV station with higher quality." Unfortunately what we have is far from that.
Nitpick: ATSC 1.0 only offers broadcast in 720p or 1080i... of course with overscan and all, nobody actually notices the resolution of TV.
Only "18% of U.S. TV households had at least one TV set enabled to receive free, broadcast programming."
https://www.nielsen.com/insights/2024/beyond-big-data-the-au...
Wow. Thanks. So when an Americans say they are watching TV, I assume that mostly meant watching Netflix or Cables?
Yes. Satellite dishes also provide service like cable does, a number of "basic" channels included plus options for "premium" channels that cost extra. The basic channels include the broadcast networks for one's geographic area.
They're not that popular but there are similar bundles available over the Internet, YouTube TV is one.
All the national broadcast networks have Internet options, Hulu has shows from multiple networks, Paramount+ has CBS. Both also have shows made for cable & satellite channels and Internet-only programming.
There's a lot more than Netflix too, Amazon Prime, AppleTV+, Disney+, Max, and many others.
Live sports kept people signed up to cable & satellite for a long time, I think now there are Internet options (and probably exclusives, I don't watch sports).
This is from 2022: https://www.nielsen.com/insights/2022/broadband-only-tv-home...
Be aware that the cable tv infrastructure is also the main Internet service provider, many people are like me, paying the cable company for home Internet but not for TV (my plan does include a legally mandated minimum TV service and a TV box but I only have it because it's cheaper than Internet alone for some reason).
Cable is losing subscribers, too.
https://evoca.tv/cord-cutting-statistics/
Thank You. I guess I will submit this as an operate entry. Mind blowing figures.
Broadcast TV after the digital rollout was so bad many people just stopped watching TV. Picking it up is such a hassle it's simply not worth the effort for some ad laden TV.
At the time of the switchover in the early 2000s I lived about 40 miles from a major metropolitan area, Minneapolis, which is pretty close in US terms. We spent hundreds of dollars on different antennas (indoor and outdoor) and signal boosters and what not and it was simply never reliability.
In 2008 I moved to my current location, three miles outside of downtown Minneapolis. Again I tried a number of antennas and still found operation to be anything but reliable. I gave up and began just watching Netflix.
The people who live close enough to the broadcasts to pick it up have easy access to cable TV. The people who live in the countryside who used to depend on it can't pick it up. There's just no place for the TV system we were given.
> Broadcast TV after the digital rollout was so bad many people just stopped watching TV.
That is the first time I've heard that. Everything I've heard has been positive - people amazed that others aren't doing it. Are there any numbers on user satisfaction?
I used it myself once or twice and it worked simply with antennas that were relatively cheap (<$50 iirc). Maybe there was a problem in Minneapolis?
> The people who live close enough to the broadcasts to pick it up have easy access to cable TV.
Cable is expensive for many people and broadcast is free, of course. (Also, Broadcast is more private, for now.)
> I used it myself once or twice and it worked simply with antennas that were relatively cheap (<$50 iirc). Maybe there was a problem in Minneapolis?
I don’t know about Minneapolis is particular, but 40 miles is far enough that it gets tricky, and in my Canadian city, I’m close to the towers as the crow flies, but in the RF shadow of a huge hill - so I’d actually get better reception if I was further away from the broadcast towers.
I live in downtown Chicago and get tons of channels, despite no line of sight due to buildings in the way. Though they tend to go out when the El passes by.
> The demo on the show floor was also using eLoran to distribute time from a site in Nevada to the transmitter facility on Black Mountain outside Vegas, showing a way to be fully GPS-independent (though the current eLoran timing was sourced from GPS).
There's been a consistent call by many people that there needs to be a diversity of options for navigation and timing:
* https://rntfnd.org/2025/02/04/pnt-gps-critical-issue-for-new...
China has GNSS (BeiDou, plus plans for LEO), plus terrestrial navigation (eLoran), plus a fibre-based network for accurate timing:
* https://rntfnd.org/2024/10/03/china-completes-national-elora...
* https://rntfnd.org/2024/03/01/patton-read-their-book-chinas-...
* https://rntfnd.org/2024/11/29/china-announces-plan-to-furthe...
Russia has a Loran-equivalent:
* https://en.wikipedia.org/wiki/CHAYKA
Well... and there's the electricity grid which can be used for timing needs accurate enough to a single second, and in Europe there's DCF77 [1] which can not just be used as a 2*10^-12 seconds-accurate timing standard but also a frequency standard.
[1] https://de.wikipedia.org/wiki/DCF77
Did you actually mention what BPS actually stands for in the article? I read the whole thing and don't recall reading that. Yes, I'm capable of searching and finding the information myself, but in an article about something something esoteric like this, explaining the acronym would be useful.
Edit: Broadcast Positioning System for anyone that didn't figure it out.
How does it solve for time without location? With GPS location and time are one solution to an equation with 4 unknowns (x,y,z,t). Without location you won't know the time delay between you and the transmitter.
The the transmitters are of fixed terrestrial locations.
So you set your clock up by telling it its own location, so it can offset for the signal's flight time?
No, you tell it the location of multiple towers it receives signals from, then it can compute the unique solution x, y, z, t
But the comment several levels up said they were demoing time with a single tower.
You can get time with a single tower, but not location.
How do you know time of flight for the signal? Tower sends its coordinates, client uses GPS?
The satellites are on known positions too, once you know the time.
High-power, and ideally authenticated, alternatives to space-based GNSS are desperately needed, given the sharp uptick in jamming and spoofing incidents in many places.
In a true "end of history" moment, the US and other NATO members discontinued both of their ground-based systems (which are inherently harder to jam due to their much higher transmission power, since transmitters are not power limited) – Omega in the late 1990s and Loran-C in the early 2010s – in favor of GPS, while Russia kept their equivalent functional, and China completed an eLoran network last year.
Add to that the FAA's reduction of their ground-based VOR/DME station network that lets planes navigate when GPS is unavailable...
GPS jamming, and much more concerningly spoofing, will probably quickly come within reach of non-nation-states and smaller groups of all kinds, and ultimately individual actors, and that can't possibly end well for civil aviation if robust countermeasures don't become available very soon.
You can't really beat a jammer, sure you can compete for power output, but there is no real stopping it.
Aircraft and military positioning concepts are evolving towards more map and dead reckoning, lessening the benefit of GPS jamming.
The reason that dead reckoning was inaccurate was because of clock and vector inaccuracies. Looking at the advances in clockpieces and gyroscopes (both of these has benefitted over the optical revolution) over the years, I am not shocked that dead reckoning is back in vogue.
Dead reckoning is also inaccurate due to unknown winds. Even if you take off with the best available forecast, it’s often wrong by 5mph+. After three hours your position is off by 15 miles. That’s not remotely good enough for most aviation purposes.
Dead reckoning based on heading and time alone, but if you have a good INS it's not affected by wind only by accuracy of the gyroscopes/sensors.
Current systems drift by about 0.5 miles per hour. And that's normal commercial grade systems, I'm sure the military has an option for better systems if they need them.
As t0mas88 said, you don't rely on the measured speed of the aircraft/ship, you rely on gyroscopes (which are much more resistant to external factors), and both clocks and gyroscopes have improved signifcantly (clocks are now better than cesium atoms - read about atomic clocks) and so are gyroscopes (again, optical gyroscopes that are miles better than mechanical ones).
Portable clocks are not better than static caesium clocks, and optical clocks which are better than caesium clocks are not portable.
Eh, not smartphone-like portable, sure, but publicly (https://english.kyodonews.net/news/2025/03/c0945eb14bb6-japa...) it can now be fitted on a ship or submarine (and I won't be surprised if there is classified miniturization out there).
Correct me if I’m wrong, but wouldn’t a jammer be very easy to disable kinetically?
A missile would simply have to follow the jammer’s signal.
Missels are expensive. Jammers can be farther away than a cheap drone can reach.
Jammers often move. Your missle often cannot manovure well enough to hit. jammers often turn off - if you missle is detected they turn the jammer off and move it. They are often running more than one jammer so getting one to turn off isn't going to matter.
The obvious problem with this approach: destroying a jammer in foreign country with a missile is an act of war.
Janming is an act of war too.
Sure, use energy beams to strike their jammers.
Be an interesting feature to add to the AGM-88E.
Plus aircrafs can use Earth gravity map. Sensors became accurate enough to detect minuscule changes in gravity strength to position aircraft to few hundred meters.
You can defeat a jammer if you are willing to use more spectrum than your opponent and/or can sacrifice information rate.
True, but both very hard to do in a system that's deployed to space and (heavily regulated) avionics part of aircraft that get upgraded very infrequently, to say nothing of the billions of other civilian receivers.
What if you used directional antennas?
A university of Texas research group demonstrated more than ten years ago that they could spoof GPS in the vicinity of an automatically navigating UAV, and force it to land at a point of their choosing. This has been within the reach of garage hackers for a long time.
Now the UAV needs to track where the signal is coming from. “Hey, this isn’t coming from the sky, what gives”
Gets trickier when you're using dGPS. And you need at least 2 antennas/receivers to know direction of arrival. Beamforming in the direction(s) of the expected satellite(s) seems to help a lot with e.g. starlink. But you'll need a phased array and a beamformer.
GPS jamming, and much more concerningly spoofing, will probably quickly come within reach of non-nation-states and smaller groups of all kinds, and ultimately individual actors
It may already be so:
https://hal.science/hal-03456365v1
You don't need ATSC 3.0 to do this kind of thing! The short-term stability of the oscillators they use for commercial DTV transmission is apparently good enough that just having one local reference to compare GPS vs. each TV station's phase (and distribute that data) can produce a pretty good positioning system. Rosum was doing this back in 2005: https://www.tvtechnology.com/news/tv-signals-used-for-geopos...
Slide deck of BPS (Broadcast Postioning System) https://www.gps.gov/governance/advisory/meetings/2022-11/mat...
Thanks for sharing this. It creates a clear picture of its use cases and roll out plans.
GPS is such a critical infrastructure component to modern society- knowing that a redundancy system like this is in the works is great.
ATSC 3.0 channels (there are some already) are encrypted. So no more free-to-air, no open standards, no more open source viewers. Watch TV using Kodi? VLC? Not anymore.
It's a travesty that this was ever approved.
Nice article on HackADay from yesterday covering this:
https://hackaday.com/2025/04/11/gps-broken-try-tv/
I’m trying to understand if this depends on something specific to FM or TV signals, or if it’s more of a protocol-level idea (i.e., any time-synced, known-location transmitters would work).
If it’s not intrinsic to FM, why not use existing cellular towers to do this? They’re everywhere, and phones already receive broadcast messages (like Amber Alerts) even without a SIM (I think) — so it feels like this could be done without needing new radios.
What makes this more accurate than cell tower triangulation today? Is the limitation in timing sync across towers, or something else in how cell networks are structured?
And for indoor use — how does this handle multipath? Reflections from walls or even atmospheric bounce seem like they’d throw off timing accuracy, similar to what messes with GPS in dense areas.
If planning/designing a timing system like this using existing antenna, why wouldn't you choose to use cellular base stations? The cellular network reaches most places with overlapping coverage and carries network time. The lowest cellular frequencies are adjacent the upper broadcast TV channels. Aren't modern cellular receivers what we call software defined radios? They can choose which channels to receive.
Interestingly, cellular base stations are one of the major customers for high precision timing systems.
They use precise timing to coordinate timed broadcast slots between base stations with overlapping coverage.
This sounds interesting but it most likely will only be of use in populated areas where there is enough signal overlap from broadcast towers. You’ll still need GPS in the countryside and on water.
In a lot of cities the broadcast towers are concentrated in the same place, I wonder how effective it could be.
At least in Europe, when broadcasting went digital (DVB-T), a lot of cities started being covered by single frequency network transmission, which specifically leverages different transmitter locations transmitting the same signal to decrease dead zones.
Due to how OFDM works, I suppose the idea here is to intentionally send a heterogeneous signal on a few non-overlapping subcarriers (for single-frequency networks) or on different transponders at different locations (since single frequency networks aren't as common in the US due to how broadcasting evolved there, although ATSC 3.0 apparently also allows single frequency networks).
What about RTK/PPS? Here's a module that implements them along with GPS and GGNS.
https://www.sparkfun.com/sparkfun-gps-rtk2-board-zed-f9p-qwi...
The datasheet: https://cdn.sparkfun.com/assets/f/8/d/6/d/ZED-F9P-02B_DataSh...
https://www.nab.org/bps/
for people who don't want to watch videos
The OP link is a blog post, which includes links out to the primary resources (much more in depth than the BPS landing page). The video is a byproduct of my conversations at NAB, and both are just preliminary... I've been working on a more in depth look at GPS and BPS (and other alternatives).
I'm fighting through a cold so granted my reading comprehension is way down but at least in my diminished state I was reading through that and was baffled ...
I'm sure the average reader who deals with broadcast signal electronics knows what's going on here but I just walked away from it confused. It looks like terrestrial broadcasters sending out time codes for triangulation?
I was amazed to not even find a Wikipedia article about BPS.
I'm guessing the long term vision is phones and cars will receive broadcast television because traditional TVs are usually pretty stationary objects?
It sounds like a hail mary. How many people use the fm radio transceivers in their smartphone?
Maybe it's a total re-imagining of what to do with high power terrestrial band broadcasting?
Or a way to try to preserve ownership of some spectrum. IMO it may follow the same route as HD Radio adoption.
I have that in my Hyundai Kona. It's fascinating to hear what's on those stations. I can't imagine simultaneous listenership numbers ever breaking 100.
Every time I show someone I first have to introduce the concept of it existing. And these are technical people.
quick, call in wiki support & take cover!
I'm surprised that broadcast TV is used as a basis for this. It's not a topic with which I'm familiar, but I would have guessed that it was only slightly more popular than Fax and that it would have faded out is most of the world.
>an oscilloscope that costs 3x the value of your car on a trade show floor
Typical high end microwave measurement system cost as much as a Ferrari car.
Good cable and connectors can set you back by several thousand dollars.
It's a very good business space prime for disruption (hint SDR - or software-defined radio).
Fun facts, the grand daddy of Silicon Valley start-up is HP (then Agilent, and now Keysight) selling function signal generator.
Good cable and connectors can set you back by several thousand dollars.
Another domain where that is true involves logic analyzers. A few years ago, on a bit of a lark, I bought a (used) fairly high-end Keysight logic analyzer. The kind of thing that cost like $20,000 or more when it was brand new. But I got a sweet deal on it, so I bought it. Only... it came with no test leads. And then I started shopping for the leads.
Yikes.
I forget the exact numbers now, but as best as I can recall, the leads came in 64pin sets, where the device supported up to 4 test lead sets, for 256 total channels. And just one of the 64pin test lead sets cost something like $1500. So a full set would cost another $6000 on top of the device itself. I think that was about what I paid for the analyzer itself in the first place!
Now I don't regret buying it and in truth I never needed to use 256 channels anyway, so I only bought 1 of the test lead sets so far. But yeah... test leads / cables /etc. for high bandwidth / low latency / high frequency applications get pretty damn expensive.
I've got a rack of equipment that sometimes requires a special calibration where I need to lug over a signal generator. Of course the only ones we have available that go to the necessary frequency weigh like 50lbs. I've recently been eyeing a little gadget that costs about 1/10 or 1/20 the cost of the Keysight units, interfaces using USB oe Ethernet, and is about the size of a deck of cards. The accuracy isn't perfect on its own but that's what a 10MHz ref clock is for. It's amazing how far tech has come and it's amazing how much we are still paying for these dinosaur pieces of test equipment.
Interesting. Though he didn't say what kind of car he drives, it could be a real shitter
2007 Toyota Camry. I looked it up, it's actually worth even less than I thought it was haha.
Is there any DVB-T equivalent?
Czech technical university - 2018 - https://www.radioeng.cz/fulltexts/2018/18_04_1155_1165.pdf
But concepts are translatable to other technologies, for example mobile phone network signals (even without decrypting it) which in most populated areas can have hundreds frequencies by itself.
there are literally literally thousands of radio signals around us which can be used for various unintended / non-cooperative purposes. also not only ground based signals, satellites are transmitting all kinds of signals towards earth, some for communication, some for remote sensing / earth observation.
Or not only is it possible to use non-cooperative signals for timing, but also for passive radar. For example DVB-T - you receive bounces/echoes of signal from airplanes, drones and measure its characteristics.
NATO public document - UAV Detection and Localization Using Passive DVB-T Radar MFN and SFN - https://www.sto.nato.int/publications/STO%20Meeting%20Procee...
Good community is around GNURadio, they have all kinds of enthusiast and profesional usecases, explorations, videos, ...
Or just simple 30$ RTL-SDR + laptop, you can sit next to road and listen for tire pressure monitoring sensors data, they contain unique ids, so you can know when postman enters your street...
(some of those thousands signals can be dependent on GPS too...)
it is possible to listen to small part of spectrum thru receivers which enthusiasts connected to internet, without buying anything for example -http://kiwisdr.com/public/
but "high performance signals" are not in frequency range of those radios. but it is possible to hear ham radio, aviation, military, maritime, not only voice but weather fax, other digital signals, all sorts of timing signals...
There are all kinds of terrestrial alternatives to GPS. The US used to have LORAN-C. The trick is to deploy them...
I want to like this — I think having ground-based alternatives to GPS and other space-based PNT systems is a very good thing! But after reading the paper at https://www.nab.org/bps/Broadcast_Positioning_System_Using_A... and other BPS information on the NAB's website, I think the NAB is being wildly optimistic about BPS:
• ATSC 3.0's physical layer can already transmit GPS time in a way that receivers could get it back out. What BPS brings to the table is a requirement and specification for accurately and consistently filling in the physical layer preamble fields containing the time data, along with a new physical layer pipe (think "low-level data stream") that contains additional information about the transmitter and, optionally, its neighboring transmitters.
• BPS is capable of producing time fixes when the receiver only has a lock on one source. This isn't surprising at all — GPS receivers can do the same thing. But either type of receiver with only one source would see a clock offset proportional to the path delay, which it wouldn't be able to compute and back out without knowing its position.
• BPS is only designed for 2-D position fixes. While that's a reasonable design decision (the vertical position error would be massive), it also makes BPS less useful for the NAB's "indoor positioning for first responders" use case, especially in areas with multi-story buildings.
• The need to receive and process/decode multiple, most likely non-adjacent 6 MHz channels for positioning increases receiver complexity and cost.
• The NAB claims that 1 kilometer of separation between two BPS transmitters is "sufficient for useful position determination." I don't buy it, especially in the face of poor transmitter geometry.
• They note that 16 TV stations in the New York City area broadcast from One World Trade Center, so for the purposes of BPS, they're effectively one station. This kind of transmitter colocation is incredibly common, both in urban areas (ten TV stations broadcast from Sutro Tower in San Francisco) and in more rural areas (six TV stations in the Roanoke-Lynchburg DMA broadcast from towers within ~1 mile of each other on the ridgeline of Poor Mountain). Even if every ATSC TV station became an ATSC 3.0 w/ BPS transmitter, bad transmitter geometries would destroy BPS's position accuracy in lots of markets.
• What's the business case for broadcasters? BPS won't be free for broadcasters to implement, and there doesn't seem to be a path to it generating revenue except for a hand-wavy "maybe one day televisions will be able to determine their locations without Internet connections using BPS, and then broadcasters can do location-targeted advertising with those TVs!"
My uncharitable take is that BPS will never be a usable standalone PNT system. A timing system in the "rebroadcasts GPS" sense? Maybe. Standalone positioning? No way. Broadcasters implementing BPS (or ATSC 3.0 at all) without being forced to by the government? I don't see it.
> What's the business case for broadcasters?
My uneducated guess is government funding, plus becoming part of a new "essential backbone" infrastructure, thus guaranteeing incentives to stay operational for a longer period of time.
Is there a COTS component that gives you something like a GPS Sentence return from this?
tldr; BPS is Broadcast Positioning System. Same principle as GPS: a known waveform is used to triangulate position and time. Advantage: indoor available, less easy to jam/spoof due to high tx power of broadcasting stations. BPS can be added to ATSC 3.0 Next Gen TV signal which is rolled out since 2019 in the US.
Current planning is public availability in 2027-2029.
A good gov presentation with an overview and technical details is here [1].
[1] https://www.gps.gov/governance/advisory/meetings/2022-11/mat...
While this is is interesting, the "nobody's heard of" phrase is rather condescending and such phrases leave a bad taste in the mind.
Hmm it's just a turn of phrase. I would bet you $100 that no more than 0.001% of the population have heard of BPS. I hadn't. That's functionally "nobody".
The title is still clickbait given the reason nobody has heard of it is that it barely exists and is not useful yet.
Also, it smelled a bit like wishful thinking to assume the high precision clock would not be driven by GPS on real world deployments. I know some cell towers synchronize via PTP, but a great many others use GPS as their time source.
For anyone who deploys GPS-based timing systems at scale, having more sources of precise time is a huge boon. (Some companies pay many millions for dark fiber just to have a redundant time source).
Holdover can only help so much, if there's a persistent jamming effort, it can wreak havoc on many time-critical systems.
It's worse in every way than just omitting it. 'BPS is a GPS alternative' is better as a title, on HN at least
yes saying jeff geerling is the nobody who never heard of that thing is offensive to me. XD
It's a curiosity gap headline; it's a lazy form of headline that insults the intelligence of the audience. It also extends into clickbait.
Poor form. Do better.
Could be cheated with a retartd line?
A alternative, but only for timing and as GPS supplement. Unless you’re in a place where you can pick up 4 ATSC transmitters at different locations you won’t get position or navigation with it.
So if you can get more than 3 different TV stations you should be good. Most stations don’t share transmission towers, AFAIK.
There are places, especially in the mountains where you don’t get the requisite number of towers, but large portions of the US will, and the required signal to noise ratio is better than to decode regular TV signals, so you have a larger area covered than for TV.
GLONASS? Baidu?
Controlled by other nation states.
Galileo. Controlled by the EU, and therefore a better choice than GPS, since the United States is no longer trustworthy.
Honestly how trustworthy was the US before? Are we supposed to be completely fine with PRISM and XKeyscore now?
well i do not share your "enthusiasm" do not forget those systems used twitter,google,amazon,microsoft infrastructure, so those private companies build it first...
It's a little unclear to me from reading the Wikipedia page; is it fully functional today, and worldwide? It'd be cool if my phone showed me which systems it was using at any time, but I have chosen The One True Apple Way so I don't think that'll come any time soon
Yes it has full world coverage, see the esa navipedia for more info.
No idea how it is in the US, but in EU you can't really easily choose, it will by default use GPS+Galileo combined for better accuracy.
I guess you can through developer settings on android though.
If you're on Android there's an app, GPS Test that shows you a chart with all the signals it's picking up with different symbols for each system and a filter too. My phone is currently picking up 5 GPS, 4 GLONASS, 8 Galileo, and even 3 Beidou sat signals (I'm in Western Europe).
Also you should be able to look up your phone specifications to see what GNSS services it's capable of using on GSMArena
Edit:oh I missed that you're on Apple so that app is useless for you. Still might be of some use to others though.
This system should be shutdown. What if enemies use it to guide their rockets?
your phone ai can recognize dogs in your photos, and militaries have all kinds of aerial survey, satellit photos of your house, so do they really need to use external radio signals, or is it enough for them to use fully internal system with just cameras and khadas mind 2 ?