This would be my use case too. But data is extremely cheap here in India (as of now at least; after Jio happened). My main concern was huge battery drain while using data.
Side note: If you ask your local station to contact T-Mobile to be included in their zero rating program for content steaming (and you’re on T-Mobile), you’ll get the same effect and be able to listen to your local NPR affiliate from anywhere in the US.
Disclaimer: My hometown NPR affiliate was happy to apply, and now I listen to NPR on my occasional commute ~1000 miles away from my hometown station.
FM radio is both wideband and very high power, so I imagine it should be able to get at least 100kbps if you replaced the audio with trellis-modulated data, though I'm sure the FCC wouldn't be very fond of that
I still have a few lying around, though the data service has long since been turned off. It was low-bandwidth, but suitable for stock prices, weather, and incoming-only text messages via (IIRC) MSN Messenger. Cell phones have since replaced the functionality, but I loved mine at the time.
There have been several schemes over the years for using FM broadcasts for data. In the early 80's, you could hook your home computer (Commodore 64, etc...) to the headphone jack of a radio and late at night some stations would carry a program that would send data. It sounded a lot like an old-school modem.
In the mid-90's I had a TV set-top box that gathered TV guide information over an FM data subcarrier. The company went out of business.
These days, data over broadcast is done on TV channels instead of FM because the bandwidth is larger. There's one of these operating on channel 20ish in Houston. I have no idea what data it's broadcasting.
This is also great for safety often you only get disaster information from radio and TV. In the event of a major earthquake or other disaster this could be a life saver.
NextRadio requires support from your carrier. A phone with an enabled chip is not enough. I have a Sony Z3 and a Sony Z3C and the FM radio has always worked. NextRadio has never supported them. (I got them right after T-Mobile stopped their brief support of the Z3.) The same thing happened with my AT&T NEC Terrain -- the FM radio chip was always enabled; but, NextRadio would not work (and was not supported).
You still need an app to turn on and tune the FM receiver, that is what the http://nextradioapp.com/ app is. Apparently it does have a fallback to stream but its focus is on the FM chip. They even have a search page on their site to help you figure out which phones have an FM chip.
I know they have FM receiver chips built in. They are built into the QCOM chips. If you use the NextRadio app you can use the FM chip on the Radio to tune into FM stations. I am not sure why I am getting downvoted for providing some information.
Feels like the people who still listen to radio are the people who don’t have smartphones: age-based. I only have one friend whom I know listens to the radio, and that in his car.
I guess I just assume that radio is just for the elderly.
when driving in radio is great for traffic information and up to date weather as some weather apps seem to drag when it comes to being current other than active RADAR maps.
considering the number of billboards and other advertisements there is a big following in the general populace. many rating services would dispute that it is consumed only by the elderly.
Speaking of adverts, the thing that killed my use of the radio is adverts. It’s brutal to listen to so many. It baffles me that anyone tolerates it. That and DJs who seem to believe people want to hear them rather rather than the content.
It is why I listen only to one of the NPR affiliates or other listener-supported radio (e. g., KEXP in Seattle). Not that I’m a public radio nut (though, kinda), I’d just rather listen to nothing than put up with the cackling hyenas on commercial drive-time radio. My wife leaves the car radio on the local classic rock station, and it rarely is playing a song when I start the car. An iPhone with access to every song iTunes has, and she listens to that crap. I don’t get it.
Between promoting sponsors (ads), promoting their own programs (ads), and trying to get me to give them my car (ads), it seems like my local NPR station's ~25-30% ads even when it's not pledge drive week.
I've always had phones with FM receivers when possible. They're not rare (in UK) - my Huawei has it, my wife's Samsung has it. In the past our LG and Sony Ericsson phones had them.
> I guess I just assume that radio is just for the elderly.
My unwittingly inflammatory comment was justifiably (it turns out) downvoted as my assumption turns out to be quite incorrect.
I looked up some stats (just free ones) and indeed, radio listenership turns out to be quite high (mid 90% of age band) pretty uniformly across age bands (which Nielson calles "millenial" "Gen X" and "boomer"). This is not the case of TV, which has noticeably higher penetration in boomers compared to younger demographic groups. These are WAU numbers so some groups may spend a higher percentage of time listening, but I couldn't find that data.
Radio varies quite a bit across metropolitan areas. You could grow up and not really be a "radio person" based on what's available in your market. I have found when traveling to various cities that a few of them have multiple, really fun radio stations.
Regardless of local radio choice, some people just aren't radio fans. If you are into EDM, for example, you probably won't find satisfaction in radio.
Another factor is how much friction there is in your particular car and car stereo for hooking up your smartphone. Not all cars have Bluetooth and those that do may not have it for audio (voice calls only). Finally even if your car has an aux input it may not be in a convenient place. For short trips you may not want to spend the overhead hooking up your phone each time.
So there are many factors that go into whether an individual is a "radio person" besides age.
I fall into exactly this category. 90% of my car trips are 10 minutes or less. My 2003 vehicle doesn't have bluetooth or aux. I've tried a couple different 12v adapters but the friction in setting it up and the compromises make it not worth my time. I'm lucky enough to live in a market with plenty of music/news options so I stick to radio almost entirely. When I visit my family in the less populated areas of Michigan, radio makes me want to kill myself. :)
Every now and then I wonder if we're making a mistake with the new tech we're bringing in to replace radio and TV broadcasts. FM/UHF broadcasts scale infinitely! There's something quite beautiful about them, technologically.
It's not difficult to imagine that in any kind of emergency scenario internet-based broadcast systems will collapse. And maybe it's just me, but I always found broadcast to be pretty reliable (or at least consistently unreliable in ways I could predict) - online broadcasts have a tendency to fail/buffer/etc. at totally random intervals.
The spectrum is regulated by governments everywhere, so it doesn't have to. Or, if you prefer, "that ship has sailed" a long time ago, so let's look at what it gives us as it exists now.
Technologically effortless dissemination of content from a central source, scaling to infinite receivers with no congestion and no loss of quality. The production of the content itself need not be vertically integrated; individual programs and segments are licensed and syndicated from third-parties.
Airwave broadcast has a natural place in the world, ideally by playing popular content that's always in demand. In our rush to go point-to-point, full-duplex, and on-demand, with both cabling and wireless, we have occasionally reimplemented services that are one-to-many simplex on top of lower layers that aren't made for that, whereas airwave broadcast has always fulfilled the same usecase with a different set of tradeoffs.
Broadcasting is too efficient. There's no way to require individual authorization from receivers, so subscription fees are hard to collect. For free content, ads are not very targeted.
One mechanism to recoup a portion of this cost is a state-run licensing fee that's usually worked into the retail price of receivers [1]. A more elaborate evolution of this, to keep up with advancements in technology, is the blank recording media tax [2].
Assuming there is a network. With enough bandwidth to support audio streaming. And there isn't an aggressive FUP threatening to cut you off. That's a lot of assumptions.
I'm talking about a protocol to be implemented by the mobile network operators themselves - they control the bandwidth allocation and any FUPs in place. An emergency protocol would likely override all that.
Well, that's a rather pie-in-the-sky fiction (requiring total cooperation from everybody at once, btw), given that IP-based solutions have already eaten the world. Also, a broadcast radio network is useful outside of emergencies as well. (Not to mention that you're still assuming mobile coverage)
We could also try to fix/enable multicasting, if we wanted internet broadcasts to scale a hundred times as well, but nobody seems to think it's worth the trouble.
Classic stereo, wideband FM broadcast also sounds great when you have a good signal and good production.
In theory, the newer HD Radio scheme can provide equivalent or better quality even with marginal signals, but most broadcasters choose to continue regular FM simulcast and subdivide the remaining digital bandwidth across multiple virtual channels. This results in audible compression artifacts on most stations.
Wideband FM does sound lovely - FM Stereo however, less so - much.. uhh, crappier signal to noise radio, and relatively low channel separation depending on conditions.
All told, I generally prefer analog FM to FM HD Radio - though I also listen to AM extensively - and I like how it sounds on a receiver with more than communications grade bandwidth - AM can push upwards of 10 khz - before 1982, it was not uncommon to find stations who ran closer to 15khz though - I've heard test recordings that just sound fantastic.
In 1982 the FCC allowed stations to apply for C-QUAM [1] operation. Don't let the OP fool you, it uses a nearly identical technique to FM stereo and thus has nearly the same limitations and impact on quality of the station.
Or he's thinking about 1989 when the FCC actually limited AM bandwidth to 20kHz (10kHz audio).
> but most broadcasters choose to continue regular FM simulcast and subdivide the remaining digital bandwidth across multiple virtual channels.
The FCC has not approved all-digital modes yet. Further, we cannot control the bitrate of the "main" digital simulcast. We _can_ control the sub-channels, but it doesn't matter how much bandwidth you throw at it, the HDC codec (which is a bastardized form of HE-AAC) always sounds like garbage. This is partially owing to the codec, but also to the fact that we only have 96kbit/s in total to allocate to all sub-channels.
Looks like IBOC DAB like HD Radio has, at best, an audio codec rate of 96 kb/s. A CD has 2 x 16 bits x 44,100 samples per second = 1,411,200 b/s of audio data (doesn't include FEC).
Seems to me that even with the best codec there's going to be loss going from 1,411 kb/s to 96 kb/s.
That's equivalent to about 12 bits dynamic range, so already we see that analog FM is not as good as CD. If we take also the fact that the highest frequency is 15 kHz on analog FM, let's set the sample rate at (wave hands) 32 k sample/sec; so the 'equivalent' best-case uncompressed digital rate that's equivalent to the best analog FM is 2 x 32000 x 12 bit/sample = 768 kb/s. Given that when you add in that stereo pilot at 19 kHz and then do the L-R and L+R de-muxing thing in analog, you lose more dBs in SNR, wave hands and say the 'true' non-compressed equivalent of analog FM is around 500 kb/s. AAC gets 50% +/- 10% compression, so we're down to 250 kb/s.
So, it's hard to see how HD Radio can claim it is 'as good as' old-fashioned analog FM.
Forget "will" and try "do." If power to the cell towers is out, you get no emergency info. This used to be a yearly occurrence back when I lived in a more rural area. Just as you keep flashlights around, you've got to keep an AM/FM radio around.
Also, for reasons that aren't entirely clear to me, weather/emergency radio in the US, run by NOAA, is FM on a different VHF band between 162.4 MHz and 162.55 MHz, which most run-of-the-mill receivers don't tune. To be emergency-prepared in the US, you are wise to own such a weather band radio, a lot of which come with built-in hand-crank dynamos, flashlights, and other features useful in a dicey situation.
However, this development does segregate the most useful set of government-run emergency functionality away from ordinary consumer devices and into a special product category.
I will venture ahead and point out that 162MHz is within (or close to?) the Marine VHF band.
Guessing that historically the need for weather broadcasts was from marine navigation it would make sense that the weather forecast have stayed on these frequencies.
> Forget "will" and try "do." If power to the cell towers is out, you get no emergency info. This used to be a yearly occurrence back when I lived in a more rural area.
Or, only five years ago, for me living in downtown Manhattan (when Hurricane Sandy hit). The next morning, all cell service was completely offline (in addition to us having no power).
In the case of large events they can easily overload cell networks as well. That happened in the Boston Marathon bombing[1]. Thankfully there was already hams running communication for the event and could get messages through when the towers were down.
Radio broadcast does scale "infinitely" in terms of the number of possible "clients" connected to the "server". It has no limits to the number of possible "connections" - because, of course, it's actually connectionless.
It does suffer from severe bandwidth limitations. For emergency communications this is not a problem.
FM (or anything above 30 MHz) also has very limited range - line of sight more or less. Frequencies below 30 MHz could and do occasionally reach the antipodes.
Also keep in mind there's a network of radio operators that is everywhere, and we are prepared to intervene in case of massive telecom collapse - the HAM radio operators. Emergency messaging should continue to function, at least for a while, even in the context of massive catastrophes.
Totally agree with you. One of the beautiful thing about AM is the simplicity of it. The fidelity of the signal may not be as good as RDS, but you can understand the message and take action in an emergency situation. You don't need high speed electronics to decode the data.
In fact, you could cobble up a radio that does not need batteries.
> And maybe it's just me, but I always found broadcast to be pretty reliable (or at least consistently unreliable in ways I could predict) - online broadcasts have a tendency to fail/buffer/etc. at totally random intervals.
Do you live anywhere that gets regular tropical storms? Broadcast towers are lightning magnets and they regularly go out, usually not for long but I've seen them be down overnight more than once. They also used to degrade a fair bit in electrical storms in the pre digital TV age. It wasn't that long ago that a neighbor mowing the lawn meant that the TV signal would be awful/out.
What we need is for our internet and power systems to be more distributed.
This idea of using FM and UHF radio as a dependable emergency communication system lead me to the idea for my current project im working on which is a redundent mesh network built using radio networks. At least that's where I started. The project is a combination of standard "new" IoT technologies like GSM and Wi-Fi with my own mesh radio system. Only some nodes are GSM enabled all of the nodes use traditional UHF communications. At first I wanted to use different FM radio frequencies with frequency reuse patterns to implement a simple mesh network routing protocol as a proof of concept. But I was still a beginner in RF and I soon relaized that the FM, marine, and air bands have a bunch of FCC regulations making it illegal to transmit data at my goal of at least 500 m (0.5 km) let alone finding a cheap/simple implementation circut or chip for someone new to RF design like I was. This lead to the idea of just using 433 MHz transivers to accomplish the same goal. And lucky, there are tons of simple tranciver boards by various manufacturers with simple interfaces and long ranges even with non ideal antennas. I've gotten a point where I have these small solar powered packages you can just mount anywhere and can last up to 12/14 days on 4 hours of full sunlight charge. I've also reached the stage where I can top worrying about hardware implementations and work more on software such as a nice dashboard, a more thought out routing algorithm (instead of just simple backtracking), and more ideas such as being able to send data back into the network to take certain actions in the physical world such as localized warnings. A more powerful use case I witnessed firsthand would be to use a robust system like this to control water systems such as wastewater and freshwater systems for municipalites in sever weather incidents such as hurricanes. Pump stations can be equipped with backup power but data from these stations and various sensors in the system are interrupted durring sever stroms like hurricane when these systems are most critical and need sensor data to make sure the system keeps running.
I see the older technologies as solid foundation for robust networks. Most of these old systems are behind in terms of implementation technology but the foundations of these technologies are very strong. I believe that by integrating the robustness of older technologies with newer systems you can get the befits of new systems and technology but keep the robustness and stability of older systems.
Pretty sure there's not a separate chip so much as it's built into one of the chips that's already used. Presumably it's built into those chips for markets in which FM radio support is considered important and it doesn't take up enough die space to be worth making an FM-less version.
Probably there are no separate "chips", but functionality built in into the same integrated circuit as CPU and other things (SoC). The reason to include it into SoC is that the same SoC is used in various devices, not only phones, and it's not so complicated thing, just heterodyne and ADC.
Mainstream media loves the word "chip" and uses it in any context they like.
> what is the exact motivation for including FM chips that are going to be disabled in the first place?
A single chip can do multiple things (WiFi, Bluetooth, FM, etc). For the chip manufacturer, it's simpler and cheaper to provide a single version of the chip with everything, and let the device manufacturer simply disable the unused parts, than to provide several different versions of the chip, some with FM and some without FM.
That is, the phone manufacturer decides "I want Bluetooth and WiFi", and the chip they chose for that happened to also have FM. Since they won't use the FM part of the chip, they don't even have to connect the "FM antenna input" pin, saving the space on the board that would be used for the corresponding trace(s) and passive components (which they also don't have to install, reducing the costs).
You may want to read about software defined radio. It's quite possible that it's not even extra circuitry going unused. As the others say, it's so small the die area savings isn't even worth making a different variant of the chip.
Both my parents cheap flip and small android phone have working FM tuners. The headphones work as antennas and it's quite nice actually... I'm sitting there with a >$500 "smart" phone and envious.
For emergency purposes I wonder how hard it is to include an AM receiver. AM waves can travel much farther than FM. I'd guess it's one more part that adds some marginal cost, and there's more music/fun stuff on FM.
AM has a much longer wavelength. AM is super simple. It is Amplitude modulation. You take a signal and multiply it by a sinewave. The issue is you need a bigger antenna, and probably need to block noise better since AM has lot of issues with noise.
Aircraft bands use AM rather than FM because of the FM capture effect. When there is a double transmission with FM, the receiver will lock on to one signal and exclude the other. With AM, you will hear both as well as, possibly, a heterodyne tone if the carriers aren't exactly the same frequency which is much preferable.
FM demodulators can't really demodulate AM signals. AM demodulation can demodulate FM by tuning a bit off the carrier frequency thanks to the fall-off of the filters but the quality isn't great.
> FM demodulators can't really demodulate AM signals. AM demodulation can demodulate FM by tuning a bit off the carrier frequency thanks to the fall-off of the filters but the quality isn't great.
By "isn't great" you mean, "I might be able to understand something with a tailwind, downhill" - right? :-P
The mode of operation for an AM radio listening to FM is akin to a slope detector.
That's because SDRs hog a lot more power than discrete components. For something like a phone stand-by/screen-off power usage is a pretty critical component.
Some phones have optional removable components like extra batteries, higher-quality speakers/cameras, or even projectors. It would be cool if someone made a SDR add-on for these phones.
Ive used a cheapo SDR on my phone before, with a microusb adapter. There aren't a ton of Android apps but IIRC I was able to look at ADS-B transponder data
Obviously there is a trade off, either you get a large amount of low quality streams or a few high quality streams. You can do the same thing with FM, if you only allow stations to transmit mono audio you can fit more. I don’t know how many channels you get in the UK on FM vs. on DAB+ but it seems like the list of digital stations in that link is longer than would be possible using FM.
This all doesn’t change the fact that DAB+ uses the spectrum much more effectively. Of course, on low bitrates you can learn to hear the artifacts. Just as you can hear the distortions in FM. But you need less spectrum for a stream where you can’t hear the artifacts.
There isn’t some big conspiracy selling you digital radio, it’s just better.
In the UK there was something of a "conspiracy" (misselling is probably more like it) in that initially DAB was presented as high quality, giving a big reason to buy in, but it was quickly downgraded in quality once momentum had built for the change.
My impression is a simple radio set is now about 4 times what it was before DAB, not sure where that fits in ...
The conspiracy, if you want to see it that way, is not about selling you the devices but in dividing the spectrum differently so they have space for more stations to sell.
An FM station uses some specified amount of spectrum and the government can sell that space for the amount of money one station is willing to pay. If you can change the system so more stations fit in the same amount of spectrum, they get the amount all these stations together are willing to pay. So they get more money with DAB. And it looks modern with more features to boot!
You can just solder an FM radio yourself from generic components and some wire while a DAB radio requires a processor, which is obviously going to be more expensive. I think all of the patents expired though so I don't think someone is becoming rich by licensing the technology. At least the patents on the audio codec have expired.
>not about selling you the devices but in dividing the spectrum differently //
The point there is that initially it was hard to sell DAB in the UK because FM is pretty good, and very cheap. So people could only be convinced to buy DAB because the channel width allowed much higher quality. My recollection is that once momentum built on purchases then channel width was changed, making the perceived quality similar .. but now radio sets cost a lot more. The additional features don't really do anything for me, the only effective change for me is that it takes much longer to tune to a new station.
The cost of the DAB processor can't really be so much, the quality increase allowed prices to be anchored high; cheapest DAB is still 4x FM price, I can't see that being all tech costs.
You can’t sell spectrum to broadcasting if the listeners don’t have receivers.
You can buy DAB (and DAB+) receivers directly from China if you want. They’re still more expensive than FM receivers but then you can be sure there is no shady conspiracy in your own country profiteering.
In fact, if you want you can buy a SDR device which gives you the data an antenna would receive, and do the rest in software (both FM and DAB decoding).
My point wasn't really that FM is better per se though (it clearly isn't, as even high bitrate stereo streams would be a better use of the spectrum), rather that I don't see it as "clinging to obsolete technology" on the user side. It is just, IMO, the better user experience as it currently stands in the UK - I don't think you need to learn to hear the artifacts in 80-128Kbps MP2 streams, as they are often fairly obvious (note that adoption of DAB+ in the UK is virtually nil, and there are no plans to migrate from DAB to DAB+). I think it's somewhat telling that the industry describe it as a "sound quality upgrade for _AM_ stations" (my emphasis, per http://www.ukdigitalradio.com/advice/thebasics/).
Will require two things, a shift in vehicle insurance costs.
And the costs for personal insurance and fuel to be a barrier swaying public interest.
There will still be a desire to drive, although falling out of popularity including stigma against "drivers" who less safe than the systems designed to protect passengers, but are willing to pay for the pleasure.
I'm confused. Both my Samsung Galaxy Ace GT-S5830T (January 2011) and Galaxy Ace 3 GT-S7275Y (June 2013) phones came with an app called "FM Radio" that works. They cost me $100 on sale. Why don't the more expensive ones have that feature?
The radio is built into most chips, even on feature phones. They are generally blocked, or have been until recently, mainly because of politics--using an FM receiver means you might use less bandwidth, which means less revenue for carriers. I have a couple of feature phones built for the Russian market that have FM enabled. I think most non-US phones actually have working FM receivers, but I am not certain of that.
116 comments
[ 2.7 ms ] story [ 130 ms ] threadDisclaimer: My hometown NPR affiliate was happy to apply, and now I listen to NPR on my occasional commute ~1000 miles away from my hometown station.
HAM operators have been using that since the 80's (maybe earlier?), broadcasting data, pictures (i.e. SSTV) or text (i.e. hellscreiber)
In some cars i can see display of the song name.
It's also possible to turn a raspberry pi into an FM transmitter. http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspb...
I still have a few lying around, though the data service has long since been turned off. It was low-bandwidth, but suitable for stock prices, weather, and incoming-only text messages via (IIRC) MSN Messenger. Cell phones have since replaced the functionality, but I loved mine at the time.
In the mid-90's I had a TV set-top box that gathered TV guide information over an FM data subcarrier. The company went out of business.
These days, data over broadcast is done on TV channels instead of FM because the bandwidth is larger. There's one of these operating on channel 20ish in Houston. I have no idea what data it's broadcasting.
Edit: http://nextradioapp.com/supported-devices/
[1] AFAIK in that scenario nextRadio falls back on streaming over the Internet, but we are not talking about that.
I guess I just assume that radio is just for the elderly.
considering the number of billboards and other advertisements there is a big following in the general populace. many rating services would dispute that it is consumed only by the elderly.
Jokes aside, my girlfriend upgraded to a LG V30 specifically because I bought one and discovered it had an enabled FM tuner by accident.
My unwittingly inflammatory comment was justifiably (it turns out) downvoted as my assumption turns out to be quite incorrect.
I looked up some stats (just free ones) and indeed, radio listenership turns out to be quite high (mid 90% of age band) pretty uniformly across age bands (which Nielson calles "millenial" "Gen X" and "boomer"). This is not the case of TV, which has noticeably higher penetration in boomers compared to younger demographic groups. These are WAU numbers so some groups may spend a higher percentage of time listening, but I couldn't find that data.
I am quite surprised to learn this.
https://www.marketingcharts.com/demographics-and-audiences/h...
https://www.marketingcharts.com/demographics-and-audiences/m...
Regardless of local radio choice, some people just aren't radio fans. If you are into EDM, for example, you probably won't find satisfaction in radio.
Another factor is how much friction there is in your particular car and car stereo for hooking up your smartphone. Not all cars have Bluetooth and those that do may not have it for audio (voice calls only). Finally even if your car has an aux input it may not be in a convenient place. For short trips you may not want to spend the overhead hooking up your phone each time.
So there are many factors that go into whether an individual is a "radio person" besides age.
It's not difficult to imagine that in any kind of emergency scenario internet-based broadcast systems will collapse. And maybe it's just me, but I always found broadcast to be pretty reliable (or at least consistently unreliable in ways I could predict) - online broadcasts have a tendency to fail/buffer/etc. at totally random intervals.
They do for the number of listeners. They don't scale at all for the number of broadcasters.
Technologically effortless dissemination of content from a central source, scaling to infinite receivers with no congestion and no loss of quality. The production of the content itself need not be vertically integrated; individual programs and segments are licensed and syndicated from third-parties.
Airwave broadcast has a natural place in the world, ideally by playing popular content that's always in demand. In our rush to go point-to-point, full-duplex, and on-demand, with both cabling and wireless, we have occasionally reimplemented services that are one-to-many simplex on top of lower layers that aren't made for that, whereas airwave broadcast has always fulfilled the same usecase with a different set of tradeoffs.
It's great for emergency communication, though.
[1] https://en.wikipedia.org/wiki/Television_licence [2] https://en.wikipedia.org/wiki/Private_copying_levy
I know that BBC is financed (partly?) by the TV tax in UK. But BBC is state-run; private companies have harder time.
That doesn't mean we need to stick with 1930s-era broadcast standards indefinitely.
We could also try to fix/enable multicasting, if we wanted internet broadcasts to scale a hundred times as well, but nobody seems to think it's worth the trouble.
In theory, the newer HD Radio scheme can provide equivalent or better quality even with marginal signals, but most broadcasters choose to continue regular FM simulcast and subdivide the remaining digital bandwidth across multiple virtual channels. This results in audible compression artifacts on most stations.
All told, I generally prefer analog FM to FM HD Radio - though I also listen to AM extensively - and I like how it sounds on a receiver with more than communications grade bandwidth - AM can push upwards of 10 khz - before 1982, it was not uncommon to find stations who ran closer to 15khz though - I've heard test recordings that just sound fantastic.
Or he's thinking about 1989 when the FCC actually limited AM bandwidth to 20kHz (10kHz audio).
[1]: https://en.wikipedia.org/wiki/C-QUAM
The FCC has not approved all-digital modes yet. Further, we cannot control the bitrate of the "main" digital simulcast. We _can_ control the sub-channels, but it doesn't matter how much bandwidth you throw at it, the HDC codec (which is a bastardized form of HE-AAC) always sounds like garbage. This is partially owing to the codec, but also to the fact that we only have 96kbit/s in total to allocate to all sub-channels.
Seems to me that even with the best codec there's going to be loss going from 1,411 kb/s to 96 kb/s.
So, HD Radio cannot achieve CD quality.
The analog "Accuphase" T-101 FM tuner gives 70 dB SNR, guaranteed. http://www.accuphase.com/cat/e-202en.pdf
That's equivalent to about 12 bits dynamic range, so already we see that analog FM is not as good as CD. If we take also the fact that the highest frequency is 15 kHz on analog FM, let's set the sample rate at (wave hands) 32 k sample/sec; so the 'equivalent' best-case uncompressed digital rate that's equivalent to the best analog FM is 2 x 32000 x 12 bit/sample = 768 kb/s. Given that when you add in that stereo pilot at 19 kHz and then do the L-R and L+R de-muxing thing in analog, you lose more dBs in SNR, wave hands and say the 'true' non-compressed equivalent of analog FM is around 500 kb/s. AAC gets 50% +/- 10% compression, so we're down to 250 kb/s.
So, it's hard to see how HD Radio can claim it is 'as good as' old-fashioned analog FM.
Everything around it is "High Def", "now broadcasting in High Def..."
HD Radio isn't High Definition radio, it's Hybrid Digital Radio, effectively simulcasting a digital and an analog signal.
However, this development does segregate the most useful set of government-run emergency functionality away from ordinary consumer devices and into a special product category.
Guessing that historically the need for weather broadcasts was from marine navigation it would make sense that the weather forecast have stayed on these frequencies.
Or, only five years ago, for me living in downtown Manhattan (when Hurricane Sandy hit). The next morning, all cell service was completely offline (in addition to us having no power).
[1] http://www.arrl.org/news/radio-amateurs-provide-communicatio...
Radio broadcast does scale "infinitely" in terms of the number of possible "clients" connected to the "server". It has no limits to the number of possible "connections" - because, of course, it's actually connectionless.
It does suffer from severe bandwidth limitations. For emergency communications this is not a problem.
FM (or anything above 30 MHz) also has very limited range - line of sight more or less. Frequencies below 30 MHz could and do occasionally reach the antipodes.
Also keep in mind there's a network of radio operators that is everywhere, and we are prepared to intervene in case of massive telecom collapse - the HAM radio operators. Emergency messaging should continue to function, at least for a while, even in the context of massive catastrophes.
In fact, you could cobble up a radio that does not need batteries.
(1) - http://www.buildcircuit.com/how-to-make-a-batteryless-crysta...
Do you live anywhere that gets regular tropical storms? Broadcast towers are lightning magnets and they regularly go out, usually not for long but I've seen them be down overnight more than once. They also used to degrade a fair bit in electrical storms in the pre digital TV age. It wasn't that long ago that a neighbor mowing the lawn meant that the TV signal would be awful/out.
What we need is for our internet and power systems to be more distributed.
I see the older technologies as solid foundation for robust networks. Most of these old systems are behind in terms of implementation technology but the foundations of these technologies are very strong. I believe that by integrating the robustness of older technologies with newer systems you can get the befits of new systems and technology but keep the robustness and stability of older systems.
What series of events lead to FM capable hardware being incidentally included, but disabled in modern smartphones?
Mainstream media loves the word "chip" and uses it in any context they like.
A single chip can do multiple things (WiFi, Bluetooth, FM, etc). For the chip manufacturer, it's simpler and cheaper to provide a single version of the chip with everything, and let the device manufacturer simply disable the unused parts, than to provide several different versions of the chip, some with FM and some without FM.
That is, the phone manufacturer decides "I want Bluetooth and WiFi", and the chip they chose for that happened to also have FM. Since they won't use the FM part of the chip, they don't even have to connect the "FM antenna input" pin, saving the space on the board that would be used for the corresponding trace(s) and passive components (which they also don't have to install, reducing the costs).
Although having a Phone + proper I/Q SDR in one package would be pretty darn awesome though.
FM demodulators can't really demodulate AM signals. AM demodulation can demodulate FM by tuning a bit off the carrier frequency thanks to the fall-off of the filters but the quality isn't great.
By "isn't great" you mean, "I might be able to understand something with a tailwind, downhill" - right? :-P
The mode of operation for an AM radio listening to FM is akin to a slope detector.
[0] Personally I find FM preferable to HE-AAC, but it's just a different set of trade-offs, not necessarily better.
This all doesn’t change the fact that DAB+ uses the spectrum much more effectively. Of course, on low bitrates you can learn to hear the artifacts. Just as you can hear the distortions in FM. But you need less spectrum for a stream where you can’t hear the artifacts.
There isn’t some big conspiracy selling you digital radio, it’s just better.
My impression is a simple radio set is now about 4 times what it was before DAB, not sure where that fits in ...
An FM station uses some specified amount of spectrum and the government can sell that space for the amount of money one station is willing to pay. If you can change the system so more stations fit in the same amount of spectrum, they get the amount all these stations together are willing to pay. So they get more money with DAB. And it looks modern with more features to boot!
You can just solder an FM radio yourself from generic components and some wire while a DAB radio requires a processor, which is obviously going to be more expensive. I think all of the patents expired though so I don't think someone is becoming rich by licensing the technology. At least the patents on the audio codec have expired.
The point there is that initially it was hard to sell DAB in the UK because FM is pretty good, and very cheap. So people could only be convinced to buy DAB because the channel width allowed much higher quality. My recollection is that once momentum built on purchases then channel width was changed, making the perceived quality similar .. but now radio sets cost a lot more. The additional features don't really do anything for me, the only effective change for me is that it takes much longer to tune to a new station.
The cost of the DAB processor can't really be so much, the quality increase allowed prices to be anchored high; cheapest DAB is still 4x FM price, I can't see that being all tech costs.
You can buy DAB (and DAB+) receivers directly from China if you want. They’re still more expensive than FM receivers but then you can be sure there is no shady conspiracy in your own country profiteering.
In fact, if you want you can buy a SDR device which gives you the data an antenna would receive, and do the rest in software (both FM and DAB decoding).
My point wasn't really that FM is better per se though (it clearly isn't, as even high bitrate stereo streams would be a better use of the spectrum), rather that I don't see it as "clinging to obsolete technology" on the user side. It is just, IMO, the better user experience as it currently stands in the UK - I don't think you need to learn to hear the artifacts in 80-128Kbps MP2 streams, as they are often fairly obvious (note that adoption of DAB+ in the UK is virtually nil, and there are no plans to migrate from DAB to DAB+). I think it's somewhat telling that the industry describe it as a "sound quality upgrade for _AM_ stations" (my emphasis, per http://www.ukdigitalradio.com/advice/thebasics/).
I can easily forsee within my lifetime the banning of traditional human road drivers.
And the costs for personal insurance and fuel to be a barrier swaying public interest.
There will still be a desire to drive, although falling out of popularity including stigma against "drivers" who less safe than the systems designed to protect passengers, but are willing to pay for the pleasure.
One just needs to make the right options and give money to OEMs that favour us.
"Your phone has an fm chip. So why can't you listen to the radio?" https://www.wired.com/2016/07/phones-fm-chips-radio-smartpho...