Sending Data In Bursts of SMS Messages 181
An anonymous reader writes "Canadian carrier Rogers has been experiencing some extreme loads of late, as researchers at the University of Waterloo investigate the potential for sending data spread across bursts of hundreds of text messages. They sent around 80,000 messages in the course of a project testing a new protocol able to cram 32KB into 250 messages sent from a BlackBerry, reaching a rate of 20 bytes per second. The group thinks its protocol could be useful in rural areas of the developing world where text messaging is the only affordable, reliable link."
Oops (Score:5, Funny)
What do you mean? (Score:4, Funny)
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Yeh, I really don't get it myself.
Quick calculations, your average 1hr TV show would end up costing you around $500 000 if you didn't have a cap.
Why even research this technology? It's not like we weren't aware that SMS was capable of this, it is text after all. I see nothing of value in this research, I'm sure that someone with a bit of coding skills and access to a mobile could do this without much hassle.
I'm usually the first to say to people on slashdot that research is worthwhile, but this is really st
Re:Oops (Score:5, Informative)
It's completely idiotic. There are two ways in which SMS is implemented:
On older GSM networks, it's part of the control channel. There is some unused space in one of the control packets. It was a scarce resource and flooding it could actually prevent anyone making calls (there was a fairly simple DoS attack possible). This was the original reason for SMS being expensive - the network couldn't handle much SMS traffic.
On newer networks (GPRS and newer), it's just treated as data. It's wrapped in a packet header indicating that it's SMS and then sent in the same way as IP data.
In any area where you just have GSM, there isn't enough bandwidth available for SMS for this to be useful. In an area where you have GPRS or anything newer then SMS is just a way of adding a huge packet header to your IP packets. It's transmitted the same way as IP data, you're just using the available bandwidth less efficiently.
Re:Oops (Score:4, Insightful)
In these circumstances CSD is probably available too at a heady (in comparison) 9.6kbps.
OT (Score:2)
I'm not religious but some can be learnt, for good or ill, from the various faiths of the world.
Anyway, their is seriously only one entity -- Reality -- over which we and everything else are more or less a distribution of matter and energy (or who knows what more).
You probably think that's all poppycock, but I wondered...
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You are assuming this is to solve a technical issue, that they are trying to efficiently use resources.
However, if you consider that they are trying to solve an issue with how phone carriers charge for data usage, you will see where this might provide value.
You are correct about text messages on modern networks being just data; however, providers do not charge the same for this data usage.
In some places, they charge much more for text messages than data usage (here in the U.S. is an example of one of those
so now will they bill $1 per txt each way? (Score:3, Insightful)
so now will they bill $1 per txt each way?
Re:so now will they bill $1 per txt each way? (Score:5, Insightful)
In emerging economies SMS is dirt cheap. In Philippines: $0.50, 24 hour all you can eat (on-net only) deals are common.
This is a bad idea for a large number of technical reasons : very inefficient use of the GSM channel because of all of the excessive handshaking and control just to transmit a 140 byte data packet for one (sms is 7bit per character. 160 chars = 140bytes) and rubbish throughput & latency. But economically it makes sense. Also accessibility of 2G mobile phones is very high in such environments, 3G wireless or twisted pair copper not so much. Depends where you deploy it, for what eventual purpose and actual real bandwidth requirements.
Re:so now will they bill $1 per txt each way? (Score:4, Informative)
Obviously the poor people in the sticks might not have fancy 3G stuff; but why would you attempt to shove data over SMS(aside from short message snippets from embedded devices, and suchlike applications), when GPRS already exists? All sorts of dirt cheap phones support being used as modems, without any special software, and, while it might well be more expensive now, for economically perverse reasons, SMS won't be cheaper for long if it becomes standard practice to do general-purpose data transfer over SMS on a large scale...
Re:so now will they bill $1 per txt each way? (Score:5, Insightful)
Maybe they should just make normal data transfer reasonably priced instead of jacking up SMS pricing...
My 300 baud modem shivered... (Score:5, Funny)
...and got to feel the thrill of competition again.
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Yeah, how backwards is this text method? Put the phone on one of those old modems al la Wargames [imdb.com] and send data like it's 1989!
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aka an Acoustic Coupler [wikipedia.org].
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You must be young. I remember using acoustical modems back in 1974 and they weren't that new back then. The reason we used them was because it was illegal to connect to the copper on a POTS line back then and Ma Bell's solution was VERY expensive and very non-portable.
Re:My 300 baud modem shivered... (Score:5, Interesting)
I remember using acoustical modems back in 1974 and they weren't that new back then
I've actually considered seeing if I could get a v.32 in-software stack to communicate over the bluetooth headset/microphone protocol so I could do very basic data networking over a cell phone without a data plan. Like ssh.
I came to my senses, but I kinda still want to try it anyway.
Re:My 300 baud modem shivered... (Score:5, Interesting)
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the rapid phase transitions used by quadrature amplitude modulation
ah, good point. I wonder who's done research into modulations that can survive better. Maybe some FEC in the data stream (if it could exceed 300bps, say)?
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At 110/300 Baud, you did a lot of mental pre-processing of your requests.
Listing out hundreds of lines (unless you were getting a listing) was
not the way to go.
Vi runs OK at 1200 baud on a 24X80 display, If you know that you're
looking for.
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I don't think I've ever had a cell phone (except my most recent, which is a Motorola Droid) which was unable to do that by itself.
The process is simple: Connect it to a PC with an appropriate cable (and the appropriate drivers, if applicable), start issuing AT commands, and go.
I used to dial a local ISP like this every now and then, and I've sent faxes with it back when that still mattered.
Billing was the same as a regular voice call, and data rates were pretty ugly compared to what we're used to these day
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The reason we used them was because it was illegal to connect to the copper on a POTS line back
That became legal in 1968 with the Carterphone ruling. You probably had an acoustic coupler in 1974, because the modular jack wasn't introduced until 1976.
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We did have the 4 prong plug. IIRC the DataSet 300 used an RJ21 25 pair connector and came with a modified 5 line keyset.
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...or just buy the data cable (or USB cable, if your phone uses USB) and download the modem drivers.
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>>>send data like it's 1989!
A wee bit off laddy. 20 bytes/second == about 200 bits per second, which is ancient technology. More like 1979 - break out the disco and the polyester pants!
I'd sooner use a 56k dialup modem, even if the noise on the lines only let me do 24,000 bits per second (as has happened in some low-budget motels). Or a wireless modem. It's a lot faster than the text 0.2k SMS messaging method.
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ok
you bring your modems and I'll use this.
we'll go to Africa, somewhere random, like Congo or Darfur. We'll both use our preferred method to call for help. Survivor is the winner.
-nB
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Well, GSM codecs will wreak havoc on these modems, as GSM voice channels are not simply bandlimited like POTS, but they use an artificial acoustic model of human voice tract.
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So the clear answer is voice-over-ip-over-sms
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>>>less than 5 watts of radio power on CW
On what? (googles). Oh continuous wave. Using morse code I presume. Like in the old days of the Titanic, before humans learned to transmit audio. There is one place CW can't reach - under the ocean. Which is why submarines carry ELF receivers that can penetrate a few hundred feet before attenuating to nothing. Since the frequency is so low, they can only send a few characters per minute.
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Unusable and expensive (Score:3, Insightful)
You pay: Monthly for a cellular package with unlimited texting
You get: 20 baud
Re:Unusable and expensive (Score:4, Informative)
You pay: Monthly for a cellular package with unlimited texting
You get: 20 baud
Actually, (ignoring the fact that "baud" is the incorrect term) that would be either 160 or 200 baud, depending on whether you include error correction bits in the calculation. :)
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Whoops, yeah, slipped my mind when posting. 1 byte per second = 8 baud (bits per second).
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In the case of the SMS (short message service) one symbol has 7 bits, so, for 1 message per second you get: 160 baud; 160*7=1120bps; 1120/8=140Bps.
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>>>You're still wrong
You're not correct either. I don't know what modulation SMS uses, but let's just assume 4 bits per symbol to keep the math simple. So 20 bytes == about 200 bits / 4 bits per symbol == 50 symbols sent every second. i.e. 50 Baud.
For comparison a 300 bps modem uses 300 baud, a 2400 bps modem is 600 baud, a 28k modem is 3200 baud, and a 56k modem is 8000 baud in digital mode and 3429 baud in analog mode (33.6k).
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You pay: Monthly for a cellular package with unlimited texting You get: 20 baud
What's so new about this? Seems that's what AT&T gives most iPhone users anyway...
Big money, no wammies (Score:5, Funny)
How truely AWFUL... (Score:5, Insightful)
Text messages are one of the most awful forms of data on the cell network. On a 3G type network, they are just data, so hey, if you can do TXT on 3G, just do data. So what?
But on older networks, such as the proposed usage, they take up CONTROL channel space, and too much SMS is a DOS attack!
See Exploiting Open Functionality in SMS-Capable Cellular Networks [smsanalysis.org]:
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Beyond that, as a student currently at Waterloo, I'm fairly certain that this PhD student, some prof, or some other smart ass student (there are a LOT
Huh? (Score:3, Insightful)
They couldn't have built their own network and emulated phones to test this protocol, they had to go live with their phone provider? Some University. I bet MIT is laughing out loud.
Also, how's the coverage out there? [worldbank.org]
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Or they could set up their own GSM network [wikipedia.org]. Burning Man did it.
Calling smart people (Score:4, Insightful)
Anyone care to describe why they couldn't just use airtime minutes and an acoustically coupled modem? Looking it up on Wiki, in general they were able to transfer 300 bps instead of 160.
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Or just use a phone that has a modem, most of new ones do, IIRC you can get a few kilobits with it.
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This is for rural places, maybe they didn't want to depend on recent phones. A ten year old phone can be connected using a serial cable and you can send SMS using AT commands.
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I thought most phones that could talk to a PC could at least do an old fassioned GSM data call (which is very slow by modern standards but still fast comared to this).
A friend of mine has an old HP dos based PDA which has a socket in the back for a nokia 2110 and we managed to get it to dial up an ISP and access email.
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The Nokia 3310 (most common phone here in Portugal shortly after it was released) didn't have a modem interface - I know because I've tried.
Many old phones didn't, it depended on the price, afaik.
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What they're doing is just an awkward, slow and very limited way of what WAP was doing over a decade ago, also via channels used for SMS.
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I don't know the specifics but I'd start by looking at whether the digitisation, filtering and encoding/compression of the acoustic signal by the mobile phone system preserves the frequency, amplitude and phase information used by an acoustic modem. (I think 300 baud modems made use of frequency shifting only.)
Then you could try to design a physical coupler that will interface with the utterly non-standard collection of shapes and sizes present in mobile phone handsets and still exclude sufficient external
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Totally a waste of time. UUCP over Bluetooth works just fine. Supports arbitrary packet sizes, checkpoint/restart, low overhead, etc. In short, UUCP is designed for efficient data transfer over a low speed unreliable network like the cell phone network, unlike SMS.
SMS over a cell phone is probably one of the worst ideas anyone has ever come up with. Are we sure this wasn't a late April Fool's joke?
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While the frequency or amplitude will not be reproduced perfectly, you can assume that it won't change by much, for example if you sent 1kHz it probably won't arrive as 2kHz and 2kHz won't become 1kHz. Also, if you send it vs sending nothing it probably won't change that much either, so it's just a matter of figuring out how fast can you go until the signal becomes too distorted to use. Analog modems seem to be pretty capable of determining the speed at which a reliable connection can be made (and the line
Hope they had the unlimited plan (Score:2)
Let's see, at 20 cents a message that test only cost them $16,000 worth of messages! And they managed to move all of 10MB... If my math is right. They should just spring for the pay-as-you-go data plan at the bargain basement cost of $1.99 a MB, they would cut the "cost" down to 20 bucks!
Are rural, developing countries really selling unlimited txting plans for affordable rates? If so, why is it that we let carriers in the developed world get away with robbing us blind?
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Because the FCC is run by a combination of ineffective pussies and telecom industry insiders. The people in charge support the cartel pricing!
Wrong solution (Score:4, Insightful)
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Not even a real challenge (Score:2)
Not even a real challenge.
Take the available character set; use that as your base (like base64/base92 to send binary data as clear text); toss in forward error correction and a you could do TCP/IP over SMS if you wanted to.
This is Tailor-Made for... (Score:5, Funny)
... next year's April 1 RFC -- "IP over SMS Carrier".
yEnc? (Score:2)
Yawn... (Score:2)
So they essentially rediscovered WAP? Great work...
Also:
http://conversations.nokia.com/2008/11/05/nokia-life-tools-opens-side-door-to-the-internet-in-rural-india-and-beyond-via-sms/ [nokia.com]
http://conversations.nokia.com/2009/11/19/nokia-life-tools-a-life-changing-service/ [nokia.com]
http://conversations.nokia.com/2010/05/07/ovi-life-tools-lands-in-china/ [nokia.com]
(and related on above pages)
New Protocol Must be Stopped (Score:2)
Speaking on behalf of the interests of the RIAA & MPAA, it is clear to us that this "new" protocol will be used only for the piracy of copyrighted materials. Sure, downloading a DVD using this protocol might seem like harmless way to pass the summer months, but the damage to our industry is incalculable. And although we are headed for another record year, we calculate that this has clearly cost us over $10 billion dollars in losses and must be stopped.
Sincerely,
Jack Valenti
(Yes, I know I'm dead. Want to
Neato! (Score:5, Funny)
This is good news (everyone), by the time you have torrented your bluray rip, it will be out of copyright.
Or not.
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At 601.90 MB per gregorian year, that's not so far off...
Worst. Transport. Ever. (Score:3, Insightful)
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Bittorrent, in effect, deals with rather similar issues(since it is typically used to transfer files so large that they make common home internet connections feel like ghastly retro shit) reasonably effectively. It may take a while; but sufficient patience will get you past any number of corrupted blocks, dropped packets, hosts that disconnect, etc.
Any sort of latency-sensitive application will be ri
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Actually, it was an April Fools story.
They just used the described means to submit it, and it just now finished.
Bit of fun! (Score:2)
Sometimes it's not about being a good idea. Sometimes it's just about seeing if it's possible. Lots of things are like this... like using a fishing pole for flying your kite, or building a makeshift jet engine out of a turbocharger. It's not necessarily practical, but it can be a bit of fun?
What about GPRS? (Score:3, Insightful)
> The group think their protocol could be useful in rural areas of the developing world where text messaging is the only affordable, reliable link
It's a fun little project, but in what circumstance would this *ever* be the best use of a mobile network? If you've got the signal for SMS then you should be able to also at least use a voice call to transmit data (not sure what the max would be, 14.4kbps? 9.6kbps?) if not full GPRS (56-114 kbps). 160bps is not very impressive
Not too impressive... (Score:2)
160 character limited frame
Just using "a-zA-Z0-9" gives us 62 characters - throw in a few punctuation for 64 which we can use for base64/MIME encoding. Giving us 6 bits to use per character(byte)
Assuming an 8-bit byte in original data, 33% larger
160*6/8 = 120 bytes, 8 bits each in each SMS
250 messages of 120 uncompressed bytes each is 30 KB or 240 Kb
If I remember SMS already has sequencing in its protocol so you shouldn't have to sacrifice your own bits for that. SMS has
Yak Protocol (Score:5, Funny)
Maximum carrying load of a Yak: 70kg
Weight of a 32GB micro sd card. 0.5g
Having your own 3rd world petabit network: priceless.
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This like WiFi degrades significantly with distance..
Doing some rough math.. A Yak that can go 5km/hour when fully loaded using your numbers can Transter about 25 Peta-bytes per second over 1 Meter... at 25 Meters your down to 1 Peta-byte/s.. This is Payload Only.. It does not include packing or transferring information on and off the SD's. The Latency would be extremely high... I am gussing that the Protocols that have been developed for data transmissions to the Moon might still not have enough forgivenes
Strained by just 80K messages ? (Score:2)
A single low-end jury-rigged SMSC is well capable of over 5K TPS. 80K messages won't even break sweat on any telco's network.
That said, it's a pretty useless medium of communicating any significant amount of data. GPRS or even WAP are much more efficient and capable of dialup speeds. And hey, developing worlds have much better telecom networks than these kind of "for developing worlds" stories give credit for. At least in India, SMS is essentially free (costing less than $0.0001 (yes not a typo!) per SMS in
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That said, it's a pretty useless medium of communicating any significant amount of data. GPRS or even WAP are much more efficient
Hell even old fassioned GSM dialup is way faster and more efficiant.
While (Score:2)
I'm not one to stand in the way of research - but 20 bytes per second? I'm sure they should be able to design some sort of adapter for 300bps modems and use those over the cell phones as voice signals instead, and have a substantial gain in transmission speed...
Now considering that most cell phone carriers world-wide actually charge a fee nowadays for SMS messages, ESPECIALLY in underdeveloped countries, sending a whole lot of SMS messages is probably not going to be more economically viable than hiring Jos
Old hat - it was a late-1980s experiment (Score:2)
About 25 years ago, TCP/IP experimenters on BITNET were sending IP packets as RSCS messages, which were limited to the same scale of data as SMS messages. It was slow as hell, but just like the SMS network, the RSCS network prioritized these short messages above other traffic.
This is the same network facility that inspired the IBM Reseach folks who moved to AOL to create the buddy list and everything that arose from there.
Funny how things come around over and over in the computing world - it's like nobody
permabanned? (Score:2)
This is ridiculous... (Score:2)
OK, I just don't get something.
GPRS would be a logical choice for data transmission on a barebones GSM network. Assuming that those "rural" providers absolutely don't offer affordable GPRS, you can use circuit-switched connections and just send our own data instead of GSM-compressed voice. IIRC, most random bit patterns are valid GSM packets (in all variants of compression), so that shouldn't be a problem. I presume one could even encode the data such that it could survive decoding, as long as you have a di
Affordable? (Score:3, Insightful)
Reliable? (Score:2)
Perversely ... It makes sense (Score:2)
It is totally insane, but given the expense of having a data plan and the usefulness of even tiny amounts of data it actually makes some amount of sense to contemplate routing data over the SMS channel. It's no use for anything real time, but if you are doing things like constantly reporting data (latitude, etc.), sending or downloading things in the background (eg: email) then it might be possible to have no data connection at all and still get significant use out of certain types of connectivity.
Also, wh
..text messaging is the only affordable.. (Score:2)
You are kidding, right?
ouch... (Score:2)
Very old hat trick - This existed before (Score:3, Interesting)
Remember WAP?
The WAP service had three posible bearers, GPRS (the best for it), a circuit switched dedicated 9600bps link (later upgraded to 14.4kbps, or even 56kbps), or SMS.
Well yes, in WAP times there was a full spec on how to transport data on lowly SMS. As other posters have said, using SMS as a bearer for other data services is painfull, slow, ackward, and not such a good idea.
Ah, this brings memories!
http://www.m-indya.com/wap/wap_bearers.htm
20 bytes per second (Score:2)
Hey that's great. If the dumb kids at Waterloo are excited about 20 bytes / sec, I have this here bleeding-edge V32 modem that'll do over one thousand bytes per second over a plain old telephone line. You can't imagine all the fun I had downloading JPGs on this thing back in the 80's^H^H^H^Hfuture telecommunications lab. Mmmm.. V32, that's like four mustang engines on a modem.
Re:Why bother? (Score:4, Funny)
If it's anything else, drive to Starbucks for free wifi.
Because Starbucks is so commonplace in the "rural areas of the developing world."
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>>>Beats transfering 15mb in 14 hours
I agree. SMS data transmission is blase'. With my superduper speedy 56k modem (upgraded from the old 28k model) I can download an entire episode of Stargate in just over 3 hours! Amazing.
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A Steganography of sorts, hiding data in plain sight. I can see groups using this to communicate covertly without attracting attention.
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Hundreds or thousands of "gibberish" SMS, in series, will avoid attracting attention?
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I was going to bring that up. I frequently see out of order messages on quite a few providers, in various locations (major cities around the US and Canada). I had a server monitoring the rest of my servers. It would send timestamped messages when there was a problem status. In the event of a big problem, it would send a whole flurry of them. When your pager goes nuts, you know it's something major that needs your undivided attention immediately. Most would arrive on time. Sometimes mess
Re:Why??..... (Score:5, Interesting)
I think this is more a case of "Look mama, IP over SMS! With No hands!" than a solution for any real world problem.
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They're trying to compete with the existing RFC1149 implementation [slashdot.org].
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But still, isn't a lot of research done for the very reason "because I can"? It's even repeated ad nauseaum in
I read a lot of posts saying this is the worst way to transmit data, the most idiotic idea ever, etc etc....ok, so what if it is? They are doing it "because they can". How many useful things have come out from research done for this very same reason? and even if nothing come
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Because the carriers' pricing strategies are fucked up in such a way as to make SMS data orders of magnitude cheaper than regular data, that's why.
That'll end quick once the carriers catch on to this scheme, of course.
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Something like this, and properly integrated, was on the market over a decade ago. Many phones are still compatible. It's called WAP.
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Yup, parent is right. SMS message delivery is not guaranteed as per GSM specifications. The network is allowed to drop them on the floor if the recipient device is not reachable, the network is overloaded, or whatever.
So this is a pretty stupid idea.
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the largest drawback to this scheme is the cellcos. Everything is a major cash cow for them.
FTFY. YW!