Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Sending Data In Bursts of SMS Messages

timothy posted more than 3 years ago | from the out-of-band-and-back-again dept.

Cellphones 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."

cancel ×
This is a preview of your comment

No Comment Title Entered

Anonymous Coward 1 minute ago

No Comment Entered


Cram it! (1, Funny)

Anonymous Coward | more than 3 years ago | (#32682820)

Don't give AT&T any ideas, you jackasses!

fst (-1)

Anonymous Coward | more than 3 years ago | (#32682826)

sometimes i like to spank it with the bathroom door open.

so now will they bill $1 per txt each way? (2, Insightful)

Joe The Dragon (967727) | more than 3 years ago | (#32682858)

so now will they bill $1 per txt each way?

Re:so now will they bill $1 per txt each way? (4, Insightful)

geekpowa (916089) | more than 3 years ago | (#32683140)

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? (3, Informative)

fuzzyfuzzyfungus (1223518) | more than 3 years ago | (#32684200)

It's an especially terrible plan, if widely adopted, because SMS comes out of the control channel. If you have enough SMS traffic flying around, the carrier will either have to start dropping it, or have plenty of available voice/data channel lying idle because they don't have enough control channel capacity to set up and tear down calls.

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? (1, Funny)

Anonymous Coward | more than 3 years ago | (#32683612)

so now will they bill $1 per txt each way?

Good. Maybe teenagers will start paying attention in school.

Now get off my lawn!

My Sprint service isn't reliable (1, Insightful)

Anonymous Coward | more than 3 years ago | (#32682866)

and I'm in a major US city. it sucks when it's commonplace to get text messages out of order. Sometimes I'll get one that was sent several hours earlier.

Re:My Sprint service isn't reliable (2, Interesting)

JWSmythe (446288) | more than 3 years ago | (#32683088)

    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 messages would show up out of order, or hours late. It's scary when you think the whole issue has been resolved, and then you get another "down" page an hour or so later. That's why we timestamped them, so we'd know if it was just late showing up.


Re:My Sprint service isn't reliable (1)

91degrees (207121) | more than 3 years ago | (#32683710)

Well, it's part of the spec that there's no guaranteed delivery time.

But the protocol should be able to deal with this. It's a well understood problem - TCP/IP needs to deal with out of order packet delivery. As far as I understand it you just need a sequence number.

My 300 baud modem shivered... (5, Funny)

Overzeetop (214511) | more than 3 years ago | (#32682870)

...and got to feel the thrill of competition again.

Re:My 300 baud modem shivered... (2, Insightful)

Anonymous Coward | more than 3 years ago | (#32683014)

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!

Re:My 300 baud modem shivered... (1)

MasterOfMagic (151058) | more than 3 years ago | (#32683150)

If you have enough signal for a voice call. My office is weird. I can't make a voice call, but I can text just fine.

There are plenty of situations where you have a radio signal strong enough and reliable enough for slow data but not for voice. Those are the kind of places that they're talking about.

There's a reason that you can get around the world with less than 5 watts of radio power on CW.

Re:My 300 baud modem shivered... (3, Funny)

Anonymous Coward | more than 3 years ago | (#32683352)

So the clear answer is voice-over-ip-over-sms

Re:My 300 baud modem shivered... (1)

commodore64_love (1445365) | more than 3 years ago | (#32684088)

>>>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.

Re:My 300 baud modem shivered... (1)

mirix (1649853) | more than 3 years ago | (#32684532)

It's not that they weren't capable of transmitting voice (AM), it that it needs way more power to get the same range as CW.

Re:My 300 baud modem shivered... (2, Informative)

Nethead (1563) | more than 3 years ago | (#32683156)

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... (4, Interesting)

bill_mcgonigle (4333) | more than 3 years ago | (#32684472)

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... (2, Insightful)

xaxa (988988) | more than 3 years ago | (#32683318)

...or just buy the data cable (or USB cable, if your phone uses USB) and download the modem drivers.

Re:My 300 baud modem shivered... (1)

commodore64_love (1445365) | more than 3 years ago | (#32683408)

>>>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.

Why bother? (0, Offtopic)

qoncept (599709) | more than 3 years ago | (#32682892)

20 bytes a second? As in an SMS every 8 seconds? I can't think of a single situation I would consider this worthwhile. If it's a word document, why not send the plain text? If it's a JPEG, call the person and describe what you see. If it's anything else, drive to Starbucks for free wifi.

Sometimes when I get home from work my wife will be watching Judge Judy. When she tells me "there's nothing else on," it seems the best solution would be to turn the TV off.

Re:Why bother? (4, Funny)

EricJ2190 (1016652) | more than 3 years ago | (#32683084)

If it's anything else, drive to Starbucks for free wifi.

Because Starbucks is so commonplace in the "rural areas of the developing world."

Re:Why bother? (1)

qoncept (599709) | more than 3 years ago | (#32683428)

Fine. Walk. Beats transfering 15mb in 14 hours.

Re:Why bother? (1)

commodore64_love (1445365) | more than 3 years ago | (#32684182)

>>>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.

Re:Why bother? (1)

e2d2 (115622) | more than 3 years ago | (#32683470)

A Steganography of sorts, hiding data in plain sight. I can see groups using this to communicate covertly without attracting attention.

Re:Why bother? (1)

sznupi (719324) | more than 3 years ago | (#32683614)

Hundreds or thousands of "gibberish" SMS, in series, will avoid attracting attention?

Re:Why bother? (1)

Lehk228 (705449) | more than 3 years ago | (#32683628)

if you are trying not attract attention, sending out a deluge of data encoding SMS messages is not the way to do it.

Re:Why bother? (0)

Anonymous Coward | more than 3 years ago | (#32683502)

Remote sensor networks publishing data to the cloud, or sending commands to those remote sensor networks. The internet is used for more than porn, and SMS messaging is used for more than LOLing.

Re:Why bother? (0)

Anonymous Coward | more than 3 years ago | (#32683780)

Specifically, I'm thinking of the web cam I use to peep at your mom.

Re:Why bother? (1)

bjartur (1705192) | more than 3 years ago | (#32684150)

Almost all word documents should be sent in plain text anyway (and most of the rest should probably be in RTF).

And try to at least read the four line summary when the subject doesn't make sense to you, even on /.

Never gonna work (0)

Anonymous Coward | more than 3 years ago | (#32682894)

If I was a cell phone company I would throttle anybody that tried something like this. Like one SMS per 5 seconds or even longer.

The SMS system isn't designed for 10,000 people all sending tens of thousands of messages per hour or whatever.

Re:Never gonna work (1)

bjartur (1705192) | more than 3 years ago | (#32684012)

GSM Short Messages are embedded in control messages that will be sent anyway, no? GSM phones simply queue messages for delivery and send them in the next heartbeat, and while that's quite short lag on average for "normal" uses it will always be the max (around 8 secs. I think) if you're packeting larger data streams to short messages.

Bandwidth skyrocketing due to massive overuse of the system the same way Bittorrent seems to have to done to DSL is another issue (though Short Messager will be much less of a problem for obvious reasons).

Unusable and expensive (2, Insightful)

clone53421 (1310749) | more than 3 years ago | (#32682902)

You pay: Monthly for a cellular package with unlimited texting
You get: 20 baud

Re:Unusable and expensive (3, Informative)

schon (31600) | more than 3 years ago | (#32682984)

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. :)

Re:Unusable and expensive (1)

clone53421 (1310749) | more than 3 years ago | (#32683346)

Whoops, yeah, slipped my mind when posting. 1 byte per second = 8 baud (bits per second).

Re:Unusable and expensive (1)

dziban303 (540095) | more than 3 years ago | (#32683484)

You're still wrong. Baud != bits per second. Baud [wikipedia.org] = symbol rate. Why do people (people on /. no less) make this mistake?

Re:Unusable and expensive (1)

conspirator57 (1123519) | more than 3 years ago | (#32683662)

because most people on /. are CS or IT and don't know much about modulation schemes or the physical layer other than the recommended max cable lengths for Ethernet.

and also because the marketing idiots for modems back in the day did their fair share of confusing the situation. kinda like the disk drive people did, necessitating the language distinction between megabytes and mebibytes. how many people use megabyte (or its abbreviation MB) when they mean MiB? (or GB for GiB)

cut them some slack, jack.

Re:Unusable and expensive (1)

commodore64_love (1445365) | more than 3 years ago | (#32684342)

>>>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).

Re:Unusable and expensive (0)

Anonymous Coward | more than 3 years ago | (#32684120)

Almost there... 1 byte per second + 2 error correction bits = 10 baud.

Re:Unusable and expensive (0)

Anonymous Coward | more than 3 years ago | (#32684142)

Baud Bits per second. Please finish your research

Big money, no wammies (4, Funny)

Itninja (937614) | more than 3 years ago | (#32682904)

In a completely unrelated story, the University of Waterloo has an unexpected ~$16,000 shortfall this quarter.

How truely AWFUL... (4, Insightful)

nweaver (113078) | more than 3 years ago | (#32682914)

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]:

ABSTRACT: Cellular networks are a critical component of the economic and social infrastructures in which we live. In addition to voice services, these networks deliver alphanumeric text messages to the vast majority of wireless subscribers. To encourage the expansion of this new service, telecommunications companies offer connections between their networks and the Internet. The ramifications of such connections, however, have not been fully recognized. In this paper, we evaluate the security impact of the SMS interface on the availability of the cellular phone network. Specifically, we demonstrate the ability to deny voice service to cities the size of Washington D.C. and Manhattan with little more than a cable modem. Moreover, attacks targeting the entire United States are feasible with resources available to medium-sized zombie networks. This analysis begins with an exploration of the structure of cellular networks. We then characterize network behavior and explore a number of reconnaissance techniques aimed at effectively targeting attacks on these systems. We conclude by discussing countermeasures that mitigate or eliminate the threats introduced by these attacks.

Re:How truely AWFUL... (1)

icegreentea (974342) | more than 3 years ago | (#32683868)

The intended use of this is for once a day updates of information to locations with poor internet connectivity. These people weren't pulling in high data to begin with, and likely were sending even less. For example, if all you need to do is send crop prices, weather reports, etc that update once a day, then you can just push all that data once a day over SMS.

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 of those here) probably already considered the problem of congestion. And they probably worked out acceptable loads, or solutions, or w/e.

I've always wanted this (0)

Anonymous Coward | more than 3 years ago | (#32682936)

Being a massive cheapskate, I'm still behind the times and don't pay for data (yet), despite having a smart phone and having unlimited texts. I have to admit, I've wished something like this existed several times

Re:I've always wanted this (1)

sznupi (719324) | more than 3 years ago | (#32683320)

Something like this, and properly integrated, was on the market over a decade ago. Many phones are still compatible. It's called WAP.

Calling smart people (3, Insightful)

Applekid (993327) | more than 3 years ago | (#32682958)

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.

Re:Calling smart people (2, Insightful)

Pentium100 (1240090) | more than 3 years ago | (#32683078)

Or just use a phone that has a modem, most of new ones do, IIRC you can get a few kilobits with it.

Re:Calling smart people (1)

AvitarX (172628) | more than 3 years ago | (#32683276)

Most cell phones I've used don't duplex, this could be a problem?

I don't really know, as i don't know if modems duplexed.

Re:Calling smart people (0)

Anonymous Coward | more than 3 years ago | (#32683300)

Vocoders used on wireless networks are good (enough) for voice, but they would make a mess of the signals from an acoustically coupled modem. You could probably build something that compensated for that with fancy pulse shaping and error correction, but then the system is getting complicated ($). Also, this whole system is based on the idea of having unlimited text messaging plans, and although those might not actually exist in the sorts of places where this system is targeted, they have a better chance of existing than unlimited voice service.

Re:Calling smart people (2, Insightful)

sznupi (719324) | more than 3 years ago | (#32683370)

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.

Re:Calling smart people (1)

GumphMaster (772693) | more than 3 years ago | (#32684444)

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 noise to work reliably.

Hope they had the unlimited plan (1)

jeffmeden (135043) | more than 3 years ago | (#32682974)

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?

Re:Hope they had the unlimited plan (1)

mrchaotica (681592) | more than 3 years ago | (#32683296)

If so, why is it that we let carriers in the developed world get away with robbing us blind?

Because the FCC is run by a combination of ineffective pussies and telecom industry insiders. The people in charge support the cartel pricing!

Email over SMS (1, Informative)

Anonymous Coward | more than 3 years ago | (#32683002)

A company called Jamun (http://jaamun.in/) already offers a email over SMS service in India.

Wrong solution (3, Insightful)

maxrate (886773) | more than 3 years ago | (#32683010)

Not trying to troll, but this is the wrong 'solution' for so many reasons. If SMS's can make the connection, so can other forms of packet radio.

Re:Wrong solution (2, Insightful)

colinnwn (677715) | more than 3 years ago | (#32683630)

It's sub-optimal, but not necessarily the "wrong solution". Rather than setting up your own packet radio network, this allows you to piggyback on existing infrastructure for the cost of a mini-USB cable and unlimited txt plan. There may be some valid uses.

Re:Wrong solution (1)

aBaldrich (1692238) | more than 3 years ago | (#32683916)

I think it's the wrong solution but for another reason: they take the network for granted. In the country where I live there are places where you can travel 300 km and find 2 towns. Anyone living between those towns (native reservations, lonely settlers, etc) don't have an antenna anywhere nearby. I don't want to imagine the state of the cellphone network in the middle of Africa, but I suppose that a place with telephone connection is bound to have some kind of internet access.

Why??..... (1)

ThermalRunaway (1766412) | more than 3 years ago | (#32683026)

I don't get the point of this. If you have a cell connection to send SMS, you already have SOME form of data connection. Even on a typical 2G network you can get 60-100kbps data. Are they trying to make this work on some old school network that no one in the US is using anymore? On top of that, Verizon had great rural coverage, 3G even in a lot of places. The only thing I can see that is useful, would be some sort of cleaver phone to phone direct transfer. But then again, if you are already on a data capable network... why??

Re:Why??..... (4, Interesting)

GNUALMAFUERTE (697061) | more than 3 years ago | (#32683128)

I think this is more a case of "Look mama, IP over SMS! With No hands!" than a solution for any real world problem.

Re:Why??..... (1)

mrchaotica (681592) | more than 3 years ago | (#32683322)

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.

Re:Why??..... (1)

ThermalRunaway (1766412) | more than 3 years ago | (#32683746)

If you have a "smartphone" then you are required to get a data plan anyway, so this isn't really going to save you any money.

It's not like I could cancel my data plan and use this SMS data on my Droid instead.

For that matter, the unlimited txt options on ATT aren't that cheap either... Maybe $10 a month less than the data plans.

Re:Why??..... (1)

icegreentea (974342) | more than 3 years ago | (#32683918)

Because this isn't meant for use in North America at all. There are places in the world where all they have is base GSM without GPRS. Or as another poster pointed out, you could have whacked out data pricing schemes.

Say what? (0)

Anonymous Coward | more than 3 years ago | (#32683046)

Since when were text messages affordable or reliable? I thought delivery was not guaranteed. And as for affordable...not so long as the cell phone companies have anything to say about it!

Re:Say what? (1)

metamatic (202216) | more than 3 years ago | (#32683950)

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.

Not even a real challenge (1)

topham (32406) | more than 3 years ago | (#32683082)

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.

Why not voice? (0)

Anonymous Coward | more than 3 years ago | (#32683096)

Seems to me a voice connection would provide faster data transfer rates than sending text messages.

yEnc? (1)

pak9rabid (1011935) | more than 3 years ago | (#32683132)

Why not use yEnc (no pun intended)? It's been working for years on usenet.

Re:yEnc? (0)

Anonymous Coward | more than 3 years ago | (#32684206)

Because SMS is 7 bit, and yEnc is 8 bit minus a few characters.

New Protocol Must be Stopped (1)

gooman (709147) | more than 3 years ago | (#32683176)

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.

Jack Valenti
(Yes, I know I'm dead. Want to make something of it?)

Neato! (5, Funny)

zmollusc (763634) | more than 3 years ago | (#32683210)

This is good news (everyone), by the time you have torrented your bluray rip, it will be out of copyright.
Or not.

Worst. Transport. Ever. (2, Insightful)

straponego (521991) | more than 3 years ago | (#32683236)

I'll mostly leave it to others to enumerate the many flaws in this, except to note that under AT&T I often had text messages arrive hours or days late, or never. But I do have to applaud this group. This is, by a wide margin, the worst idea I have ever seen in a /. story. Are we sure this wasn't a belated April Fool's gag?

Re:Worst. Transport. Ever. (1)

dragisha (788) | more than 3 years ago | (#32683594)

It was submitted as April 1st gag. Using itself, of course.

Only it's not too efficient, you know...

Re:Worst. Transport. Ever. (0)

Anonymous Coward | more than 3 years ago | (#32684226)

I agree. SMS MEANS BY NO MEANS guaranteed delivery.
It works almost like e-mail and generally carries low priority.
We use SMS in our login procedure and we lose lots of messages. Or, they are delayed. Around 2%, i guess.
But I also do understand were they are coming from. Most systems actually don't need to send that much data.
For example, two b2b-systems could use SMS to place orders and stuff like that.
A remote repair shop or business could order parts and other goods through SMS, for example.
It could be used to send encrypted data between hospitals.
But it feels like there must be better options.

Re:Worst. Transport. Ever. (2, Insightful)

fuzzyfuzzyfungus (1223518) | more than 3 years ago | (#32684298)

Never is, of course, a serious issue; but hours or days late would be solvable with the right protocol.

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 right out the window; but dumping blocks of data from point A to ghastly-end-of-the-earth B should be totally doable....

What about GPRS? (2, Insightful)

AC-x (735297) | more than 3 years ago | (#32683342)

> 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... (1)

EkriirkE (1075937) | more than 3 years ago | (#32683368)

If I'm doing my math right:
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 a broader set of characters than 64 so we can inflate that number. What's the big deal?

Nice Invention 10+ years too late (0)

Anonymous Coward | more than 3 years ago | (#32683418)

The old WAP1 protocol had the ability to use SMS as a bearer.

This was thrown out and done away with. Its slow, ineffective, and fucks up the control channel.

P.S. this is still in use for WAP Push on many networks (like you know, for MMS notifications). Good way to invent nothing while fucking up a production network guys!

Strained by just 80K messages ? (1)

mritunjai (518932) | more than 3 years ago | (#32683464)

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 volumes of a thousand.

While (1)

Dunbal (464142) | more than 3 years ago | (#32683478)

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 Jose (or Ahmed or Abayomi) for a dollar to take a CD to the other town and back on his bicycle.

There's a certain type of mind that tries to innovate by brute force, and yet while it's true that if you put a pair of wings on an internal combustion engine you are close to developing something new, you also have to remember to lose the 4 wheels on 2 axles, the transmission, the heavy steel body and chassis, and add a propeller...

Simili (0)

Anonymous Coward | more than 3 years ago | (#32683530)

This sounds like Pigeon-IP without the feathers.

Old hat - it was a late-1980s experiment (1)

JohnQPublic (158027) | more than 3 years ago | (#32683702)

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 studies any prior work.

permabanned? (1)

Lehk228 (705449) | more than 3 years ago | (#32683704)

if someone were to actually do this, how many minutes would it take for their IMEI and SIM to be permabanned from the afflicted carrier

History (0)

Anonymous Coward | more than 3 years ago | (#32683756)

Texting used to be the only reliable link.

This is ridiculous... (1)

tibit (1762298) | more than 3 years ago | (#32683892)

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 digital channel (say mobile to ISDN or mobile to T1 connections).

Of course probably you can't easily do it from a Blackberry. But if you're a telecommunications researcher worth your salt, you can easily get access to a software GSM stack, and inject arbitrary data into voice circuits, instead of GSM-compressed packets. This lets you have 6.5kbit/s or 13kbit/s depending on base station's utilization.

Those are, of course, raw numbers. With protocol overheads, this should be something like 5/10kbit/s, one would hope. Presumably to utilize the link in a best way, the TCP/IP connections would be re-terminated at both ends, and data re-packed in some custom protocol.

So using SMS for all this? It's the approach of least resistance, something you could do on a weekend as a proof of concept for your inquisitive kid maybe, but nothing more. BOO to the "reasearcher".

Affordable? (2, Insightful)

damn_registrars (1103043) | more than 3 years ago | (#32683946)

Really? Do these people not have a postal service? Per unit data a stamp is many orders of magnitude less expensive for sending data than a text message.

not a bad idea except.... (0)

Anonymous Coward | more than 3 years ago | (#32684070)

the data for a text message is sent through the control channels on the gsm system that otherwise represents unused bandwidth. this is basically free to the cellco's. it is also the reason for the small size of the payload

i have hooked up a motorola phone through usb to use as a mass sms system and can say that 8 seconds per message is the fastest i could ever send a message.

a text message is more reliable than other forms of data transfer on a cell. a message can be sent when a voice call is impossible because of a weak signal although at a slower rate.

having a protocol to be able to send large files through sms is a good thing.

the largest drawback to this scheme is the fact that cellcos charge extreme rates for sms data. it is a major cash cow for them.

Reliable? (1)

dave420 (699308) | more than 3 years ago | (#32684270)

If I remember correctly, there are absolutely no guarantees an SMS will ever arrive (maybe something like within 6 months, but that is practically the same). Seriously. It's traffic secondary to the voice/data traffic. If there is too much SMS traffic, it will saturate the control channel, and the carrier will simply discard it. In developing countries this could potentially bring down cellular networks entirely, if the hardware can't cope with the sudden increase in traffic, rendering people not just data-less, but phone-less too. Ouch.
Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account