IP packets contain 20 bytes of headers, the rest is data. Theoretically you could create the world's worst VPN by stuffing the 140 bytes of an SMS absolutely full of binary data, with some compression of course. So I went looking for "IP over SMS" and actually found this: https://github.com/spandanb/ipos but it's for web browsers only. This old HN thread talks about the same concept: https://news.ycombinator.com/item…
I managed to do something useful with iodine (IP over DNS), a couple of times. Performance is abysmal, but a simple SSH session might have some hope. Most web applications are impossible, and for email you must be lucky.
I remember staying at a hotel in the UK that rented internet in 500MB chunks... i figured out that if I tunneled everything via DNS they didn't count the traffic. I wish I had known about Iodine at that point ;)
I wrote a trilingual one (Chinese, Korean, English) circa 2005 which allowed fuzzy search and directory services. The main issues are expense, per-message character limit (which is based on your character encoding; note Unicode UCS-2 is super-wasteful vs. other alternatives), latency, and questionable inter-network reliability. If you're in Alaska, honestly, if you're not really hard up for money just get a satellite…
Could you elaborate on why UCS-2 is so wasteful? I think that makes sense on the surface level, but if you encoded a message using all the characters available in the BMP that UCS-2 provides then each character has tens of thousands of options rather than <125 with GSM-7. Considering the difference is a little less than half (70 chars per message vs 160), with the right encoding, shouldn't UCS-2 be much more efficient? Or is it not possible to encode data like that?
I wrote a trilingual one (Chinese, Korean, English) circa 2005 which allowed fuzzy search and directory services. The main issues are expense, per-message character limit (which is based on your character encoding; note Unicode UCS-2 is super-wasteful vs. other alternatives), latency, and questionable inter-network reliability. If you're in Alaska, honestly, if you're not really hard up for money just get a satellite…
Could you elaborate on why UCS-2 is so wasteful? I think that makes sense on the surface level, but if you encoded a message using all the characters available in the BMP that UCS-2 provides then each character has tens of thousands of options rather than <125 with GSM-7. Considering the difference is a little less than half (70 chars per message vs 160), with the right encoding, shouldn't UCS-2 be much more efficien…
Can't recall specifics but I think I compared some languages (maybe an abugida like Thai) with UCS-2 vs native encodings and found UCS-2 was smackdown terrible. iconv is your friend for this. If you want efficiency skip charsets and use a binary PDU. Most phones with AT command sets used to support this. All GSM modems support this. These days, I am unsure if you can get a low enough level API to a smartphone to send and receive binary PDUs. I guess probably somehow, at least on Android, at least with root, but it's almost certainly a hassle.
For what it's worth, I built a service that allows you to use Google Maps and a dictionary over SMS: https://gistsms.com I've stopped working on the project but would be curious to hear if there's still interest!
I think it's fabulous. Just signed up to be notified when it's ready. ;-)
Could you elaborate on why UCS-2 is so wasteful? I think that makes sense on the surface level, but if you encoded a message using all the characters available in the BMP that UCS-2 provides then each character has tens of thousands of options rather than <125 with GSM-7. Considering the difference is a little less than half (70 chars per message vs 160), with the right encoding, shouldn't UCS-2 be much more efficien…
Can't recall specifics but I think I compared some languages (maybe an abugida like Thai) with UCS-2 vs native encodings and found UCS-2 was smackdown terrible. iconv is your friend for this. If you want efficiency skip charsets and use a binary PDU. Most phones with AT command sets used to support this. All GSM modems support this. These days, I am unsure if you can get a low enough level API to a smartphone to send…
Good point. I was looking into a way to maximize efficiency on Android without low-level access (no root necessary), so I'm pretty much limited to the charset that I can receive from the Android APIs for encoding binary data into (36864 chars). I was wondering if even the limited character set offered by an Android SMS receiver would still be magnitudes more efficient than the standard GSM-7 character set for encoding binary data, even though the amount of characters is less for each SMS. I'm having a hard time understanding if I'm oversimplifying things by just looking at the ratios 160/128 to 36864/70, in which case I would assume there would be huge benefits to encode data with UCS-2 instead? I haven't the slightest idea in how to accomplish that, maybe iconv would be useful as you mentioned?
That is something interesting to consider though, dedicated hardware could easily take advantage of UCS-2 and encode binary PDUs to the point where you could achieve a somewhat respectable speed for TCP over SMS. Though by that point, I would assume SMS throttling would be a much larger concern so any benefits are mostly theoretical.
A while back a buddy of mine wrote a Python framework that does pretty much exactly this! It has several demo modules already, such as fetching a weather report and requesting an Uber.
I have a second SIM card that T-Mobile gave me for free (no idea why). I have it installed in an Android phone running Tasker with a bunch of jobs I created to do various things. Android phone stays at home while my primary (flip phone) comes with me. I get specific Matrix ( https://matrix.org ) messages forwarded to my flip phone, I can query the weather, I have a couple RSS feeds forwarding, and I can enable/disabl…
Your best bet is to set up something like FreeSWITCH that you can text with keywords or your own custom arguments, and have custom scripts craft a response.