A few years ago I needed a way to SSH onto a dial-up server during a trip. Since hotspot was still an add-on, I bought a cheapie $15 Verizon prepaid flip phone and used that with a USB cable. It appeared as a serial modem under Linux.
The amusing thing was that apparently Verizon didn’t setup any sort of billing for my use-case, and since I never used the voice or text the thing just continued to work for a couple of years. It worked after the service cancelled, after the number was reclaimed, and then finally stopped only once the SIM card would no longer register on the network.
Not that I really cared - it was 9600 baud and I only used it a handful of times. Still a funny hack.
There was briefly a thing called HSCSD ("high-speed circuit switched data"), which allowed for 14.4k per circuit, and you could make two simultaneous connections to get 28.8k. It was basically ISDN over GSM.
But you paid per minute (twice as much for 28k) and it was swiftly killed off by GPRS.
Used this way back in the day when we got rid of our landline phone (this was around 2000), used my Kyocera phone as a modem to dial into our Earthlink service. Since we had unlimited night and weekend calling we primarily used the internet around then, oh boy was downloading Windows NT SP6 back then fun.
The amusing thing was that apparently Verizon didn’t setup any sort of billing for my use-case, and since I never used the voice or text the thing just continued to work for a couple of years. It worked after the service cancelled, after the number was reclaimed, and then finally stopped only once the SIM card would no longer register on the network.
Not that I really cared - it was 9600 baud and I only used it a handful of times. Still a funny hack.