I knew it was possible, and that folks were taking advantage of it. For over 2 years there was free broadband internet from the cellphone companies, but they figgured how to throttle and charge for that portal.
But, there are still at least 2 legal options.
No landline required, but you need an unlimited cellphone talk account (available nationwide for under 40 bucks a month).
1st method is use Wash state's free dialup access and tether your computer to your cellphone and use itr as a regular modem.
Second method is a QNC connection to your cell provider. Available through MPT software (and similar).
I am on this free service now. I refuse to pay over $500 a year for poor dialup service (that is what I paid the last 5 yers each year because ATT said DSL would be here any day, still not here), free is good, though.
The down side?....14.4 speed. But with that $500 I will save in the next 12 months, WHOOHOO! a new S&W will be mine.
BTW, I am not in the cellphone business, do not have any interest in any of these companies. Everything mentioned is legal and widely available.