You could do what I did before AT&T went to a GSM network. I obtained an unlocked GSM phone. You probably can get one on eBay; I was looking there before a friend gave me one of his castoff. Once I had the GSM phone, I obtained a SIM chip from AT&T to put into the GSM phone. AT&T did not require me to have GSM service in the U.S. When my cellphone number was called in the U.S., the call would be picked up by the GSM phone in Europe. My spouse still uses that system; she has not switched to the GSM system.

If you are not worried about your telephone number, then you can purchase pre-paid SIM chips for use in the phone. Those were also available on eBay at one point, but I am sure that there are other sources.

Tom in Carlisle.