DTC Wireless’ Ultimate GSM Unlimited Plan offers unlimited calling to anyone in the 615 & 931 area codes. Unlimited minutes apply in the 8 county home area and phone must display the DTC Wireless network . If the phone displays another carrier's name, minutes used will be billed at the roaming rate of 59 cents per minute. Calls placed to exchanges outside the 615 or 931 area code will be billed 59 cents per minute roaming + 15 cents per minute toll.