This is the reason you can't dig out your old brick
CDMA phone from 1999 and slap it onto your account. Every phone that your carrier activates has to employ technology that allows emergency personnel to find you if you call 911. [Note: E911-compliant technology (now mandated by the
FCC) differs from carrier to carrier.
CDMA carriers Sprint and Verizon Wireless use GPS or A-GPS (GPS assisted by cellular positioning), which means you'll need a newer phone with built-in GPS technology.
GSM carriers AT&T and T-Mobile use a technology called "time difference of arrival", or TDOA, which calculates a caller's location according to how long it takes for the signal to reach three or more nearby cell towers. TDOA technology will work with any
GSM phone—no need for a special chip.]