So all the info I've found on gsm vs cdma concerns Verizon and AT&T in the States. I'm in Canada, we have Bell, Rogers, Fido, Telus. Out of curiosity, which of those companies carry CDMA iphone 4 and which carry GSM? Does CDMA have sim card slot or not for iphone 4? And I have a iphone 4s from Bell. Is it GSM or CDMA? Thanks.