I was wondering what carriers are compatible with a sim900 breakout board. I know it needs a GSM network (AT&T,T-mobile,?) but what networks can I use?

It needs a 850/ 900/ 1800/ 1900 MHz frequency to work but who offers that frequency? I personally could not find what frequency cell phone companies offered. From how I understand it is that T-Mobile definitely will work.I have heard several different answers about companies like AT&T and I have seen discussion about sprint (which I don't understand because they are a CDMA carrier).

I have also heard that there are other carriers (Vondafone, nextel,Ting) that might be more cost effective for people like me who are only going to be using the text messaging.

Can someone please set me straight on who I can use.

  • 1
    Vonda Phone? You mean Vodafone? – Alexander M Dec 27 '15 at 0:20
  • My apologizes. I have corrected the error. Thank you. – Suit Boy Apps Dec 27 '15 at 0:25

SIM900 should be compatible with both AT&T and T-Mobile. T-Mobile uses 1900Mhz for 2G and AT&T uses 850Mhz and 1900Mhz. Although both carriers are upgrading to 4G, they still support 2G devices. My personal experience is that most quadband 2G devices still work with AT&T and T-Mobile and there is no technical reason why SIM900 shouldn't work. However, there can be issues with incompatible data plans that are compatible only with their own devices. You need to be careful when selecting the contract and buying the sim card.

Nextel and Ting uses Sprint's network which is CDMA and thus wouldn't work. However Vodafone seems to be using T-Mobile's network and may work.

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