Cellular Back Door
Which Carrier Uses Which Network?

These "alternative" carriers mostly use one of the Top 4 major networks. These "re-sellers" provide your phone, plan and customer service but the actual cellular signal comes from one of the 4 carriers, below. MVNO Note.

Using the AT&T Network (GSM):

Using the Sprint Network (CDMA)

Using the T-Mobile Network (GSM):

Using the Verizon Wireless Network (CDMA):

Using Multiple Networks:
(Your Phone Can Operate or Roam on More than One Network)
*These carriers allow off-network roaming for a certain amount of Talk and Text only, no Data.

These companies are also known as Mobile Virtual Network Operators (MVNO), wholesale networks, or cellular "re-sellers", that use the main carriers' networks.  Occasionally, these MVNO's will use networks provided by carriers that are not one of Top 4. In most cases you won't know which carrier you're using, especially with the companies that use Multiple Networks, as listed above. The type of wireless device determines whether a CDMA or GSM carrier is used. Some features that are available from the "main" carriers may not be offered by these re-sellers. This is where to look if you hate your carrier but love their network.