So many options
The Nokia Lumia 800 uses GSM.
Besides technology, there are other factors that should play into your carrier decision. You should begin by deciding which carrier has the most economical service plans and the most attractive selection of phones. The quality of customer service is another determinant, but that can be difficult to evaluate beforehand. Since knowing the pros and cons of each operator isn’t easy, we invite you to take a closer look at service providers in our guide to cell phone carriers.
Besides the major operators, you might also consider Mobile Virtual Network Operator (MVNO) carriers that cater to a special demographic or lifestyle. For example, Virgin Mobile is targeted toward younger users, whereas Boost Mobile is centered on urban users who want advanced features. MVNOs do not operate their own cellular network; they lease network space from national carriers.