Why is it that AT&T, Verizon, Sprint and T-Mobile phones can’t work with one another?

by on March 18, 2010

Q: Why is it that AT&T, Verizon, Sprint and T-Mobile phones can’t work with one another?

Read Answer Here

2 Responses to “Why is it that AT&T, Verizon, Sprint and T-Mobile phones can’t work with one another?”
  1.  
    Picked as best answer

    Most current cell phones use a small (Subscriber Identification Module) SIM card to identify the phone and allow it access to a carrier’s cell network. Many of these phones also have a software lock in place that makes them only recognize SIM cards from the original carrier.

    A phone that will only work with SIM Cards from the original carrier is called a “locked” phone. Many phones can be “unlocked” meaning that a SIM Card from a competing cell phone carrier can be inserted into the phone and it will work.

    You can read more here: http://www.wisegeek.com/what-are-unlocked-cell-phones.htm

    If you want to try to unlock a phone yourself I suggest you Google for the work “unlock” and the manufacturer and model number of your cell phone.

    Note that improper or incorrect unlocking may prevent your phone from working correctly, void any warranties, or totally kill the phone.

     
  2.  

    The other thing you have to remember is that there are two types of cell phone networks, GSM and CDMA. So besides the “locked” feature, for lack of a better term, that Mark described you also have the technology aspect that ties a phone to a certain type of network.

    A good example of this is you cannot use a phone that you bought, even if it is unlocked, on a CDMA network (Sprint and Verizon in the USA) on a GSM network (AT&T and T-Mobile in the USA).