your phone will pick up whatever signal is available automatically, it will first try to find a verizon signal, if you come across a stronger signal (lets say sprint) your phone with default settings will automatically switch to the stronger signal, now if in that area we have an agreement with that service provider you will be in whats called Extended Network, no additional charges involved, most of our phone will display that along with a flashing triangle at the top. True roaming will have a solid triangle and either Roaming on the screen or Digital Roam, you know how your phone says Verizon Wireless on the screen and you cant make it go away? thats b/c you cant. its called and ERI (enhanced roaming indicator) banner which helps to tell y...
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