I signed up for Sprint's unlimited kickstart plan and noticed there is a lot of "extended network" coverage near me. Today was the first chance I had to test it when I left native coverage. It switches to US Cellular but all I got was the R indicator on my phone. Same indicator when it switches to Verizon. I have my settings as Automatic for network instead of Home only. I also have data roaming turned off. Basically my question is, how can I know when I am on extended network instead of roaming? Most of the coverage west of me shows extended network with very little roaming areas. I don't want to get charged for roaming on accident.