A:AnswerIf you purchase a phone outright or do an extended 2 year contract, essentially a set price for the phone but turn it in when you want to upgrade again, then you can keep your plan as is.
A:AnswerSamsung Galaxy S phones use Samsung KNOX for device management and encryption which is one of the only platforms allowed by the Department of Defense for use on confidential networks (iOS on iPhones being one of the very few others).