Carrying over your existing security equipment is a very rare feature. The biggest obstacle in achieving this is that each company licenses its equipment from a given manufacturer, and they integrate their units into their system. This means that that their smartphone app and console cannot recognize most other devices. Luckily, there are providers like XFINITY Home that are working in synergy with more than one equipment brand, and their system is designed to recognize numerous products. If your existing security equipment is preferred by them, then they allow you to carry it over.