I noticed that all Personal Emergency Response Systems (PERS) devices seem to use 312Mhz for their transmission. The device is usually used by the elderly and has a button when pressed the user is connected with a call center through a base station. This 312Mhz band is only approved for alert type transmissions by FCC. In my case, I am trying to have regular messages as well which would not work for the 312Mhz range so I am considering a 915Mhz radio. Does anyone know why the 312Mhz is better for emergency response? What are the implications/downside of using a 915Mhz radio? Can they be overcome? Thanks and appreciate your response.