Emergency communication system
Property-based ("on-premise") emergency communication systems are those which are mainly or completely in the same location or area as it serves, while off-property ("non-premise") based emergency communication systems are those which are in a different location or area. There are good and bad properties of each. Often, non-premise based systems are slower than systems that are premise-based, because the different locations need to be connected using data networks (for example, the Internet).