This is a question we do get asked, our recommendations are listed below:
Businesses spend a fortune on getting Customers through the door, therefore not being aware of a Visitor at any time is absolutely Criminal !!
D.T.R. this Principle can be related to most types of Security & Safety Systems
Finding a Wireless Bell System that actually works over the distance that is advertised can be a daunting exercise, they may work in open air but as soon as you any basic obstruction in the path, most become very erratic !!
The term ‘Line of Sight’ means that a Wireless Signal has been tested in open air, normally in optimum conditions for the transmission distance to be measured between two devices, commonly seen when purchasing Wireless Alarms.