When telephones were replaced by cell phones, wireless home alarms were not far behind. Whenever wireless house alarms are mentioned, they mean cellular telephone even though wireless means many things. Wireless can mean communication by infrared, optical-electrical and radar electromagnetic wave. Wireless communication by cellular phone works great in urban areas but not so great in the countryside. These wondrous marvels of the 21 st Century have a very limited range and because of their frequency, are limited to direct line of sight. This means that they must be in a direct line of sight with the other party to talk. When cellular phones became transformed from shoebox clunkers to almost matchbox sized wonders they also lost transmission power. When they had size, they had a respectable 5-10 watts transmission power. A shoebox cell phone could talk with Baltimore from downtown Washington , D.C. without any cell towers. Today's matchbox cell phone has greatly reduced wattage and can communicate only through a series of cell towers, which are installed in direct sight of each other. Other systems use a satellite relay communication or the long distance service of a fiber optic network.
Wireless security alarms work reliably when the sensors are connected through cellular communication to the alert system on the premises. This is connected through a telephone wire, a fiber optic network or a DSL cable to the alarm agency. A system may be considered totally wireless if the cellular phone coverage has been confirmed for the entire store or home. I once worked in an establishment where cell phones could only work in the front or rear of the store but not in the middle. They were covered since they had a wired alarm system.
Another example of the truth of this is in wireless security door alarms. These are convenient units, which attach magnetically to a store or home's door. The other part of the wireless security door alarm is attached to the doorframe. When contact separation occurs a loud screaming alarm is emitted and a cellular signal is transmitted to the monitoring agency's receiver. These smaller wireless burglar alarms have brought extremely effective security to smaller businesses and homes, which could not have afforded it.
Future developments in the miniaturization of alarm sensor devices, which detect movement by air pressure, radar and sonic waves, may enable direct communication to the monitoring agency or computer. The science fiction authors who gave us robotic life support systems in "Star Wars" and "Star Trek" may have been closer to reality than they thought. We have commercial alarm systems installed in our largest cities, which can pin point where fires start, route the safest evacuation for the occupants, provide emergency instructions through the buildings interface with the internet, talk with occupants and rescuers giving vital information and actually initiate preinstalled fire extinguishing systems. These wireless systems can actually communicate with fire departments and police. They can be trained to specifically communicate the cause of current fires, their location and direct, the number of affected occupants. Wireless alarm burglar systems illustrate the benefits of modern technology to improve on the safety of modern man and woman.
Wireless systems can actually communicate with fire departments and police