A monitored security system works by alerting a call center when an alarm (such as window or door sensor) is triggered. An operator at the center then calls the home in question, to check with the owner / resident and ensure that the house and its occupants are safe. If a burglar is attempting a break-in, the operator will contact the authorities and send help. According to ProfessorsHouse.com, there are two major drawbacks to monitored systems. First, they typically rely on hardwired phoned lines, which potential-burglars (and inclement weather) can cut or otherwise disable. This means call center operators may never be able to reach individuals in distress. Second, it typically takes operators 30 to 40 seconds to call after an alarm is triggered, which gives criminals time to work their way into your home before help can arrive.
Unmonitored security systems rely on the power of loud noises. They generate sirens or other irritating, typically high-pitched sounds when alarms are triggered; the goal being to scare off potential intruders and to alert occupants and neighbors of the situation. Flood lamps and other lights may also be incorporated into the systems for the same reasons. According to ProfessorsHouse.com, the upside to unmonitored security systems is that you do not have to pay monitoring fees. The downside is that the responsibility of calling the authorities falls on you and--if you are not at home--your neighbors.
Hardwired systems rely on wiring to transmit data from sensors and other security devices to a central console or control panel. The console is typically installed inside of a closet or in an otherwise hidden area and features a keypad for activating and deactivating the system with numeric codes. The biggest drawback to hardwired systems is their installation, which requires running wires through walls, crawl spaces and other home structures.
Wireless security systems are at the forefront of security system technology. They require no burdensome wires, which makes them both easy to install and incredibly flexible when it comes to sensor placement. Also, unlike with hardwired systems, you can easily bring your wireless security system with you to your next home if you decide to move. However, wireless systems--unlike the hardwired varieties--are susceptible to disruption from electromagnetic interference and require that you replace batteries in wireless sensors and other components.