I installed my own security system in my new build finished last year. I hard wired all sensors. The advantage of the wireless IMO is when I decide to add sensors (if I ever decide I need more sensors) and if wiring would be too diificult. I also think wireless makes sense if you want to alarm for window open conditions - see explanation below. Certainly wireless makes the most sense if you are adding a security system in to an existing finished house. Disadvantages of wireless (for me) were cost, battery changes, and the possibility of bad connections which I have had with other wireless gear. I installed a combination of wired magnetic sensors (for doors), glass break sensors (for windows) and motion sensors for interior spaces. I chose glass break sensors over magentic contacts or wireless sensors on the windows because I did not want to spend a lot of time drilling and installing magnetic sensors on every window nor deal with batteries on any wireless window sensors (I have a lot of windows). I decided on a strategy of using glass break sensors to monitor a series of windows in a room beacuse if a crook is going to break in, I figured they will either kick in door or break a window but not take the time to open the window frame. Using magnetic sensors on window frames seems like a waste for burglar protection IMO. However - I think there is a good reason to alarm every window with contact sensors especially in a big house with kids and that is people (kids) forget to close and lock them. Having a contact sensor on every window would let you know if a window is left open because the alarm keypad will not let you set the alarm if any sensors are not ready. And if you leave a window open that is exactly where a burglar will enter. If you want that feature - then I would suggest wiring all of the sensors that will be used for primary burglar protection. Use glass break sensors to monitor windows for buglar penetrations through the glass. Then add on later with wireless sensors on the window frames if you want the window open detection. You can chose where you want the windows monitored by these wireless sensors and it doesn't have to be all of the windows (maybe just kids rooms and windows in far away places from the main living area). BTW - if you use glass break sensors, make sure you follow the directions on setting the sensor sensitivity. I left my GB sensors on MAX and they detected birds flying into the glass which I discovered (via several false alarms, one when I was on a cruise) occurs much more frequently than I ever imagined. Good luck.

If you want to reuse your existing wireless sensors, make sure your alarm panel is made by the same manufacturer. If you have existng Ademco sensors, you must use an Ademco panel with a wireless receiver such as the Ademco 5881. Nextalarm will support any number of different panels that use the 'contact ID' signalling standard. Don't feel you must use one of the panels that Nextalarm sells. I use a Ademco Vista 20P and have it monitored by Nextalarm. Those wireless sensors aren't cheap. You will probably want to try to reuse them. Check out the excellent forums at: Here is a link that might be useful: Home Security Store

i think when the thief want to steal things from your house, the alarm can call anyone.

Hooking up different sensors to alarms is not difficult, so nobody should have to suffer through alarm systems not suited to their predicament. There are greenhouse alarms, and not terribly expensive what can telephone another number and forward on an alert. It's typically used for power failure or heater failures, but there isn't any reason it could not be hooked up to an infra-red beam for intruders, or vibration sensors on doors or windows. If you had it programmed to call into your work number or cell, you can easily call a neighbour to check, or directly phone the police yourselves. Yes, dogs can be deterrents, but. My children's home was burgled in broad daylight some years back. They had their large dog with them, but a smaller one (still a fifty-sixty pounder) in the house. The thief let himself in through their front window in view of the street. Took what he wanted, and the dog probably made him a cup of coffee and served him appetizers. Some dogs are so well socialised, they wouldn't deter an intruder. Worked awhile as a police officer, and I have seen guard dogs stolen along with the other goods.