I have been planning for two years to upgrade with my system with three additional motion detectors. In fact, I already had installers out twice, but they were unable to access my attic either without big ladder or during rain (second time they showed up, finally with a big extension ladder, it was raining). Now, it's gotten even worse since attic access point (outside) has been "sealed". I need to create new indoor attic access point, but that's going to be a big project, probably done years from now.
So I've decided I'm just going to have to use wireless motions. How reliable are these compared to wired kind? My biggest concern is false alarms. I have a DSC system (10 years old) so I assume they will have to use DSC wireless motions. In 10 years, I have no false alarms (well, I actually had one that I think I can explain, some glass broke) and I want to keep it like that.
Do they use 2.2Ghz? I have 2.2Ghz saturation in my house with both802.11G networking and Sonos. I also use X10 wireless appliance control (work OK, but I often have to put AC line filters on fluorescent lights and LCD tvs to keep it working) and I don't know what frequencies it uses. And radio shack remote extenders (which use RF). And a microwave oven, etc.
Frankly, I hate wireless unreliability, and I use wired whenever possible, but in this case I think I'm going to have to go wireless.
When first installer couldn't access my attic with his short ladder, he suggested wireless, and quoted me a price (higher than wired). I think it requires a new zone, so two previous zones in my 8-zone system will have to be merged to allow for a new zone.