If you're a SimpliSafe customer, well...what's the backup plan?
It unfortunately can be easily jammed.
Not to pick on them, I'd guess many of these non-wired solutions are similarly vulnerable.
Shot: https://www.instructables.com/Improving-Range-for-SimpliSafe-Motion-Detectors/
Chaser:
https://hackaday.com/2019/08/23/alarm-system-defeated-by-2-wireless-dongle-nobody-surprised/