How Does a Wireless Alarm Work? (Hikvision AX PRO)

A wireless alarm works by having battery-powered sensors talk to a central control panel over encrypted radio. The panel connects to your home internet (and app), so when the system is armed and a sensor is triggered, the panel sounds the siren and sends an instant alert to your phone. Hikvision AX PRO is a good example.

The parts

• Control panel (hub) - the brain; receives signals from all sensors and decides what to do.
• Sensors - PIR motion detectors, door/window contacts, and optional smoke, glass-break and panic buttons.
• Siren - internal and/or external, to scare off intruders and alert neighbours.
• Keypad or app - to arm and disarm.

How it connects

Sensors communicate with the panel over secure, encrypted radio (no wires). The panel reaches the outside world over Wi-Fi or a network cable, with a mobile SIM as backup on many models - so no landline is needed. That connection is what lets the app send you alerts and let you arm/disarm from anywhere.

What happens when it triggers

When armed, a tripped sensor tells the panel, which sounds the siren and pushes a notification to your phone. You can then see the event, and (if you've added it) a monitoring centre can respond.

Browse Hikvision AX PRO alarms or read the alarm buyer's guide.

Frequently asked questions

How does a wireless alarm communicate?
Sensors send encrypted radio signals to a central control panel. The panel connects to the internet over Wi-Fi, network cable or a mobile SIM to send app alerts - no landline required.

Does a wireless alarm need Wi-Fi?
It needs an internet connection for app alerts, usually Wi-Fi or a network cable, often with a mobile SIM as backup. The sensors themselves talk to the panel by radio, not Wi-Fi.

What happens if the power or internet goes off?
Panels have a backup battery, and models with a mobile SIM keep signalling if the broadband drops - so the alarm keeps working.