Locktel 620
How does it work?:
The Locktel 620 contains an ordinary SIM card. The"pre paid" type works perfectly.
Users call Locktel 620 and hang up. In fact the Locktel 620 "rejects" the call.
Users do not pay fees, as communication could not be established.
However, the callers CLIP has been sent to the device.
If that CLIP is listed in the pre-programmed Locktel list, a contact will be activated for a few seconds and cause the opening of the garage.
CLIP: "Calling Line Identification Presentation"
CLIR: "Calling Line Identification Restriction"