Embrace records physiological signals on it’s internal memory and sends it to the paired smartphone via Bluetooth connection
From the paired smartphone, these physiological signals are sent to Empatica’s servers through WiFi or mobile data internet connection.
When the Embrace detects a seizure, caregivers enabled on the paired smartphone are alerted through phone calls and SMS, as long as there is stable Bluetooth and Internet connection on the paired smartphone.
For more details see How Does The Embrace Work
To know more about what happens if a seizure is detected but the Embrace is not correctly connected, read What does Alert not sent mean?