Tabs uses the LoRa network, giving you longer range than Bluetooth, lower cost than cell networks, and longer battery life than both. Check your own network coverage here.
Your own Tabs Hub will cover an area of up to one mile around the house. The actual coverage depends on obstacles between the Hub and the sensors. In any case, all places in and around your house will be covered. The Hub easily reaches your basement, your garage or your garden house. No more worries about WiFi or bluetooth coverage when installing a sensor.
You will benefit from the coverage generated by all existing Hubs. Thus, if the existing coverage is not sufficient for locating your children, e.g. on the way to school, your can install additional Hubs along the way. For instance, you could recommend Tabs to one of your finds living along the way or install a Mini Hub in the School to close network coverage gaps.