The problem is nobody wants to carry a dongle. Also, localizing the dongle inside the house is not as straightforward. Would the users need to put one dongle-detector in each room? one near each exit? If it has long transmission range, then it would probably be big/heavy due to larger batteries.
The problem is nobody wants to carry a dongle. Also, localizing the dongle inside the house is not as straightforward. Would the users need to put one dongle-detector in each room? one near each exit? If it has long transmission range, then it would probably be big/heavy due to larger batteries.