Zigbee. Whilst battery powered devices don’t repeat as it would use up too much battery life, The first generation ST motion sensor could work on either battery power or USB and is a zigbee repeater when on USB power. It was very popular for exactly that reason. I was sorry to see it discontinued. As zigbee pocket socket makes a good repeater for many cases as you get dual use out of it, but there has to be a receptacle to plug it into.