The new standard makes it possible to stream data from sensors married to passive tags, by allocating a frequency channel to each device. When radio waves reaches a tag, the device wakes up and broadcasts the basic info it contains and then negotiates a clear channel on which to stream data.
Mostly Zigbee. Depending on the sensor, location and activity I’m getting between 6-18 months per battery, but I do have a lot of sensor, so there’s a regular churn of batteries.