In some implementations, electronic tags 206 are active radar devices capable of transmitting radio frequency tones or pulses independent of any received waves. In various implementations, electronic tags 206 are capable of reflecting, amplifying, and/or modulating received radio waves. Active radar devices comprise single transistor devices, MEMS-based devices, and mechanical gated (shuttered) devices.
In some implementations, electronic tags 206 are configured to communicate via radar in response to enablement commands received via a communications channel (e.g., an RFID channel) from a smart device, such as smart device 204-6 in FIG. 2. In some implementations, electronic tags 206 are configured to communicate via radar at particular intervals, such as intervals preset by a smart device. For example, electronic tags 206-1 and 206-2 are configured by device 204-6 such that only one of the tags is communicating via radar at any given time. In some implementations, electronic tags 206 are configured to communicate via radar in response to detecting a change in the environment, such as motion of the object to which the electronic tag is affixed. For example, in some embodiments, electronic tags 206 include one or more of: a humidity sensor; a temperature sensor; an accelerometer; a gyroscope; and/or an optical sensor. In this example, the tags are configured to communicate via radar in response to changes detected by one or more of the sensors.
In some implementations, the smart home environment 100 includes service robots 168 (FIG. 1) that are configured to carry out, in an autonomous manner, any of a variety of household tasks.
