Radio activity, base consumption, and application activity determine total power consumption for a SED.
Radio activity is made up of several factors that affect its power consumption: network commissioning and link maintenance logic, application-specific data transfer, and environment (for example, the availability of the radio channel).
Base consumption is affected by power consumption in the sleep state (powered peripherals, RAM).
Application activity is affected by the CPU utilization and the peripherals in use.
When a device first starts up, it is in a detached state not connected to a network. Because a
SED is not able to form a network on its own, it must connect to an already existing network.
To join an existing network, the device needs to obtain and store the network credentials in
its persistent memory. Once the device connects to a network it transitions between the
following states:
- Sleep state - this is where the device waits for events
- Radio operation - here the device transmits or receives data
- Application activity - the device communicates with connected wired peripherals and performs operations required for the application it is running
Figure 1. Sleepy End Device states
