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A mote needs to send a keepalive packet to each of its parents every 15s in the absence of a data packet being sent. This places a lower bound on the energy a mote consumes while in the network. Blink replaces the contents of a normal join packet with user data, allowing the mote to stay in low power mode out of the network for long periods (typically hours), and only synchronizing to the network briefly when data is sent. Because
Because the mote never joins the network, it cannot receive data downstream from the manager while blinking, but the user can switch between blink and proper joining at any time. Because the mote synchronizes The mote does however synchronize to the network in order to blink, so precise network time is available to the user application after a blink packet is sent, however this synchronization drifts as time passes.
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