Digi XBee3 - Airplane Mode; Power Saving Mode (PSM); PSM Behavior; Deep Sleep Mode

Power saving features Airplane mode
Digi XBee3 Cellular LTE-M Global Smart Modem User Guide
81
Airplane mode
While not technically a sleep mode, Airplane mode is another way of saving power. When set, the
cellular component of the XBee Smart Modem is fully turned off and no access to the cellular network
is performed or possible. Use AM (Airplane Mode) to configure this mode.
Power Saving Mode (PSM)
To enable PSM, set DO (Device Options) bit 3.
Note We strongly recommend that you clear DObit 0 (Enable Remote Manager) if you set bit 3. If not,
the connection that the device retains with Remote Manager causes the cellular component to spend
very little time in low power, negating the value of selecting that feature.
When PSM is enabled, the cellular component spends most of its time in a low power state. In the low
power state the XBee Smart Modem still has an IP address and is registered to the network, which
allows for quick resumption of activity, but is not reachable so cannot receive IP or SMS traffic until it
wakes up.
The cellular component wakes to participate in maintaining the network state periodically based on
timers negotiated with the cell tower. It is also triggered to wake up when the user performs any
activity requiring network connectivity such as mobile-originated traffic like sending an SMS or
UDP/TCP traffic. When it wakes up, it spends a short time awake so that it is reachable through the
network at that time and then returns to the low power state.
PSM behavior
Commands exist to influence the PSM behavior when PSM is enabled (DO = 8). They are:
n PA (Requested Active Timer)
n PU (Requested Tracking Area Update Timer)
n A? (Network-specified Active Timer)
n U? (Network-specified Tracking Area Update Timer)
PA and PU are the values the XBee Smart Modem requests from the network. The network is free to
assign values other than those which have been requested. You can read the assigned values with A?
and U?.
See the LTE-M Deployment Guide from GSMA for a description of what the PSMtimers are and what
functions they perform on the network.
Deep Sleep mode
In Deep Sleep mode the cellular component is shut off and the XBee processor is put to sleep.
Note When the XBee Smart Modem enters deep sleep mode, any MicroPython code currently
executing is suspended until the device comes out of sleep.