Power Saving Features And Design Recommendations; Airplane Mode; Power Saving Mode (Psm); Enable Psm - Digi XBee 3 Cellular LTE-M User Manual

Power saving features and design recommendations

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

Power Saving Mode (PSM)

Enable PSM

To enable PSM, set
Note For NB-IoT, TCP and SMS support is dependent on the network. Contact your network provider
for details.
Note The cellular module comes out of the PSM low-power state whenever any network activity
occurs, including Remote Manager activity. See
Manager.
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. This low power state is used even when taking advantage of XBee sleep features (such as
Pin Sleep or Cyclic
readiness when exiting sleep.
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.

Overview of PSM functionality on XBee 3 Cellular

Before you enable PSM, you should be aware of these behaviors.
Actions taken when the cellular component enters a PSM dormant state
When the cellular component enters into the PSM "dormant" state:
Any existing TCP or TLS connections are immediately closed.
n
Existing sockets are implicitly closed.
n
Any queued or not-yet-in-progress transmissions such as data sent on sockets, or requested
n
SMS transmissions, are canceled and an error status is returned.
Wake up a dormant cellular component
The following sections explain the different activities that will wake a dormant cellular component.
Mobile-originated activity
If the cellular component is "dormant"
network connectivity will trigger the cellular component to wake up, including creating a TCP or TLS
connection, sending a UDP datagram, or sending an SMS. Typical applications do not need to
Digi XBee® 3 Cellular LTE-M/NB-IoT Global Smart Modem User Guide
AM (Airplane Mode)
DO (Device Options) bit 3.
Sleep), rather than powering the cellular component off entirely to ensure
(AI = 0x2C), any mobile-originated activity which requires
to configure this mode.
Verify the connection between a device and Remote
Airplane mode
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