NB-IoT against LTE-M When the Device Crosses Borders
NB-IoT offers superior signal penetration and lower single-mode hardware costs, but LTE-M delivers seamless global cross-border roaming and continuous mobility.
Microampere PSM Sleep
Meaning
Low-power operating states in cellular modules reduce electrical current draw to a tiny fraction of active levels while maintaining network registration. Reaching a microampere psm sleep state allows a device to remain dormant for hours or days without being disconnected from the mobile network. This mode is active when the device is inactive and does not apply during active data transmissions.
Current Draw
The total current consumed during this sleep state drops to less than five microamperes, preserving the battery. Only the internal real-time clock and essential memory remain powered to wake the module at the scheduled interval. This extreme reduction in power consumption is critical for long-term battery-powered deployments.
Wakeup Latency
Leaving the sleep state requires a short transition period as the internal oscillators and processor initialize. Although the device does not need to perform a full, energy-intensive network re-attach, this transition still introduces a slight delay before data can be transmitted. Designers must account for this delay when planning time-sensitive data reports.
Lifetime Projection
Minimizing the power consumed during inactive periods is the primary factor in extending the operating life of a device. A device that spends most of its life in this sleep state can operate for a decade on a single battery. This long life is essential for infrastructure monitoring.