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.
Maximum Output Power Class 5
Meaning
Standardized cellular transmitter power categories restrict the highest allowable transmit power to a specific lower tier to optimize battery runtime and thermal performance in small devices. For narrow-band internet of things devices, complying with the maximum output power class 5 limit restricts the transmitter to a nominal output of twenty decibels milliwatt. This specification applies to the transmitter output power and is not used to evaluate the receiver.
Transmit Constraint
Limiting the maximum power to twenty decibels milliwatt reduces the physical distance the signal can travel compared to higher power classes. However, it simplifies the radio front-end design, allowing for smaller, cheaper antennas and fewer shielding components. This lower power output is ideal for compact tracking devices and smart meters that do not require high bandwidth.
Battery Economy
Transmitting at a lower power level reduces the peak current drawn from the battery. This allows the device to operate on small, low-capacity lithium batteries that would otherwise be damaged or depleted by high current surges. It ensures the battery can sustain the device for years in the field.
Network Access
Mobile network operators use this power classification to plan cell coverage and allocate resources. Devices must report their power class during the initial handshake so that the base station can adjust its receiver parameters. This ensures a stable and efficient connection.