Meaning
Transmitter classifications in wireless standards define the maximum output power a user terminal is allowed to emit during uplink transmissions. Under the 3GPP specifications for cellular IoT, the designation of power class 5 specifies a maximum output power of 20 dBm. This limits the peak current draw during transmission, making it suitable for devices with restricted thermal budgets or smaller battery capacities.
System Balance
Hardware design benefits from the reduced power requirement through smaller battery sizes and simpler thermal management. Utilizing power class 5 allows designers to employ less complex power amplifiers and power management integrated circuits. This choice lowers the overall bill of materials for high-volume smart devices.
However, the lower transmit power reduces the maximum uplink range, which requires careful planning of device deployment locations.
Range Evaluation
Link budget calculations determine the coverage footprint of the module. A system operating under power class 5 has a lower uplink margin than a standard 23 dBm device. Field trials must confirm that the target coverage is maintained even in subterranean or obstructed locations.
Certification Run
Regulatory testing verifies that the terminal does not exceed the allowed output power. Radiated power measurements confirm that power class 5 devices operate safely within standard spectral mask limits.
