LoRa Duty Cycle Ceilings That Decide Payload Frequency
LoRa duty cycle ceilings restrict packet frequency by limiting hourly transmission airtime, forcing trade-offs between spreading factor, payload size, and battery life.
Carrier Frequency
Meaning
Radio wave oscillations provide the baseline signal upon which data is modulated for transmission over a wireless link. The carrier frequency is the center point of the allocated channel and determines how the signal propagates through the environment. By shifting the properties of this wave, such as its amplitude or phase, the transmitter can encode digital information for a receiver to decode.
Bandwidth Allocation
Regulatory bodies assign specific ranges of the electromagnetic spectrum to different services to prevent overlap and interference. A carrier frequency must stay within these bounds to comply with local laws and to ensure that it does not disrupt neighboring communications.
Propagation Characteristic
Lower frequencies in the sub-gigahertz range travel further and penetrate obstacles like walls and foliage more effectively than higher frequencies. This behavior makes a specific carrier frequency more suitable for industrial or agricultural applications where nodes are spread over large distances.
Interference Mitigation
Radio designers select a channel based on the existing congestion in the local environment and the requirements of the application. If multiple systems attempt to use the same carrier frequency, the resulting noise can lead to lost data and reduced throughput. Modern devices often employ frequency hopping to switch between different channels and avoid localized interference sources that might block a single frequency.