  Long Range (LoRa) has become one of the most popular Low Power Wide Area
(LPWA) technologies, which provides a desirable trade-off among communication
range, battery life, and deployment cost. In LoRa networks, several
transmission parameters can be allocated to ensure efficient and reliable
communication. For example, the configuration of the spreading factor allows
tuning the data rate and the transmission distance. However, how to dynamically
adjust the setting that minimizes the collision probability while meeting the
required communication performance is an open challenge. This paper proposes a
novel Data Rate and Channel Control (DRCC) scheme for LoRa networks so as to
improve wireless resource utilization and support a massive number of LoRa
nodes. The scheme estimates channel conditions based on the short-term Data
Extraction Rate (DER), and opportunistically adjusts the spreading factor to
adapt the variation of channel conditions. Furthermore, the channel control is
carried out to balance the link load of all available channels with the global
information of the channel usage, which is able to lower the access collisions
under dense deployments. Our experiments demonstrate that the proposed DRCC
performs well on improving the reliability and capacity compared with other
spreading factor allocation schemes in dense deployment scenarios.
