Multi-hop communication protocol for LoRa with software-defined networking extension

Long Range (LoRa) is a leading low-power wide-area networking technology, and LoRaWAN is the open MAC layer specification for LoRa technology. LoRaWAN operates in a star network topology, thus LoRaWAN forms single-hop network. LoRa technology allows customization of its PHY layer transmission parameters, such as bandwidth, spreading factor, transmission power, and coding rate, therefore long coverage can be achieved by using a lower bandwidth. However, a single-hop LoRaWAN network cannot achieve high data rate and long coverage simultaneous. To simultaneously achieve high data rate and long coverage, the LoRa PHY layer setting that yields the fastest data rate can be used, however it reduces coverage. To makeup for the reduced coverage multi-hop communication can be used. To enable multi-hop communication here a routing protocol for LoRa-based networks is presented. Moreover, to enable traffic engineering in LoRa-based networks, such as traffic load balancing a software-defined networking (SDN) extension for the protocol is also presented. Performance evaluation has shown that the proposed protocol and its SDN-based extension can match the coverage of LoRa PHY layer setting that offers maximum coverage at a relatively very high data rate and lower energy consumption. The protocol demonstrates up to 5 times higher packet reception ratio, and 63% lower energy consumption compared to the LoRa PHY layer setting that offers maximum coverage and reliability. Moreover, the protocols also outperform an existing state-of-the-are routing protocol for low-power wireless networks. (C) 2021 Elsevier B.V. All rights reserved.