Efficient Rebroadcast Location-Unaware Protocol for LoRaWAN Mesh Networks in the IoT Domain

Long-range Wide Area Network (LoRAWAN) is one of the most widely used low-power wide-area network technologies for enabling long-range and extensive coverage for Internet of Things (IoT) ecosystems. The network performance and sustainability metrics are crucial to effectively and efficiently implementing such IoT ecosystems. However, existing broadcasting protocols (e.g., ECHO) typically suffer from high collision rates and low network throughput when deployed in the IoT domain and, thus, may adversely impact the network performance. Therefore, a key objective in designing broadcast routing protocols in IoT is to increase the packet delivery success rate while reducing the packet collision rate. In this paper, we present an efficient rebroadcast location-unaware protocol for LoRaWAN mesh networks in the IoT domain. The proposed protocol dynamically adjusts the rebroadcast delay (i.e., timing) based on the network conditions. We in-depth analyzed the critical performance parameters (i.e., rebroadcast delay, packet size, and re-transmission strategy) that influence LoRaWAN mesh networks in various IoT environments operating in a low-data-rate context. As a result, we identified the causes of higher collision rates and, consequently, low network throughput in such a context. Experimental results showed that our protocol outperformed the ECHO protocol regarding the packet collision rate and energy efficiency.