A review of LoRaWAN performance optimization through cross-layer-based approach for Internet of Things

The Internet of Things (IoT) is proliferating in technology and automation. Some popular IoT applications include environmental monitoring, home automation, agriculture, aquaculture, healthcare, transportation, and logistics. The construction of the IoT system is determined by where it will be used. The design can be tailor-made for short-range or long-range communication, rural or urban areas, indoor or outdoor applications, real-time or delay-tolerant communication, and much more. Low-Power Wide Area Networks (LPWAN) are frequently used for long-distance, energy-efficient, cost-effective communication. In LPWAN technology, Long-Range Wide Area Network (LoRaWAN) is one of the most popular choices because of its remarkable features and openness, making it highly suitable for IoT applications. However, despite its exceptional features, there are still ways to optimize the system to become more efficient and address several challenges during runtime. One possible way to address issues and challenges in LoRaWAN is through cross-layer optimization. This optimization technique violates the restrictions set by the Open System Interconnection (OSI) model and gives freedom to its protocol layers to communicate depending on the intended purpose. This paper surveys the state-of-the-art cross-layer approaches that optimize LoRaWAN for IoT applications. The cross-layer approaches were categorized according to the layer combinations and architecture. In addition, this paper provided observations on the effects of cross-layer optimization in LoRaWAN. Lastly, possible issues and solutions, challenges, and future directives from cross-layer optimization approaches were included.