A Novel Routing Method with Load-Balancing in Wi-SUN FAN Network

This paper proposes a novel routing method considering load balancing to improve transmission characteristics of a large-scale Wi-SUN field area network (Wi-SUN FAN) based on IEEE 802.15.4. Wi-SUN FAN is a wireless communication standard that enables the interconnection of many Internet-of-Things (IoT) devices outdoors. Wi-SUN FAN prevents packet collisions by frequency hopping in the media access control (MAC) layer. Besides, Wi-SUN FAN constructs multi-hop networks autonomously using Internet protocol version 6 routing protocol for low-power and lossy networks (RPL) at the network layer. In RPL, each node determines its parent node based on the quality of communication. Therefore, many nodes are likely to choose the same parent node with good radio reachability, resulting in many packets being sent to the parent node. The heavy load for the specific node makes frequency hopping not work effectively, and transmission characteristics deteriorate. The proposed routing method with a load-balancing algorithm eliminates the load concentration and improves the average transmission success rate by approximately 9.4% on the specific nodes.