Higher Throughput Ad-Hoc Networks Considering Tree Density in a Forest.

To achieve higher throughput communication in a forest, we construct communication environment using IEEE802.11 ad-hoc networks from points where LTE/5G reach. We propose the construction method of ad-hoc networks to change a path depending on tree density. When tree density is low, attenuation is considered to be low, and the NLOS Shortest Path which ignores the obstacles is effective. When tree density is high, attenuation will be also high, and the LOS Detour Path which relay APs and avoid obstacles should be used. We have demonstrated it in experiments. The NLOS Shortest Path was 22.6 Mbps higher at low tree density (625 trees/ha). In contrast, the LOS Detour Path was 5.8 Mbps higher at high tree density (1903 trees/ha). We confirmed that the effective path differs depending on tree density. In addition, we evaluated how much throughput could be obtained at a large communication range required for actual operation. The result was 5.12 Mbps at 288 m even with reasonably high tree density (1308 trees/ha). This experimental result indicates the possibility of obtaining enough high throughput to use video communication service in a forest.