How is the confidence value for a neighbor node calculated in APID, and what factors (e.g., timestamp freshness, relative speed) influence this value? How does this confidence metric improve the stability of link selection compared to traditional geographic routing?
In APID, the confidence value for a neighbor is calculated by combining the freshness of its location timestamp, the relative speed between it and the current node, and its remaining energy. A newer timestamp, lower relative speed, and higher residual energy all result in a higher confidence score.
Compared to traditional geographic routing, which usually picks the next hop only based on which neighbor is geographically closest to the destination, APID’s confidence metric improves link stability significantly. It does this by ensuring that the selected forwarder is not only well-positioned but also stable over time—meaning it is moving similarly to the current node, has enough energy to participate, and its location information is up-to-date. This integrated approach reduces the chance of link breaks caused by mobility or node failure, leading to more reliable packet delivery in dynamic underwater networks.
