Physics-based modeling of skier mobility and avalanche rescue in mountainous terrain

Mobility models play an important role in the evaluation of wireless ad hoc networks. However, most existing mobility models are limited to 1D or 2D user movement. In this paper, we propose a novel 2.5D mobility model suitable for modeling the movement of backcountry skiers in mountainous terrains. These skiers carry wireless devices for communication in the event of emergencies, such as an avalanche, and thus form a dynamic mobile wireless ad hoc network. Our model represents groups of skiers, with each group having an invisible leader who determines the general direction of movement. We calculate the acceleration, velocity, and position of the group leader based on properties of the terrain, gravitational force, and a randomized sine function. To simulate the coordinated mobility of group members, we use a flocking model, which applies cohesion, separation, and alignment forces to influence group members to follow their leader, while avoiding collisions with each other. To demonstrate the applicability of our model, we use simulation to evaluate the skier rescue probability in the event of an avalanche.